Condensing Solar X-ray and EUV Flare and Coronal Dimming Information Down to a Few Bytes for Lagrange-Point Space Weather Missions

Transcription

1 Condensing Solar X-ray and EUV Flare and Coronal Dimming Information Down to a Few Bytes for Lagrange-Point Space Weather Missions Tom Woods, Frank Eparvier, Andrew Jones, James Mason University of Colorado (CU) Laboratory for Atmospheric & Space Physics (LASP) tom.woods@lasp.colorado.edu (303)

2 Outline! GOES-R EUV and X-ray Irradiance Sensors (EXIS) overview! Motivations for compact-exis at L5 and L1! Capabilities for compact-exis = SEEDS! Summary & Recommendations 2

3 Space Weather Instrumentation on GOES-R! Space weather sensors have flown on NOAA GOES satellites since the 1970s. " The four new GOES spacecraft has four space weather (SpWx) sensors, including a large solar-pointing platform on the articulated solar panels. " GOES-R + operations are planned from 2017 to The solar instruments are not needed for a L1 mission but could be considered for a L5 mission. The particle and field instruments would be useful for a L1 mission. GOES-R 2 large weather sensors 4 small SpWx sensors GOES Space Weather Sensors EXIS Solar EUV & X-ray Irradiance SEISS In-situ Energetic Electrons & Protons SUVI Solar EUV Imager Magnetometer & Boom In-situ Magnetic Field Figures are from GOES-R Fact Sheets 3

4 Key Products for Space Weather Operations Space Weather Product / Alerts GEO (GOES-16) Desired Location L1 L5 L4 Research Satellites, Other Satellites Flare: X-ray magnitude XRS # X SDO, PROBA2 Flare: location SUVI & XRS # X SDO, PROBA2 Flare: EUV SUVI & EUVS # X SDO, PROBA2 SEP: forecast with X-rays XRS # X SDO, PROBA2 CME: velocity / mass CD with SUVI CD X X SOHO, STEREO CME: direction / extent (halo) X X SOHO, STEREO Forecasts with B fields (desired) X X X SDO, GONG Forecast with AR features SUVI # X SDO, STEREO SW & CME Alerts (ρ, B) SEISS X X ACE, DSCOVR, Ground Mag SW: forecasts cor. holes SUVI # X SDO GEO Fields & Particles ITM Composition, Winds Aurora energy, boundary MAG, SEISS DMSP, TIMED DMSP, TIMED 4

5 Key Products for Space Weather Operations Space Weather Products / Alerts GEO (GOES-16) Desired Location L1 L5 L4 Research Satellites, Other Satellites Flare: X-ray magnitude XRS # X SDO, PROBA2 Flare: location SUVI & XRS # X SDO, PROBA2 Flare: EUV SUVI & EUVS # X Note that SDO, PROBA2 CD = Coronal Dimming SEP: forecast with X-rays XRS # X SDO, PROBA2 CME: velocity / mass CD with SUVI CD X X SOHO, STEREO CME: direction / extent (halo) X X SOHO, STEREO Forecasts with B fields (desired) X X X SDO, GONG Forecast with AR features SUVI # X SDO, STEREO SW & CME Alerts (ρ, B) SEISS X X ACE, DSCOVR, Ground Mag SW: forecasts cor. holes SUVI # X SDO GEO Fields & Particles ITM Composition, Winds Aurora energy, boundary MAG, SEISS Focus for this talk DMSP, TIMED DMSP, TIMED 5

6 GOES-R EUV & X-ray Irradiance Sensors (EXIS) built by CU/LASP Key Requirements and Performance Observation Requirement Performance X-Ray Irradiance EUV Irradiance nm: W/m 2 ; nm: x10-3 W/m nm: 0.1*Solar Min to 10*Solar Max Accuracy XRS: 10% EUVS: 20% Cadence XRS: 3 sec EUVS: 30 sec nm: 4x x10-2 W/m 2 ; nm: 6x x10-2 W/m 2 discrete lines to models nm; meets req. dynamic range XRS: <7% EUVS: <20% XRS: 1 sec EUVS: 30 sec Instrument Flight Institution GOES-R EXIS Flight Heritage 1st Launch Nov 2016 LASP SDO EVE 2010-present LASP EXIS Metrics Mass 29 kg Power 31 Watts X-Band Data Rate 9.7 kbps SORCE 2003-present LASP TIMED SEE 2001-present LASP L-Band Data Rate 0.7 kbps 6

7 Innovations for GOES-R EXIS! Addition of quad X-ray photometers to XRS provides monitor of flare location " Simple design without requiring an imager! Development of low-noise (fa) and low-power (0.03 W) electrometer ASIC with digital interface for the EXIS X-ray and EUV diodes! Three EUV spectrograph channels to monitor variability of the chromosphere, transition region, and corona XRS! Three EUVS channels have on-board tracking for degradation " EUVS-C: chromospheric Mg II index is self-calibrated as core-to-wing ratio " EUVS-B: has chromosphere lines calibrated by EUVS-C and transition region emissions " EUVS-A: has transition region lines calibrated by EUVS-B and coronal emissions 7

