Status of SORCE and LASP EUV Missions M. Snow T. Woods, J. Harder University of Colorado/LASP

Solar Radiation and Climate Experiment (SORCE) Launched in January 2003 Instruments: –TIM (Total Irradiance Monitor: TSI) –XPS (Xray Photometer System: EUV) –SOLSTICE (Solar-Stellar Irradiance Comparison Experiment: FUV and MUV) –SIM (Spectral Irradiance Monitor: visible through IR) 2

SORCE Spacecraft Status Battery degradation has caused daily observations to cease entirely. Spacecraft is in safe hold with the hope of TSI measurement campaign in December 2013 to overlap TCTE. 3

SORCE Data Availability Most data products start in June 2003 and continue until June SIM is the exception (version 17): –Daily Irradiance begins April 2004 Version 19 will include through June 2003 –Daily Irradiance ends August 2009 –Version 20 will expand SIM time range to full mission! 4

SORCE Data Sources LASP Interactive Solar IRadiance Datacenter (LISIRD) SORCE Web Page 5

Instrument Updates: TIM 6

Instrument Updates: SOLSTICE Current data version: 12 FUV ( nm): no significant changes from version 11. MUV ( nm): improved solar/stellar field-of-view correction over version 11. 7

SOLSTICE V13 Detector dead-time correction (MUV) Detector dark current correction (MUV) Scattered light correction (MUV) Wavelength scale algorithm (FUV) Refinements to FOV correction 8

Filter Calibration Analysis 9

Dark & Dead 10

Preliminary SOLSTICE MUV Correction still requires more analysis and is not this significant at all wavelengths. 11

Spectral Irradiance Monitor (SIM) Upcoming version 19 includes a reanalysis of entire SIM processing code (Stéphane Béland has been indispensible). 12

Release notes for Version 19 relative to Version 17 1.Extends record back to April 2003 from April 23, Extends the record forward from Sept 22, 2010 to Nov Extends ultraviolet wavelength range from 310 to 240 nm 4.Reanalysis of the wavelength scale 5.Reanalysis of the solar exposure time 6.Reanalysis for improved AB comparisons to account for changes in instrument behavior after spacecraft safe-hold events. 7.V19 will be publicly available late Oct/early Nov Improvements to be implemented in Version 20 (Spring 2014) 1.Implement dynamical wavelength shifter to account for thermal/mechanical stresses induced by spacecraft power cycling 1.Particularly important for visible and infrared wavelengths 2.This will extend the record the end of mission and reduce changes after safe- hold events 2.Improve agreement between A&B spectrometer and between ESR and photodiodes 1.Particularly important for Sept 2010 to present time frame 13

SIM V17 V19 comparison 14

SIM Irradiance from all Photodiode vs TIM Maximum deviation between TIM and SIM is ~ 0.08% divided in all the wavelength bins corresponds to < 1 ppm per bin 15

Overview of Current LASP EUV Observations TIMED Solar EUV Experiment (SEE): 2002-present – nm broadband – nm with 0.4 nm spectral resolution –NASA has extended TIMED until at least 2016 SORCE XUV Photometer System (XPS): – nm broadband (same as TIMED SEE XPS) –Spacecraft battery has lost several cells and is in emergency state as of July 29, 2013 campaign mode possible in December 2013 and June 2014 daily observations might be possible with changes in spacecraft computer flight software SDO EUV Variability Experiment (EVE): 2010-present –0.1-7 nm and H I nm broadband –6-105 nm with 0.1 nm spectral resolution –Prime mission ends May extended mission likely 16

TIMED SEE SEE Level 3 Version 11 SEE has a 3% duty cycle (only a few minutes per orbit). Appropriate for daily average irradiances, but not suitable for flare studies. Calibration in FUV uses SOLSTICE (version 11). Future versions will need to use a model. Calibration in EUV uses rocket underflight or SDO EVE. Funding for future data processing has not yet been approved, but is expected. 17

SDO EVE Overview LASP / USC / MIT-LL / SI built solar EUV irradiance instruments for the EVE suite with significant improvements in spectral resolution (0.1 nm) and time coverage (24/7, 0.25 s -10 s cadence) Channel Range tt MEGS-A16-18 nm0.1 nm10 sec MEGS-A nm0.1 nm10 sec MEGS-B nm0.1 nm10 sec MEGS-SAM0.1-7 nm(1 nm)10 sec MEGS-P121.6 nm1 nm0.25 s ESP nm4 nm0.25 s 18

EVE Status Instrument Operation Status Data Products Version 3 Degradation FilterDetector MEGS-A124/7 (10-sec)0C, 2S, 2L, 3MinorNone MEGS-A224/7 (10-sec)0C, 2S, 2L, 3Moderate MEGS-BCampaign Mode0C, 2S, 2L, 3NoneMajor InstrumentStatus Data Products Version 3 Degradation FilterDetector ESP24/7 (0.25-sec)0CS, 1P, 2L, 3ModerateNone MEGS-P (Ly-  )24/7 (0.25-sec)0CS, 1P, 2L, 3MinorNone MEGS-SAM24/7 (10-sec)0C-SAMNone 0.1 nm Spectral Resolution Spectrographs 1-7 nm Spectral Bandpass Photometers MEGS-B degradation is more than expected so operations have been reduced to 5-min every hour and 24-hour flare campaign once a month. 19

Overview of Future EUV Observations GOES-R EUV and X-ray Irradiance Sensors (EXIS): –X-Ray Sensor (XRS): nm and nm bands –EUV Sensor (EUVS) EUVS-C: chromosphere proxy: Mg II core-to-wing ratio EUVS-B: transition region proxy: H I Lyman-alpha EUVS-A: coronal proxy: Fe XV 28.4 nm CubeSat Soft X-Ray (SXR) mission proposals: pending –MinXSS: keV ( nm) with 0.15 keV resolution –CubIXSS: keV ( nm) with 0.15 keV resolution & SXR spectral images 20

XRS EUVS GOES-R EXIS Overview …. The Big Picture EXIS Subsystems –Extreme Ultraviolet Sensor (EUVS) –X-Ray Sensor (XRS) –EUVS/XRS Electrical Box (EXEB) E UV & X -Ray Irradiance S ensors (EXIS) EXEB EXIS will reside on a Sun Pointing Platform mounted in the yoke of the solar array* *Spacecraft rendering courtesy Lockheed Martin Space Systems EXIS measurements in a few bands will be used in a proxy model to provide solar EUV and FUV irradiance from nm in 1-5 nm intervals and with 30-sec cadence. 21

New Solar SXR Observations are Needed The Soft X-Ray (SXR: nm) irradiance has had many broadband measurements (SOHO, SNOE, TIMED, SORCE, SDO, LYRA), but there are very few spectral measurements of the SXR. CubeSat MinXSS mission (pending NASA proposal, launch Nov. 2014) can help to fill the spectral gap between SDO and RHESSI. 22

Summary SORCE: data analysis is ongoing –Observations, not so much TIMED SEE: observations are ongoing –Data analysis, not so much SDO EVE: Prime of its life! GOES-R: Ready for delivery (1 of 4) MinXSS & CubIXSS: Still a twinkle in Dad’s eye 23