Plenary - Space Weather Forecast Verification

Peter Wintoft, Ioanna Tsagouri, Alan Thomson, Andrew Bushell
Friday 22/11, 09:00 - 10:30 and 11:00 - 12:30

Forecast verification within the meteorological community has a long tradition, starting in the 1880's and with the introduction of a new verification framework in the mid-1980's. Forecast verification is the process of assessing the quality of a forecast, both in absolute terms and for comparing forecast models. Evaluating the quality of space weather forecasting models faces similar challenges as for terrestrial weather forecasting. In this session we invite presentations related to space weather nowcast and forecast verification. We welcome contributions from forecasters concerned with, for example,
  • forecast verification applied by forecast providers;
  • future development of forecast verification; * communicating verification results and requirements between users and providers
  • metaverification -- evaluating performance measures;
  • magnetic and other space weather indices;
  • ground effects of space weather;
  • ionospheric and magnetospheric processes;
  • solar and interplanetary data.

Oral contributions

Seq   Time   Title
1   09:00   A Critical View on the Space Weather Forecasts at the Regional Warning Center in Belgium
Devos, Andy; Verbeeck, Cis; Robbrecht, Eva
Royal Observatory of Belgium, BELGIUM

The ISES Regional Warning Center in Brussels for space weather forecasting at the Royal Observatory of Belgium (ROB) has been providing daily space weather forecasts for more than a decade. As part of the FP7 project AFFECTS (Advanced Forecast For Ensuring Communications Through Space), ROB has applied a thorough verification analysis of the forecasts of the RWC over the past decade. From now on this procedure will be applied annually.

Forecasts of fundamental space weather parameters as the K value (the local geomagnetic index), the 10.7 cm radio flux and solar flaring probabilities are under critical evaluation. Strengths and weaknesses are determined compared to common numeric models. The verification analysis can easily be extended with extra analysis and facilitate embedding new forecasting models in the future.

Descriptive model statistics, common verification measures, error analysis and conditional plots between forecasts and observations are available on The analysis allows us for example to detect the influence of solar activity on the confidence level of the forecasts. The output aids to identify the strong and weak points of forecasting as well as those of the models considered. As such, it creates the opportunity to continuously reevaluate, stimulate ideas for improvement and increase the reliability of space weather forecasting.

This work has received funding from the European Commission FP7 Project AFFECTS (263506).

2   09:30   Developing an Ensemble Prediction System for Operational Space Weather Forecasting
de Koning, Curt A1; Pizzo, Vic2; Odstrcil, Dusan3
1University of Colorado, UNITED STATES;
3George Mason University, UNITED STATES

At present, almost all space weather forecasts are made using a deterministic approach to numerical space weather prediction (NSWP), that is, a single forecast (estimate of the future state of the heliosphere) is obtained from a single known initial state. However, due to intrinsic uncertainties in initial conditions, finite model resolution, and the use of simplifying MHD equations that do not fully capture the relevant processes in the heliosphere, forecast uncertainty and predictability limitations are an important, but unexplored, property of NSWP. Dynamically specifying an error for each forecast is essential for assessing the quality of a forecast, both in absolute terms and for comparing forecast models.

We describe ongoing research on an ensemble prediction system for use in an operational space weather environment. The numerical model used in our ensemble prediction system is Enlil, a time-dependent, 3D-MHD code that predicts CME arrival time at Earth. We assess the relative importance of the model inputs (CME size, speed, and direction as derived from near-real-time coronagraph observations), as well as background stream structures, for determining an accurate arrival time at Earth and the contribution of these inputs to the forecast uncertainty. We also discuss ways of analyzing the output from a multitude of model runs to arrive at a consensus forecast. Finally, we present an ensemble visualization that will convey information about the ensemble inputs and forecast.

3   10:00   The NWRA Flare-Forecast Comparison Workshops: Approaches for Meaningful Verification and Comparison.
Barnes, Graham1; Leka, K.D.1; The Int'l Flare Forecasting, Comparison Group2

Two workshops have been held recently, in 2009 and 2013, to begin systematic comparisons of methods for forecasting solar flares. We discuss here the requirements for the data and the methods in order to provide meaningful comparisons of the performance of participating methods. These include standardized data sets for input to the forecasting methods, and standardized event definitions that allow for statistically useful sample sizes. Crucially, meaningful comparisons require the use of standard verification statistics such as skill scores and reliability estimates. Given the often low sample size for the larger solar events, estimates of the uncertainties in these verification statistics are particularly important. We present here the approaches used for these two workshops, and some of the preliminary results which have been obtained thus far, with a particular emphasis on the uncertainty estimates.

Funding for the workshops and the data analysis was provided by NASA/Living with a Star contract NNH09CE72C and NASA/Guest Investigator contract NNH12CG10C.

4   10:15   Statistical Study of False Alarms of Geomagnetic Storms
Leer, Kristoffer1; Vennerstrom, Susanne1; Veronig, A.2; Rodriguez, L.3; Vrsnak, B.4; Dumbovic, M.4
2UniGraz, AUSTRIA;
4HVAR Observatory, CROATIA

Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue. A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs.
The ability to identify potential false alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates for false alarm signature.

