High-Resolution Satellite-Derived Dataset of the Surface Fluxes of Heat, Freshwater, and Momentum for the TOGA COARE IOP

Abstract

An integrated approach is presented for determining from several different satellite datasets all of the components of the tropical sea surface fluxes of heat, freshwater, and momentum. The methodology for obtaining the surface turbulent and radiative fluxes uses physical properties of the atmosphere and surface retrieved from satellite observations as inputs into models of the surface turbulent and radiative flux processes. The precipitation retrieval combines analysis of satellite microwave brightness temperatures with a statistical model employing satellite observations of visible/infrared radiances. A high-resolution dataset has been prepared for the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) intensive observation period (IOP), with a spatial resolution of 50 km and temporal resolution of 3 h. The high spatial resolution is needed to resolve the diurnal and mesoscale storm-related variations of the fluxes. The fidelity of the satellite-derived surface fluxes is examined by comparing them with in situ measurements obtained from ships and aircraft during the TOGA COARE IOP and from vertically integrated budgets of heat and freshwater for the atmosphere and ocean. The root-mean-square differences between the satellite-derived and in situ fluxes are dominated by limitations in the satellite sampling; these are reduced when some averaging is done, particularly for the precipitation (which is from a statistical algorithm) and the surface solar radiation (which uses spatially sampled satellite pixels). Nevertheless, the fluxes are determined with a useful accuracy, even at the highest temporal and spatial resolution. By compiling the fluxes at such high resolution, users of the dataset can decide whether and how to average for particular purposes. For example, over time, space, or similar weather events.

Seasonal and Interannual Variations of the Energy Flux Equator and ITCZ. Part I: Zonally Averaged ITCZ Position

“…The errors in the columnintegrated energy budgets of the ERAI and NCEP-NCAR data are greatest over land, in particular near high topography (Trenberth et al 2001). In situ measurements indicate that the net shortwave fluxes are the largest source of uncertainties and errors (e.g., Curry et al 1999), causing local biases that can exceed 30 W m 22 in ERAI (Trenberth et al 2001). Our focus here is on zonal-mean quantities.…”

Cloud Feedbacks in the Climate System: A Critical Review

“…A major obstacle in determining the radiation budgets of both the atmosphere and surface are the limitations of the input cloud properties and other information needed in radiative transfer calculations. Nevertheless, different global climatologies of the surface radiation budgets, based largely on satellite data, have been developed over the years (e.g., Zhang et al 1995;Bishop et al 1997;Gupta et al 1999;Curry et al 1999;L'Ecuyer and Stephens 2003;among others).…”

“…It was remarked in section 2 how control theory has been used as a guiding framework for analyzing climate feedbacks (e.g., Schlessinger and Mitchell 1987;Arking 1991;Curry and Webster 1999), and most notably for analyzing feedbacks in GCMs. For this reason and to provide more substance to the discussion of section 2, a brief review of the system approach is presented.…”

A note on reviving the Goddard Satellite-based Surface Turbulent Fluxes (GSSTF) dataset

“…The SSM/I on board a series of Defense Meteorological Satellite Program (DMSP) satellites spacecraft has provided global radiance measurements for sensing the atmosphere and the surface. A number of techniques have been developed to derive the turbulent fluxes using parameters such as the surface air humidity and winds inferred from the SSM/I radiances (e.g., Chou et al, 1997;Schulz et al, 1997;Curry et al, 1999;Kubota et al, 2002).…”