Rapidly changing geomagnetic field variations constitute a natural hazard, for example in navigation and, through geomagnetically induced currents, to power grids and pipeline networks. To understand this hazard we have continuous magnetic measurements across the world for typically less than 100 years. Much of the older data is also in analogue form, or is only available digitally as hourly or daily magnetic indices or mean levels. So it may not yet be clear what the true extremes in geomagnetic variations are, particularly on time scales - seconds to minutes - that are relevant for estimating the hazard to technological systems.

We therefore use a number of decades of one minute samples of magnetic data from observatories across Europe, together with the technique of ?extreme value theory?, to explore estimated maxima in field variations in the horizontal strength and in the declination of the field. These maxima are expressed in terms of the variations that might be observed once every 100 and 200 years. We also examine the extremes in the one-minute rate of change of these field components on similar time scales.

The results should find application in both hazard assessment and in navigation applications. The results can also be used to more rigorously answer the often-asked question: "just how large can geomagnetic variations get?"

Solar Particle Events (SPEs) of the 23rd Solar Cycle detected by the ESA Standard Radiation Environment Monitor (SREM) onboard the INTEGRAL satellite have been studied in order to find their connection to solar sources. X-ray, optical and radio data of solar flares that occurred during the aforementioned solar cycle and were observed by several space- and ground-based instruments have been selected, reduced and analyzed in order to establish the corresponding solar origin of the selected SPEs. The extensive scientific analysis has produced clear correlations with X class solar flares for the events of the October-November 2003, January 2005 and December 2006 periods while for the events that occurred during September 2005, correlations with X class flares are possible but not straightforward due to the complexity of the registered solar particle fluxes.

Downstream of a quasi-perpendicular bow shock of the Earth, various wave modes associated with the different boundaries have been confirmed and different methods have been used to find frequency and instantaneous frequency of these different modes. We applied Hilbert-Huang Transform in the determination of instantaneous frequency by decomposing the data observed by in-situ spacecraft in certain region in space called the magnetosheath into intrinsic mode functions (IMFs) using empirical mode decomposition (EMD) technique of Huang et al., 1998. Instantaneous frequencies for the different IMFs were computed using Hilbert transform. The determined instantaneous frequency supports the non-stationary and non-linear nature of the data. The observed data were taken from FGM instrument on Cluster II mission which provides 3-dimensional advantage for this analysis, and the results compared with that of electric field measurements of Cluster II mission already carried out with simple Hilbert transform.

Space weather forecasts reliability strongly depends on many factors such as operator experience, quality and quantity of the incoming information. Therefore the appearance and the development of the new thematic resources can directly improve the forecast quality. Novel EIT wave Machine Observing technique (NEMO) allows us to extract the CME precursors from EUV solar corona observed by SOHO mission during 12 years. In this work we present the primary analysis of obtained results, namely: - the global statistical analysis of obtained series of EUV precursors, - physical characteristics of some atypical events, interrelation of physical and geometrical parameters of the similar events at different scales. First, the obtained results will be used for automatic cataloguing of EUV precursors and construction of catalogs with the extended set of parameters.

Fast halo CMEs are considered as the most geoeffective solar events. When the halo CME comes with velocities higher than 1000 km/s and originating from the Western hemisphere close to the solar center, a large disturbance is expected at terrestrial environment. However, large disturbances have been also associated to halo CMEs from regions located far from central solar meridian, as Hallowing storm, related to CMEs from active regions farther than W80 and resulting a Dst index below -400 nT.
In this work we have studied all halo CMEs of solar cycle 23, as observed by the Solar and Heliospheric Observatory (SOHO) mission, with solar source close to solar limb, from 60° up to 90° far from central meridian. For this task, we have analyzed not only solar atmosphere and the terrestrial surface, but every link in the Sun-Earth chain. The results of this work are useful, not only for understanding solar-terrestrial interaction, but also in order to establish the requirements of space weather models based on solar observations.

The Met Office Unified Model (MetUM) is a global atmosphere general circulation model (GCM) for the lower atmosphere (up to 85km) that has been designed for use both as a research tool and as a numerical weather prediction model in an operational forecast and analysis system. If a meteorological service such as the Met Office is to attempt similar provision for global analysis of the ionosphere and thermosphere, based upon physical models of the upper atmosphere, it will be necessary to address issues raised in a recent small-scale exploratory activity carried out under the FP6 GEO6 project (sponsored by GNSS Supervisory Authority, GSA) to investigate the potential use of GNSS data for ionospheric data assimilation. In particular, the task of bringing together observation and model data for quantitative comparison underlined the fact that physical models are used somewhat differently in an operational data assimilation system than would be the case in a research environment, where cases are generally carefully selected in order to highlight desired aspects of a physical problem, data quality can be carefully controlled and timeliness of data availability or results is not an issue.

Hence, in a context where research models might be developed into operational models, a fundamental part of any assessment of suitability is the decision as to how precisely an assessor intends to use the model, as this will ultimately dictate the kind of modifications that will be needed. Experience with the MetUM suggests that the ability of models to produce realistic daily background simulations prior to the assimilation of ionospheric data will be a key concern. As a first step towards quantitative comparison of observation and model data, the Met Office and University College London are collaborating to validate the neutral atmosphere temperatures of the lower atmosphere MetUM and upper atmosphere CMAT2 model against satellite data for the mesosphere region where the two models overlap. Results will be presented from this process, intended to help us develop quantitative numerical methods for assessing the suitability of different models for alternative data assimilation approaches.

Based on recent scientific findings we review the effects of solar related disturbances on the Martian environment that need to be taken into consideration for manned missions to Mars. The emphasis is put on SEPs, which provide challenges for scientists that work on the prediction of these phenomena, as well as for engineers who design mitigation strategies for spacecraft. First, we discuss how SEPs and CMEs can affect the environment at Mars. We then describe recent advances on the radial dependence of solar proton peak intensities and fluences. The low-energy heliospheric particle environment at ,,d 1 AU is then discussed and the importance for its impact on spacecraft surface materials and solar arrays. Furthermore, we discuss some critical aspects of modelling and forecasting solar energetic particle events at Mars and also present current ESA/NASA-funded projects which aim to provide easy-to-use radiation models and engineering tools to predict the radiation environment for the surface/sub-surface conditions or in the atmosphere of Mars as well as for orbital spacecraft and Phobos/Deimos landers. All the considered issues and current results presented need to be addressed and taken into consideration seriously by designers and planners of future manned missions to ensure their success.

The importance problem of Solar-terrestrial physics is regular forecasting of solar activity phenomena, which negatively influence the human?s health, operating safety, communication, radar sets and others. The opportunity of development of short-term forecasting technique of geoeffective solar flares is presented in this study. This technique is based on the effect of growth of pulsations of horizontal component of geomagnetic field before the solar proton flares. The long-period (30-60 minutes) pulsations of H-component of geomagnetic field are detected for the events of different intensity on March 22, 1991, November 4, 2001, and November 17, 2001 using the method of wavelet-analysis. Amplitudes of fluctuations of horizontal component of geomagnetic field with the 30-60 minute?s periods grow at the most of tested stations during 0.5-3.5 days before the solar flares. The particularities of spectral component are studied for the stations situated on different latitudes. The assumptions about the reason of such precursors-fluctuations appearance are made.

Recent solar researches lead to the concept of general approach to solar active events: CMEs are global phenomenon of solar activity and the analysis of it includes entire process of energy release as strictly the solar flare with its manifestations in all ranges of radiation (electromagnetic and corpuscular) as entire spectrum of the associated dynamic phenomena. This access intends the development of approach to CMEs forecast.

