Retrieval of nitrous oxide from Atmospheric Infrared Sounder: Characterization and validation. Issue 14 (17th July 2014)

• Record Type: Journal Article
• Authors: Xiong, Xiaozhen; Maddy, Eric S.; Barnet, Chris; Gambacorta, Antonia; Patra, Prabir K.; Sun, Fengying; Goldberg, Mitchell
• Is Part Of: Journal of geophysical research. Volume 119:Issue 14(2014)
• Page Start: 9107
• Page End: 9122
• Publication Date: 2014-07-17
• Subjects: Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2013JD021406
• Languages: English
• ISSNs: 2169-897X

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>This paper presents the retrieval algorithm of nitrous oxide (N<sub>2</sub>O) using the Atmospheric Infrared Sounder (AIRS) on EOS/Aqua, its validation using aircraft measurements, and one possible application for monitoring the global N<sub>2</sub>O annual trend from 2003 to 2013. The results demonstrate that AIRS is sensitive to N<sub>2</sub>O in the middle to upper troposphere, with the peak vertical sensitivity between 200 and 750 hPa and the sensitivity in the tropics larger than in the high‐latitude regions. The degrees of freedom of the N<sub>2</sub>O retrieval are mostly between 1.0 and 1.5. Validation using the aircraft measurement profiles by the High‐Performance Instrumented Airborne Platform for Environmental Research Pole‐to‐Pole Observations program over the Pacific Ocean indicated that the retrieval RMS error is mostly less than 8 ppb (or ~2.1%). One important feature is that the variability of N<sub>2</sub>O from AIRS is more than 2 times than that of the aircraft measurements in the lower troposphere. In agreement with surface measurements, a nearly linear trend of N<sub>2</sub>O can be obtained based on limited AIRS data of 1 day in 15 May in each year from 2003 to 2013, and the increase rate of N<sub>2</sub>O is about 0.72 ppb yr<sup>−1</sup>. This algorithm will be implemented in AIRS operational retrieval system, enabling the derivation of the N<sub>2</sub>O for over 20 years using the AIRS, the Infrared Atmospheric Sounding Interferometer, and the Cross‐track Infrared Sounder. Such a unique product will be complementary to currently sparse ground‐based observations for monitoring the N<sub>2</sub>O trend associated with climate change.</p> </abstract>