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Temporal and Frequency Variations of Flares observed by LYRA onboard of PROBA2

Temporal and Frequency Variations of Flares observed by LYRA onboard of PROBA2. Joe.Zender@esa.int (1) B. Foing (1), D. Vagg(2), M. Dominique(3), I. Dammasch(3), M. Mierla(3) and the LYRA Team Science and Robotic Exploration Directorate, ESA, ESTEC, Noordwijk, The Netherlands

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Temporal and Frequency Variations of Flares observed by LYRA onboard of PROBA2

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  1. Temporal and Frequency Variations of Flares observed by LYRA onboard of PROBA2 • Joe.Zender@esa.int (1) • B. Foing (1), D. Vagg(2), M. Dominique(3), I. Dammasch(3), M. Mierla(3) and the LYRA Team • Science and Robotic Exploration Directorate, ESA, ESTEC, Noordwijk, The Netherlands • Waterford University, Waterford, Ireland • (3) Royal Observatory of Belgium, SIDC, Brussels, Belgium

  2. Outline Discussion of Solar activities on 15 June 2010 based on temporal and frequency analysis of Zirconium (1-20nm) and Aluminum (17-80nm) channels of the LYRA instrument flown on board of PROBA • INTRODUCTION TO PROBA2 • INTRODUCTION TO LYRA • TEMPORAL ANALYSIS OF CX FLARE ON 2010-06-15T • FREQUENCY ANALYSIS OF SAME FLARE • INTRODUCTION TO WAVELET • WAVELET ANALYSIS OF LYRA DATA • FLARE RESULTS • CONCLUSION AND DISCUSSION LYRA EUV channels are suitable for flare analysis in time domain. Some flares show oscillations during initial flare phase, e.g. 0.1Hz and 0.014Hz for the 2010-06-15 flare

  3. PROBA2 – in a nutshell Built as part of ESA’s PRoject for OnBoard Autonomy Launched on 2nd November 2010 into Earth – sun synchronous - orbit • Ground Segment • - Mission Operations Centre located at Redu • - ~10 daily passes from Redu or Svalbard (S-band) • Spacecraft • Dimension: 80x70x60cm • Mass: 120kg, of which 35 for payload • Highly autonomous • ~720km altitude • sun-pointing • Technology Demonstrators • 17 technological demonstrators: BepiColombo star tracker (Galileo Avionica), Digital Sun Sensor (TNO), GPS Receiver (Alcatel, DLR), Laser Reflector (ESTEC), … Flexible commanding at Science Centre (P2SC) Data processing at P2SC within 30-45min after data reception. SWAP LYRA

  4. Large Yield Radiometer (LYRA) • 3 Units, each with 4 channels: Lyman-Alpha 121.6nm, Herzberg 200-220nm, Aluminum 17-80nm, Zirconium 1-20nm • Unit 2 is operated continuously at 20 Hz (100Hz demonstrated), Unit1 and Unit3 for calibration purpose and dedicated campaigns

  5. Spectral Response of LYRA EUV Channels Measured spectral transmittance of the Al (157.9 nm thick) and the Zr (141.3 nm thick) filters from Luxel corp. between 1 and 30 nm Measured spectral transmittance of the Acton Research corp. filters: Lyman-α filters (N122, XN122) and 210-B Herzberg filter between 110 nm and 2600 nm From Astronomy & Astrophysics manuscript no. aa13089-09, November 27, 2009 BenMoussa et al, “Pre-Flight calibration of LYRA, the solar VUV radiometer on board PROBA2”

  6. Events on 13 June 2010 Several flares were observed by LYRA 2010/06/13 00:06:00-00:26:00 B8.8 1079 2010/06/13 02:28:00-02:35:00 B4.6 1079 2010/06/13 05:30:00-05:44:00 M1.0 1079 2010/06/13 06:08:00-06:13:00 C1.2 1081 2010/06/13 06:55:00-07:00:00 B5.3 1081 2010/06/13 07:05:00-07:10:00 C1.2 1080 2010/06/13 07:31:00-07:38:00 C1.2 1079 2010/06/13 08:06:00-08:16:00 C1.2 1081 2010/06/13 09:41:00-09:48:00 C1.7 1081 2010/06/13 10:47:00-10:55:00 C1.5 1081 2010/06/13 12:24:00-12:29:00 B4.3 1081 2010/06/13 13:20:00-13:26:00 B2.5 1081 2010/06/13 14:24:00-14:30:00 B2.4 1081 2010/06/13 15:45:00-15:59:00 B4.2 1081 2010/06/13 18:10:00-18:17:00 B1.8 1081

