Modeled radar surface signature of deep ocean convection

Abstract

Deep ocean convection, the process by which the deep waters of the world's oceans are created and renewed, plays a key role in the global thermohaline circulation and hence the world's heat balance. The process of deep ocean convection involves a vigorous overturning of the ocean water column down to depths of 2000-3000 m in an area probably not larger than 50 km in diameter. This paper details the results of a theoretical study to identify remotely sensible surface signatures for deep ocean convection. Due to the all-weather capability, efforts have focused on the microwave part of the spectrum, particularly the high resolution imaging capability of synthetic aperture radar (SAR). The goal of this research is to use the SAR surface signature or fingerprint to identify and characterize areas- of convection in the open ocean. This information is then used to improve model parameterizations for deep convection used in general circulation models. Electromagnetic simulations of remote sensing signatures of deep ocean convection have been performed based on existing hydrodynamic models. Simulated surface signatures of deep convection are presented for various hydrodynamic and imaging conditions along with a discussion of applicability of these simulations to real SAR data. Key findings are the existence of a definite identifiable radar surface signature in convective regions and a set of conditions under which one would expect to observe these signatures.