5   11:00   Forecast Evaluation as Applied to Geomagnetic Activity Categories
Clarke, Ellen1; Thomson, Alan2
1British Geological Survey, UNITED KINGDOM;
2British Geological survey, UNITED KINGDOM

Daily forecasts of geomagnetic activity have been provided by BGS since the 1990s. The predictions are globally averaged levels of activity over a 24-hour period, going from noon to noon (UT), for one, two and three periods ahead. Noon to noon was chosen in order to capture storms occurring in the night time local to the UK. Four possible categories are used: QUIET-UNSETTLED (Ap <= 15); ACTIVE (16 <= Ap <= 29); MINOR-STORM (30 <= Ap <= 49); and MAJOR-STORM (Ap >= 50). These forecasts are prepared daily by a duty forecaster reviewing all available information on solar activity, solar wind parameters and other space weather data, to predict the impact at the Earth. Recipients of these forecasts have been power companies and the oil and gas industry.

Evaluation methods for categorical forecasts of this type are not yet well established in Space Weather, unlike those used for meteorological forecasts. Using examples applied in meteorology, we first investigate the use of various skill scores and other metrics for a "STORM" vs. "NO-STORM" prediction using 2x2 contingency tables. We then extend this to 4x4 contingency tables for predictions which fall into all 4 categories.

Results over 14 years are presented and we discuss the merits of equitable skill scores (ESS), such as that proposed by Gandin and Murphy (1992) and improved by Gerritt (1992) for forecasts of more than two categories. Comparisons are made between individual forecasters, over time and also against benchmark forecasts. The value of ESS is discussed with respect to both the end-user and the individual forecasters.

6   11:30   Verification and Validation System of the UAH-SWS Service
Guerrero, Antonio1; Cid, Consuelo1; Cerrato, Yolanda1; Saiz, Elena1; Aguado, Jesús2; Palacios, Judith1
1University of Alcala, Space Research Group - Space Weather, SPAIN;
2E.U. Cardenal Cisneros, Space Research Group - Space Weather, SPAIN

The adopted model for verification and validation of the UAH-SWS (Space Weather Service of the University of Alcala) has been running in V&V (Verification and Validation) mode during more than one year. Data of every step involved in the process to produce the outputs of the service have been saved in order to be able to reproduce the execution of different versions of the software when needed. We show in this presentation, the structure of the system and the configuration of the modules we have adopted in order to accomplish the needs for V&V. We review some hints and failures of the service allowing us to assess the accuracy of the physics of the model by being able to discard failures due to software design or operation errors.

7   11:45   Exploring the use of ESPAS Data for Validation of a Thermosphere-Ionosphere Physical Model Data Assimilation System
Bushell, Andrew; Henley, Edmund; Jackson, David

As test users for FP7 project ESPAS, we plan to exploit the Near-Earth Space Data Infrastructure for e-Science which is currently under development for a set of experimental cases (historical events, not in real time) in which a thermosphere-ionosphere physical model data assimilation system will run for an extended period.

A free-running simulation of a selected case run with the Coupled Middle Atmosphere Thermosphere (CMAT2) model, developed at University College London, is under way to produce results for comparison with data accessible from the ESPAS system. The purpose of this activity is (i) to gain experience with accessing data from the system and (ii) to establish what ESPAS data is best-suited for comparison with the model output either for validation or for data assimilation purposes. Preliminary assessment may be at the level of spatial- and time-aggregated fields from the model and data, although for data assimilation purposes the requirement is rather for comparison to be carried out locally, which implies access to individual profiles (satellite passes) from the database.

In order to run an experiment with the CMAT2 model as part of a data assimilation system that cycles through an extended case period, there is a further requirement to access metadata with which to calculate errors associated with observation data, used

  • in quality control of data assimilation and
  • to calculate the weighting given to the data (observation error covariance matrix) when calculating the optimal model analysis.

    Such scenarios explore both the behaviour of the model data assimilation system and that of the ESPAS data infrastructure, helping to define its relevance for future user communities.

    8   12:00   Verification of DIAS Ionospheric Forecasts in the high Latitude Ionosphere
    Tsagouri, Ioanna; Belehaki, Anna
    National Observatory of Athens, GREECE

    Ionospheric forecasting products and services for Europe are provided routinely by the European Digital upper Atmosphere Server (DIAS, These include alerts and warnings for upcoming ionospheric storm time disturbances as well as single station and regional ionospheric forecasts up to 24 hours ahead for the middle latitude European region. As a step forward, in the frame of the ESA/SSA Programme the DIAS forecasting services are upgraded to cover the whole European region, including Scandinavia, based on the expanded implementation of the Solar Wind driven autoregression model for Ionospheric short-term Forecast (SWIF).
    In the operational mode, SWIF combines historical and real-time ionospheric observations with solar wind parameters obtained in real time at L1 point from ACE spacecraft through the cooperation of an autoregression forecasting algorithm, namely TSAR with an empirical ionospheric storm time model, namely STIM that is triggered by solar wind disturbances detected by STIM's alert detection algorithm. The ionospheric storm time response is then empirically formulated taken into account the latitude and the local time of the observation point at the storm onset.
    While SWIF's prediction efficiency has been fully documented previously for the middle latitude ionosphere, the work presented here includes the evaluation of the SWIF's performance over high latitude locations under disturbed geophysical conditions. For this purpose, high latitude foF2 observations obtained during a significant number of storm events occurred in the previous as well as the current solar cycle are analyzed in respect with the foF2 reference level and the model's predictions. The results verify the validity of SWIF's storm alert detection algorithm for high latitudes and quantify the accuracy of SWIF's forecasts through relevant metrics' estimations.

