SPARC stands for Stratosphere-troposphere Processes And their Role in Climate and is a core project initiated by WCRP. The SPARC WAVAS activity and G-VAP both assess, among others, the quality of upper air temperature and water vapour data records, with SPARC focusing on the stratosphere and G-VAP focusing on the troposphere. Details are given in the G-VAP assessment plan and a SPARC presentation at the 3rd G-VAP workshop.

The „water vapor II“ activity is an important contribution to SPARC. Its major objective is to update the SPARC Water Vapour Assessment (WAVAS-1) report from 2000. The focus of this activity is on water vapour in the stratosphere. In contrast, the main objective of G-VAP is the characterisation of long-term satellite data records of water vapour products in the troposphere.

There is a clear need for the consistent generation and validation of water and temperature profiles that span the full atmosphere. The cooperation between SPARC and G-VAP mainly aims at establishing a common basis in terms of metrics and data records.

Also, a joint analysis of full period cloud, precipitation and water vapour data records is needed to better understand the physical processes that link upper troposhere (UT) and lower stratosphere (LS). SPARC and G-VAP will keep this in mind when cooperating on the analysis of UTH (G-VAP) and UTLS data records (SPARC) and potentially provide recommendations with the aim to foster intense analysis of processes that link UT and LS.