CYGNSS Sea Surface Heat Flux Product Validation and Its Applicability

Sea surface heat flux is an important factor for studying ocean-atmosphere interaction. The heat flux product developed based on the Cyclone Global Navigation Satellite System (CYGNSS) wind speed provides a new platform for studying sea surface heat flux under extreme sea conditions. The wind speed and heat flux measured by the Kuroshio Extension Observatory (KEO) and Tropical Atmosphere Ocean (TAO) buoys were employed as reference data to evaluate the accuracy and applicability of CYGNSS heat flux products in the northwestern and equatorial Pacific Ocean. The results show that the heat flux of CYGNSS is in good agreement with the measured heat flux of the KEO, and the correlation coefficient is up to 0.90. There is a large error and weak correlation between CYGNSS and TAO array, which may be due to the use of reanalysis data in TAO heat flux. The effect of 25 km spatial matching statistical parameters is better than that of 50 km spatial matching. The effectiveness of the CYGNSS heat flux product in the mid-latitude sea area was verified. In the absence of field observation data in the low latitude sea area, the heat flux product has a certain reference significance.