SOLSTICE I and II:
Calibrations and Comparisons
Marty Snow, Bill McClintock, Tom
Woods, and Gary Rottman
Laboratory for Atmospheric and
Space Physics
Outline
•
•
•
•
•
SOLSTICE I and II
SOLSTICE I Validation review
SOLSTICE I degradation corrections
SOLSTICE II ground calibration
SOLSTICE II validation of
measurements.
September 19, 2006
SSI Workshop: SOLSTICE
2
What is SOLSTICE?
SOLar-STellar Irradiance
Comparison Experiment.
• SOLSTICE I
–
–
–
–
• SOLSTICE II
UARS – 1991-2005
FUV 0.1 nm
MUV 0.2 nm
Vis (“N” channel)
• Data Versions:
– V18 CDHF
– V19 LASP
September 19, 2006
– SORCE – 2003+
– FUV 0.1 nm
– MUV 0.1 nm
• Data Version
– V6 (current)
SSI Workshop: SOLSTICE
3
SOLSTICE I Validation
Ratio to Average on March 29, 1992 (ATLAS1)
1.4
SOLSTICE V19
SUSIM V22
SOLSTICE V18
X/Avg
1.2
1.0
0.8
150
200
250
300
“Average” irradiance is taken from Woods et al. 1996 paper.
September 19, 2006
SSI Workshop: SOLSTICE
4
SOLSTICE I Validation
Ratio to Average on March 29, 1992 (ATLAS1)
1.4
SOLSTICE V19
SUSIM V22
SOLSTICE V18
X/Avg
1.2
1.0
0.8
150
200
250
300
“Average” irradiance is taken from Woods et al. 1996 paper.
September 19, 2006
SSI Workshop: SOLSTICE
5
UARS Stellar Observations
G Channel Stellar Observation -- alf_cma at 153.5 nm
1.30
1.20
440
420
1.10
400
380
360
0
Flux
Count Rate
480
460
1.00
50
100
150
200
Elapsed Time (seconds) -- Date =1994.7630
0.90
250
All UARS SOLSTICE G Channel Observations of ALF_CMA at 153.5 nm
1.50
40
30
1.40
20
10
0
0.95
1.00
1.05
1.10
1.15
Uncorrected Flux
ALF_CMA -- 1994.7630
1.20
1.25
Uncorrected Flux
Number of Samples
Histogram of Flux Measurements with Model Fit
1.30
1.20
1.10
1.00
0.90
1992
September 19, 2006
SSI Workshop: SOLSTICE
1994
1996
Year
1998
2000
6
Ensemble of Stars
UARS SOLSTICE G Channel Degradation (153.486 nm)
alf_cma (1.00)
alf_cru (3.30)
alf_lyr (0.36)
alf_pav (0.62)
bet_cen (2.97)
eta_uma (0.58)
tau_sco (0.72)
Extrapolated ()
1.00
Normalized Flux
0.95
0.90
0.85
0.80
0.75 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
0
September 19, 2006
1000
2000
UARS Day (Exposure Time)
SSI Workshop: SOLSTICE
3000
4000
7
Ensemble of Stars
UARS SOLSTICE G Channel Degradation (153.486 nm)
“one day hit”
anomalies
change
solar/stellar
FOV correction
0.95
Normalized Flux
Tape
recorder
failure
11/99. No
more stars.
alf_cma (1.00)
alf_cru (3.30)
alf_lyr (0.36)
alf_pav (0.62)
bet_cen (2.97)
eta_uma (0.58)
tau_sco (0.72)
Extrapolated ()
1.00
0.90
Change to
closed loop
tracking on the
Sun. (star
tracker failure)
2/02
0.85
0.80
0.75 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
0
September 19, 2006
1000
2000
UARS Day (Exposure Time)
SSI Workshop: SOLSTICE
3000
4000
8
FOV Correction
The illumination of the
optics is not identical in
solar and stellar modes.
The solar image burns a
“hole” in the center of the
FOV. The depth of this
“hole” can be measured with
an alignment scan and
corrected.
This correction is applied on
top of the stellar
degradation correction.
September 19, 2006
SSI Workshop: SOLSTICE
9
SOLSTICE I in 2003
Solar Irradiance at 135.500
5.5•10-5
FUV: Nearly full mission has been
reprocessed at LASP and is consistent
with prior CDHF processing.
5.0•10-5
4.5•10-5
Solar Irradiance at 182.500
2.50•10-3
4.0•10-5
2.45•10-3
UARS FUV
SORCE FUV
2.40•10-3
3.5•10-5
Jan
1993
2.35•10
Oct
1995
Jul
1998
Mar
2001
Dec
2003
-3
MUV: LASP data processing system
cannot fully reproduce CDHF processing
yet, therefore no MUV data exists (yet)
after 2000.
