An assessment of surface heat fluxes from J‐OFURO2 at the KEO and JKEO sites

Abstract

The daily mean air‐sea heat fluxes over the global oceans have been developed as the version 2 of Japanese Ocean Flux data sets with use of Remote sensing Observations (J‐OFURO2). Net heat flux is available from 1988 to 2006, and the turbulent heat flux is available from 1988 to 2007. To assess the accuracy of the J‐OFURO2 product over the Kuroshio Extension region, air‐sea heat fluxes and related state variables were compared with independent in situ observations from the Kuroshio Extension Observatory (KEO) and JAMSTEC KEO (JKEO) surface moorings. Although seasonal biases were found, these tended to cancel out over the total period, resulting in a total bias and RMS in J‐OFURO2 net heat fluxes of 8.6 and 56.8 W/m2, respectively. Comparisons with other global air‐sea heat flux products from numerical weather prediction, i.e., the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis (NRA1), the NCEP/Department of Energy reanalysis (NRA2), and satellite observations, i.e., Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data and merged product, i.e., Objectively Analyzed Air‐Sea Fluxes were also conducted at the KEO and JKEO sites. Comparison results show that the total and seasonal biases are smallest compared with other products, and J‐OFURO2 air‐sea heat fluxes are best data set for air‐sea interaction study over the Kuroshio Extension region.