Chong Jia, Rosenstiel: Sea Surface Temperatures

COMPASS 2024-04-17: Chong Jia, Rosenstiel School
"Characteristics of the Sea-Surface Temperatures in the Arctic Derived From Measurements From Saildrones and Satellites"

Sea-surface temperature (SST) is one of the most important variables in the global ocean-atmosphere system. The accuracy of SST retrievals from infrared satellite remote sensing is generally lower at northern high latitudes than elsewhere, and the density of in-situ SST measurements needed to refine and test algorithms for the correction of atmospheric effects on the infrared radiative transfer is relatively sparse as well. From May 15 to October 11, 2019, two Saildrone uncrewed surface vehicles (USVs) funded by NASA were deployed for 150-day cruises from Dutch Harbor, Alaska, transiting the Bering Strait into the Chukchi Sea and the Arctic Ocean, carrying infrared (IR) radiation pyrometers on the deck for the determination of the sea-surface skin temperature (SSTskin). This study produced an algorithm to derive SSTskin and an estimate of the sources of inaccuracies. After stringent quality control of data by restricting the acceptable tilt angles of the USV determined using radiative transfer simulations, SSTskin can be derived to an accuracy of ~0.12 K. Thus, Saildrones can provide sufficiently accurate SSTskin retrievals for scientific research. Our study has demonstrated how the Saildrone-derived SSTskin along with the subsurface temperature measurements and meteorological data has improved our understanding of upper ocean thermal structure (including cool / warm skin effects and diurnal warming events) and benefit the validation of IR satellite SSTskin retrievals, to alleviate the challenges in deriving SST at high latitudes.