8 Motivations for Compact EXIS at L1-L5! On-board, high-cadence monitor of flare magnitude & location without an imager " GOES-R XRS heritage design " This info can be used on-board to automate operations and image selection area! Provide coronal dimming data as proxy for CME velocity &mass without an imager " Key result from SDO EVE, but not learned in time to be implemented on GOES-R EXIS Onset Impulsive Phase Gradual Phase Coronal Dimming Late Phase Fe XX Fe XVI Fe IX He II / 10! Provide impulsive phase flare data from He II 304 Å as warning for eruptive flares " Compact version of GOES-R EUVS-A! Provide high-cadence flare results from irradiance instruments that have a very low data rate and thus reduced operations cost Time on 2010-May-5 (UT hours) Flare C M X Gradual Ph. 100% 100% 100% Impulsive Ph. 56% 90% 100% Coronal Dim. 13% 39% 67% EUV Late Ph. 5% 22% 39% Figure is from Woods et al. (ApJ, 2011). Table values are from Hock (PhD Thesis, 2012). 8

9 Coronal Dimming and CME Relationships! Cool coronal emission lines, such as Fe IX, exhibit dimming (darkening) during eruptive flares " Irradiance coronal dimmings need a correction for the impulsive phase contribution (Mason et al., 2014) to match EUV image dimming result " Mason et al. (2016) analyzed many dimming- CME events to derive relationships! CME velocity can be estimated using the coronal dimming slope! CME mass can be estimated using the square root of the coronal dimming depth! Coronal dimming analysis works best for on-disk events " On-disk halo CMEs are difficult to analyze in coronagraph data " Coronagraphs work best for limb events 9

10 Compact EXIS = SEEDS Solar Eruption Early Detection System SEEDS is a re-packaging of GOES-R XRS to have one X-ray channel and four EUV channels. Observation Flare X-ray Magnitude Flare Location Eruptive Flare Monitor Solar Position (center) Coronal Dimming Monitor (CME proxy) EUV Late Phase Flare Monitor Channel X-ray nm X-ray nm Quad Diode He II 304 Å He II 304 Å Quad Diode Fe IX 171 Å (1) Fe IX 171 Å (2) Fe XV 284 Å SEEDS & EXIS Comparison SEEDS EXIS Mass 0.6 kg 29 kg Power 0.4 Watts 31 Watts Data Rate 15 bps 9,700 bps Cadence 30 sec 3 sec XRS 30 sec EUVS 10

11 Complementary Data from EUV Imager and SEEDS Pros for EUV Imager Tracking Active Regions (AR) Tracking Coronal Holes (CH) Imaging of flares eruptive loops and dimming regions Imaging of flare 4 phases with well-selected EUV bandpasses Cons for EUV Imager Larger instrument Higher data volume means low cadence and/or downlinking just eruptive events region Pros for SEEDS Flare magnitude & location can be used for on-board automation Coronal Dimming is proxy for CME velocity & mass Flare 4 phases monitored with small irradiance instrument Low data rates == high cadence Cons for SEEDS No imaging of source regions so unable to track ARs or CHs Active Region magnitude & location from quad diode is just center of mass of all ARs 11

12 Operations Cost Consideration (in US$ M)! Operations cost for L5-L1 missions will likely drive decisions! Mission Type LEO LEO GEO L1/L5 Mission Purpose CubeSat Sci. Research Res. or Oper. Operations Communication UHF S-band Ka-band Ka-band Ground Station Cost $M 0.02 $M 0.5 $M 25 $M 300 x 3 Antenna Dish Size N/A 3 m 18 m 70 m Number Contacts 2/day 2/day 24-7 continuous 24/day Data Volume 0.3 MB/day 300 MB/day 1,600,000 MB/day 9,000 MB/day Average Data Rate kb/sec 3.5 kb/sec 18,750 kb/sec 100 kb/sec Cadence for 2k x 2k image (x2 compression) Operations Cost per Month 11 days 19 min 0.2 sec 40 sec $M $M 0.06 (NASA NEN) $M 1.0 (NASA SDO) $M 4.2 (NASA DSN) Cost per kilobyte $0.11 $0.01 $ $0.02 Cost for 3-year Ops $M 0.04 $M 2.2 $M 36 $M

