Uncertainties of satellite-derived surface skin temperatures in the polar oceans: MODIS, AIRS/AMSU, and AIRS only
Uncertainties in the satellite-derived surface skin temperature (SST) data in the polar oceans during two periods (16–24 April and 15–23 September) 2003–2014 were investigated and the three data sets were intercompared as follows: MODerate Resolution Imaging Spectroradiometer Ice Surface Temperatur...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2015-10-01
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Series: | Atmospheric Measurement Techniques |
Online Access: | http://www.atmos-meas-tech.net/8/4025/2015/amt-8-4025-2015.pdf |
Summary: | Uncertainties in the satellite-derived surface skin temperature (SST) data
in the polar oceans during two periods (16–24 April and 15–23 September)
2003–2014 were investigated and the three data sets were intercompared as
follows: MODerate Resolution Imaging Spectroradiometer Ice Surface
Temperature (MODIS IST), the SST of the Atmospheric Infrared
Sounder/Advanced Microwave Sounding Unit-A (AIRS/AMSU), and AIRS only. The AIRS
only algorithm was developed in preparation for the degradation of the
AMSU-A. MODIS IST was systematically warmer up to 1.65 K at the sea ice
boundary and colder down to −2.04 K in the polar sea ice regions of both the
Arctic and Antarctic than that of the AIRS/AMSU. This difference in the
results could have been caused by the surface classification method. The
spatial correlation coefficient of the AIRS only to the AIRS/AMSU
(0.992–0.999) method was greater than that of the MODIS IST to the AIRS/AMSU
(0.968–0.994). The SST of the AIRS only compared to that of the AIRS/AMSU
had a bias of 0.168 K with a RMSE of 0.590 K over the Northern Hemisphere
high latitudes and a bias of −0.109 K with a RMSE of 0.852 K over the
Southern Hemisphere high latitudes. There was a systematic disagreement
between the AIRS retrievals at the boundary of the sea ice, because the AIRS
only algorithm utilized a less accurate GCM forecast over the
seasonally varying frozen oceans than the microwave data. The three data sets
(MODIS, AIRS/AMSU and AIRS only) showed significant warming rates
(2.3 ± 1.7 ~ 2.8 ± 1.9 K decade<sup>−1</sup>) in the northern
high regions (70–80° N) as expected from the ice-albedo feedback. The
systematic temperature disagreement associated with surface type
classification had an impact on the resulting temperature trends. |
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ISSN: | 1867-1381 1867-8548 |