    9   12:15   Verifying GIC Nowcast Models with Geo-Electric Field Measurements
    Kelly, Gemma S.; Beggan, Ciaran D.; Shanahan, Tom; Thomson, Alan W.P.
    British Geological Survey, UNITED KINGDOM

    To understand how space weather impacts the GB power grid, the British Geological Survey Geomagnetism team have developed a near real-time system for "nowcasting" geomagnetically induced currents in the high voltage electrical network. External magnetic field measurements from the three UK geomagnetic observatories (Lerwick, Eskdalemuir and Hartland) are used to predict the induced surface electric field within the conductive Earth. A model of the network topology of the power grid is then used to determine the size of GICs at each node from the predicted electric field.

    Previously we have been unable to verify the electric field model, as electric field measurements have not been routinely undertaken anywhere in the UK. However, in 2012, the British Geological Survey initiated a project to produce long-term measurements of the electric field at each of our observatories. We are now able to make comparisons between the output from our electric field model and measured electric field data.

    We describe the field set up and instrumentation and present our initial results from this project, including comparisons between measured and modelled data for recent geomagnetic storms. The measurements are already helping us to constrain our electric field models and hence should improve the estimation of induced currents in the GB power system. The results will also ultimately aid numerical model developments of surface conductivity.


    Seq   Title
    1   Connecting white Light to In Situ Observations of Coronal Mass Ejections from the Sun to 1 AU
    Möstl, C.1; Amla, K.2; Hall, J. R.2; Liewer, P. C.2; De Jong, E.2; Veronig, A.1; Rollett, T.1; Temmer, M.1; Liu, Y.3; Davies, J. A.4; Lugaz, N.5; Farrugia, C. J.5; Luhmann, J. G.6; Galvin, A. B.5
    1Kanzelhöhe Observatory-IGAM, Institute of Physics, University of Graz, AUSTRIA;
    2Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, UNITED STATES;
    3State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, CHINA;
    4RAL Space, Harwell Oxford, Didcot, UNITED KINGDOM;
    5Space Science Center and Department of Physics, University of New Hampshire, Durham, NH, UNITED STATES;
    6Space Science Laboratory, University of California, Berkeley, CA, UNITED STATES

    We study the feasibility of using a Heliospheric Imager (HI) instrument, such as STEREO/HI, for unambiguously connecting remote images to in situ observations of coronal mass ejection (CMEs). Our long-term goal is to develop and test methods to predict CME parameters from heliospheric images, suitable for real-time operational space weather forecasting. We do this with an eye on future missions, for example Solar Orbiter, when it is in a suitable position with respect to the Sun-Earth line, or for a dedicated space weather mission at the L5 point in the Sun-Earth system (e.g. EASCO mission concept).
    We compare the predictions for speed and arrival time for about 20 CME events, each observed remotely by one STEREO spacecraft, to the speed and arrival time observed at various in situ observatories. We use "geometrical modeling", which means we approximate the CME fronts with various shapes (Fixed-Phi, Harmonic Mean (HM), Self-Similar Expansion (SSE)). These models are fitted to the time-elongation functions extracted from STEREO/SECCHI images with the SolarSoft SATPLOT package. We use these techniques for a single-spacecraft HI observer, and consequently assume constant CME speed and direction. For assessing the accuracy of the parameters derived from HI we look at plasma and magnetic field data of interplanetary CME sheath regions by Wind (MFI, SWE instruments) and STEREO-A/B (IMPACT, PLASTIC), all located close to 1 AU. The results show that the arrival times derived from imaging generally closely match the in situ ones to within roughly 6 hours, and speeds agree to within 200 km/s for slow CMEs. However, for very fast CMEs in the range > 1500 km/s, the predicted speeds are too high by up to 1000 km/s, even though we include effects caused by the ICME flank, which moves slower than the apex in the HM and SSE models. This calls for an update of these methods to include deceleration, if they want to be successfully used to predict the fastest and potentially most geoeffective CMEs from outside the Sun-Earth line.
    This work has received funding from the European Commission FP7 Project COMESEP (263252).

    2   Verification of Solar Microwave Precursors of Geoeffective Coronal Mass Ejections
    Sheiner, Olga; Fridman, Vladimir; Ledaschev, Sergey
    Radiophysical Research Institute, RUSSIAN FEDERATION

    It has been shown that a significant number of coronal mass ejections in a two-hour interval before their recording by coronagraphs are preceded by sporadic radio emission that can be defined as radio precursors of coronal mass ejections. The results of statistical studies evidence that the width of the most developed CMEs affecting the near-Earth space depends on the characteristics of microwave sporadic radio emission observed during two-hour intervals preceding CME registration on coronagraph. It was shown also that the absolute majority of such CMEs an the stage of their formation is associated with sporadic microwave radiation having the certain characteristics, such as its broadband and time duration of more than 10 minutes. This allows to assess potential geoeffectiveness of CMEs using data on the radio emission, taking into account expected CME source position on the solar disk.
    The verification of geoeffective CMEs forecast is carried out on the base of SOHO/LASCO data.

