Ice Surface Temperature Retrieval from a Single Satellite Imager Band

Abstract

Current methods for estimating the surface temperature of sea and lake ice—the ice surface temperature (IST)—utilize two satellite imager thermal bands (11 and 12 μm) at moderate spatial resolution. These “split-window” or dual-band methods have been shown to have low biases and uncertainties. A single-band algorithm would be useful for satellite imagers that have only the 11 μm band at high resolution, such as the Visible Infrared Imaging Radiometer Suite (VIIRS), or that do not have a fully functional 12 μm band, such as the Thermal Infrared Sensor onboard the Landsat 8. This study presents a method for single-band IST retrievals, and validation of the retrievals using IST measurements from an airborne infrared radiation pyrometer during the NASA IceBridge campaign in the Arctic. Results show that IST with a single thermal band from the VIIRS has comparable performance to IST with the VIIRS dual-band (split-window) method, with a bias of 0.22 K and root-mean-square error of 1.03 K.

The Case for a Single Channel Composite Arctic Sea Surface Temperature Algorithm

“…IST retrieval systems commonly use the same split window algorithm as SSTs (Equation (1)) [6]. The determination of IST using satellite thermal data is more complex and generally less accurate than SST because the surface may consist of ice, snow or a combination of the two.…”

“…The different factors affecting emissivity for IST retrievals lead to solutions that are characteristically less accurate than SST algorithms. (1)) [6]. The determination of IST using satellite thermal data is more complex and generally less accurate than SST because the surface may consist of ice, snow or a combination of the two.…”

“…The viability of a single channel IST algorithm for TIR sensors was examined recently by Liu et al [6]. The study, which was part of NASA's Operation IceBridge in northern Alaska, found that that IST retrieval with a single channel had comparable performance to the split window algorithm using VIIRS (Channel M15, 10.26-11.26 µm), with a root-mean-square error of 1.03 K and a bias of 0.22 K. The results showed the IST retrieval biases did not have an apparent dependence on atmospheric water vapor or sensor zenith angle, likely as a result of the dry Arctic climate [6].…”

“…The viability of a single channel IST algorithm for TIR sensors was examined recently by Liu et al [6]. The study, which was part of NASA's Operation IceBridge in northern Alaska, found that that IST retrieval with a single channel had comparable performance to the split window algorithm using VIIRS (Channel M15, 10.26-11.26 µm), with a root-mean-square error of 1.03 K and a bias of 0.22 K. The results showed the IST retrieval biases did not have an apparent dependence on atmospheric water vapor or sensor zenith angle, likely as a result of the dry Arctic climate [6]. Although the research was aimed at finding a solution for satellite imagers that only detect BT 11 , the atmospheric and surface physics in the Arctic maritime environment, where high BTD [11][12] values potentially render split window algorithms less effective, suggest that a single channel solution may be the preferred method.…”

“…The determination of high latitude surface temperatures is an important factor in assessing climate change in polar environments [1][2][3][4][5][6]. This is particularly true in the Arctic where surface air temperatures are increasing more rapidly than the global average [7,8].…”