Exceptional stratospheric contribution to human fingerprints on atmospheric temperature.
Exceptional stratospheric contribution to human fingerprints on atmospheric temperature.
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DOI：
10.1073/pnas.2300758120
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发表时间：
2023-05-16
影响因子：
11.1
通讯作者：
Taylor, Karl E.
中科院分区：
文献类型：
--
作者：
Santer, Benjamin D.;Po-Chedley, Stephen;Zhao, Lilong;Zou, Cheng-Zhi;Fu, Qiang;Solomon, Susan;Thompson, David W. J.;Mears, Carl;Taylor, Karl E.
关键词：
Differences between tropospheric and lower stratospheric temperature trends have long been recognized as a “fingerprint” of human effects on climate. This fingerprint, however, neglected information from the mid to upper stratosphere, 25 to 50 km above the Earth’s surface. Including this information improves the detectability of a human fingerprint by a factor of five. Enhanced detectability occurs because the mid to upper stratosphere has a large cooling signal from human-caused CO2 increases, small noise levels of natural internal variability, and differing signal and noise patterns. Extending fingerprinting to the upper stratosphere with long temperature records and improved climate models means that it is now virtually impossible for natural causes to explain satellite-measured trends in the thermal structure of the Earth’s atmosphere. In 1967, scientists used a simple climate model to predict that human-caused increases in atmospheric CO2 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 (S25 − 50). To date, however, S25 − 50 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 S25 − 50 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 S25 − 50 have smaller-scale temperature changes and lack uniform sign. These pronounced spatial differences between S25 − 50 signal and noise patterns are accompanied by large cooling of S25 − 50 (1 to 2C over 1986 to 2022) and low S25 − 50 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.
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影响因子：
4.4
作者：
Lott, F. C.;Stott, P. A.;Thorne, P. W.
通讯作者：
Thorne, P. W.
影响因子：
8
作者：
Hawkins, Ed;Sutton, Rowan
通讯作者：
Sutton, Rowan
影响因子：
9
作者：
Feldl, Nicole;Po-Chedley, Stephen;Kushner, Paul J.
通讯作者：
Kushner, Paul J.
影响因子：
4.6
作者：
KAROLY, DJ;COHEN, JA;WETHERALD, RT
通讯作者：
WETHERALD, RT
影响因子：
4.9
作者：
Mears, