Infra-red sounding of the Trade-wind boundary layer: AIRS and the RICO Experiment

Shallow cumulus boundary layers are prevalent over the sub-tropical oceans, and a better understanding of their properties is essential to correctly model local and large scale circulations. Recently, the Rain In shallow Cumulus over the Ocean (RICO) campaign addressed some of the persistent problems in modeling this type of boundary layers by providing an observational perspective. RICO yielded a comprehensive dataset with a number of applications. In this work we used part of the RICO dataset to validate atmospheric temperature and moisture profiles measured by the Atmospheric InfraRed Sounder (AIRS), using the AIRS V5 L2 Support product. It is shown that AIRS behaves as expected in this type of regime, independently of factors like cloud and land fractions. The high vertical resolution available through the support product is used to explore the characteristics of the planetary boundary layer, particularly its height. Results from AIRS and RICO sondes are in good general agreement. This suggests a potential to estimate climatological values of boundary layer height for validation of boundary layer parameterizations in climate and numerical weather prediction models.