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Exceptional stratospheric contribution to human fingerprints on atmospheric temperature.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2023 May 16; Vol. 120 (20), pp. e2300758120. Date of Electronic Publication: 2023 May 08. - Publication Year :
- 2023
-
Abstract
- In 1967, scientists used a simple climate model to predict that human-caused increases in atmospheric CO <subscript>2</subscript> should warm Earth's troposphere and cool the stratosphere. This important signature of anthropogenic climate change has been documented in weather balloon and satellite temperature measurements extending from near-surface to the lower stratosphere. Stratospheric cooling has also been confirmed in the mid to upper stratosphere, a layer extending from roughly 25 to 50 km above the Earth's surface (S <subscript>25 - 50</subscript> ). To date, however, S <subscript>25 - 50</subscript> temperatures have not been used in pattern-based attribution studies of anthropogenic climate change. Here, we perform such a "fingerprint" study with satellite-derived patterns of temperature change that extend from the lower troposphere to the upper stratosphere. Including S <subscript>25 - 50</subscript> information increases signal-to-noise ratios by a factor of five, markedly enhancing fingerprint detectability. Key features of this global-scale human fingerprint include stratospheric cooling and tropospheric warming at all latitudes, with stratospheric cooling amplifying with height. In contrast, the dominant modes of internal variability in S <subscript>25 - 50</subscript> have smaller-scale temperature changes and lack uniform sign. These pronounced spatial differences between S <subscript>25 - 50</subscript> signal and noise patterns are accompanied by large cooling of S <subscript>25 - 50</subscript> (1 to 2[Formula: see text]C over 1986 to 2022) and low S <subscript>25 - 50</subscript> noise levels. Our results explain why extending "vertical fingerprinting" to the mid to upper stratosphere yields incontrovertible evidence of human effects on the thermal structure of Earth's atmosphere.
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 120
- Issue :
- 20
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 37155871
- Full Text :
- https://doi.org/10.1073/pnas.2300758120