gerb-ceres shortwave and longwave/day comparisons

GERB-CERES Shortwave and Longwave/Day

Comparisons

G. L. Smith and P. E. Mlynczak

Langley Research Centre

et Belgae

Shortwave Comparisons• December 03/January 04 and

June/July 04 comparisons have been upgraded using CERES edition 2 data

• December 04/January 05 comparisons use CERES edition 1 data

• Compare first on detector and then on latitude grid basis

GERB SW/CERES SW Detector basis, Dec.03/Jan04, CERES Edition 2

GERB SW/CERES SW Detector basis, Dec.03/Jan04, CERES Edition 2

GERB SW/CERES SW Detector basis, Dec.03/Jan04, CERES Edition 2

GERB SW/CERES SW Latitude basis, Dec.03/Jan04, CERES Edition 2

GERB SW/CERES SW Detector basis June/July04, CERES Edition 2

GERB SW/CERES SW Detector basis June/July04, CERES Edition 2

GERB SW/CERES SW Detector basis June/July04, CERES Edition 2

GERB SW/CERES SW Latitude basis June/July04, CERES Edition 2

GERB SW/CERES SW Detector basis, Dec.04/Jan05, CERES Edition 1

GERB SW/CERES SW Detector basis, Dec.04/Jan05, CERES Edition 1

GERB SW/CERES SW Detector basis, Dec.04/Jan05, CERES Edition 1

GERB SW/CERES SW Latitude basis, Dec.04/Jan05, CERES Edition 1

Conclusions for SW: Ratio

Detector DJ04 DJ05 JJ04

32 – 112 .98(.01) .97(.01) .97(.03)*

128 – 160 .95(.01) .95(.01) .96(.02)

193 - 224 .95(.02) .95(.02) .96(.03)

*eyeball guess

Conclusions for SW: Differences

• Detector No.

DJ04 & DJ05: JJ04:

1 - 31 Inadequate sampling

32 – 112 -2 (1) 48 – 224 -2.5 (2)

128 – 192 -4 (2)

193 – 240 -7 (4)

240 – 256 Inadequate sampling

Conclusions for SW: Difference in Latitude Bins

DJ04 -3.3 W-m-2-Sr-1

DJ05 -3.1

JJ04 -2.3

In NH many grids are within 1 of 0

In SH many grid are below 0 by > 1

Conclusions for SW• Detector to Detector variation is slow in Northern

Hemi. and more erratic in SH for both DJ04 and JJ04.

• DJ04 and DJ05 agree very well, thus

Any degradation of GERB SW matches

CERES ed. 1 degradation.

Detector to Detector variations match

between DJ04 and DJ05, indicating that the variations are real and not sampling noise.

GERB LW/CERES LWDecember 03/January 04

GERB LW/CERES LWDecember 03/January 04

GERB LW/CERES LWDecember 03/January 04

GERB LW/CERES LWJune/July 04

GERB LW/CERES LWJune/July 04

GERB LW/CERES LWJune/July 04

Conclusions reLW/day: Ratio

• CERES FM-2 Comparisons are excellent.

• ARG Row Dec3/Jan04 June/July04

1 - 31 Inadequate Sampling

32 - 128 0.995 (0.005) 1.000 (0.005)*

129 - 192 1.000 (0.007) 0.995 (0.005)

193 - 224 1.000 (0.02) 0.995 (0.02)

*eyeball guess

Conclusions reLW/day: Differenec

• ARG Row Dec3/Jan04 June/July04

0 - 31 Inadequate Sampling

32 – 128 -0.5 (0.5) 0.0 (0.5) W-m-2-Sr-1

129 – 192 0.0 (0.5) -0.3 (0.5)

193 - 224 0.0 (1.-2.) 0.0 (1)

SEVIRI LW EstimatesDecember 03/January 04

SEVIRI LW EstimatesDecember 03/January 04

SEVIRI LW EstimatesDecember 03/January 04

SEVIRI LW EstimatesJune/July04

SEVIRI LW Estimates June/July04

SEVIRI LW Estimates June/July04

Conclusions reSEVIRI LW/Day Retrievals

• Inadequate sampling to get accurate comparisions, especially for ARG 96 – 256

ARG 32 - 50 -1.5+/- 1.5*

51 - 96 1.5 +/- 1.5

97 - 135 0 +/- 1.5

136 - 200 -2. +/- 3 *eyeball

201 - 224 -2.5 +/- 2.5 guess