Extending the NVAP Global Water Vapor Climate Data Record to 40 Years

The existing NASA Water Vapor Project (NVAP) 1988-2009 global total column water vapor (TCWV) and layer water vapor daily time series is an Essential Climate Variable ( ECV ) with extensive international users. It will be described with plans to extend the record to 40 years using NASA research and NOAA operational satellites. Satellite microwave observations provide the core data for NVAP including the ATMS instrument on the joint NASA/NOAA Suomi NPP satellite and its successors. Hypersectral infrared instruments such as the NASA AIRS provide a foundation for the 21st century portion of the time series. Examples of analyses of the early record segment for both climate and weather / climate interface studies will be presented, and the impact of observing system changes will be illustrated. Plans for extending the record with passive microwave and other sensors will described.