In this work the possibilities of the prediction of the evidence of CMEs formation and initial propagation are examined. They are based on effects observed in solar sporadic radio emission. Such prediction is possible because of complex events observed in solar microwave emission on the time interval from 2-3 days till the point of CMEs registration on the coronagraphs.

That sort of effects consists of: a) an increase of the long-period (T > 20 min) fluctuations in 2-3 days prior to the formation of the Coronal Mass Ejections (CMEs) that exceeds in 2 times calm periods; b) appearance and maintenance of the narrow-band (Δf abot 200-400 MHz) spectral special features in microwave emission intensity within 5-8-hours prior to the point of CMEs registration; c) presence of radio precursors in 1-2 hours prior to CMEs registration, that possess broadband, directivity; their duration depends on the morphological type of recorded CMEs; d) presence of periodic components with the periods in the range of 6-22 seconds in solar microwave emission directly preceded CMEs registration (less than the half-hour).

We present a new list of ICME events deduced from the ACE data at L1.
This list is automatically produced from four different criteria (proton temperature, interplane- tary magnetic field, alpha to proton ratio and iron charge state). It spans from 1998 to 2006.
This list is then correlated to CMEs at the sun. We compute the energy trans- fer to the magnetosphere during the selected events. We corrrelate this coefficient to the Dst geomagnetic index and show that the correlation increases after a few hours.
Finally, we show that the most reliable parameter for such a comparison is the Akasofu ǫ3 pa- rameter.

The paper addresses to understand the appearance of a prolonged solar minimum phase and its effects on the terrestrial environment as well as on the activity level during the next solar cycle. We determined and analysed the high speed streams in solar wind during interval 2006 - 2008, from their origins to the impact on geospace. The degree of the high speed stream impact depends on its parameters (especially, speed and duration) and also on the heliospheric magnetic field polarity. We used the superposed epoch method to extract the common features of the streams and geomagnetic variability induced by them. The level of the fast stream activity during the last minimum is compared with the ones registered during the previous four solar minima. Some assumptions about how fast solar wind during the minimum phase could be used to forecast the level of activity in the next 11-yr solar cycle are made.

In this work, the relationship between the twist of TL and solar flare is analyzed. The correlations between the evolution of TL and solar flare, CME are also considered. From a statistical study, the length of TL varies following solar cycle. What will be the variation of the tendency of the next cycle? Through the above study, we are trying to find TL as an index for space weather and forecasting.

When strong southward magnetic field during several hours affects the Earth?s magnetic field a substantial transfer of energy into the terrestrial magnetosphere occurs. In these conditions the entire magnetosphere becomes disturbed and this situation is characterized as a geomagnetic storm. The primary measure of intensity of a geomagnetic storm is strength of the ring current, as measured by the Dst index.

At the present time measurements of interplanetary magnetic field and solar wind are available from the libration point L1, providing the 1-hour advance of the Dst index prediction.

An increase of the prediction advance time based on the certain stationarity of solar wind structures is the research task of this work.

Our approach to the Dst index prediction is based on the introduced by Burton et al. a simple differential equation of the Dst index evolution

The simple assumption about the stationarity of the large-scale structures of the solar wind allowed us to estimate the negative maximum Dst index characterizing the geomagnetic storm strength and time interval of its prediction. In the conditions of the constant solar wind parameters the differential equation has the steady state solution Dst*. The true negative maximum is close to its steady state value Dst* which can be defined at the beginning of a geomagnetic storm.

To correct the negative maximum Dst index estimation in the conditions of abrupt change of the solar wind parameters Q the storm intensification detection is included into the prediction algorithm.

An effectiveness of the proposed algorithm is confirmed by its application to events in 2001 (the year of high solar activity). The prediction errors belong to the 25% accuracy range. The most of them do not exceed 10% .

Obtained results confirm the prognostic potential of the proposed algorithm and the reasonability of its future development for the application in real time.

What one commonly considers for reproducing the recovery phase of magnetosphere, as seen by the Dst index, is exponential function. However, the magnetosphere recovers faster in the first hours than in the late recovery phase. The impulsivity in the response is a feature that leads to the proposal of a hyperbolic decay function to reproduce the recovery phase, instead of the exponential function. A superposed epoch analysis of recovery phases of intense storms from 1963-2006 was performed, categorizing the storms by their intensity into five subsets. The hyperbolic decay function reproduces experimental data better than what the exponential function does for any subset of storms. Moreover, this kind of mathematical function, where the degree of reduction of the Dst index depends on time, allows for explaining different lifetimes of the physical mechanisms involved in the recovery phase.

Combined models simulating the interplanetary shock propagation and particle acceleration and transport are the necessary ingredients in order to generate tools for the operational-prediction of solar energetic particle (SEP) events associated with interplanetary CME-driven shock waves. In the frame of the Solar Energetic Particle Environment Model (SEPEM) project we have developed a new 2D MHD model for the description of the interplanetary shock propagation from 4 solar radii till the orbit of Mars, in the ecliptic plane. This model allows us to study the influence of the shock properties and the observer magnetic connection to the shock front on the radial and longitudinal variation of proton peak intensities of gradual SEP events, which are crucial to predict the radiation environment in the inner heliosphere. We have performed a simulation of the propagation of three interplanetary shocks characterized by different transit times from the Sun to 1.6 AU. We consider two sets of spacecraft placed at different radial distances from the Sun and sharing the same archimedean interplanetary magnetic field line in the undisturbed solar wind. These two sets of observers are placed with different longitudes with respect to the nose of the interplanetary shock: at western and central meridian positions, as seen at 1AU. We obtain the synthetic 8 MeV and 32 MeV proton flux time-intensity profiles for each of the considered spacecraft by assuming: (1) that the injection rate of shock-accelerated particles, Q, takes place at the cobpoint and (2) that a functional dependence between Q and the speed jump across the shock front, VR, exists. The particle transport is modelled via the transport equation by Lario et al. (1998) that includes the source of shock-accelerated particles, Q. We deduce power-law dependences of the peak intensities on the observer's radial distance that vary with the particle energy, the strength of the shock and the longitude of the observer. We conclude that the radial variation of peak fluxes is determined by the way each observer establishes magnetic connection with the travelling shock.

Reference:
Lario, D., Sanahuja, B. and Heras, A.M., Astrophysical J., 509, 415-435 (1998).

Los Alamos has been flying energetic particle detectors on the GPS constellation for over two solar cycles. The recent generation of detectors the Combined X-ray Dosimeters (CXD), is currently flying on 9 GPS satellites, with a further three BDD-IIR type detectors on three other GPS satellites. This constellation of detectors delivers unprecedented temporal and spatial particle data in the outer radiation belt from L=4 outward, with a combined 1 hour temporal resolution and 0.1 L resolution in the L=4 to 8 region. This data shows extremely rapid and drastic variations in the outer electron radiation belt, revealing electron loss processes on timescales of an hour or less, and energization processes on timescales of 12 hours or less - both these observations challenging current theories of electron loss and energization processes: The time scale, energy range and radial extend of loss processes is inconsistent with current wave-particle interaction theories (EMIC waves) and challenges existing theories on possible outward radial diffusion rates; while chorus-wave energization processes are generally though to operate on the timescale of days. The GPS energetic electron data offers not only challenges to conventional wisdom in this important area of radiation belt dynamics, but also the most detailed look yet at the rapid environmental variations in this area of near-Earth space.