    3   SuperDARN HF Radar Data Coverage for Ionospheric Electric Field Measurement
    Chisham, Gareth; Freeman, Mervyn; Kavanagh, Andrew
    British Antarctic Survey, UNITED KINGDOM

    Specification of the ionospheric electric field, and its extension into the magnetosphere, is of fundamental value to many space weather research problems, and will be essential to assimilate into whole atmosphere, magnetospheric, and radiation belt models now under development for space weather forecasting. To this end, we analyse the data coverage provided by the Super Dual Auroral Radar Network (SuperDARN) which currently comprises 33 radars around the world and has data going back over 20 years from some radars. We compare the coverage with the observing goals set by the World Meteorological Organisation and that needed by current models and identify the main factors influencing coverage.

    4   Investigation of Ionospheric and Magnetospheric Processes using High Frequency Induction Coil Magnetometers in the UK
    Beggan, Ciaran; Kelly, Gemma; Thomson, Alan
    British Geological Survey, UNITED KINGDOM

    In June 2012, the British Geological Survey Geomagnetism team installed two high frequency (100 Hz) induction coil magnetometers at the Eskdalemuir Observatory, in the Scottish Borders of the United Kingdom. The induction coils permit us to measure the very rapid changes of the magnetic field.

    We present initial results from first year of data. Analysis of spectrograms and power spectral density plots in the frequency band of 3-40 Hz from the coils show diffuse bands of peak power around 7.8 Hz, 14.3 Hz, 20.8 Hz, 27 Hz, 34 Hz and 39Hz related to the global Schumann resonances. We also detect a strong narrow peak at 25 Hz, which is a harmonic of the UK electrical power system.

    There are a number of features in the data of interest, such as intermittent variation of the Schumann resonance harmonics and magnetospheric pulsations. The data are freely available on request to the community.

    5   Geomagnetic Conditions Forecasting by using Solar Activity Parameters
    Gerontidou, Maria; Paouris, Evangelos; Paschalis, Pavlos; Papaioannou, Athanasios; Mavromichalaki, Helen
    National and Kapodistrian University of Athens, GREECE

    Enhancements of geomagnetic activity resulted from the interaction of solar wind originated from solar flares, coronal mass ejections and coronal holes at the Earth magnetosphere have been studied in the frame of Space Weather. The space weather effects can roughly be divided into two categories: those effects quickly and directly associated with solar activity, and those effects resulting from the impact of solar activity-generated interplanetary coronal mass ejections on Earth's magnetosphere. The scientific community managed to implement centers for the continuous monitoring of the geomagnetic conditions which resulted into short and long term forecasting of the planetary geomagnetic activity such as Ap index. A new forecasting center at the Athens Neutron Monitor Station (A.Ne.Mo.S) has been established from 2012. A first estimation of the accuracy of the predicted Ap index which provided by the Athens Forecasting Center is calculated about 82% during the first year of its operation. In this work a statistical treatment of crucial parameters of about 119 X-Ray flares and 1408 M-class flares as well as their associated coronal mass ejections during the time period 2000-2012 has been performed. These results have been used in order to have a first estimation of the geomagnetic Ap index. This method has been applied on the Space Weather Forecasting Center of University of Athens and these results are briefly discussed.

    6   The Spatial and Temporal Distribution of Solar and Galactic Cosmic Rays
    Shatov, Pavel1; Tasenko, Sergey1; Skorohodov, Ilya1; Getselev, Igor1; Podzolko, Mikhail1; Anashin, Vasily2; Protopopov, Grigory2
    1Fiodorov Institute of applied geophysics, RUSSIAN FEDERATION;
    2Institute of Space Device Engineering, RUSSIAN FEDERATION

    The areas of energy particles on the Sun from 1956 to 2012 are considered. The significant irregularity of their distribution is registered.
    The ranges of longitudes, in which particles are considerably injected, are discovered. The areas of the Sun with very law radiation effectiveness are at particular interest. The deficiency of the solar proton events during the inversion period of the Earth's main magnetic field is noticed. The one made a conclusion about the obtained data reasonability for estimation of the observation probability and solar cosmic ray appearance risk.
    For the estimation of the charged particle contribution, going from the interplanetary space on the measuring instruments, the data base on cosmic rays is created. It includes maximum, minimum and average values of proton fluence from 1 month to 10 years space of time.

    7   Variability of the Main Ionospheric Parameters during Magnetic Storm Recovery Phase
    Buresova, Dalia; Lastovicka, Jan; Boska, Josef; Novotna, Dagmar
    Institute of Atmospheric Physics AS CR, CZECH REPUBLIC

    Intensive ionospheric research, numerous multi-instrumental observations and large-scale numerical simulations of ionospheric response to magnetic storm-induced disturbances during the last several decades were primarily focused on the storm main phase, in most cases covering only a few hours of the recovery phase following after storm culmination. Ionospheric behaviour during entire recovery phase still belongs to not sufficiently explored and hardly predictable features. In general, the recovery phase is characterized by an abatement of perturbations and a gradual return to the "ground state" of ionosphere. However, observations of stormy ionosphere show significant departures from the climatology also within this phase. This paper deals with the quantitative and qualitative analysis of variability of the main ionospheric parameters during magnetic storm recovery phase over middle latitudes and under high and low solar activity conditions for nowadays and future modelling and forecasting purposes. We compared critical frequencies, peak heights and TEC observed during recovery phase with the corresponding outputs of the IRI and NeQuick models.

