ESA / ECSAT CCIWV.REP.022 Water Vapour Climate Change Initiative (WV_cci) - CCI+ Phase 2 D2.2 1. INTRODUCTION 1.1 Purpose This document presents the algorithm theoretical baseline document (ATBD) for the merged VRWV CDR-3 v4.0 and CDR-4 v2.0 products as produced within Phase 2 of the ESA physical, mathematical and functional descriptions used in the merging algorithms for the two Water_Vapour_cci project. The purpose of the ATBD is to provide detailed information on the products and also their input datasets. 1.2 Structure of the document This ATBD is structured as follows:
Algorithm definition for CDR-3 and SPARC Data Initiative climatology input fields (Section 2) Algorithm definition for CDR-4 (Section 3) Summary and Conclusions (Section 4). 7