Deriving Sea Surface Salinity and Density Variations from Satellite and Aircraft Microwave Radiometer Measurements: Application to Coastal Plumes Using STARRS

Abstract

Using brightness temperature Tb measurements from L-band airborne microwave radiometers, with independent sea surface temperature (SST) observations, sea surface salinity (SSS) can be remotely determined with errors of about 1 psu in temperate regions Nonlinearities in the relationship between Tb, SSS and SST produce variations in the sensitivity of salinity S to variations in Tb and SST. Despite significant efforts devoted to SSS remote sensing retrieval algorithms, little consideration has been given to deriving density D from remotely sensed SSS and SST. Density is related to S and T through the equation of state. It affects the ocean's static stability and its dynamical response to forcings. By chaining together two empirical relationships (flat-sea emissivity and equation of state) to form an inversion algorithm for sea surface density (SSD) in terms of Tb and SST, we develop a simple L-band SSD retrieval algorithm. We use this to investigate the sensitivity of SSD retrievals to observed Tb and SST and infer errors in D for typical sampling configurations of the airborne Salinity, Temperature, And Roughness Remote Scanner (STARRS) and satellite-borne Soil Moisture and Ocean Salinity (SMOS) and Aquarius radiometers. We then derive D from observations of river plumes obtained using STARRS and demonstrate several oceanographic applications: the observations are used to study variations in T and S effects on D in the Mississippi plume, and the across-shelf density gradient is used to infer surface geostrophic shear and subsurface geostrophic current in the Plata plume. Future basin-scale applications of SSD retrievals from satellite-borne microwave radiometers such as SMOS and Aquarius are anticipated.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2007
Accession Number
ADA482176

Entities

People

  • A. Camps
  • A. Piola
  • C. Cabarro
  • Derek Burrage
  • J. Font
  • Jerry Miller
  • Joel Wesson

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Cyber
  • Ground and Sea Platforms
  • Sensors
  • Space

DTIC Thesaurus Topics

  • Algorithms
  • Dielectric Permittivity
  • Frequency
  • Geographic Regions
  • Geography
  • Geostrophic Currents
  • L Band
  • Measurement
  • Meteorology
  • Ocean Currents
  • Oceanography
  • Oceans
  • Remote Sensing
  • Sea Surface Temperature
  • Sea Water
  • Surface Temperature
  • Topography

Fields of Study

  • Environmental science

Readers

  • Atmospheric Remote Sensing.
  • Oceanography.

Technology Areas

  • AI & ML
  • AI & ML - Bayesian Inference
  • Space