Apparent precision of GPS radio occultation temperatures

Abstract

The abundant atmospheric data provided by radio occultation (RO) via the Global Positioning System satellite network have improved short and long-term forecasts and have demonstrated the potential to provide a long-term, consistent, and independent climate dataset. Previous studies have already verified the consistency and reliability of the RO method, listing a range of precision estimates. Uncertainties arising during temperature retrievals, and confounding effects of atmospheric variability, have made the precision of RO temperature data difficult to determine. In this paper, we introduce the concept of apparent precision, and describe a simple, robust method for estimating the apparent temperature precision using data from the COSMIC project. We examine apparent RO temperature precision by latitude, and find it to be somewhat lower than previous estimates. We attribute this to apparent precision being a function of the true precision plus representativeness errors. Copyright 2009 by the American Geophysical Union.