The solar electromagnetic and corpuscular emissions are the main drivers of the Earth's atmosphere, including both neutral and ionized components. The deposition of solar energy determines the atmospheric thermal structure, composition, and ionization. During the last few decades, remote sensing and in situ observations have been providing detailed information about the variability of the solar-terrestrial environment. However, there are large uncertainties of the variability of key solar and geomagnetic parameters on longer time scales, which lead also to uncertainties on the evolution of space weather processes (including the atmospheric-oceanic coupled system). Here, we discuss the empirical modeling of the solar irradiance on time scales from months to centuries. We concentrate in this work on short-wavelength emission (< 240 nm), which is a region of the spectra not well reproduced by previous models. Following others (e.g. Krivova et al. 2007, 2009), the empirical model is based on the assumption that the long-term evolution of the solar irradiance is due to the evolution of the solar magnetic field configuration, which is partially recorded on solar activity proxies. In the model discussed here, the group sunspot number is employed to drive the model for the evolution of the solar magnetic flux emerging in bipolar regions (active and ephemeral regions) as well as in large regions with a predominant polarity. Then, the area covered by bright and dark features laying in the solar surface is computed from the magnetic flux components. Finally, the emission at a given wavelength is computed as a linear combination of the area covered by the bright and dark features

The solar extreme ultraviolet (EUV) irradiance is a key input for thermospheric and ionospheric models. As a consequence, the continuous monitoring of the solar spectral irradiance is essential for many space weather applications. However, the monitoring of the full EUV irradiance spectrum is a difficult task and modelers are often left with the use of proxies, although these lead to unsatisfactory results.

We propose a different approach based on a statistical analysis. By using 6 years of daily EUV spectra, we first reconstruct the output of different sets of filters coming from different existing or future projects (LYRA/PROBA2, PREMOS/PICARD, EUV/GOES,...). Next we consider linear combinations of these fluxes to reconstruct the EUV spectrum. This work aims at validating the instrumental concept of LYRA and to prepare a new instrumental project based on an optimal set of filters.

The radiation hazard en route to and at Mars and back to the Earth mostly is determined by galactic cosmic rays (CR), by their propagation and modulation in the Heliosphere. Only in case of great solar flares with generation big fluxes of solar CR (or as it frequently called in scientific literature, solar energetic particles - SEP), the induced radiation hazard during this short periods may be also important. In this paper we consider probabilities of great SEP events during en route to and at Mars in dependence of the level of solar activity and how to forecast expected SEP fluxes on the basis of on-line one minute data in real time-scale from ground observations during the first 20-40 min by neutron monitor and observations on satellite by solving inverse problem of SEP generation and propagation in the frame of theory of isotropic diffusion and then forecasting for about two days ahead. The solution of inverse problem based on observations of the beginning of SEP event give a possibility to determine the SEP source function on the Sun, time of ejection of SEP into solar wind, and diffusion coefficient in dependence of particles rigidity and distance from the Sun. On the basis of this information we can then determine expected time variation of SEP fluxes on the Earth (at satellite altitude and on the ground), as well as in space between the Earth and Mars, and at Mars.
We also check the developed model by data of historical event by comparison of forecasting SEP fluxes and observed. We show that the model based on the theory of isotropic diffusion starts to work well only after 10-15 minutes from the beginning of SEP observations (what corresponds for relativistic SEP to one-two scatterings in space before arriving to the Earth).
To give more exact and earlier forecast we need to use more complicated theory of SEP propagation in the interplanetary space based on the kinetic equation (Dorman, 2008). Let us underline that for practical using of this complicated model based on the kinetic equation we need on-line one min data from many neutron monitors and several satellites, what will be available, as we hope, only in near future.
After solving of the inverse problem of SEP generation and propagation in space, and determining expected time variation of SEP fluxes on the Earth as well as in space between the Earth and Mars, and at Mars, we can determine expected differential and integral radiation doses inside spacecraft on the way to and at Mars. We consider here in details following problems.
1. On the probability of solar CR fluency during SEP event for spacecraft near Earth, in way to Mars, and at Mars, based on three solar cycles observations
2. Statistical properties of the radiation hazard probabilities derived from GOES 7-11 for 1994-2004 data on daily fluencies
3. Data from the past and classification of space weather radiation hazard (NOAA classification and its modernization)
4. The first step of forecasting: Automatically search of the start of great SEP events
5. The second step of forecasting: Determination of SEP energy spectrum out of atmosphere
6. The third step: On-line simultaneously determination of time of ejection, diffusion coefficient, and SEP energy spectrum at the source by neutron monitor data
7. The fourth step: Forecasting of SEP event development by the on-line using of both neutron monitor and satellite one-min data
8. The fifth step: Forecasting of expected differential and integral radiation doses during great SEP events inside spacecraft in the way to and at Mars.

Reference: Dorman L.I., Forecasting of radiation hazard and the inverse problem for SEP propagation and generation in the frame of anisotropic diffusion and in kinetic approach, Proc. 30-th Intern. Cosmic Ray Conf., Merida, Mexico, Vol. 1, 175-178, 2008.

The global atmospheric electrical circuit (GAEC) is supplied by the totality of thunderstorms and electrified clouds on the Earth. An electric potential of the ionosphere of about 250 kV with respect to the surface is maintained by GAEC, and a related fair-weather ionosphere-to-ground electric current of about 2 pA/m² is created. These characteristics depend on the Wilson?s electric currents from the electrified clouds and thunderstorms into the ionosphere, which are theoretically investigated by a series of authors, e.g. by Velinov and Tonev (1995; 2008) - for the DC currents above highly electrified clouds and quasi-electrostatic currents above lightning discharges.

While the most significant diurnal variations in GAEC are caused by changes of the global thunderstorm activity, there are different outer sources of influence on the ionospheric potential and the fair-weather electric current. One of these sources is the potential difference of 40-150 kV (80-100 kV in average) formed in the ionosphere between the dawn and the dusk side in each polar cap (Rycroft et al., 2000; Tinsley and Zhou, 2006). This trans-polar potential difference is created by currents of magnetospheric origin and is determined on the solar wind parameters. Because of the dawn-to-dusk potential difference, the ionospheric potential at high latitudes is modified by about of 80 kV, while it is uniform at geomagnetic latitudes below 50-60°, due to the high conductivity. Because of the large horizontal scale of the polar cap potential pattern (3000 km), the fair-weather current at high latitudes can be modified as down as the Earth?s surface. Previous estimations of the mapping of the dawn-to-dusk potential difference on the surface are made e.g. by Roble (1985).

We develop a 3D numerical DC model, in order to reveal the effect of the ionospheric potential pattern on the ionosphere-ground fair-weather current. Our model is based on the continuity equation for the electric current density. As a first step, we use an approximate representation of a simple symmetric potential difference pattern at altitude of 120 km. The fair-weather current is computed as a function of the magnetic field component B_y (which determines the dawn-to-dusk difference) and of the atmospheric conductivity. The model allows the computation of the DC electric current and field at altitudes between 0 and 120 km and at geomagnetic latitudes 0 - 90° in a specified hemisphere. The results show that the air-earth current at the surface is significantly modified at high geomagnetic latitudes by the dawn-to-dusk potential difference by about 20% under quiet conditions. The modifications of the ionosphere-ground electric current are much larger in the lower ionosphere and the mesosphere.

