European Space Weather Week - 13 Space weather products based on Energetic Particle Telescope (EPT) data measured on-board PROBA-V by S. Borisov, S. Benck and M. Cyamukungu (UCL/ELI/CSR) 14-18 November 2016 Oostende, Belgium

EPT instrument and mission Overview of the products Conclusions The EPT concept Detecting electrons, protons and He without inter-species contamination Δx Stack E2 E1 Two particles belonging to different species (1 and 2), having the same «range» can be readily identified if their stopping power (S1, S2) in Δx are different. Achieve ~error-free particle discrimination through «coincident identification» where the result from the «Δxa-Stack assembly» is cross-validated by that from the «Δxb-Stack assembly». Δxa Δxb E2 E1

EPT instrument and mission Overview of the products Conclusions Proba-V with EPT onboard was launched on 7 May 2013 into a sun-synchronous polar orbit at 820 km altitude (inclination 98.7°, Local Time at Descending Node 10:45) The EPT is oriented WEST when in daylight and oriented EAST when in eclipse The formal EPT commissioning has started on 21 June 2013 and completed on 3 September 2013. Volume: 21.15 x 16.2 x 12.75 cm3 Mass: 4.6 kg Power consumption: < 6 W

Overview of the products EPT instrument and mission Overview of the products Conclusions Product available today for electrons, protons and helium: Flux time-series along the orbit at 2 s step (mainly). Flux time-series in fine B-L bins. Static radiation model for covered region of magnetosphere. Up to 4 day ahead radiation environment prediction. Weekly average flux maps on regular geographical grid with 4° step. Characteristic energy spectra for the Polar region L>3 (electrons) and SAA, 1.1<L<2.1 and 0.16<B(G)<0.22 (protons and helium).

Overview of the products EPT instrument and mission Overview of the products Conclusions Flux time-series along the orbit at 2 s step (mainly)

Overview of the products EPT instrument and mission Overview of the products Conclusions Flux time-series in fine B-L bins 47 bins for B [0.15 – 0.5] G; 160 bins for L [1.0 – 30.] +1 for positions without L. ~4050 B-L bins visited. 1 B-L bin = 1 file for one year. The same time series format as in along-orbit measurements file.

Overview of the products EPT instrument and mission Overview of the products Conclusions Static radiation model for covered region of magnetosphere Time period 24/06/2013-27/06/2014 Selection on boresight orientation (90°± 25°)

Overview of the products EPT instrument and mission Overview of the products Conclusions Electrons - Outer Radiation Belt Convenient for cross-validation purposes

Overview of the products EPT instrument and mission Overview of the products Conclusions Up to 4 day ahead radiation environment prediction Flux forecast based on lifetime measurements (by S. Benck et al, 2010) for every B-L bin for every channel of every particle: Forecasting decaying flux. Updated after every new run processed.

Overview of the products EPT instrument and mission Overview of the products Conclusions Electron lifetime calculation Possible 3-week flux forecast possible based on lifetimes and real-time flux measurements. The relationship between Dst and the flux variation remains to be understood. See also Benck et al. , Low altitude energetic electron lifetimes after enhanced magnetic activity as deduced from SAC-C and DEMETER data, Ann. Geophys., 28, 849–859, 2010 L=3.6-3.8, B=0.22-0.46 G, E=0.52-0.61 MeV, T = 4.9±1.1 days

Overview of the products EPT instrument and mission Overview of the products Conclusions Electrons - Outer Radiation Belt Mis-forecasting probability is equivalent to geomagnetic storm occurrence probability.

Overview of the products EPT instrument and mission Overview of the products Conclusions Weekly average flux maps on regular geographical grid with 4° step

Overview of the products EPT instrument and mission Overview of the products Conclusions Characteristic energy spectra for the Polar region L>3 (electrons) and SAA, 1.1<L<2.1 and 0.16<B(G)<0.22 (protons and helium)

EPT instrument and mission Overview of the products Conclusions Conclusions PROBA-V/EPT project provides a number of high quality particle data products available to the space research community. The UCL/CSR team is open for collaboration with space radiation research community for further exploitation of the EPT data. http://web.csr.ucl.ac.be/csr_web/probav/

Thank you! Acknowledgments EPT instrument and mission Overview of the products Conclusions Acknowledgments BELSPO for funding of PROBA-V/EPT DE project ESA Redu station for PROBA-V operations BUSOC for initial PROBA-V/EPT data handling Thank you!

Overview of the products EPT instrument and mission Overview of the products Conclusions Spare info. Active PROBA-V/EPT data users: ESA BIRA (Belgium) DH Consultancy (Belgium) NOA (Greece) BAS (UK) University of Calgary (Canada) SINP (Russia) University of Arkansas at Pine Bluff (USA) SES - Luxembourg

EPT instrument and mission Overview of the products Conclusions The EPT Volume: 21.15 x 16.2 x 12.75 cm3 Mass: 4.6 kg Power consumption: < 6 W Particle Channel limits (MeV) Electron 0.50 - 0.60 - 0.70 - 0.80 - 1.00 - 2.40 - 8.00 Proton 9.50 - 13.0 - 29.0 - 61.0 - 92.0 - 126. - 155. - 182. - 205. - 227. - 248. Helium 38.0 - 51.0 - 116. - 245. - 365. - 500. - 615. - 720. - 815. - 900. - 980. Modular and reconfigurable Extended version (6 DAMs instead of 10): bigger energy range and smaller size and mass: protons up to 1 GV in 11 channels with (approx.) 17x14x11 cm3-3.5kg-5W

Overview of the products EPT instrument and mission Overview of the products Conclusions Model generation Path average the data in all the position bins For each (B,L) bin draw the cumulative distribution function CDF for the fluxes in each energy bin Fit the data with a Weibull function to determine the lower part of the CDF function delimited by the flux sensitivity limit of the detector (the selected dataset must at least have 10 data points) Draw the normalized PDF for the flux based on the data as well as the fit result CDF PDF

Overview of the products EPT instrument and mission Overview of the products Conclusions ? Flux Sensitivity limit = 110 (s-1•sr-1•MeV-1•cm-2)

Overview of the products EPT instrument and mission Overview of the products Conclusions Electrons - Outer Radiation Belt

Overview of the products EPT instrument and mission Overview of the products Conclusions Electrons - Outer Radiation Belt

Overview of the products EPT instrument and mission Overview of the products Conclusions Protons - Inner Radiation Belt

Overview of the products EPT instrument and mission Overview of the products Conclusions Protons - Inner Radiation Belt !!! East – West asymmetry not taken into account

Overview of the products EPT instrument and mission Overview of the products Conclusions Study of relevant parameters for flux forecasting. Example: Flux enhancement (deltaF in cm-2 s-1 sr-1) distribution functions as deduced from the SAC-C data. Probability of mis-forecasting Waiting time distribution (Time between the occurrence of two events characterized by a Dst <-50nT). The continuous lined histograms: quiet solar activity periods and the dashed lined histograms: high solar activity periods. The blue continuous and dashed lines represent a fit of the probability functions with a poissonian distribution: P( Tw ) = r exp( - r TW ) with r=1/ 𝑻 𝑾 .

Overview of the products EPT instrument and mission Overview of the products Conclusions Helium and protons during SPE-2014/01 38-51 MeV 51-116 MeV 116-245 MeV 245-365 MeV