tsi and vuv radiative energies during x-class solar flares

TSI and VUV Radiative Energies During X-Class Solar Flares

Chris MooreUndergraduate Student

U. of Iowa (2 summers at LASP/U. Of Colorado)

Phillip Chamberlin, Rachel Hock, Greg KoppLASP/U. of Colorado

04/22/23 Moore - Onset of SC 24

Research Objectives

• Analyzing the energy contribution of solar flares, in the VUV, soft/hard X-rays and the microwave wavelengths.

• Finding the energy composition from the impulsive and gradual phase of each spectral region

• Search for a center to limb variation

Impulsive and Gradual phasesImpulsive and Gradual phasesNeupert effect (1968)

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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.

• Phil Chamberlin developed for his Ph.D. Dissertation (U. of Colorado, 2005)

• Current version released June 2008

– Updated for SEE V9 data

• Uses traditional proxies (MgII c/w, F10.7, and Ly) 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 0.1-0.8 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.


Solar Variation on Various Time Scales

EUV irradiance increased by a factor of 2 and XUV increases by a factor of 100 during the gradual phase

Transition region emissions increased by up to a factor of 10 during the impulsive phase

Flare Variations were as large or larger than the solar cycle variations for the Oct 28, 2003 flare


TSI Flare Budget - Revisited• Reanalysis of TSI and VUV spectral contributions

from Woods, Kopp, and Chamberlin, JGR, 2006

• Updated using V9 TIMED SEE data– Lower contributions from 0.1-27 nm (/10)– Revised spectral distribution

• Better TSI fitting algorithm• Addition of RHESSI Contribution• Have run analysis for 21 April 2002 and 23 July 2002 events

(Emslie, Dennis, Holman, and Hudson, JGR, 2005)• Using TSI “Model” –NOTE: Very limited: based on 5 flares

TIM/TSI scalingTIM/TSI scaling Accuracy of 100 ppm (.01%)Accuracy of 100 ppm (.01%)


TSI Flare Budget - RevisitedOctober 28, 2003 - X17 - (E08, S16)

November 4, 2003 - X28 - (W83, S19)

Numbers from WKC

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 selected because of good RHESSI data)

TSI resultsTSI results Impulsive PhasesImpulsive Phases

– Oct. 28, 2003 (X17)Oct. 28, 2003 (X17) 1.56 x 10^31 ergs1.56 x 10^31 ergs


– Nov. 4, 2003 (X28)Nov. 4, 2003 (X28) 5.7 x 10^30 ergs5.7 x 10^30 ergs

– Sep. 7, 2005 (X17)Sep. 7, 2005 (X17) 2.18 x 10^30 ergs2.18 x 10^30 ergs

– Dec. 6, 2006 (X6.5)Dec. 6, 2006 (X6.5) 8.83 x 10^30 ergs8.83 x 10^30 ergs

Gradual PhasesGradual Phases– Oct. 28, 2003 (X17)Oct. 28, 2003 (X17)

3.46 x 10^32 ergs3.46 x 10^32 ergs


– Nov. 4, 2003 (X28)Nov. 4, 2003 (X28) 1.36 x 10^32 ergs1.36 x 10^32 ergs

– Sep. 7, 2005 (X17)Sep. 7, 2005 (X17) 1.48 x 10^32 ergs1.48 x 10^32 ergs

– Dec. 6, 2006 (X6.5)Dec. 6, 2006 (X6.5) 3.75 x 10^31 ergs3.75 x 10^31 ergs


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 1031 +/- 0.3 x 1031

• 23 July 2002: 1 x 1031 +/- 0.3 x 1031

• New TSI Model

• Use the FISM energy and location on disk to estimate TSI energy released in flare

• 21 April 2002: 3.4 x 1031

• 23 July 2002: 3.3 x 1031

TSI model• Based on VUV, TSI can be modeled to show energy release that would have been

seen during TSI eclipse periods or before TIM operation– N = # of center/limb flares seen in TSI (Take limb flares to be greater than 70º

east or west)– TI = impulsive phase energy in TSI– TG = gradual phase energy in TSI– VI = impulsive phase energy in VUV– VG = gradual phase energy in VUV– FI = VI/TI = fraction of impulsive phase energy from VUV compared to TSI– FG = VG/TG = fraction of gradual phase energy from VUV compared to TSI– a = (1\N) * [∑ (from N to i =1) (FI(i))] = average fraction of impulsive phase

energy from VUV– b = (1\N) * [∑ (from N to i =1) (FG(i))] = average fraction of gradual phase

energy from VUV– A = 1/a = factor that can be multiplied by the observed impulsive phase VUV

wavelengths to obtain an estimated value for the TSI– B = 1/b = factor that can be multiplied by the observed gradual phase VUV

wavelengths to obtain an estimated value for the TSI

TSI Flares

5.17 x 10^31 (38%)

2.35 x 10^30 (41%)

1.1 x 10^ 32 (34%)

7.17 x 10^30 (46%)

VUV [0.1-190 nm] (% of TSI)

1.36 x 10^32 5.7 x 10^30 3.46 x 10^321.56 x10^31 TSI

Grad. PhaseImp. Phase Grad. PhaseImp. Phase Spectral Region

4-Nov-2003 (X28) (W83 S19)28-Oct-2003 (X17) (E08 S16)

Flares (GOES Classification) (Location)

4.35 x 10^31 (34%)

5.17 x 10^30 (61%)

VUV [0.1-190 nm] (% of TSI)

1.28 x 10^32 8.54 x 10^30 TSI

Grad. PhaseImp. Phase Spectral Region

29-Oct-2003 (X10) (W10 S17)

1.07 x 10^32 ergs (72%)