We study also the electric current variations in the strato-mesosphere, where a considerable reduction of the conductivity can take place at high and polar latitudes (Tinsley and Zhou, 2006, etc.). This reduction is caused by the enhanced aerosol density, whose increase is especially large after volcano eruptions. Significant diurnal variations of the fair-weather electric current in the strato-mesosphere due to the dawn-to-dusk potential difference in the ionosphere, together with the decrease of the conductivity at some altitudes, leads to generation of large electric fields in the region specified. These results can possibly explain the large quasi-static electric fields, experimentally measured in the region of consideration.

The results obtained show that the dawn-to-dusk potential difference in each polar cap influences GAEC significantly at high latitude, and is an important factor of conducting the solar activity to GAEC through the solar wind.

In space plasmas, the number density of the particles is generally very low, so that the kinetic approach is the most appropriate one to develop models. At BISA, kinetic models have been developed for planetary exosphere and solar plasmas. Kinetic models provide the velocity distribution functions (VDF) of the particles as a solution of the kinetic equation. The calculation of the VDF moments gives the macroscopic quantities like the number density, bulk velocity, temperatures and heat flux. Recent models concern the terrestrial plasmasphere, the auroral regions, the polar wind, the solar wind and exospheres Saturn and Jupiter. Such models have practical space weather applications. The solar wind model and the terrestrial plasmapause model can be run on the space weather portal on www.spaceweather.be.

We analyse an observation of a 5 minute quasi-periodic oscillation detected in the coronal line FeXII at 19.5nm, near the footpoint of a coronal loop in Hinode/EIS data on 08 Feb 2007. The same oscillation is detected simultaneously in two other coronal lines, FeXIII at 20.4nm and CaXVII at 19.2nm. The oscillation is observed for a full 2 periods in both Doppler shift and intensity. We use Fourier and wavelet analysis to determine the period of the oscillation. We use simple models of the oscillation and determine the phase between the Doppler shift and intensity time series. We determine the period of oscillation to be P=314±83s in Doppler shift and P=344±61s in intensity. We observe negligible phase shift between Doppler and intensity time series. This is strong evidence for the existence of a propagating slow magneto-acoustic MHD mode. We detect intensity oscillations in three spectral lines with a wide range of temperatures. This suggests a structure of multi-threaded, multi-thermal loops.

Solar images from space telescopes contain a wealth of information on solar variability, of great importance both in solar physics and in view of Space Weather applications. Obtaining this information, however, requires the ability to process large amounts of data over long periods in an objective fashion.

In previous work, we have proposed a multi-channel unsupervised spatially-constrained multichannel fuzzy clustering algorithm (SPoCA) that automatically segments EUV solar images into Active Regions (AR), Coronal Holes (CH), and Quiet Sun (QS). After having corrected for the limb brightening effect, SPoCA computes an optimal clustering with respect to the regions of interest using fuzzy logic on a quality criterion to manage the various noises present in the images and the imprecision in the definition of the above regions. Next, the algorithm applies a morphological opening operation, smoothing the cluster edges while preserving their general shape. The process is fast and automatic. While we presently apply SPoCA to EUV data, the method is generic enough to allow the introduction of other channels or data, e.g., DEM maps.

Applying SPoCA to SoHO-EIT images along almost a full solar cycle (January 1997 till May 2005), we obtained variations of area, mean intensity, and relative contributions of AR, CH, and QS to the solar irradiance, consistent with previous results. Furthermore, we found evidence for a small but significant variation of the mean intensity of each region in correlation with the solar cycle. The method also revealed the rotational and other mid-term periodicities in the extracted time series across solar cycle 23. Combining SPoCA's detection of AR, CH, and QS on subsequent images allows automatic tracking and naming of any region of interest, paving the way for systematic temporal follow-up studies of AR, CH, and QS.

In the present poster, we present the results of ongoing research concerning the fine-tuning of the algorithm and its implementation for optimal segmentation and performance. We also show how to tailor the method to the needs of the high resolution EUV images soon to be delivered by SDO-AIA.

Seasonal/solar cycle NmF2 variations as well as summer saturation effect in NmF2 have been analyzed using Millstone Hill ISR daytime observations. An original self-consistent approach to the Ne(h) modelling has been applied to extract from ISR observations a consistent set of main aeronomic parameters (solar EUV flux, neutral composition and temperature) and to estimate their qualitative contribution to the observed NmF2 variations, this is a distinguishing feature of the present consideration. Unlike IRI model recommendations the saturation in NmF2 v.s. solar activity dependence does not take place in winter at middle latitudes. Different temperatures in winter and in summer in the course of solar cycle overlapped on the O⁺+ N2 reaction rate coefficient temperature dependence result in different NmF2 dependences on solar activity - a steep practically linear increase with a tendency to turn up in January and a slow increase with a tendency to saturate at high solar activity in July despite increasing solar EUV radiation. In winter the EUV flux and thermospheric parameters (linear loss coefficient βm = γ1[N2] + γ2[O2] at the hmF2 height) provide approximately equal contributions to the NmF2 increase while in summer the contribution of thermospheric parameters (mainly βm) is very small ≈ 6% due to parameters mutual compensation. Both in winter and in summer the variations of atomic oxygen [O]m are small at the F2-layer peak and its contribution is small compared to βm one. It is shown that the summer saturation effect in NmF2 under high solar activity is not just reduced to O/N2 or EUV flux solar cycle variations, but is determined by βm via the γ1(T) temperature dependence.

Over the last few years coronagraphic and spectroscopic observations demonstrated that small scale eruptions
occur ubiquitously on the Sun, such as ``jets'', ``narrow Coronal Mass Ejections (CMEs)'', ``mini CMEs'',
``streamer puffs'', ``streamer detachments'', and others. Nevertheless, the origin of small scale eruptive events
and how these are interrelated with larger scale CMEs have been poorly investigated so far. In this work we study a series of small scale eruptions which occurred during and after a large scale CME. Observations show that a
CME can be associated not only to a single reconnection process, leading to the large scale phenomenon, but
also to many other reconnections occurring at different locations and times around the main flux rope, possibly
induced by the CME expansion in the surrounding corona. White light and EUV data from SOHO/LASCO and UVCS
instruments are analyzed to infer plasma physical parameters and the evolution of magnetic reconnection rates
M at the reconnection site. It turns out that above 2 solar radii, the reconnection rate progressively
decrease with time/altitude from M=1 down to M=0.3, suggesting the occurrence of a continuous
transition from a fast Petschek-type to a slow Sweet & Parker-type reconnection. Starting from a potential
pre-CME coronal magnetic field configuration similar to what extrapolated in the corona from SOHO/MDI data,
the occurrence of such small scale eruptions is also
simulated and reproduced here with a modified version of the Versatile Advection Code (VAC). Simulations
confirm that these small scale eruptions are a consequence of the CME expansion against the surrounding
coronal streamers; the simulated and observed evolutions of reconnection rates are also in qualitative
agreement.

Research conducted
within the European Commission's Seventh Framework Programme (FP7/2007-2013) under the
grant agreement n° 218816 (SOTERIA project, www.soteria-space.eu).

