Abstract
Latent heat flux (LHF) plays an important role in the global hydrological cycle and is therefore necessary to understand global climate variability. It has been reported that the near-surface specific humidity is a major source of error for satellite-derived LHF. Here, a new empirical model relating multichannel brightness temperatures ( T B ) obtained from the Fengyun-3 (FY-3C) microwave radiometer and sea surface air specific humidity ( Q a ) is proposed. It is based on the relationship between T B , Q a , sea surface temperature (SST), and water vapor scale height. Compared with in situ data, the new satellite-derived Q a and LHF both exhibit better statistical results than previous estimates. For Q a , the bias, root mean square difference (RMSD), and the correlation coefficient (R2) between satellite and buoy in the mid-latitude region are 0.08 g/kg, 1.76 g/kg, and 0.92, respectively. For LHF, the bias, RMSD, and R2 are 2.40 W/m2, 34.24 W/m2, and 0.87, respectively. The satellite-derived Q a are also compared with National Oceanic and Atmospheric Administration (NOAA) Cooperative Institute for Research in Environmental Sciences (CIRES) humidity datasets, with a bias, RMSD, and R2 of 0.02 g/kg, 1.02 g/kg, and 0.98, respectively. The proposed method can also be extended in the future to observations from other space-borne microwave radiometers.
Highlights
Air–sea latent heat flux (LHF), combined with momentum flux and sensible heat flux, represents an important aspect of the atmosphere–ocean interaction, energy budget, water cycle variability, and global climate systems [1]
The other was from mooring buoy networks: The National Data Buoy Center (NDBC) buoys off the U.S Atlantic, Pacific, and Gulf coasts maintained by the National Oceanic and Atmospheric Administration (NOAA); the European offshore data acquisition system (ODAS) buoys in the eastern Atlantic, maintained by the UK Met Office and Météo-France (MFUK); and the Tropical Atmosphere Ocean (TAO) buoys located in the tropical Pacific Ocean, maintained by NOAA’s Pacific Marine Environment Laboratory (PMEL)
Satellite-derived specific humidity has been a major source of error for the estimation of LHF
Summary
Air–sea latent heat flux (LHF), combined with momentum flux and sensible heat flux, represents an important aspect of the atmosphere–ocean interaction, energy budget, water cycle variability, and global climate systems [1]. LHF can be estimated by the bulk aerodynamic formula that includes sea surface temperature (SST), surface winds, air temperature (Ta), and near-surface air specific humidity (Qa) These flux-related variables can be obtained from three major sources: In situ measurements, satellite observations, and numerical weather prediction models. Depending on the data fusion techniques, blended global surface heat flux datasets have been derived from multi-satellite information These mainly include the Hamburg Ocean–Atmosphere Parameters and Fluxes from Satellite Data (HOAPS-3; [8,9]), Japanese Ocean Flux Data Sets with Use of Remote Sensing Observations (J-OFURO; [10]), Goddard Satellite-Based Surface Turbulent Flux (GSSTF-3; [11]), and French Research Institute for Exploitation of the Sea (IFREMER) turbulent flux products [12]. Using the column water vapor (W) as an independent parameter is a common way to determine the Qa from satellite measurements [14,15] This Qa−W relationship is widely used in LHF-retrieval algorithms.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