  7. Events on 13 June 2010 Several flares were observed by LYRA 2010/06/13 00:06:00-00:26:00 B8.8 1079 2010/06/13 02:28:0002:35:00 B4.6 1079 2010/06/13 05:30:00-05:44:00 M1.0 1079 2010/06/13 06:08:00-06:13:00 C1.2 1081 2010/06/13 06:55:00-07:00:00 B5.3 1081 2010/06/13 07:05:00-07:10:00 C1.2 1080 2010/06/13 07:31:00-07:38:00 C1.2 1079 2010/06/13 08:06:00-08:16:00 C1.2 1081 2010/06/13 09:41:00-09:48:00 C1.7 1081 2010/06/13 10:47:00-10:55:00 C1.5 1081 2010/06/13 12:24:00-12:29:00 B4.3 1081 2010/06/13 13:20:00-13:26:00 B2.5 1081 2010/06/13 14:24:00-14:30:00 B2.4 1081 2010/06/13 15:45:00-15:59:00 B4.2 1081 2010/06/13 18:10:00-18:17:00 B1.8 1081

  8. Events on 13 June 2010 - Movie

  9. Temporal Analysis of M1.0 Flare R1: summed average of SWAP 17.4 nm over AR1079 (also including AR1078 and AR1080) R2: LYRA Aluminum: 17-80nm R3: LYRA Zirconium: 1-20nm R4: GOES long wavelength 0.1-0.8nm R5: GOES short wavelength 0.05-0.4nm

  10. Temporal Analysis of M1.0 Flare Large Angle Rotation

  11. Frequency Analysis of Flares using Wavelet The continuous wavelet transform of a discrete sequence xn is defined as the convolution of xn with a scaled and translated version of ψo(η): By varying the wavelet scale s and translating along the localized time index n, one can construct a picture showing both the amplitude of any features versus the scale and how this amplitude varies in time. Several motherwavelets were analyzed and for no specific reasons, we selected the Morlet wavelet for our analysis.

  12. Frequency Analysis of Flares using Wavelet ;; standard IDL parameters ;; motherfunction: MORLET ;; order,w0 6 ;; dscale: 0.1 ;; pad: no padding ;; start_scale: 2*delta_t ;; nscale: default value, but compute ;; wv_args = {args, $ family: 'morlet', $ order: 6, $ dscale: 0.1 , $ nscale: 0 , $ pad:0 , $ start_scale: 10 , $ freq_scale: 1.02 $ from Torrence and Compo } wv_args.nscale = (ALOG2( ((size(*data))[1]) / wv_args.start_scale )) / wv_args.dscale + 1 The following frequencies are obtained: 9.8039 8.2440 6.9324 5.829 4.901 4.1220 3.4662 2.9147 2.450 2.0610 1.7331 1.4573 1.2254 1.0305 0.866 0.7286 0.61274 0.51525 0.43327 0.36434 0.30637 0.25762 0.2166 0.1821 0.1531 0.1288 0.10831 0.091085 0.076593 0.064406 0.054159 0.04554 0.038296 0.03220 0.02707 0.02277 0.019148 0.01610 0.013539 0.011385 0.009 0.008 0.0067 0.0056 0.0047 0.0040 0.0033 0.0028 0.0023 0.00201 0.00169

  13. Frequency Analysis of Flares using Wavelet • Processing time is long. All the following plots have been based on 10 minutes intervals. • Scales on all following plots are all identical: xrange=10minutes • Uncertainty area not yet determined

  14. Wavelet of M1.0 flare

  15. Wavelet Training I: Two Frequencies 0.014 Hz Linear scale 0.1 Hz frequencies

  16. Wavelet Training II: noise Z-axis plotted in linear scale Z-axis plotted in log10 scale

  17. Wavelet Training III: frequencies + noise

  18. Frequency Analysis of M1.0 Flare using Wavelet Analysis Plots in 10 minutes interval 05:10 – 05:20 05:20 – 05:30 05:30 – 05:40 05:40 – 05:50 All x-scales and y-scales and z-scales are identical over the plots.

  19. 05:10 – 05:20 05:20 – 05:30

  20. 05:30 – 05:40 05:40 – 05:50

  21. 05:10 – 05:20 05:20 – 05:30

  22. 05:30 – 05:40 05:40 – 05:50 0.002 0.003 0.007 0.014 0.028 0.054 Hz 0.118 0.238 0.477 0.980 1.96

  23. 05:10 – 05:20 05:20 – 05:30

  24. 05:30 – 05:40 05:40 – 05:50

  25. Conclusion • LYRA EUV channel time series (Zirconium, Aluminum) suitable for analysis of solar events • Frequency analysis • No frequencies components/oscillations higher than 0.1/0.2 Hz found so far, but can not be excluded -> more analysis needed • Oscillations found at 0.1 Hz and 0.014 Hz • No indication that these components could be caused by instrumental or spacecraft effects • Components detected for other flares, but are very seldom • For the observed flare, there were 3 active regions near the limb, so it can not be excluded that the oscillations are caused by superposition of several events • It’s likely however that the observed oscillations are caused by • Geometry: e.g. energy released in different directions and these are seen as oscillations • Energy: e.g. physical processes at chromosphere • Energy: e.g. energy loss during electron and ion evolution through corona

  26. Next Steps • More systematic analysis • Production of wavelet space as data product • Processing using grid technology • Further development of analysis tools • Combine with modeling efforts Any comments, suggestions and discussions are welcome. I am happy to share results and software with you.

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