Abstract

This work is in direct line with the Concordiasi international project. It aims to better constrain atmospheric analyses by improving the assimilation of low-level Advanced Microwave Sounding Unit (AMSU)-A and AMSU-B microwave observations over Antarctica. So far, a very small amount of available AMSU observations is effectively assimilated over Antarctica. To assimilate more observations, different issues have to be dealt with. In this work, the surface emissivity issue over Antarctica is examined. In a first step, a thorough review of the use of a specular assumption to calculate emissivity from AMSU-A measurements has been undertaken. The effect of five different assumptions about the surface on retrieved AMSU emissivities has then been evaluated using a one-year database: specular, Lambertian, and three intermediate assumptions. Simulations of brightness temperatures at AMSU sounding frequencies have been produced using a radiative transfer model. The emissivities obtained using the five assumptions have been found very useful in improving these simulations. The most successful schemes are found to be the Lambertian scheme during the winter season and a specular or an intermediate scheme (50% specular, 50% Lambertian) during Antarctica's short summer.

Full Text
Paper version not known

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 call

Disclaimer: 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.