CLARREO: Cornerstone of the climate observing system measuring decadal change through accurate emitted infrared and reflected solar spectra and radio occultation

摘要

The CLARREO mission addresses the need to provide accurate, broadly acknowledged climate records that can be used to validate long-term climate projections that become the foundation for informed decisions on mitigation and adaptation policies. The CLARREO mission accomplishes this critical objective through rigorous SI traceable decadal change observations that will reduce the key uncertainties in current climate model projections. These same uncertainties also lead to uncertainty in attribution of climate change to anthropogenic forcing. CLARREO will make highly accurate and Si-traceable global, decadal change observations sensitive to the most critical, but least understood climate forcing, responses, and feedbacks. The CLARREO breakthrough is to achieve the required levels of accuracy and traceability to SI standards for a set of observations sensitive to a wide range of key decadal change variables. The required accuracy levels are determined so that climate trend signals can be detected against a background of naturally occurring variability. The accuracy for decadal change traceability to SI standards includes uncertainties associated with instrument calibration, satellite orbit sampling, and analysis methods. Unlike most space missions, the CLARREO requirements are driven not by the instantaneous accuracy of the measurements, but by accuracy in the large time/space scale averages that are necessary to understand global, decadal climate changes.