When Will MISR Detect Rising High Clouds?

Journal Article · 20 January 2022 · Journal of Geophysical Research: Atmospheres

DOI: https://doi.org/10.1029/2021JD035865 · OSTI ID:1841452

Aerenson, Travis  ^[1]; Marchand, Roger ^[1]; Chepfer, Hélène ^[2]; Medeiros, Brian  ^[3]

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1. Department of Atmospheric Sciences University of Washington Seattle WA USA
2. LMD/IPSL Sorbonne Université Palaiseau France
3. Climate and Global Dynamics National Center for Atmospheric Research Boulder CO USA

Abstract It is predicted by both theory and models that high‐altitude clouds will occur higher in the atmosphere as a result of climate warming. This produces a positive longwave feedback and has a substantial impact on the Earth's response to warming. This effect is well established by theory, but is poorly constrained by observations, and there is large spread in the feedback strength between climate models. We use the NASA Multi‐angle Imaging SpectroRadiometer (MISR) to examine changes in Cloud‐Top‐Height (CTH). MISR uses a stereo‐imaging technique to determine CTH. This approach is geometric in nature and insensitive to instrument calibration and therefore is well suited for trend analysis and studies of variability on long time scales. In this article we show that the current MISR record does have an increase in CTH for high‐altitude cloud over Southern Hemisphere (SH) oceans but not over Tropical or the Northern Hemisphere (NH) oceans. We use climate model simulations to estimate when MISR might be expected to detect trends in CTH, that include the NH. The analysis suggests that according to the models used in this study MISR should detect changes over the SH ocean earlier than the NH, and if the model predictions are correct should be capable of detecting a trend over the Tropics and NH very soon (3–10 years). This result highlights the potential value of a follow‐on mission to MISR, which no longer maintains a fixed equator crossing time and is unlikely to be making observations for another 10 years.

• Research Organization: University Corporation for Atmospheric Research, Boulder, CO (United States)
• Sponsoring Organization: National Aeronautics and Space Administration (NASA); National Oceanic and Atmospheric Administration (NOAA); National Science Foundation (NSF); USDOE; USDOE Office of Science (SC)
• Grant/Contract Number: SC0022070
• OSTI ID: 1841452
• Journal Information: Journal of Geophysical Research: Atmospheres, Journal Name: Journal of Geophysical Research: Atmospheres Journal Issue: 2 Vol. 127; ISSN 2169-897X
• Publisher: American Geophysical Union (AGU)Copyright Statement
• Country of Publication: United States
• Language: English