The PACE mission will extend key climate data records whose future was in jeopardy prior to the FY2011 budget request. Global ocean color measurements, essential for understanding ocean ecology and the global carbon cycle and how it affects and is affected by climate change, will be made by a radiometer instrument on this mission. These data will extend the high quality observations on ocean ecology, biogeochemical cycling, and ocean productivity begun by NASA in the late 1990s with the SeaWiFS and MODIS instruments. A polarimeter instrument will extend data records on aerosols and clouds using this approach begun by the French PARASOL mission, as well as multi-spectral and multi-angle measurements made by NASA's MODIS and MISR instruments on NASA's EOS platforms (MODIS on Terra and Aqua, MISR on Aqua).
The Intergovernmental Panel on Climate Change (2007) identified the largest uncertainty in our understanding of physical climate as that due to aerosols and clouds. New and continuing global observations of ocean ecology, biology, and chemistry are required to quantify aquatic carbon storage and ecosystem function in response to human activities and natural events. A key goal is improvement of climate-carbon and climate-ecology model prediction. The blend of atmospheric and oceanic requirements is critical as ocean biology is affected by deposition of aerosols onto the ocean, which in turn, produce aerosol precursors that influence climate.