EVE Improvements to The Flare Irradiance Spectral Model. (FISM) Improvements to space weather research, the flare energy budget, and instrument design

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1 EVE Improvements to The Flare Irradiance Spectral Model Image Courtesy ESA/NASA SOHO EIT Consortium (FISM) Improvements to space weather research, the flare energy budget, and instrument design Phillip C. Chamberlin

2 Outline FISM Overview EVE contributions to FISM Flare Energy Budget Space Weather studies Ionosphere Thermosphere Instrument design GOES EXIS October 8, 2008 EVE Improvements for FISM 2

The Flare Irradiance Spectral Model (FISM) FISM is an empirical model of the solar vacuum ultraviolet (VUV; 0.1-190 nm) irradiance at 60 second temporal resolution. Developed for my Ph.D. Dissertation (U.

3 The Flare Irradiance Spectral Model (FISM) FISM is an empirical model of the solar vacuum ultraviolet (VUV; nm) irradiance at 60 second temporal resolution. Developed for my Ph.D. Dissertation (U. of Colorado, 2005) Current version released June 2006 XUV EUV FUV Updated for SEE V9 data Uses traditional proxies (MgII c/w, F10.7, and Lyα) as well as new proxies (0-4 nm, 36.5 nm, and 30.5 nm) to model the daily component - provide more accurate CLV. Uses the GOES nm irradiance as the proxy to model flare variations. FISM is the first flare model that can be used for near real-time space weather operations. October 8, 2008 EVE Improvements for FISM 3

4 FISM Main Algorithm E(t UTC ) = E min +ΔE SC (t d ) + ΔE SR (t d ) +ΔE GP (t UTC ) + ΔE IP (t UTC ) E min : Solar minimum reference spectrum, FISMref, (Constant) Daily Component Variations (Modeled on a daily basis): - Solar Cycle (SC) - linear with 108-day smoothed daily proxy - Solar Rotation (SR) - linear with TIFF are (Uncompressed) needed (daily to see this decompressor picture. proxy - SC proxy) Flare Component Variations (Modeled on a 60 seconds basis): - Gradual Phase (GP) - Power Law with GOES nm - Impulsive Phase (IP) - Power Law with d/dt GOES (Neupert Effect) Center-to-Limb variations accounted for by representative proxies in daily component but must be corrected for in flare components October 8, 2008 EVE Improvements for FISM 4

5 FISM Solar Cycle Variations (A) SC F10.7 MgII c/w and Ly-a All Proxies (B) October 8, 2008 EVE Improvements for FISM 5

6 FISM Solar Cycle Variations (A) SC F10.7 (A) MgII c/w and Ly-a All Proxies (B) (B) October 8, 2008 EVE Improvements for FISM 6

7 FISM Solar Rotation Estimations Day 14 Day 20 Day 25 FISM EUVAC SEE L3 FISM EUVAC SEE L3 October 8, 2008 EVE Improvements for FISM 7

8 X17 Flare Comparison to SEE nm Si IV; Log(T)=4.85 October 8, 2008 EVE Improvements for FISM 8

9 Solar Variation on Various Time Scales Flare Variations were as large or larger than the solar cycle variations for the Oct 28, 2003 flare Transition region emissions increased by up to a factor of 10 during the impulsive phase EUV irradiance increased by a factor of 2 and XUV increases by a factor of 100 during the gradual phase October 8, 2008 EVE Improvements for FISM 9

10 NASA Spectrum - April 14, 2008 October 8, 2008 EVE Improvements for FISM 10

11 How will EVE help FISM? 10 sec (0.25 sec for ESP) temporal resolution, 100% duty cycle EVE will measure all flares with very good temporal resolution and concurrent spectral information. FISM is currently based on 11 impulsive phase observations and 29 gradual phase observations at one point during the flare from TIMED SEE. Extend the solar XUV and EUV irradiance measurement set with better accuracy. Higher spectral resolution, especially for λ<27nm EVE measurements will allow FISM to improve to 0.1 nm resolution. EVE will help determine the relationship between EUV and XUV flares. Can there be an EUV flare with no XUV component? October 8, 2008 EVE Improvements for FISM 11

12 TSI Flare Observations From Woods, Kopp, and Chamberlin (WKC), JGR, 2006 October 8, 2008 EVE Improvements for FISM 12

13 TSI Flare Budget - Revisited Chris Moore, U. of Iowa, Summers 2007, 2008 Updated using V9 TIMED SEE data Lower contributions from nm (/10) Revised spectral distribution Better TSI fitting algorithm Addition of RHESSI Contribution Need to run analysis for 21 April 2002 and 23 July 2002 events (Emslie, Dennis, Holman, and Hudson, JGR, 2005) Need TSI Model October 8, 2008 EVE Improvements for FISM 13

14 TSI Flare Budget - Revisited October 28, X17 - (E08, S16) Numbers from WKC November 4, X28 - (W83, S19) TIFF are (Uncompressed) needed to see this decompressor picture. Also have data for 10/29/03, 11/2/03*, 1/15/05*, 1/19/05*, 1/20/05*, 9/7/05, 12/5/06*, 12/6/06, 12/13/06* * - Modeled TSI (can do for any flare, but these had good RHESSI data) October 8, 2008 EVE Improvements for FISM 14