2.30•10-3
2.25•10-3
2.20•10-3
UARS MUV
SORCE MUV
2.15•10-3
Jan
1993
Oct
1995
Jul
1998
September 19, 2006
Mar
2001
Dec
2003
SSI Workshop: SOLSTICE
10
Preflight Calibration of
SOLSTICE II
Combined Uncertainty in Solar Irradiance
7
Percent Uncertainty
6
5
4
3
2
1
100
150
200
250
Wavelength (nm)
300
350
Full details are in McClintock, Snow, & Woods (2005).
September 19, 2006
SSI Workshop: SOLSTICE
11
MUV Comparison
Ratio to SORCE SOLSTICE on 2003/067
1.2
X/SORCE SOLSTICE
1.1
1.0
0.9
SUSIM
NOAA 16 SBUV
0.8
180
September 19, 2006
200
220
240
260
SSI Workshop: SOLSTICE
280
300
12
MUV with Uncertainty
Ratio to SORCE SOLSTICE on 2003/067
1.2
X/SORCE SOLSTICE
1.1
1.0
0.9
SORCE Prelaunch Uncertainty
0.8
180
September 19, 2006
200
220
240
SUSIM
NOAA 16 SBUV
260
SSI Workshop: SOLSTICE
280
300
13
UARS MUV Data Availability
Unfortunately, the existing data processing system needs to be
revised before we can produce irradiances after the end of 1999.
September 19, 2006
SSI Workshop: SOLSTICE
14
UARS MUV Data Availability
Unfortunately, the existing data processing system needs to be
revised before we can produce irradiances after the end of 1999.
This complicates comparisons with SORCE.
September 19, 2006
SSI Workshop: SOLSTICE
15
UARS MUV Data Availability
Unfortunately, the existing data processing system needs to be
revised before we can produce irradiances after the end of 1999.
This complicates comparisons with SORCE.
Solution: use day(s) from one solar cycle earlier to remove solar
variability from comparison. Pick days with same F10.7 and
F10.7a as 2003/067:
Selected UARS Days: 331, 332, and 575
(1992/220, 1992/221, and 1993/098)
September 19, 2006
SSI Workshop: SOLSTICE
16
Solar Cycle Match
Ratio to SORCE SOLSTICE on 2003/067
1.2
X/SORCE SOLSTICE
1.1
The
1992/2003
match
works
great on
SUSIM
data!
1.0
0.9
SUSIM (1992)
SUSIM
NOAA 16 SBUV
0.8
180
September 19, 2006
200
220
240
260
SSI Workshop: SOLSTICE
280
300
17
MUV with UARS
Ratio to SORCE SOLSTICE on 2003/067
1.2
X/SORCE SOLSTICE
1.1
1.0
0.9
UARS SOLSTICE (1992)
SUSIM
NOAA 16 SBUV
0.8
180
September 19, 2006
200
220
240
260
SSI Workshop Introduction
280
300
18
UARS MUV Calibration Ratio
Ratio to SORCE SOLSTICE on 2003/067
Ratio to Average on March 29, 1992 (ATLAS1)
1.2
1.4
SOLSTICE V19
SUSIM V22
SOLSTICE V18
X/SORCE SOLSTICE
1.1
X/Avg
1.2
1.0
1.0
0.9
Ratio of UARS SUSIM to SOLSTICE
1.00
0.8
0.98
200
SUSIM/SOLSTICE
150
250
0.8
180
300
200
220
0.94
0.92
0.88
180
2003 & 1992
March 29, 1992 (ATLAS1)
April 15, 1993 (ATLAS2)
200
220
240
240
260
280
300
Therefore ratio to
SORCE SOLSTICE
is consistent with
known calibration
difference between
the two UARS
instruments.
0.96
0.90
September 19, 2006
UARS SOLSTICE (1992)
SUSIM
NOAA 16 SBUV
260
SSI Workshop: SOLSTICE
280
300
19
Overlap with SORCE SIM
Ratio to SORCE SOLSTICE on 2003/067
1.2
X/SORCE SOLSTICE
1.1
1.0
0.9
SIM
UARS SOLSTICE (1992)
SUSIM
NOAA 16 SBUV
0.8
180
September 19, 2006
200
220
240
260
SSI Workshop Introduction
280
300
20
Grand MUV Comparison
Ratio to SORCE SOLSTICE on 2003/067
1.2
|----- ESR Calibration ---->
X/SORCE SOLSTICE
1.1
1.0
0.9
SIM
UARS SOLSTICE (1992)
SUSIM
NOAA 16 SBUV
0.8
180
September 19, 2006
200
220
240
260
SSI Workshop Introduction
280
300
21
FUV Ratio of SOLSTICEs
2003/067 Ratio of SOLSTICEs in FUV
1.2
UARS/SORCE
1.1
1.0
0.9
SORCE Preflight Uncertainty
0.8
120
130
140
150
Wavelength
160
170
Seems too good to be true….