    8   3D CME Parametrization - Comparison of GCS and CAT Techniques and ENLIL Applications
    Bosman, Eckhard1; Bothmer, Volker1; Millward, George2; Venzmer, Malte1; Odstrcil, Dusan3
    1Institute for Astrophysics, Georg-August-University Göttingen, GERMANY;
    2National Oceanic and Atmospheric Administration (NOAA), Space Weather Prediction Center (SWPC), Boul, UNITED STATES;
    3NASA/GSFC Goddard Space Flight Center, Greenbelt, Maryland, USA, UNITED STATES

    Since launch of the STEREO twin spacecraft in October 2006, 1071 large-scale CMEs were identified
    in STEREO/SECCHI/COR2 observations between January 2007 and December 2011 covering the full range of spacecraft separation angles between 0 and 180 degrees. Based on their bright and clear white-light appearance in the COR 2 field of view 242 CMEs were selected and analyzed with the Graduated Cylindrical Shell (GCS) modeling technique developed by Thernisien, Vourlidas and Howard. For a set of selected modeled CMEs their 3D topology, direction of propagation and speed was analyzed based on multipoint observations (STEREO, SOHO) with the CME Analysis Tool (CAT) developed by Millward et al. at the Space Weather Prediction Center, Boulder, CO, and with the GCS model. The analyzed events comprise earthward directed CMEs of low (~300 km/s), medium (~600 km/s) and high (>1.000 km/s) speed observed by STEREO and SOHO under various viewing angles. The results from the modeling comparison provide important implications for the use of CME parameters as input for ENLIL simulations yielding CME arrival times and 1 AU CME speeds.

    9   Accuracy Assessment of the Space Weather Aspects Forecasts used in the Russian Federal Space Agency Monitoring System
    Anashin, Vasily1; Protopopov, Grigory1; Gaidash, Sergey2; Belov, Anatoly2
    1Institute of Space Device Engineering, RUSSIAN FEDERATION;
    2Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), RUSSIAN FEDERATION

    The Russian Federal Space Agency Monitoring system of space radiation exposure on spacecraft electronic equipment elements were developed by the Institute of space device engineering and operates successfully.
    The Monitoring System covers two parts: the scientific monitoring system (ground-based segment) and the engineering monitoring system (space-born segment). The ground-based segment comprises forecast station that provides the following daily forecasts and alerts:
    - Geomagnetic activity forecast for 1 - 3 days;
    - Geomagnetic activity forecast for 6 - 8 days;
    - Daily GSO high energy electron fluence forecast for 27 days;
    - Space weather review and forecast, covering solar proton increasing forecast;
    - Proton events alert;
    - GSO high energy electron fluence increasing alert (electronic equipment killers).
    Efficiency and accuracy are the major criteria of performance forecast usage. Forecasts are made promptly owing to round-the-clock space weather characteristics monitoring and use of modern communication facilities.
    The paper presents accuracy assessment of the given forecasts which were made by forecast correlation analysis with the measured values in various time intervals. These estimations were correlated with the similar results from the world forecast centers.

    10   Comparison of Thermospheric Data Assimilation with a Drag Temperature Model for Operational Nowcasting and Forecasting.
    Murray, Sophie A.1; Henley, Edmund M.1; Jackson, David L.1; Bruinsma, Sean L.2
    1Met Office, UNITED KINGDOM;

    The thermosphere hosts thousands of low-earth-orbit objects, including operational satellites. In addition to regular patterns, local variations of drag forces can be induced in the wake of intense solar activity. Accurate orbit prediction is thus imperative to keep satellites operational. The work of the Advanced Thermospheric Modelling for Orbital Prediction FP7 project aims to improve upon current semi-empirical models used for prediction in order to enable accurate forecasting.

    A thermospheric data assimilation procedure has been developed using general circulation models (such as the Coupled Middle Atmosphere-Thermosphere model, and the Thermosphere-Ionosphere-Electrodynamics General Circulation Model) with inferred neutral densities from satellite observations (e.g., from CHAMP, GRACE, and GOCE). Data assimilation results were compared with the outputs of an advanced semi-empirical drag temperature model (DTM) that uses proxies to describe the solar and geomagnetic forcing of the thermosphere, as well as some corrections from observations. Independent observations from periods at solar maximum (2002) and solar minimum (2009) were also used for inter-comparison with analyses and forecasts from the two approaches. The results of this work will allow schemes to be developed for near-real-time assimilation of thermospheric data into the predictive DTM and physical models, ultimately enabling near-real-time modelling.

    11   The Polar Cap (PC) Index and Power Grid Disturbances.
    Stauning, Peter
    Danish Meteorological Institute, DENMARK

    The strong geomagnetic storm in the evening of 30 October 2003 caused high-voltage power grid disturbances in Sweden that expanded to produce hour-long power line outage in Malmoe located in the southern part of the country. Similar events have occurred earlier, among others, during the great storms of 13 - 14 July 1982, 8 - 9 February 1986, and 13 March 1989. Most cases of space weather related power grid disturbances are caused by extraordinarily intense substorm events. Such events may have a sudden onset but are usually preceded by lengthy intervals of very high values of the Polar Cap (PC) index. The PC index monitors the transpolar convection of plasma and magnetic fields building the stresses in the magnetospheric tail region that are released in strong substorms. During the 30 October 2003 event the intense solar proton radiation disabled the ACE satellite observations widely used to provide forecast of magnetic storm events. Hence in this case the alarmingly high PC index could provide useful warning of the storm in back-up of the missing ACE-based forecast. In further cases, on-line monitoring of the PC index could provide alternative or supplementary magnetic storm and substorm warnings to the benefit of power grid operators.

