HR: 0800h
AN: A31B-0316    [Abstracts]
TI: CLARREO Mission Requirements, Technological Readiness, and Calibration/Validation Concepts
AU: * Revercomb, H E
EM: hankr@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Anderson, J G
EM: anderson@huarp.harvard.edu
AF: Harvard Univerity, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Best, F A
EM: fredb@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Tobin, D C
EM: davet@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Knuteson, R O
EM: bobk@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Holz, R E
EM: Robert.Holz@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Taylor, J K
EM: joet@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Dykema, J A
EM: dykema@huarp.harvard.edu
AF: Harvard Univerity, 12 Oxford Street, Cambridge, MA 02138, United States
AU: Adler, D
EM: douga@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Mulligan, M
EM: markm@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Nagle, F
EM: fredn@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AU: Dutcher, S
EM: Steved@ssec.wisc.edu
AF: Space Science and Engineering Center, University of Wisconsin-Madsion, 1225 West Dayton Street, Madison, WI 53706, United States
AB: NASA has selected a new climate mission named CLARREO in the recent Decadal Survey from the National Research Council (NRC) as a promising new start in 2008. CLARREO stands for Climate Absolute Radiance and Refractivity Observatory, conveying that it will measure spectrally resolved radiance from the earth and atmospheric bending of GPS signals related to atmospheric structure (refractivity) to detect climate change. The CLARREO mission is based on some new paradigms for making climate benchmark observations. First, when defining the right radiation measurements to choose for a climate record, the goal should be to maximize the information content about atmospheric and surface properties, rather than to monitor the total radiative energy budget, the conventional calorimeter experiment. The idea is to use spectrally resolved radiances to gain sensitivity, because the spectrally integrated total energy budget can miss significant changes that cancel each other out, and at the same time to characterize the changes. For CLARREO, regional averages of nadir-viewing radiance spectra will reveal signatures of changes in climate forcing and response that can be related to changes in temperature and water vapor structure, atmospheric stability, cloudiness or aerosols, surface properties, and trace gases. The far infrared region of the spectrum, out to 200 wavenumber (50 microns), is required for sensitivity to thick ice clouds and upper level water vapor. Radiative signatures from climate models will be used for interpretation. Second, to reduce the time to unequivocally resolve climate trends, IR radiance spectra and GPS refractivity were selected as quantities with high information content that can be measured with high calibration accuracy referenced to international standards provided on orbit (SI measurements). For the infrared radiance spectra, a brightness temperature accuracy of 0.1 K confirmed on orbit is practical (with a 99% confidence that the limit is not exceeded). The accuracy of GPS refractivity depends on time measurements that can be made extremely accurately, with a corresponding accuracy for upper level temperature that can also be better than 0.1 K. Establishing SI measurements in space alleviates the need to overlap subsequent generations of satellites to establish a climate record. Third, CLARREO will make use of a new set of orbits that give coverage of the whole globe and all times of day to minimize sampling biases. Sampling biases have equal importance to measurement errors (the RSS of both contributions gives the overall accuracy). This new sampling approach uses three, equally-spaced, truly polar obits (90º inclination) that do not precess in inertial space. These orbits will cover all latitudes and longitudes, and give equal sampling for all times of day every two months. Recent simulations using MODIS data and NPP PEATE processing capabilities show that these orbits will also allow CLARREO to be used for highly accurate cross-calibration to the high spectral resolution sounders in sun-synchronous orbit (AIRS on NASA Aqua, IASI on EUMETSAT MetOp, and CrIS on NPOESS).
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting