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Prediction of Geospace Radiation Environment and solar wind parameters

Periodic Reporting for period 2 - PROGRESS (Prediction of Geospace Radiation Environment and solar wind parameters)

Reporting period: 2016-01-01 to 2018-07-31

Just as weather can be charactrised by a set of atmospheric conditions, space weather is charactrised by conditions related to the local geospace environment. Knowledge of these conditions is crucial for the operation of modern technological systems that provide services such as communications, navigation, power transmission etc. The Sun drives space weather and may result in events such as magnetic storms and significant enhancements of the energetic particles fluxes in the near Earth space that are hazardous to the operations of these technological systems. Accurate forecast of these hazards is essential for the mitigation of their effects.

PROGRESS aims to exploit spacecraft and ground based data combined with state of art methodologies to develop accurate and reliable forecasts of space weather hazards. The main objectives are:

1: Develop a European numerical MHD based model to enable advanced forecasting of solar wind parameters at L1.
2: Use state of the art system science methodologies to develop new forecasting tools for geomagnetic indices.
3: Construct a new set of statistical wave models describing the interaction of plasma waves with the local particle population.
4: Extend IMPTAM, a physics based numerical code for keV electrons in the inner magnetosphere, to provide forecasts.
5: Develop a novel, reliable, and accurate forecast of the radiation environment in the inner magnetosphere.
6: To combine the outputs of the various forecast tools and provide access to their results.
During the whole project the work performed toward the stated objectives and the main results are as follows.

1.AWSoM a code to model the solar atmosphere, was modified to run in real time. It has been coupled to SWIFT, enabling forecasts of the solar wind at L1 to be made based on GONG magnetograms. The resulting forecasts are available via a web interface.

2.New forecast models for Kp, Dst and AE have been developed by IRF, SRI and USFD. Based on different techniques (ANN, NARMAX, and GNM) these models are run using inputs from the satellites ACE or DSCVR or the outputs from the SWIFT/AWSoM model.

3.Using data from the Cluster and THEMIS missions as well as solar wind measurments from ACE and DSCVR, the NARMAX ERR analysis method was used to determine the most important driving parameters for chorus, hiss, and magnetosonic waves within the inner magnetosphere. These parameters were then used to develop a new set of statistical wave models to characterise the interaction between these wave modes and the local particle population.

4.Results from the IMPTAM numerical simulation code have been significantly improved following improvements resulting from the incorporation of more realistic boundary conditions and electron lifetimes. Output from the IMPTAM model is used to define the low energy seed population of electrons that is used within the VERB code. Using the forecasts of the solar wind, the IMPTAM code was modified to provide online realtime forecasts. The PROGRESS web site provides access to a number of data products including comparisons with GOES 15 measurements, equatorial maps, and radial distance-energy and energy-time spectrograms for Galileo, MEO, and Van Allen Probe orbits.

5.The current set of NARMAX flux prediction models operated by USFD has been extended to cover all energies measured by the GOES 13 EPS instrument. The VERB code was extended by incorporating data assimilation techniques, allowing it to import measurements for comparative and corrective purposes. A new coupled model, VNC, in which the PROGRESS forecasts for GEO electron fluxes and Kp are used as inputs to the VERB model, has been developed.

6.The results menu on the PROGRESS web site provides access to the online forecasts of geomagnetic indices, sets of statistical wave models, electron flux forecasts at GEO, IMPTAM (FMI), VERB (GFZ), and VNC (USFD) forecasts for the electron environment of the inner magnetosphere. In addition, the orbit tool can provide along orbit electron flux forecasts for user specified satellites. The home page displays a table of the latest solar wind conditions, together with forecasts of geomagnetic indices and electron fluxes at GEO. Plots of these data are also available and numerical values downloadable.
1.This real time coupled version of AWSoM /SWIFT, provides timely forecasts of the solar wind parameters at L1 and hence enable forecasts of the state of the magnetosphere and its level of geomagnetic activity with a lead time of a few days, rather than hours that are currently available. These results are available from the University of Warwick web site https://warwick.ac.uk/fac/sci/physics/research/cfsa/people/bennett/swift-data/results3/. These results have also be used as a driver for the models that have been developed to forecast the geomagnetic indices Kp, Dst, and AE (WP3) as well as the models to forecasts the electron fluxes at Geostationary orbit (WP6).

2. PROGRESS has created a suite of new models for Dst, Kp and AE. These models employ different data based methodologies - Artificial Neural Networks and three variants on the NARMAX system identification methodology. These models enable to forecast of geomagnetic activity up to a few hours in advance when driven by the available real time data from DSCVR and ACE, providing some warning of potential space weather threats. By incorporating the results from the AWSoM/SWIFT coupled model developed in WP 2 the forecast horizon may be extended of the order of a day or more

3. PROGRESS has performed studies using the Error Reduction Ratio to determine which of the solar wind parameters are most influential on the observed wave activity, incorporating the evolution of both the solar wind and the magnetosphere. The resulting set of statistical models may be used to compute sets of diffusion coefficients that are required by numerical codes to properly incorporate these processes and hence provide a mode realistic picture of the electron environment within the radiation belts and enable the forecast of its evolution.

4. The IMPTAM model has been improved to use better estimates of boundary conditions electron life times so that it provides better estimates of the low energy (<1MeV) electron populations. This information allows satellite operators to assess the current particle environment in which their satellites are operating.

5. NARMAX models for the fluxes of electrons in the energy range 30-500keV have been developed to characterise and forecast the fluxes of electron radiation environment at geostationary orbit. These models complement the already existing models for higher (>800keV and >2MeV) electrons that were available before PROGRESS began. These systems models require large amounts of data and so their results are only applicable to geostationary orbit. The main advantage of such models is that they are mode accurate than current numerical models. In order to provide an assessment of the high energy electron populations (>1MeV) throughout inner magnetosphere, these models have been coupled to the VERB simulation code.

6. The results of all models that are generating realtime forecasts are available via the PROGRESS web site as well as the host institute. By comparing these results users can quickly ascertain the current and forecasted levels of geomagnetic activity and the electron environment within the inner magnetosphere.
A comparison of NARMAX model predictions for 350-600keV electron fluxes with measurements from GOES
Model solar wind test with artificial mass injection co-rotating with the Sun.