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) [email protected](303) 492-4224
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Condensing Solar X-ray and EUV Flare and Coronal Dimming ......existing instrument data sets from SDO, STEREO, PROBA2 ! For example, SDO EVE has implemented on-board flare trigger
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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) [email protected] (303) 492-4224
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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
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Space Weather Instrumentation on GOES-R
Figures are from GOES-R Fact Sheets
SUVI Solar EUV Imager
GOES Space Weather Sensors EXIS
Solar EUV & X-ray Irradiance
SEISS In-situ Energetic
Electrons & Protons
Magnetometer & Boom In-situ Magnetic Field
GOES-R 2 large weather sensors 4 small SpWx sensors
! 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 2034. 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.
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Key Products for Space Weather Operations
Space Weather Product / Alerts
GEO (GOES-16)
Desired Location Research Satellites, Other Satellites L1 L5 L4
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 MAG, SEISS
ITM Composition, Winds DMSP, TIMED
Aurora energy, boundary DMSP, TIMED
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Key Products for Space Weather Operations
Space Weather Products / Alerts
GEO (GOES-16)
Desired Location Research Satellites, Other Satellites L1 L5 L4
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 MAG, SEISS
ITM Composition, Winds DMSP, TIMED
Aurora energy, boundary DMSP, TIMED
Focus for this talk Note that CD = Coronal Dimming
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GOES-R EUV & X-ray Irradiance Sensors (EXIS) built by CU/LASP
EXIS Metrics Mass 29 kg
Power 31 Watts
X-Band Data Rate 9.7 kbps
L-Band Data Rate 0.7 kbps
Observation Requirement Performance
X-Ray Irradiance
0.05-0.4 nm: 10-9-10-3W/m2;
0.1-0.8 nm: 10-8-4x10-3W/m2
0.05-0.4 nm: 4x10-10-2x10-2W/m2;
0.1-.8 nm: 6x10-10-1.5x10-2W/m2
EUV Irradiance
0-127 nm: 0.1*Solar Min to 10*Solar Max
discrete lines to models 0-127 nm; meets req.
dynamic range
Accuracy XRS: 10% EUVS: 20%
XRS: <7% EUVS: <20%
Cadence XRS: 3 sec EUVS: 30 sec
XRS: 1 sec EUVS: 30 sec
Key Requirements and Performance
Instrument Flight Institution
GOES-R EXIS 1st Launch Nov 2016
LASP
SDO EVE 2010-present LASP
SORCE 2003-present LASP
TIMED SEE 2001-present LASP
Flight Heritage
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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
! 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
XRS
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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
! 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
Impulsive PhaseGradual Phase
Coronal DimmingLate Phase
Onset
Fe XXFe XVIFe IXHe II / 10
Time on 2010-May-5 (UT hours)
Figure is from Woods et al. (ApJ, 2011). Table values are from Hock (PhD Thesis, 2012).
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%
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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
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Compact EXIS = SEEDS Solar Eruption Early Detection System
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
Observation Channel
Flare X-ray Magnitude X-ray 0.1- 2 nm
Flare Location X-ray 0.1-2 nm Quad Diode
Eruptive Flare Monitor He II 304 Å
Solar Position (center) He II 304 Å Quad Diode
Coronal Dimming Monitor (CME proxy)
Fe IX 171 Å (1) Fe IX 171 Å (2)
EUV Late Phase Flare Monitor
Fe XV 284 Å
SEEDS is a re-packaging of GOES-R XRS to have one X-ray channel and four EUV channels.
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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
■ 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 EUV Imager ■ Larger instrument ■ Higher data volume means low
cadence and/or downlinking just eruptive events region
■ 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
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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 0.004 kB/sec 3.5 kB/sec 18,750 kB/sec 100 kB/sec
Cadence for 2k x 2k image (x2 compression)
11 days 19 min 0.2 sec 40 sec
Operations Cost per Month
$M 0.001 $M 0.06 (NASA NEN)
$M 1.0 (NASA SDO)
$M 4.2 (NASA DSN)
Cost per kiloByte $0.11 $0.01 $0.0001 $0.02
Cost for 3-year Ops $M 0.04 $M 2.2 $M 36 $M 150
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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
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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
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BACKUP SLIDES
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Observation Requirement Performance
Coronal Holes Location & Morphology
Fe XV 28.4 nm
Flares Location & Morphology
Fe XVIII 9.4 nm & Fe XX 13.3 nm
CMEs & Active Regions
Coronal Dimming AR Complexity
Fe IX 17.1 nm & Fe XII 19.5 nm
Filaments & Quiet Regions
Location & Complexity
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
Key Requirements and Performance GOES-R SUVI
Instrument Flight Institution
GOES-R SUVI 1st Launch Oct 2016
LMSAL
GOES-N SXI 2010-present LMSAL
SDO AIA 2010-present LMSAL
Flight Heritage SUVI Metrics Mass 66 kg
Power 172 Watts (peak) 144 Watts (operational)
X-Band Data Rate 3.5 Mbps
L-Band Data Rate 1 kbps
GOES-R Solar UltraViolet Imager (SUVI) built by LMSAL
Solar EUV
Images
Figures from LMSAL SUVI
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Observation Requirement Performance Low Energy Electrons &