Uncertainties of satellite-derived surface skin temperatures in the polar oceans: MODIS, AIRS/AMSU, and AIRS only

Abstract

Abstract. Uncertainties in the satellite-derived Surface Skin Temperature (SST) data in the polar oceans during two periods (16–24 April and 15–23 September) of 2003–2014 were investigated and the three datasets 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. AIRS only algorithm was developed in preparation for the degradation of the AMSU-A. MODIS IST was systematically up to 1.65 K warmer at the sea ice boundary and up to 2.04 K colder 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 datasets (MODIS, AIRS/AMSU and AIRS only) showed significant warming rates (2.3 ± 1.7 ~2.8 ± 1.9 K decade−1) in the northern high latitude 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.

Uncertainties of satellite-derived surface skin temperatures in the polar oceans: MODIS, AIRS/AMSU, and AIRS only

“…11c-d clearly showed that the temperature difference had a significant impact on the trend difference over the Southern Hemisphere. The trend of the T skin (AA_V6) and T skin (AO_V6) agreed well except for at the region of the sea in Kang and Yoo (2015).…”

“…As expected, the MODIS and AIRS showed the spatial distribution of the climatological SST, warmer at the lower latitudes than the higher latitudes. The SST distributions over the Northern Hemisphere during 16-24 April 200316-24 April -2014 have been shown in Kang and Yoo (2015). Figure 2a displays the number of years when both T skin (MODIS) and T skin (AA_V6) are available at each grid point over the Southern Hemisphere.…”

Skin Effect of Fresh Water Measured Using Distributed Temperature Sensing

“…A colder layer of water on the surface is a documented phenomenon in oceanography and most research about the skin effect of water bodies has been focused on oceans [8,13,14]. The greater of research focussed on skin effect in oceanography as compared to fresh water reservoirs is related to the fact that the surface of oceans is particularly interesting from biological and chemical perspective.…”

“…Although the skin effect has been previously measured (e.g., [13,14,19,20]), the measurements of the skin effect thickness remain scarce. Previous work on the skin effect thickness suggested that the effect is limited to about one millimeter.…”

Optimal Use of Space-Borne Advanced Infrared and Microwave Soundings for Regional Numerical Weather Prediction

“…The former stands the best quality in temperature retrievals within these pressure levels, while the later indicates the retrieved moisture is of best quality. Through applying both criteria to control the quality of soundings, we may reduce the retrieval uncertainties in this study, which is a consistent approach in the validation works such as [2,32,33].…”