Algorithms for estimation of air-specific humidity using TMI data
Abstract:We developed two empirical algorithms for estimating the surface air-specific humidity (Q a) at 10 m over the ocean using Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) brightness temperature data. We used the in situ data included in the International Comprehensive Ocean-Atmosphere Data Set for 2003–2006 as true values in this study. We estimated the Q a using the developed regression formulae and validated the results by comparing with moored buoy data. The biases of our product were relatively small, i.e. 0.03 and 0.29 g kg–1 for TMI_4CH and TMI_9CH, respectively, when compared with other Q a retrievals. Moreover, we investigated the relationship between the brightness temperature observed by each channel and the in situ Q a. We concluded that the use of the brightness temperature determined by the 85 GHz polarized radiation can considerably reduce the bias.
Document Type: Research Article
Affiliations: 1: Centre for Marine Environmental Studies,Ehime University, Matsuyama,Ehime,790-8577, Japan 2: School of Marine Science and Technology,Tokai University, Shimizu,Shizuoka,424-8610, Japan
Publication date: 2012-12-10