Surface Heat Flux Analysis and Products for the CYGNSS Mission

Latent and sensible heat fluxes can transport mass, momentum, and energy between the ocean surface and lower troposphere, playing a critical role in Earth’s weather and climate. Frequent and spatially contiguous observations over the oceans are critical given their importance to various weather phenomena. While these fluxes can be measured and estimated with in-situ instruments, such as buoys, spatial and temporal coverage is limited over the world’s oceans. Additionally, previous and current satellite missions can experience signal attenuation from precipitation and infrequent temporal sampling, leading to significant gaps in their data.

Early on-orbit results from the Cyclone Global Navigation Satellite System (CYGNSS) have shown that it is able to estimate latent and sensible heat fluxes by using its surface wind speed observations. Given that surface winds are critical in estimating surface heat fluxes, the improved wind speeds from CYGNSS have the potential to offer surface heat fluxes in nearly all weather conditions. By using the latest results, we are developing a Level-2 surface heat flux product for the entire CYGNSS mission that will be made available to the public in the near future. This product will use CYGNSS’s Level-2 surface wind speed observations, along with satellite and reanalysis data for the other variables (e.g. temperature, specific humidity), and will estimate the surface heat fluxes with the latest version of the Coupled Ocean-Atmosphere Response Experiment (COARE) algorithm. We expect that this product will aid the scientific community given surface heat fluxes role in various tropical and sub-tropical activity, such as tropical convection, convectively coupled waves, and low-latitude extratropical cyclones.