    12   Differences of Slow and Fast Solar Wind Stream Effects on the Earth Foreshock: THEMIS Observations
    Urbar, Jaroslav
    Czech Space Office, CZECH REPUBLIC

    We provide the foreshock model of plasma parameter modification based both on magnetic fluctuations and energetic particle fluxes.
    In the statistical study, we separate effects of the slow and fast solar wind streams on the foreshock region. We use multi-point observations from the THEMIS-ARTEMIS mission and compare to WIND solar wind monitor, estimating evolution of solar wind during interactions in the foreshock. We evaluate the differences emerging from the fast or slow solar wind streams, taking advantage of the recent prolonged solar minima. Most studies of the solar wind-magnetosphere interaction rely on L1 observations that are propagated toward the Earth assuming negligible evolution of upstream parameters along the solar wind path and not taking proper account on the different instrumentation and measurement modes being used. We quantify the effect of a systematic deceleration of the average solar wind speed with a decreasing distance to the bow shock that is controlled by the level of magnetic field fluctuations and by the flux of reflected and accelerated particles in the foreshock region with evaluating the established physical mechanisms. We show that the reflected particles not only excite the waves of large amplitudes but also modify mean values of either fast or slow solar wind parameters measured either in the foreshock or in an un-perturbed solar wind within broad range of Mach numbers.

    13   Modeling of Severe Geomagnetic Storms of Solar Cycle 23
    Revallo, Milo¨1; Valach, Fridrich2; Hejda, Pavel3; Bochníček, Josef3
    1Geophysical Institute of the Slovak Academy of Sciences, Bratislava, SLOVAKIA;
    2Geomagnetic Observatory, Geophysical Institute of the Slovak Academy of Sciences, Bratislava, SLOVAKIA;
    3Institute of Geophysics, Academy of Sciences of the Czech Republic, Prague, CZECH REPUBLIC

    We try to model selected strong geomagnetic storms of solar cycle 23 using a logistic regression model combined with an empirical model of the solar wind magnetosphere interaction. The set of solar wind data obtained from the ACE satellite is considered and the corresponding geomagnetic response is modeled and compared with real data. The discontinuity in magnetic field at the magnetopause is shown to play a key role in this study. The geomagnetic response is evaluated using the scale: no response, weak, medium and strong response, respectively. The question is how much past solar wind data is needed to obtain the most accurate one step ahead forecasts. We compare the current approach based on logistic regression with the method of artificial neural networks used in our previous study.

    14   TEC Mapping and Short Time Forecast
    Pozoga, Mariusz; Tomasik, Lukasz; Dziak-Jankowska, Beata; Stanislawska, Iwona
    Space Research Centre, POLAND

    GNSS permanent station are valuable source data for TEC mapping. In this work we presents maps and short time forecast of TEC valule over Europe region. For this purposes we have tested universal kriging and autocovariance for forecast. Using historical data we test our method for quite and disturb space weather conditon.

    15   The EISCAT_3D Science Case
    Tjulin, Anders1; Mann, Ingrid1; McCrea, Ian2; Aikio, Anita3; Ulich, Thomas4
    1EISCAT Scientific Association, SWEDEN;
    2STFC Rutherford Appleton Laboratory, UNITED KINGDOM;
    3University of Oulu, FINLAND;
    4Sodankylä Geophysical Observatory, FINLAND

    The EISCAT_3D radar system will be a world-leading international research infrastructure located in the Fenno-Scandinavian Arctic, using the incoherent scatter technique to study geospace and to investigate how the Earth's atmosphere is coupled to space. The EISCAT_3D phased-array multistatic radar system will be operated by EISCAT Scientific Association and thus be an integral part of an organisation that has successfully been running incoherent scatter radars for more than thirty years.

    The baseline design of the radar system contains a core site with transmitting and receiving capabilities located close to the intersection of the Swedish, Norwegian and Finnish borders and five receiving sites located within 50 to 250 km from the core. The EISCAT_3D project is currently in its EU FP7 funded Preparatory Phase and can smoothly transit into implementation in 2014, provided sufficient funding. Construction would then start in 2016 and first operations in 2018.

    The EISCAT_3D Science Case is prepared as part of the Preparatory Phase. It is updated annually with new releases, and it aims at being a common document for the whole future EISCAT_3D user community. The areas covered by the Science Case are atmospheric physics and global change; space and plasma physics; solar system research; space weather and service applications; and radar techniques, new methods for coding and analysis.

    Although incoherent scatter radars, such as EISCAT_3D, are few in number, the power and versatility of their measurement technique mean that they can measure parameters which are not obtainable otherwise, and thus also be a cornerstone in the international efforts to measure and predict space weather effects. Accordingly, the incoherent scatter data is also useful for verifications of space weather forecast.

    Two of the other aims for EISCAT_3D are to understand the ways the natural variability in the upper atmosphere, imposed by the Sun-Earth system, can influence the middle and lower atmosphere, and to improve the predictivity of atmospheric models by providing higher resolution observations to replace the current parametrised input. The EISCAT_3D observations will also be used to monitor the direct effects from the Sun on the ionosphere-atmosphere system and those caused by solar wind magnetosphere-ionosphere interaction. In addition, EISCAT_3D will be used for remote sensing the large-scale behaviour of the magnetosphere from its projection in the high-latitude ionosphere.

