VIII. The observational strategy: What are the issues; What must be done

摘要

Throughout its development, the observational strategy of the Earth Observing System (EOS) and its precursor programs has been consistent with that of the Mission to Planet Earth (MTPE) to detect and quantify climate change, document natural climate variability, understand variation and change, determine the causes and impacts of stratospheric ozone depletion, determine the impact of change on ecosystems and mitigate them. Space based observation can contribute significantly to each of these objectives, although its contribution will have to be carefully integrated with aircraft, in situ, international, and other contributions and carefully transitioned to long-term operational observations to achieve its maximum potential impact. The interaction between space and in situ can be in calibration, in interpretation, or in suggesting ways to make important new measurements from space. In atmospheric chemistry, it largely involves calibration and global surveys. In ecosystems, it involves calibration of EOS and improved sensors. In seasonal to interannual change, it involves the testing and calibration of new sensors. In decadal to century change, it requires the invention of new sensors. This paper presents a discussion of the principles guiding the space-based observational strategy, and the interplay between spaced-based and in situ measurements. The paper then discusses international issues, how they might be addressed, and integrated space-based observational strategy.