Climate monitoring from operational satellites: accomplishments, problems, and prospects

This paper reviews some of the long-term data sets, including those of the World Climate Research Program, constructed from the observations of the operational satellites. Operational weather satellites provide the long-term sustained observations needed for monitoring changes in the Earth's climate. But because the satellites have been designed for weather applications, they lack the orbital and instrumental stabilities needed for measuring the smaller signals associated with decadal climate trends. The lack of onboard calibration of the visible and near-infrared imagers, and the drift in local observing time during a satellite's lifetime, introduce uncertainties in the climatic time series. These effects are illustrated and attempts to correct for them are described. Contributions of these data sets to both seasonal to interrannual, and decadal, climate monitoring are illustrated. Planned improvements in future satellites will significantly enhance our capability to monitor climate from space.