8.42 x 10^30 (386%)

1.48 x 10^32 2.18 x 10^30

Grad. PhaseImp. Phase

7-Sep-2005 (X17) (E77 S11)

1.83 x 10^31 (49%)

2.06 x 10^30 (23%)

3.75 x 10^31 8.83 x 10^30


6-Dec-2006 (X6.5)

VUV [0.1-190 nm] (% of TSI)

TSI

Spectral Region

Modeled Flares

3.83 x 10^31 4.2 x 10^30

*9.82 x 10^ 31**9.70 x 10^30*


2-Nov-2003 (X8.3) (E56 N14)

1.93 x 10^31 1.05 x 10^30 9.1 x 10^30 9.7 x 10^29VUV [0.1-190 nm]

*4.94 x 10^31**2.42 x 10^30**2.33 x 10^31**2.24 x 10^30*TSI


19-Jan-2005 (X1.3) (W5 N15)15-Jan-2005 (X1.2) (E14 N8)

Flares (GOES Classification) (Location)

6.3 x 10^313.92 x 10^30 VUV [0.1-190 nm]

*1.61 x 10^32**9.05 x 10^30*TSI


20-Jan-2005 (X1.3) (W61 N14)

1.47 x 10^31 1.51 x 10^30 VUV [0.1-190 nm]

*2.67 x 10^31**7.38 x 10^29*TSI


5-Dec-2006 (X9) (E79 S07)

3.21 x 10^31 6.3 x 10^30

*8.23 x 10^31**1.45 x 10^31*


13-Dec-2006 (X3) (W23 S05)

1.81 x 10^311.89 x 10^301.87 x 10^311.04 x 10^30VUV [0.1-190 nm]

*1.81 x 10^31**9.26 x 10^29**3.4 x 10^31**5.07 x 10^29*TSI


23-Jul-2002 (X4.8) (E72 S13)21-Apr-2002 (X1.5) (W84 S14)

Future Work Search for additional spectral contributions to the

impulsive and gradual phase to the TSI RHESSI White Light, through TRACE 1600 angstrom and WL

bands SPM 9 (VIRGO-SOHO) Microwave wavelengths

Conclusion• Valid estimates of the TSI radiated energy from flares

– Very dependent on background subtraction• Able to estimate TSI energies of all other flares when not

observed by TIM with model– Model scales VUV values and incorporates CLV using flare

location– Model only based on 5 flares - very limited statistics

• Looking forward to results for new solar cycle– Continuing measurements from SORCE TIM– New TSI flare measurements from GLORY TIM (launch July

2009)– New VUV flare measurements from SDO EVE (launch Mid-

2009 to early 2010)

Back Up Slides

X17 Flare Comparison to SEE139.5 nm

Si IV; Log(T)=4.85



TSI Flare Observations

From Woods, Kopp, and Chamberlin (WKC), JGR, 2006


EUV Variability Experiment (EVE) Launch in mid-2009 onboard

the Solar Dynamics Observatory (SDO)

http://lasp.colorado.edu/eve/

University of Colorado / LASP• Thomas N. Woods (PI)• Francis G. Eparvier• Gary J. Rottman• Phillip C. ChamberlinUniversity of Southern California• Darrell L. Judge, Donald R. McMullinNaval Research Laboratory• Judith L. Lean • John T. Mariska• Harry P. WarrenMIT Lincoln Laboratory• Gregory D. BerthiaumeUniversity of Alaska • Scott M. BaileyNOAA • Rodney A. ViereckSpace Environment Technologies• W. Kent TobiskaCU/CIRES/NOAA • Timothy J. Fuller-Rowell Utah State University • Jan J. Sojka


How does EVE measure the EUV?• Multiple EUV Grating Spectrograph

(MEGS) – At 0.1 nm resolution

• MEGS-A: 5-37 nm• MEGS-B: 35-105 nm

– At 1 nm resolution• MEGS-SAM: 0-7 nm

– At 10 nm resolution• MEGS-Photometers: @ 122 nm

– Ly- Proxy for other H I emissions at 80-102 nm and He I emissions at 45-58 nm

• EUV Spectrophotometer (ESP)– At 4 nm resolution

• 17.5, 25.6, 30.4, 36 nm– At 7 nm resolution

• 0-7 nm (zeroth order)• In-flight calibrations from ESP and MEGS-

P on daily basis and also annual calibration rocket flights

0.1

1

4

7

10

nm


How will EVE help VUV Flare Studies?• 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.

– Only 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 < 27nm– EVE is 0.1 nm spectral resolution from 5-105 nm, 1.0 nm from 0.1-5 nm.

• EVE will help determine the relationship between EUV and XUV flares.– Help refine timing of the Neupert Effect?

Solar flares effect on Earth• CME’s• Release energy up to 40

billion Hiroshima sized atomic bombs

• NOAA SWPC• Particle events

– Auroras• Geomagnetic storms

– Power grids– Airlines (rerouting for

polar flights)– Disruptions

• GPS• Radio blackouts

Dynamics of Solar Flares• A magnetic flux tube emerges above the solar

surface in active regions• Magnetic flux tube is more buoyant than the

surrounding plasma• Eventually a filament of plasma is released after the

stretching of the magnetic field lines reached their eruptive limit

• This gives rise to the two phases of the solar flare

Dynamics of Solar Flares 2• Energy is forced back into the atmosphere by magnetic

reconnection, this is the energy input (Impulsive phase) • It is not visible until the Transition region, the corona is

not dense enough• This influx of energy creates thermal heating in the

atmosphere, seen in all regions• This is the slow phase (Gradual phase) of the solar flare

tsi and vuv radiative energies during x-class solar flares

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