13 Options to Advance Space Weather Operations! Risk Reduction Activities to Support Future Sp Wx Operational Missions " Develop on-board automation algorithms for L5-L1 planned instruments using existing instrument data sets from SDO, STEREO, PROBA2! For example, SDO EVE has implemented on-board flare trigger for the MEGS channel using X-ray data from the ESP channel (photometer) " Fly tech-demo and new research instruments as low-cost LEO missions! For example, ESA PROBA2 and NASA-LASP MinXSS CubeSat! Expanding the Capabilities for Space Weather Operations Beyond GEO " What is missing from the GOES Sp Wx measurements?! Solar magnetograms for predicting flare and CME probabilities " Earth-view magnetograms are currently from SDO HMI and NSF GONG network, so L5 and L4 magnetograms would be more important than one from L1! Coronagraphs and Heliospheric Imagers (HI) for CME warnings " STEREO and SOHO currently provide CME observations, and SO and SSP will provide HI observations. L5 and L4 are better view for Earth-directed CMEs. " Coronal dimming from L1, L5, or GEO can also provide CME warnings! Solar Wind alerts from L1 is being provided now by DSCOVR " L5 measurements of solar wind could also provide 1-2 days alerts for solar wind " Coronal hole measurements from L5 would help with CIR & HSS predictions 13

14 Summary and Recommendations " Compact version of EXIS = SEEDS! Small (~1 Unit) instrument with several space weather products has very low data rate as desired for Lagrange-Point Space Weather Missions! High-cadence (1-sec) monitor of flare magnitude and location can be used on-board to automate the operations and for defining the flaring region data from solar imagers! Provide coronal dimming data as proxy for CME velocity and mass! Provide impulsive phase flare data from He II 304 Å as warning for eruptive flare events! Has strong heritage from GOES-R EXIS and SDO EVE Optimize Critical Measurements from Preferred Location " GEO (GOES) provides flare alerts and energetic particle alerts " L1 (DSCOVR) provides solar wind and CME alerts " L5 & L4 provides CME warnings " Combined L5, L1, & L4 magnetograms provide flare and CME forecasts with full-hemisphere (180 ) view of the magnetic fields! Each position is just 60 view of magnetic fields 14

15 BACKUP SLIDES 15

16 GOES-R Solar UltraViolet Imager (SUVI) built by LMSAL Key Requirements and Performance Observation Requirement Performance GOES-R SUVI Coronal Holes Flares CMEs & Active Regions Filaments & Quiet Regions Location & Morphology Location & Morphology Coronal Dimming AR Complexity Location & Complexity Fe XV 28.4 nm Fe XVIII 9.4 nm & Fe XX 13.3 nm Fe IX 17.1 nm & Fe XII 19.5 nm He II 30.4 nm Angular Res. < 5.0 arcsec 2.5 arcsec / pixel Cadence < 5 minutes for 3 spectral channels < 4 minutes for all channels Instrument Flight Institution GOES-R SUVI Flight Heritage 1st Launch Oct 2016 LMSAL GOES-N SXI 2010-present LMSAL SDO AIA 2010-present LMSAL Solar EUV Images Mass Power X-Band Data Rate L-Band Data Rate SUVI Metrics 66 kg 172 Watts (peak) 144 Watts (operational) 3.5 Mbps 1 kbps Figures from LMSAL SUVI 16

17 GOES-R Space Environment In-situ Suite (SEISS) built by ATC Key Requirements and Performance Observation Requirement Performance Low Energy Electrons & Protons High Energy Electrons & Protons Very High Energy Protons Energetic Heavy Ions 30eV 30keV 15 energy bands 5 angular views 30 sec cadence 50keV 4MeV 7 energy bands 5 angular views 30 sec cadence 1MeV 500MeV 10 energy bands 2 angular views 60 sec cadence MeV/ion 5 energy bands 1 direction 5 min cadence 30eV 30keV 15 energy bands 12 angular views 1 sec cadence 50keV 4MeV 11 energy bands 5 angular views 1 sec cadence 1MeV 500MeV 10 energy bands 5 angular views 1 sec cadence MeV/ion 5 energy bands 1 direction 5 min cadence Instrument Flight Institution GOES-R SEISS Flight Heritage 1st Launch Oct 2016 ATC GOES-N 2010-present ATC DMSP SSJ present ATC Figure from ATC SEISS team Assurance Technology Corp Mass Power X-Band Data Rate L-Band Data Rate GOES-R SEISS SEISS Metrics UNH Space Science Center 74 kg 53 Watts 24 kbps 1 kbps 17

18 GOES-R Magnetometer & 8-m Boom (MAG) built by LM (GOES-R spacecraft vendor) Key Requirements and Performance for measuring the magnetic field Parameter Requirement Performance Sensitivity 0.1 nt 0.1 nt Resolution nt 0.01 nt Range +/ nt +/ nt Cadence 0.5 sec 0.4 sec Axes 3-axis 3-axis GOES-R Magnetometer Boom Flight Heritage Instrument Flight Institution GOES-R/S/T/U Mag Boom GOES-N/O/P Mag Boom MMS AFG & DFG Magnetometers 1st Launch Oct present 2015-present Orbital ATK Orbital ATK UCLA Mag Sensor + Boom Metrics Mass 25 kg Power 5 Watts X-Band Data Rate 1 kbps L-Band Data Rate 1 kbps Figures are from GOES-R website 18