The galactic cosmic rays create ionization in the D region of the lower ionosphere where the mesosphere and the lower thermosphere are disposed. This ionization [electron production rate profiles q(h)] is characterized by strongly expressed latitudinal effect. The cosmic ray (CR) ionization has three types of variations: I class - meteorological variations (related to the atmosphere density changes), II class - geomagnetic variations (during the magnetic disturbances and storms) and III class - primary variations (related to CR spectra) [Velinov, 1971 and 1974]. During geomagnetic storms with SSC (Sudden Storm Commencement) the geomagnetic cut-off rigidity of the penetrating CR particles changes (II class of variations) and their differential spectra are modulated (III class of variations). These variations are most strongly expressed in the main phase of the magnetic storms when the magnetosphere is compressed. The geomagnetic field decrease leads to corresponding geomagnetic threshold Rc decrease and to ionization increase due to cosmic ray intensity growth.
These processes are described quantitatively with the corresponding equations. A physical model is created. The storm influence is described with the simple model of Obayashi and Hakura (1960), which gives the decrease of the geomagnetic cut-off rigidity Rc. The CR ionization variations are analyzed in altitude and in geomagnetic latitude (from polar to equatorial regions) for different concrete big geomagnetic storms in the last solar cycle, for example: 29 October 2003, 27 July 2004, 10 November 2004, 21 January 2005 etc. Some of them are connected to solar proton events or GLE (Ground Level Events) and also SPE (Solar Particle Events). The provided quantitative analysis can be used for modeling of the solar-terrestrial influences and for explanation of their physical mechanisms (Velinov and Mateev, 2008a; 2008b). The equations take into accaunt the different levels of modulation of CR protons and CR hevier nuclei. For the CR protons Z/A = 1, but for the CR hevier nuclei Z/A is approximately 0,5 (Z is the charge and A is the atomic weight of the penetrating and ionizing CR particles).

The Objective of this paper is to investigate further the possible effects of the magnetic storm variability induced on the KOERI (Kandilli Observatory and Erthquake Research Institute) horizontal geomagnetic field components (H). For this purpose, the declining phases of the 19th; 20th; 21st; 22nd; and 23rd Solar Cycles are considered. The regular, diurnal, seasonal and solar cycle variation in the KOERI daily H data were removed by subtracting the daily mean of the KOERI H for the same days on all magnetically quiet days (Ap<9). This yields the deviation from the average quiet time value ΔH. There are two different types of "EVENT" dates are considered. That is the "the storm" criteria are fulfield if Ap ≥9 and alternatively FI ≥10 (Flare Index).

The KOERI daily H data were sorted according to the EVENT days, and the effects of the storm indices were discussed by considering the ΔH within 15 days around the storm indices (or for each one of the Ap index which had been greater than 9 or FI greater than 10) by employing the SPE analysis technique.

The effect of the storm was observed very clearly on the data processed as explained above.

The varying ultraviolet and corpuscular radiations from the Sun and cosmic rays have important consequences for the life on Earth, for they produce and modulate the ozone layer within the middle atmosphere, or stratosphere. Up to now our investigations of the relationships and the reactions of the stratospheric ozone at different altitudes as a result from the proton fluxes at extreme situations (GLE - Ground Level Enhancements of cosmic rays, and SEP - Solar Energetic Particles) have shown cross correlation coefficients in the order of 0.4 to 0.6 (Velinov et al., 1999; Tassev, Velinov et al., 2003, 2005, 2006). It gives us the reason to suppose the existence of non-linear connections between the proton fluxes and the ozone mixture ratio.This idea begins to develop in the report of Tassev, Velinov et al. (2008).
The correlation relations between these quantities have been determined on the base of time series (in the order of a few months for different seasons) of the ozone mixture ratio at different altitudes and the proton fluxes at quiet conditions. The stratospheric levels at which the ozone values are taken are the following: 15.45 km, 18.54 km, 24.72 km, 30.90 km, 37.08 km, 43.26 km and 46.35 km. The energy intervals of the proton fluxes are the following: E = 0.8 - 4 MeV, E = 9 - 15 MeV, E = 15 - 40 MeV, E = 40 - 80 MeV, respectively.
Only night ozone profiles by satellite measurments are used in this investigation with the purpose to remove the contribution of the solar ultraviolet radiation. The data include the high latitudes from 60 to 80 degree in the Nord polar regions. The goal of this investigation is to establish the existence of more complex non-linear relationships between the proton fluxes and the ozone change at the different altitudes.

There are at present two competing paradigms for understanding the magnetosphere-ionosphere coupling. One paradigm focuses on the role of Alfven waves as mediating this coupling. The other paradigm considers the auroral current system as an electrostatic system. Using the latter approach, we have built a model of the auroral electric potentials at high and low altitudes, and of the field-aligned currents that are driven by it. This model is based on the current continuity condition. The role of the current-voltage relation in the coupling is of prime importance for the overall behaviour of the system. The model is quite general and capable of explaining the formation of diffuse aurora, discrete auroral arcs, polar cap arcs, black aurora, the subauroral polarization stream and east- and westward subauroral ion drift phenomena. One can envisage various ways to use the physics behind the electrostatic description to conceive a workable model of the auroral and subauroral ionosphere and the overlying magnetosphere.

At the high latitude ionosphere the influence of the space weather emerges e.g. as the appearance of moving polar cap patches along with changes in plasma density and temperature, that in turn causes scintillations in the transmission of GPS signals. Using the information of GPS satellites in combination with 18 ground receivers distributed in northern Europe, the Norwegian Mapping Authority (NMA) is able to produce overview maps of the vertical total electron content (VTEC) and the corresponding ionospheric delay. The extension of the map region is between 30°W and 40°E in longitude and 55°N and 85°N in latitude with a spatial resolution of 5° in each direction. The number of considered ground stations leads to a large number of ionospheric pierce points (IPP) between GPS satellites and the receivers. That allows the application of spatial linear interpolation algorithms, such as IDW and Kriging, in order to calculate the vertical delay accurately at the grid points defined above. We present how this ionospheric VTEC model of the NMA is capable to analyse the movement of plasma density irregularities in polar regions. This information can be used to establish a prediction of the location of such ionospheric disturbances above northern Europe, which becomes significant during the next maximum of solar activity expected in 2010.

As a continuation of our studies of analitical modeling the cosmic ray (CR) spectra (Buchvarova and Velinov, 2005; 2006; 2009) we present a new model, which uses a satellite particle measurments and ground based data. Our knowledge of CR modulation and ionization in the Solar system was greatly enhancent thanks to the heliospheric missions "Voyager - 1 and 2", "Pioneer - 10 and 11", "Ulysses" et al.
An empirical model for differential spectra D(E) of galactic and anomalous cosmic rays in the energy interval 1 MeV - 100 GeV during different phases of the solar cycle is proposed. The experimental spectra for protons and alpha particles are fitted to the empirical model. The modulated galaciic CR differential spectra are compared with force field (FF) approximation to the one-dimensional (1D) transport equation and with solutions of two-dimensional (2D) cosmic ray transport equation. The proposed analytical model gives practical possibility for investigation of experimental data from measurements of galactic cosmic rays and their anomalous component. For that purpose we use the measurments with the BESS spectrometer, IMAX and CAPRICE94 experiments for galactic cosmic rays and SIS spectrometer for anomalous CR component.
This empirical model will be used for the evaluation and calculation of ionization and electron production rate q(h) profiles due to galactic and anomalous cosmic rays in the atmospheres and ionospheres of the Earth and the planets from terrestrial and Jovian group. For terrestrial planets a spherical atmospheric models are used (Velinov et al., 2001), and for giant planets from Jovian group rotational ellipsoid models are applied (Velinov et al., 2004). For this purpose we introduce a modified Chapman function Ch(M) for different oblate giant planets i. We utilize this function Ch(Mi) in the expressions of cosmic ray particle depth parameters (PDF) for every planet i. Theese investigations will contribute to the clarification and explanation of the principal part of high energy cosmiic particles from the Sun and Galaxy on the space weather and climate, and also on the meteorological weather.