    EISCAT_3D can also be used to study solar system properties. Thanks to the high power and great accuracy, mapping of objects like the Moon and asteroids is possible. With the high power and large antenna aperture, incoherent scatter radars can be extraordinarily good monitors of extraterrestrial dust and its interaction with the atmosphere.

    Finally, over the years the EISCAT radars have served as a testbed for new ideas in radar coding and data analysis. EISCAT_3D will be the first of a new generation of "software radars" whose advanced capabilities will be realised not by its hardware but by the flexibility and adaptability of the scheduling, beam-forming, signal processing and analysis software used to control the radar and process its data. Thus, new techniques will be developed into standard observing applications for implementation in the next generation of software radars.

    16   Activities at SANSA Space Weather Centre
    Nxele, Teboho; Tshisaphungo, Mpho; McKinnell, Lee-Anne; Wentworth , Laura
    South African National Space Agency, SOUTH AFRICA

    The South African National Space Agency (SANSA) operates the Regional Warning Center (RWC) for Space Weather in Africa. The RWC is located within the Space Science Directorate of SANSA in Hermanus, South Africa. SANSA Space Science is a research facility for Space Science in South Africa, and operates a Space Weather Unit within its Research Group. The combination of ground and satellite based data is piped into the centre for predictions and forecasts analysis. This paper will outline the prediction and forecast procedures applied at the centre, present the measurements that are available for use by the center, and look at the applications that are currently being served within South Africa.

    17   Validation of the DIAS TEC Maps developed with the TaD Topside Profiler
    Belehaki, Anna1; Tsagouri, Ioanna1; Tziotziou, Kostas1; Kutiev, Ivan2; Marinov, Pencho2; Bergeot, Nicolas3; Chevalier , Jean Marie3
    1National Observatory of Athens, GREECE;
    2Bulgarian Academy of Sciences, BULGARIA;
    3Royal Observatory of Belgium, BELGIUM

    TaD is a topside model that extrapolates the electron density profile up to 20,000 km retrieving Digisonde characteristics at hmF2 and TEC estimates from GNSS receiver co-located with Digisonde. The TaD is based on the Topside Sounders Model (TSM), which is a set of empirical functions for the O+/H+ transition height (hT), the topside electron density scale height (HT), and their ratio, derived from the Alouette/ISIS topside soundings. To further increase the TSM accuracy, analytical formulas were developed for obtaining the shape of the vertical plasma distribution in the topside ionosphere and plasmasphere based on TSM parameters. This profiler models separately the O+ and H+ density profiles. To obtain the density distribution, the profiler needs specification of the F layer maximum density (NmF2), its height (hmF2) and its scale height (Hm) at its lower boundary. These are obtained from Digisonde measurements which are ingested to the TaD for the reconstruction of the electron density profile from the F layer peak to GNSS orbits. Above the transition height, the model calculates in addition to the other species, the distribution of He+, extracted from the analysis of the electron density profiles from ISIS-1. The plasmaspheric scale height is approximated as a function of altitude, latitude, local time, and season using an optimization procedure to achieve best fit with the measured profiles.
    A major problem that had to be resolved in order to implement the model in the DIAS environment, had to do with the accuracy of the autoscaled scale height at the hmF2, provided by the Digisondes. This was very often out-of-range, leading to unrealistic results for the modeled electron density profile. Therefore, the TEC parameter calculated from TaD model was adjusted with the TEC parameter calculated by GNSS transmitting RINEX files provided by receivers co-located with the Digisondes. This adjustment forces the model to correctly reproduce the topside scale height, despite the inaccurate values of Hm, and it is therefore very important for the application of TaD in an operational environment, such as the DIAS system. Based on this latest version of the TaD model, the DIAS system calculates maps of TEC over Europe, using (1) autoscaled bottomside electron density profiles from 8 European Digisondes and (2) TEC parameters at the Digisondes locations extracted from the ROB GNSS-based TEC maps over Europe. These maps are released in near-real time at 15 minutes resolution since November 2012.
    In this paper we present the validation of the maps, including the control for internal consistency of the model and the comparison of modeled TEC values with independent data. The validation extends to quiet and to geomagnetic storm intervals. First results show a reasonable agreement between TEC maps derived with TaD and other regional and global maps collected over a period of 6 months, with a maximum discrepancy of 3 TECU for the 96% of the cases, depending on the latitude of the geographic location under consideration. Based on this analysis, it is possible to reach conclusions about the parameters that affect the quality of the maps, i.e. the number of Digisondes contributing with data to each specific map, their geographic distribution, and the accuracy of the Digisonde autoscaled values.

    18   LDi: A Local Disturbance Index for Space Weather Purposes
    Palacios, Judith; Guerrero, Antonio; Saiz, Elena; Cid, Consuelo; Cerrato, Yolanda
    University of Alcala, SPAIN

    Real time monitoring of geomagnetic field is relevant for space weather purposes. Although some geomagnetic indices as Dst, ap or Kp are estimated in real time as proxies of global magnetic activity, in some cases, as GICs, local geomagnetic disturbances better comply with the phenomena than with the global ones. As a consequence, local magnetic activity timely available is essential for accurate forecasting of this kind of events. In this work a new index is proposed: the 'Local Disturbance index', i.e., an index (i) with local (L) information of the disturbance (D) during the storm time, obtained from the H component of geomagnetic field measured at a determined observatory.
    The requirements for a real time index for Spain guide us also to compare data recorded at three magnetic observatories (SPT, EBR and GUI) spread in longitude and latitude, looking for a relationship among them with the aim of providing a national local disturbance index. The results of this study are shown in this presentation.

