Browsing by Subject "AIRS"
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Item AIRS version 6.6 and version 7 level-1C products(SPIE, 2019-09-09) Manning, Evan M.; Strow, L. Larrabee; Aumann, Hartmut H.The Atmospheric Infrared Sounder (AIRS) introduces new Level-1C (L1C) products. AIRS Version 6.6 L1C processing addresses data quality and sampling issues as well as spectral drift, making a clean, easy to use product. This will be the first version of AIRS L1C permanently hosted at the Goddard Earth Science DAAC, making it easy for users to access. A later Version 7 L1C will incorporate v7 Level-1B (L1B) calibration improvements and use a modern netCDF4 format. We focus on the spectral changes in the AIRS instrument and the new L1C feature that corrects for it.Item Multivariate Retrieval of Carbon Monoxide(2011-01-01) Wilson, Robert Christopher; Hoff, Raymond M; Physics; Physics, AtmosphericA new technique is presented here to retrieve carbon monoxide (CO) profiles from Atmospheric Emitted Radiance Interferometer (AERI) spectra. This retrieval version deviates from the previous AERI CO retrieval method, which utilized signal processing to determine a constant CO mixing ratio representative of the entire troposphere. Instead, this retrieval version utilizes linear mapping to ascertain an estimate of the CO profile. A detailed analysis is conducted to estimate the error from all aspects of the linear mapping procedure including measurements, forward modeling of atmospheric radiation, and uncertainty from inputs to the forward model. It was found that the dominant sources of error were from cloud contaminated spectra and uncertainty in absorption line strengths inside the forward model. A new cloud flagging technique that uses a neural network to identify spectra affected by clouds was tested and compared to the previously used version based on brightness temperature contrast. The neural network method decreased uncertainty between AERI and forward model spectra by 30 percent when compared with the previously used version. First guess CO profiles to the AERI retrieval were from two different sources. One source was an a priori rofile calculated as the mean profile from 57 individual measurements where each CO profile encompasses tower, aircraft, and a satellite CO measurement. The other first guess CO profile came from the AIRS version 5 (AIRSv5) retrieved CO product. Incorporating the AIRS CO profile to the AERI retrieval provided a better estimate of free tropospheric CO when compared with the a priori ile. Using a better upper tropospheric CO estimate resulted in more accurate results from the AERI retrieval below 2 km, thus revealing that an AERI plus AIRS retrieved CO product is superior to either instrument's own CO retrieval working alone. The combined retrieval product is shown to have an RMSE of 10% in the first 2 km of the atmosphere.Item Recent global warming as confirmed by AIRS(IOP Publishing Ltd, 2019-04-17) Susskind, J.; Schmidt, G. A.; Lee, Jae; Iredell, L.This paper presents Atmospheric Infra-Red Sounder (AIRS) surface skin temperature anomalies for the period 2003 through 2017, and compares them to station-based analyses of surface air temperature anomalies (principally the Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP)). The AIRS instrument flies on EOS Aqua, which was launched in 2002 and became stable in September 2002. AIRS surface temperatures are completely satellite-based and are totally independent of any surface-based measurements.Weshow in this paper that satellite-based surface temperatures can serve as an important validation of surface-based estimates and help to improve surface-based data sets in a way that can be extended back many decades to further scientific research. AIRS surface temperatures have better spatial coverage than those of GISTEMP, though at the global annual scale the two data sets are highly coherent. As in the surface-based analyses, 2016 was the warmest year yet.