The Topside Sounder Model Profiler (TSMP) uses model topside scale height, transition height, and plasmasphere scale height provided by Topside Sounder Model (TSM) to reconstruct topside electron density profile. TSMP is based on equations of O+ and H+ vertical ion distributions with their scale heights, coupled at the transition height. One of recent application of TSMP is named TaD (TSMP-assisted Digisonde reconstruction technique), in which topside scale height and density and height of the F region peak is provided by Digisonde measurements. Combination of both reconstruction techniques was validated by using independent CHAMP and ground-based TEC measurements and proved to increase significantly accuracy of reconstructed N(h) profiles. Work is in progress to implement TaD technique to European Digisonde network (DIAS) in providing 3D electron density distribution in real time. In this paper we introduce important improvement of the basic formulation of TSMP. The whole topside electron density profile is presented by a unique Chapman formula with a unique expression of vertical scale height, explicitly dependent on topside and plasmasphere scale heights and transition height. The new formula is compared with the present two-fold (O+ and H+) plasma distribution and tested against the data. Advantages of both approaches are discussed.

A theoretical model on electron acceleration at shock waves, namely, via resonant wave?particle interaction, is tested in the solar corona and the interplanetary (IP) space. The model adopts the presence of upstream wave activity (in terms of the whistler wave mode) and calculates the flux of accelerated electrons. In the model, electrons are resonantly accelerated in the wave electric field upstream of the shock front and after that reflected by the shock wave. The whistler wave is generated by the reflected at the shock protons. We use plasma and shock parameters obtained from radio observations of shock waves in terms of type II bursts. In the solar corona, fluxes of non-thermal electrons are well produced with this mechanism. Additionally, we tested the resonant wave-particle acceleration mechanism for shock waves that are propagating in the IP medium. There, different plasma conditions in comparison with the solar atmosphere are present. The characteristic parameters of the plasma environment observed ahead of the shock wave (density, magnetic field strength, temperature) together with the shock compression and speed, are fed into the model as input data. Finally, the fluxes of accelerated electrons are calculated and presented in the poster. In summary, shock waves can accelerate electrons via resonant interaction with whistler waves up to few tens of keV in the solar corona and in the IP space.

The ESA Standard Radiation Environment Monitor (SREM) is the second generation of instruments in a program established by ESA's European Research and Technology Centre (ESTEC) to provide minimum intrusive particle radiation detectors for space science and applications.
SREM is a solid state particle detector consisting of three silicon diode detectors in a two-detectors-head configuration. All the pre-amplified detector pulses are scrutinized by a set of fifteen fast comparators. In order to determine proton and electron flux spectra without the need of pre-assuming their spectral form we have implemented a regularized unfolding method which is based on the Singular Value Decomposition (SVD) of SREM calibration matrix.
The method includes proper schemes that treat the numerical issues arising by the electron-proton contamination, the energy range overlapping and the low number of SREM counters. First test studies show that this method can successfully unfold both monotonic and non- monotonic fluxes of energetic particles using SREM data.

Radar is a critical tool for maintaining knowledge of the many objects in low Earth orbit and thus for maintaining confidence that societies around the world are secure against a variety of space-based threats. It is therefore important to raise awareness that LEO objects are embedded in the envelope of relatively dense plasma that co-rotates with the Earth (ionosphere-plasmasphere system) and thus accurate tracking must correct for the group delay and refraction caused by that system. This presentation will review those effects and highlight some key issues, e.g. (a) the need to customise correction to prevailing space weather conditions and the altitude of the tracked object, and (b) that ionospheric correction will be particularly important as an object approaches re-entry. The paper explores approaches that may lead to better techniques for handling space weather effects on ionospheric correction.

Magnetic helicity is one of the few invariant of magnetohydrodynamics. This property has important consequences for the Sun Earth system. The excess of magnetic flux and magnetic helicity, stored in the solar corona by emerging flux through the solar surface, have to be expelled by coronal mass ejections (CMEs). Recent studies confirm that the source active regions of CMEs have the same helicity sign as the one of the corresponding magnetic clouds in the geospace. I will emphasis on morphological signatures of the sign of the magnetic helicity in emerging flux. However global magnetic helicity of active regions can also be quantitatively computed by different approaches. The use of magnetic helicity density maps, showing mixed polarities in active regions, can now explain the few remaining contradictive cases.

We study the initiation and early evolution of coronal mass ejections (CMEs) in the framework of numerical ideal magnetohydrodynamics (MHD). The magnetic field of the active region possesses a topology in order for the breakout model to work. An initial multi-flux system in steady equilibrium containing a pre-eruptive region consisting of three arcades with alternating flux polarity is kept in place by the magnetic tension of the overlying closed magnetic field of the helmet streamer. The effects of two different driving mechanisms (shearing motions along the magnetic inversion line and emergence of new magnetic flux) are separately studied and then compared. The applied boundary conditions cause the central arcade to expand and lead to the eventual ejection of the top of the helmet streamer. We compare the topological and dynamical evolution of the obtained CMEs and find that the overall evolution of the systems is similar.

Various channels of influence of geomagnetic pulsations Pc3 - 5 and Pi2 on whistler ELF and VLF waves in the inner magnetosphere are compared between themselves. The importance of the resonance nature of the interaction of wave disturbances with different scales is shown. Resonance is associated not with the usual effect of space - time synchronism but with the periodic alternation stages of electron accumulation in the radiation belts and their precipitation into the ionosphere, which is typical for plasma magnetospheric maser. The obtained results are useful both in explaining conditions of excitation of quasiperiodic emissions of various types and in improvement of the magnetospheric processes diagnostic methods.

Experimental studies of Earth atmospheric flows have established the possibility of superrotation of their atmospheres at large heights. This superrotation is characterised by the ratio of the angular velocities of the atmosphere and the planet. Several possible superrotation mechanisms have been discussed in the literature, but none of them was universal indeed. Here, we consider the kinetics of a rarefied exosphere replenished with particles injected from a spherical surface inside which collisions are significant. As we show, peculiarities of the motion of a rarefied gas in the gravitational field can give rise to superrotation. It follows from the laws of motion that rather fast particles can rise high and even recede to infinity. Because of the angular rotation of the planet, the particles whose velocity has the same direction as the rotational velocity of the planet will have a higher initial velocity. Primarily these particles can recede appreciably from the planet to become its "satellites" due to weak collisions. Therefore, we have reason to expect that the mean angular velocity of the particles in the upper planetary atmosphere can exceed the angular velocity at its inner boundary. A quantitative analysis of this problem based on the exact solution of the kinetic Boltzmann equation. We consider the kinetics of a rarefied rotating planetary exosphere. The spatial distributions of the atmospheric gas density and mean angular velocity were determined by analyzing the exact solution of the two-dimensional kinetic equation. We show that the angular velocity of the gas at some distance from the planet could be higher than that in the initial layer starting from which the atmosphere is rarefied. Our model calculations elucidate the superrotation mechanism under consideration.

We analyse a relationship between various geophysical time-series describing the state of the ionosphere, magnetosphere and solar activity: fluctuations of the F layer critical frequency foF2, geomagnetic indices (Dst, Kp, AE) and solar indices (sunspot number SSN, solar flux F10.5). Time series consist of diurnal values of each parameter (e.g. foF2 noon median, ∑Kp etc.). According to availability and presence of gaps within time series we selected suitable sets. The largest analysed interval cover period longer than three full solar cycles.
The fluctuations of the observed ground-based and satellite time series result from a mix of fluctuations of different physical origin. Wavelet cross-coherence analyses are applied in order to find internal data structure and dependence of the phase between particular time series.