September 19, 2006
SSI Workshop Introduction
22
FUV Compared to both UARS
2003/067 Ratio of SOLSTICEs in FUV
1.2
UARS/SORCE
1.1
1.0
0.9
UARS SOLSTICE
SUSIM
0.8
120
September 19, 2006
130
140
150
Wavelength
160
SSI Workshop Introduction
170
23
Expected FUV Difference
2003/067 Ratio of SOLSTICEs in FUV
1.2
UARS/SORCE
1.1
1.0
0.9
Known Calibration Difference
UARS SOLSTICE
SUSIM
0.8
120
September 19, 2006
130
140
150
Wavelength
160
SSI Workshop: SOLSTICE
170
24
FUV Time Series - Lyα
Solar Irradiance at 121.500
0.012
± 5%
0.010
0.008
UARS v19
SORCE
SUSIM
0.006
0.004
SUSIM/SOLSTICE (normalized)
Jan
1993
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 121.500 nm
1.2
1.1
1.0
0.9
September 19, 2006
Jan
1993
Oct
1995
Jul
1998
Mar
2001
SSI Workshop Introduction
Dec
2003
25
The “Good”
Solar Irradiance at 145.500
-5
7.5•10
± 5%
7.0•10-5
6.5•10-5
6.0•10-5
UARS v19
SORCE
SUSIM
5.5•10-5
5.0•10-5
SUSIM/SOLSTICE (normalized)
Jan
1993
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 145.500 nm
1.2
1.1
1.0
0.9
September 19, 2006
Jan
1993
Oct
1995
Jul
1998
Mar
2001
SSI Workshop Introduction
Dec
2003
26
The “Good”
7.5•10
•Ratio flat
•Both SOLSTICES
are consistent relative
to SUSIM
Solar Irradiance at 145.500
-5
± 5%
7.0•10-5
6.5•10-5
6.0•10-5
UARS v19
SORCE
SUSIM
5.5•10-5
5.0•10-5
SUSIM/SOLSTICE (normalized)
Jan
1993
September 19, 2006
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 145.500 nm
1.2
1.1
1.0
0.9
Jan
1993
Oct
1995
Jul
1998
SSI Workshop Introduction
Mar
2001
Dec
2003
27
The “Bad”
Solar Irradiance at 155.500
-4
2.6•10
2.4•10-4
± 5%
2.2•10-4
2.0•10-4
UARS v19
SORCE
SUSIM
1.8•10-4
1.6•10-4
1.4•10-4
SUSIM/SOLSTICE (normalized)
Jan
1993
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 155.500 nm
1.2
1.1
1.0
0.9
September 19, 2006
Jan
1993
Oct
1995
Jul
1998
Mar
2001
SSI Workshop Introduction
Dec
2003
28
The “Bad”
Solar Irradiance at 155.500
-4
September 19, 2006
± 5%
2.2•10-4
2.0•10-4
UARS v19
SORCE
SUSIM
1.8•10-4
1.6•10-4
1.4•10-4
Jan
1993
SUSIM/SOLSTICE (normalized)
•UARS Ratio diverges
•SORCE SOLSTICE
has same trend as
SUSIM, although
large calibration
difference.
•Quiet Sun irradiances
may or may not be
comparable.
2.6•10
2.4•10-4
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 155.500 nm
1.2
1.1
1.0
0.9
Jan
1993
Oct
1995
Jul
1998
SSI Workshop Introduction
Mar
2001
Dec
2003
29
The “Ugly”
Solar Irradiance at 176.500
-3
1.40•10
1.35•10-3
± 5%
1.30•10-3
1.25•10-3
UARS v19
SORCE
SUSIM
1.20•10-3
1.15•10-3
1.10•10-3
SUSIM/SOLSTICE (normalized)
Jan
1993
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 176.500 nm
1.2
1.1
1.0
0.9
September 19, 2006
Jan
1993
Oct
1995
Jul
1998
Mar
2001
SSI Workshop Introduction
Dec
2003
30
The “Ugly”
Solar Irradiance at 176.500
-3
September 19, 2006
± 5%
1.30•10-3
1.25•10-3
UARS v19
SORCE
SUSIM
1.20•10-3
1.15•10-3
1.10•10-3
Jan
1993
SUSIM/SOLSTICE (normalized)
•Ratio diverged in
1992, then flattened
out, then rose for a
few years, then
flattened out again.
•SORCE SOLSTICE
trend matches
SUSIM.
•UARS SOLSTICE
now matches
SORCE, but Quiet
Sun irradiances make
no sense.
1.40•10
1.35•10-3
Oct
1995
Jul
1998
Mar
2001
Dec
2003
Irradiance Ratio at 176.500 nm
1.2
1.1
1.0
0.9
Jan
1993
Oct
1995
Jul
1998
SSI Workshop Introduction
Mar
2001
Dec
2003
31
Summary
• MUV calibration differences seem to be
consistent with previous validation.
SOLSTICE II agrees with SUSIM at the
2% level. Agrees with SOLSTICE I at the
7% level.
• FUV degradation issues for both SUSIM
and SOLSTICE may complicate
understanding of calibration. Agreement is
still within stated uncertainties.
September 19, 2006
SSI Workshop: SOLSTICE
32