    19   Comparison of EnOI Data Assimilation into Two Physical Models of the Thermosphere
    Henley, Edmund; Murray, Sophie A.; Jackson, David R.
    Met Office, UNITED KINGDOM

    The ATMOP project ( aims to improve orbital predictions for satellites close to Earth, through improved predictions of space weather effects on the thermospheric density responsible for the drag on the LEO satellites.

    A key part of ATMOP is using a physics-based model, as a complement to the semi-empirical DTM model used operationally. Specifically, we have worked on building data assimilation systems, using in situ density observations, such as those from the CHAMP satellite, to constrain the model density predictions, bringing them closer to the observed density values.

    Here we compare the results of assimilating observations into two different physical models: UCL's CMAT2 model and NCAR's TIEGCM model. Both simulate the thermosphere-ionosphere region, but differ in some details. The assimilation is performed using an ensemble optimal interpolation (EnOI) scheme, and the forecast results from both models are compared to observations not included in the assimilation.

    20   On the Present Status of Solar Activity
    Brajsa, Roman1; Verbanac, Giuli2; Sudar, Davor3; Skokic, Ivica4; Hanslmeier, Arnold5; Woehl, Hubertus6; Roth, Markus7; Ludmany, Andras8; Murakozy, Judit8; MacLeod, Chelsea L.9; Ivezic, Zeljko10; Mursula, Kalevi11; Zhang, Liyun11
    1University of Zagreb, Faculty of Geodesy, CROATIA;
    2Faculty of Science, University of Zagreb, CROATIA;
    3Faculty of Geodesy, University of Zagreb, CROATIA;
    4Cybrotech Ltd, Zagreb, CROATIA;
    5IGAM, Institute of Physics, University of Graz, AUSTRIA;
    6Kiepenheuer-Institut fuer Sonnenphyisk, Freiburg, GERMANY;
    7Kiepenheuer-Institut fuer Sonnenphysik, Freiburg, GERMANY;
    8Heliophysical Observatory, Debrecen, HUNGARY;
    9Physics Department, USNA, Annapolis, UNITED STATES;
    10Department of Astronomy, Univ. of Washington, Seattle, UNITED STATES;
    11Department of Physics, University of Oulu, FINLAND

    The amplitude and time for the actual solar cycle maximum are predicted using different methods:
    (i) asymmetry method
    (ii) correlation between relative sunspot numbers in minimum and maximum
    (iii) autoregressive moving average model (ARMA)
    (iv) damped random walk model (DRW)
    (v) connection between the starting latitudes and amplitudes of solar cycles
    (vi) relation between the number of spotless days and the subsequent amplitude
    (vii) Waldmeier effect: a relation between the rising time and maximum amplitude.

    Now it is already clear that the maximum of the 24th solar cycle will be weaker than the previous one. The estimated time of the maximum is in the years 2013-2014. Several data sets, including those from SIDC, ROB, Greenwich and Debrecen are used.
    Finally, the nonlinear effects of the solar activity and its influence on the prediction possibilities on short and long temporal scales will be briefly discussed.

    21   A prototype of a quick Information System for Space Weather Events effects on the ionosphere.
    Herraiz, Miguel1; Moreno-Monge, Beatriz2; Rodriguez-Bouza, Marta2; Rodriguez-Bilbao, Izarra2; Rodriguez-Caderot, Gracia2; Radicella, Sandro Maria3
    1Universidad Complutense de Madrid, Instituto de Geociencias, SPAIN;
    2Universidad Complutense de Madrid, SPAIN;
    3Telecommunications/ICT Development Laboratory (T/ICT4D) Abdus Salam International Center for Theoret, ITALY

    In this poster we present a prototype of a quick Information System aimed at warning about the ionospheric effects following a geomagnetic storm and based on the daily analysis of the behaviour of the ionosphere. After receiving a warning message from the different Space Weather Forecast Centres, as British Geological Survey and NOAA Space Weather, the System analyses a representative sample of ionospheric information and produces a new warning message if a ionospheric storm is detected. In this way, positioning and navigation can be more realistically calculated. For the analysis of the ionospheric state the prototype uses RINEX files from 5 International GNSS Service stations belonging to the International GPS Service network located on the South of Europe and the North of Africa. The data are obtained at 30 seconds sampling rate for the ten days previous to the day studied. This RINEX files are processed with a calibration algorithm developed at the Istituto di Fisica Applicata "Nello Carrara" of Florencia and the Abdus Salam International Center for Theoretical Physics of Trieste. This processing technique assumes the ionospheric thin shell model to obtain vertical total electron content (vTEC) from slant total electron content (sTEC) at the Ionospheric Pierce Point, IPP. The vTECmean obtained from the vTEC values of the 10 previous days is used to calculate the relative vTEC values that inform about on the changes in the ionosphere. When the values are higher than 50% or below -50% the prototype detects and anomaly and issues a message. We also present the first test of our system using five past alerts and known geomagnetic storms; four occurred in 2012 and one in 2011.