Many factors can play a role in the formation of gradual SEP flux profiles: from the strength of the expanding MHD shock, and the injection rate and transport of shock-accelerated particles in the interplanetary space, to the relative position in space of the observer with respect to the shock front.

Only scarce existing models of gradual SEP events consider the heliolongitude of the observer with respect to the shock (e.g., central meridian, west or east events) when interpreting or simulating the variety of observed flux profiles. The relevance of the observer's heliolatitude (north or south events) has not been quantified yet, simply because the existing models are based on 1D or 2D MHD codes. Nonetheless, as seen at distance, the Sun has no a priori preference for the launch direction of a CME-driven shock in 3D space.

We have performed a 3D MHD simulation of the propagation of an interplanetary shock from the Sun up to 100 solar radii and we have analyzed the passage of such shock by nine observers located at ≈ 0.4 AU but with different longitudes and latitudes. We study and discuss the evolution of the plasma conditions at the cobpoint (the point of the shock front magnetically connected to each observer), as the shock propagates away from the Sun up to the observer's position. Conclusions about the influence of the latitude on the injection rate of shock-accelerated particles and on the obtained proton flux profiles to be detected by each observer are presented.

Geomagnetic disturbances are related with the solar activity and lead to the generation of geomagnetically induced currents (GIC) in any long conducting systems at the Earth's surface, such as power networks, pipelines, telecommunication systems and railways.
The list of failure reports of the signaling system from the Oktyabrskaya railway (Russia) was analyzed in comparison with magnetic recordings from IMAGE stations for 2002 - 2005. Nearly all disturbed nights (Kp > 7) led to unstable operation of railway automatics.

Geomagnetically induced currents (GIC) in power transmission systems are ground effects of space weather. We are using a matrix method to calculate GIC in real power system, located in the Kola Peninsula, Russia. The graph representing the real power system gives chance to simplify the model of lines, then a matrix of the simplified model was used to calculate currents in the lines and along the grounded wire of autotransformers. The results of simulation are compared with the measured GIC.

This paper presents results of the analysis of the ionospheric F2 layer peak parameters variation for different solar activity conditions over middle latitudes. The analysis was carried out using hourly foF2 and hmF2 values derived from electron density profiles obtained at selected ionospheric stations from the Northern (NH) and Southern hemisphere (SH). We studied the daily, semi-annual and annual variation of the peak parameters and the latitudinal and longitudinal dependence of the variation. Effects of severe space weather events on the regular F2 peak variation have also been analysed. The observations were compared with predicted parameters from the IRI2007 and Global Neural Network (NN) model outputs. IRI2007 fails to simulate an alternation of the ionospheric storm phases, and, in general, does not provide a good representation of the variation of the mean night-time foF2 values. The quiet time hmF2 above NH middle latitudes is better represented by IRI during winter and summer months, while at SH middle latitudes the model simulates hmF2 variability more successfully during summer and equinoxes. In some cases the global NN model results showed a significant improvement over the IRI 2007 model, however, in general the improvement is not substantial for storm time periods, which is to be expected since the NN produces in general an average quiet time model. Our results indicate the importance of fully understanding the local patterns of the F2 layer peak parameter variations for the development of global models.

The observation of transient particle fluxes was found to be a convenient approach to study the dynamic of the space radiation environment. This method actually includes the following activities:
1. The determination of the steady state wave and particle fluxes
2. Accurate measurements of particle flux lifetimes as function of energy, position and pitch angle.
3. The development of an accurate phenomenological model of the event-driven flux variations as a function of solar wind parameters.
These activities already lead to some interesting results:

For in-situ monitoring of space weather parameters a low-cost monitor is presented. The device consists of three (or more) isolated spheres, a metallic sphere, one or more highly transparent Inner Grids and an Outer Grid. Each one is being connected to a sensitive floating electrometer. By setting different potentials to the grids as well as to the sphere and varying one or more of their voltages, measurements of spectral solar EUV irradiance (15-200 nm), of local plasma parameters such as electron and ion densities, electron energies and temperatures as well as ion compositions and debris events can be derived from the current recordings. This detector does not require any (solar) pointing device.
The primary goal is to study the impact of solar activity initiated space weather events as well as subsequent reactions down to the ionospheric/thermospheric systems. The sensor can be operated in LEO and MEO orbits, in the interplanetary medium and in the planetary ionospheres as well. On the other hand monitoring the space environment can lead to a better understanding of how spacecraft are affected by the space environment for example by charging of satellites which can be determined by this sensor, too. In principal the data collected can be used both for prediction, and for post-analysis of such anomalies.
SEPS is well suited for missions aboard large, medium and small satellites. It is intended to deliver this sensor for installing a satellite based network of space weather sensors for future space weather services delivering data from the interplanetary medium down to the lower thermosphere and ionosphere.
Based on laboratory tests at the BESSY electron synchrotron, at the IPM test equipment for the SolACES experiment aboard the SOLAR ISS platform and in the ESTEC plasma chamber a sensor of 8 cm diameter and about 150 g of weight (without electronics) is ready to be build for in-orbit verification. The results of these tests in the energy range from 0 to +/- 70 eV will be presented.

In addition to provide fascinating auroral displays, the large and violent magnetic substorms may endanger power grids and a variety of other important technical systems. Such substorms generally result from the build-up of excessive stresses in the magnetospheric tail region caused by imbalance between the transpolar antisunward convection of plasma and embedded magnetic fields and the sunward convection at auroral latitudes. The stresses are subsequently released through substorm processes, which may, among other, cause ionospheric currents in the million-ampere range that in turn endanger power grids through the related GIC effects. The transpolar convection can be monitored through the associated geomagnetic effects as expressed by the Polar Cap (PC) index. Thus the PC index can be considered an index for the power input from the solar wind to the magnetosphere. Part of this power is subsequently dissipated in substorm events. The presentation reports the analysis of past major events like the July 1982, February 1986, March 1989, November 1991, and October 2003 power outage events in order to qualify on-line PC data for the potential modeling and forecast of large substorms that may endanger power grids.

We present first results from a new a model of Geomagnetically Induced Currents (GIC) in the United Kingdom's National Grid. Although at mid latitudes, the UK's high voltage electrical power network is known to be affected by space weather. Therefore in order to properly model UK GIC we need to account for the complex (and developing) power network, as well as the detailed geology of the British Isles and the neighbouring shallow seas and Atlantic Ocean.

The model presented here represents the UK's national grid (400kV and 275kV) as of 2008. We calculate the GIC produced at every node in this grid for given electric field configurations. Using designed electric field configurations at a range of orientations and strengths the model is used to determine the conditions that are the most significant, in terms of causing GIC. By the use of Spherical Elementary Current Systems, real magnetometer data is used to construct an electric field representative of the actual electric field. The model is then used to tell us where in the National Grid the largest GIC are likely to occur for that field configuration. The model may be further used to determine how any proposed changes to the National Grid?s configuration may affect future GIC distributions.