15 TSI Flare Budget - Modeled Emslie, Dennis, Holman, and Hudson, JGR, 2005 Modeled the total final radiant energy of two limb flares from GOES temperature and emission measure 21 April 2002: 3 x /- 0.3 x July 2002: 1 x /- 0.3 x New TSI Model Use the FISM energy and location on disk to estimate TSI energy released in flare 21 April 2002: 3.4 x July 2002: 3.3 x October 8, 2008 EVE Improvements for FISM 15

16 Space Weather Studies Ionosphere Thermosphere October 8, 2008 EVE Improvements for FISM 16

17 TIE-GCM Model using FISM data for an X17.0 solar flare on September 7, 2005 Gang Lu, NCAR Start Time - 17:17; Peak Time - 17:40; End Time - 18:03 October 8, 2008 EVE Improvements for FISM 17

18 Neutral Temperature Change at ~350 km During Flare Flare Peak 1720UT 1730UT 1740UT 1750UT Neutral Temperature Change at ~350 km During Flare 100 O K 1800UT 1810UT 1820UT 1830UT o K 1850UT 1910UT 2000UT 2200UT O K October 8, 2008 EVE Improvements for FISM 18 Slide Slide Courtesy of of G. G. Lu, Lu, NCAR NCAR 0

19 Electron Density at ~110 km During Flare on 9/7/2005 Flare Peak Electron Density at ~110 km During Flare on 9/7/ UT 1730UT 1740UT 1750UT 3x UT 1810UT 1820UT 1830UT 1840UT 1850UT 1900UT 1910UT cm-3 cm-3 cm-3 1x10 3 3x10 5 1x10 3 3x10 5 October 8, 2008 EVE Improvements for FISM 19 Slide Courtesy of G. Lu, NCAR 1x10 3

20 TIEGCM Difference TEC Maps During Flare 1730UT 1740UT 1750UT Reference 1800UT 1810UT 1820UT 1830UT 1840UT 1850UT Slide Courtesy of G. Lu, NCAR October 8, 2008 EVE Improvements for FISM 20

21 Observed N E Modeled N E Slide Courtesy of G. Lu, NCAR October 8, 2008 EVE Improvements for FISM 21

22 Mars Ionospheric model using FISM compared to MGS RS Measurements for a flare on April 15, 2001 Paul Withers, Boston University Shinagawa, Adv. SP. Res., 2004 October 8, 2008 EVE Improvements for FISM 22

23 Mars Ne Model and Observation Results PRELIMINARY RESULTS The 110 km peak (produced by X-Rays) exceeds the 140 km peak (produced by EUV) during a flare. The red line on the right corresponds temporally to the blue line on the left, both at 14:16 UT. Mars Global Surveyor Radio Science Instrument Plots courtesy Paul Withers, 2007 October 8, 2008 EVE Improvements for FISM 23

24 Ongoing and Future Studies Further Studies of Ionosphere and Thermosphere. Lunar Dust Charging (Sternovsky et al., in press). Ionization of Saturn s rings. Voyager vs Cassini October 8, 2008 EVE Improvements for FISM 24

25 FISM use in solar monitoring instrument design Only have to measure proxies representing a region of the solar atmosphere (ideally 4-5) instead of the entire spectrum. Much easier to measure, lower date rate, easier to process data, etc. 4-5 numbers rather than 200. Measurements (proxies) drive FISM estimations of solar VUV irradiance spectrum. This is only the case for aeronomy studies, this type of a design will have little use for new stand-alone solar physics studies. Example: GOES-R EUV and X-Ray Irradiance Sensors (EXIS) - Also current GOES-13. October 8, 2008 EVE Improvements for FISM 25

GOES-R EUV and X-Ray Irradiance Sensors (EXIS) XRS CONCEPT

8 nm X-ray irradiance measurements that have been ongoing for

proxies for the emissions from the chromosphere, transition

26 GOES-R EUV and X-Ray Irradiance Sensors (EXIS) XRS CONCEPT Primary Goal: continue into the future the nm and nm X-ray irradiance measurements that have been ongoing for over 30 years EUVS Concept Three channels that provide accurate proxies for the emissions from the chromosphere, transition region, and corona. MAVEN LPW-EUV A B October 8, 2008 EVE Improvements for FISM 26 C

27 Conclusions FISM currently provides the most accurate, high temporal resolution estimations of the solar VUV irradiance to the I/T community. Feedback from these I/T studies involving FISM will help refine the FISM solar estimations. FISM estimates can contribute to the spectral distribution of the solar flare energy budget TIFF are (Uncompressed) needed to see this decompressor picture. EVE will contribute greatly to the FISM estimation, especially for λ<27 nm and in the number of flares that FISM is based on. FISM will help future solar monitoring instruments be smaller, cheaper, and quicker to build. October 8, 2008 EVE Improvements for FISM 27

Phillip Chamberlin NASA Goddard Space Flight Center Solar Physics Laboratory Greenbelt, MD USA

Phillip Chamberlin NASA Goddard Space Flight Center Solar Physics Laboratory Greenbelt, MD USA Phillip.C.Chamberlin@NASA.gov With important contributions from Ryan Milligan (QUB), Daniel Ryan (ROB), Jan