The evaluation of an ionospheric model performance for operational application involves many tests. Among others, it requires quantification of the model?s prediction accuracy under all possible conditions.To quantify the prediction accuracy of a model but also to track the improvement in specification and forecast capabilities over time, ionospheric metrics of both scientific and operational value should be established and maintained. On this basis, we report on a study in which several metrics definitions for the foF2 parameter are used to evaluate the performance of the Solar Wind driven autoregression model for Ionospheric short-term Forecast (SWIF) under various ionospheric conditions. SWIF is implemented on line in DIAS system (http://dias.space.noa.gr) to provide ionospheric forecasts up to 24 hours ahead for the European region based on historical and real-time ionospheric observations as well as solar wind parameters obtained in real time at L1 point. Following the current practice in the field, the evaluation of SWIF?s performance is established on the comparison against two simple prediction strategies, the median based and persistence predictions but also on the comparison against the empirical International Reference Ionosphere (IRI). The daily RMSE and the mean relative error are used as metric parameters to quantify SWIF?s prediction error and its relative performance against other prediction strategies. The evaluation of SWIF?s predictions is principally focused on its performance during selected disturbed periods over three European locations (Rome, Juliusruh and Chilton) for solar minimum and solar maximum conditions. The results demonstrate significant improvement over climatology, persistence and IRI predictions that depend on the latitude of the observation point and the prediction step, supporting the suitability of the SWIF algorithm for operational application. Moreover, the analysis of the results obtained under different metric definitions provides significant input for future considerations regarding the assessment of the performance of ionospheric forecasting models for operational use.

Origin of coronal shock waves is still not completely understood. Since the flare impulsive phase and the acceleration phase of a CME are usually well synchronized, it is difficult to give a conclusive answer on the shock wave origin in flare/CME events.
We present multiwavelength study of a shock wave associated with the flare event recorded on 14 November 2005. The evolution of the shock wave signature - type II radio burst - is analysed using dynamic spectra recorded by the Green Bank Solar Radio Bursts Spectrometer and NanAsay Radioheliograph imaging. The observations of the plasma dynamics in the low and high corona were provided by EIT and LASCO instruments onboard SOHO.
The strong type II emission starts at unusually high frequency of 700 MHz. The obtained values for the shock velocity, Alfven velocity and Alfven Mach number are in the range of typical shock parameters. The shock wave was closely associated with the impulsive phase of the compact M3.9 flare in the NOAA AR 10822 (located at S06E60). The short impulsive phase of the flare (4 minutes), suggests that a strong pressure pulse was ignited by the flare. Additionally, RHESSI observations show compact event of a rather high density and high temperature which gives indication of a strong, impulsive increase of pressure in the small flare loop.
SOHO/LASCO observations do not show any CME associated with this event. Since the active region is rather close to the limb, the possibility that the corresponding CME is not observed due to the unfavorable geometry is unlikely. We therefore conclude that the shock wave recorded on 14 November 2005 was a blast wave launched by the impulsive energy release in the course of the flare.

The Met Office and the Atmospheric Physics Laboratory at University College London are working together to investigate issues arising from the coupling together of the Met Office's global circulation model and APL's upper atmosphere space weather model. This will lead to a better understanding of the effects of space-weather on the lower atmosphere and ionosphere, and a fuller appreciation of how tropospheric effects can propagate upwards and influence the higher regions of the atmosphere

There has been various observational evidence that atmospheric gravity waves triggered by auroral events may have some influence on the development of tropical cyclones, and we have investigated the extent to which our space-weather model, CMAT2, shows any evidence of downwards propagating aurorally generated gravity waves, and other possible links between the lower and upper atmospheres.

The magnetosphere is a complex nonlinear dynamical system that evolves under the solar wind's influence. In spite of numerous measurements it is still impossible to deduce from the first principals the ultimate mathematical model that can be used to predict the dynamics of the magnetosphere. A much simpler question which is not completely clear is: What are the best modelling inputs, the most important parameters, that affect the evolution of the magnetosphere?
Correlations between geomagnetic indices and solar wind parameters are often used to deduce these best input parameters. However it is well known that this linear approach might lead to erroneous results for a nonlinear system such as the magnetosphere. In this study a data based NARMAX OLS-ERR approach has been used to deduce best inputs to explain the dynamics of Dst
For nonlinear systems the error reduction ratio (ERR) can be interpreted as a generalised indicator of correlation. In addition to basic solar wind parameters, Acasofu's ε parameter have been conbsidered as well. Ratings of different parameters will be shown and discussed.

ROBA2 is a technologically innovative ESA micro-satellite to be launched on November 2nd, 2009. The main scientific instruments on board are 1) SWAP, an EUV imager which will monitor space weather related events in the 1 million degree corona and 2) LYRA, an EUV radiometer which measures the Sun's irradiance in 4 passbands, carefully chosen for their relevance to space weather and solar physics. Both SWAP and LYRA make use of an innovative design and contain detectors which are new for solar physics instruments in orbit: a CMOS-APS detector for SWAP, and BOLD (Blind for Optical Light) diamond detectors for LYRA. The PROBA2 project stands for onboard autonomy, which results in several, scientifically interesting features as onboard image processing and event recognition, data prioritisation, automated CME tracking off-limb, etc. In addition, it will be possible to command the spacecraft to off-point to a maximum of 3 degrees away from the Sun's centre. Both the instrument commanding and the processing and distribution of the data will be done at the PROBA2 Science Centre, located at the Royal Observatory of Belgium. Thanks to support from the European Space Agency, SWAP and LYRA will be run as instruments in support of the solar physics and space weather communities and scientists studying the solar terrestrial relationship. In this paper we will give an overview of the various possibilities through which external scientists can participate in the SWAP and LYRA projects. In brief, these possibilities are: * open data policy * participation in the SWAP and LYRA Science Consortium (call to be issued) * joint observation campaigns with other instruments * support for synoptic space weather programs. Last but not least, starting around February 2010, a Guest Investigator Program will be set-up based on a Call for Ideas to the scientific community for the use of PROBA2 data. Selected proposers will be invited to spend one or a few months with the PI teams to obtain expert knowledge on the instruments, to participate in the daily commanding of the SWAP telescope according to the needs of their data analysis proposal, and to finalize their research. Each guest investigator will get reimbursed for travel, accommodation and living expenses.

The solar spectral irradiance in the UV/EUV range is essential to characterize the amount of solar energy the upper atmosphere receives, and this is important in particular for the determination of satellite drag. However, because of the lack of long-term and continuous observations, various proxies for solar activity are used instead in upper atmosphere models. Finding more appropriate solar inputs has become crucial for specifying the effect of air drag on satellites and on debris.

By using several years of neutral densities inferred from satellite drag measurements and a set of solar activity proxies, we perform a quantitative assessment of the performance of each proxy, and also of various spectral bands in the UV/EUV. A multivariate statistical technique for the first time allows to compare all quantities in a single plot, and on scale-to-scale basis. This study reveals which solar inputs are most appropriate for each temporal scale and provides guidance on the choice of a better set of inputs for operational density models. In particular, we show that scale-dependent combination of proxies is required in order to properly model the impact of solar irradiance.

LYRA (Large Yield Radiometer) and SWAP (Sun Watcher using APS detector and image Processing) are instruments on ESA's satellite PROBA2 (Project for On-Board Autonomy) to be launched November 2009. LYRA will deliver solar irradiances with high temporal resolution (10 ms - 10 s) in four nominal UV intervals: 120-123 nm, 200-220 nm, 17-80 nm, 6-20 nm. SWAP will be able to deliver every minute an image of the solar corona in the 17.5 nm range. Due to the spectral responsivity of the LYRA detectors, it appears possible to split the LYRA total signal of the two short-wavelength channels such that also time series of SXR radiation can be produced. In addition, the overlap of LYRA's short-wavelength channels covering the SWAP spectral interval offers two ways to estimate a "coronal" time series that can be cross-calibrated with SWAP's integrated output. - Radiometric model simulations will be presented and expected results described.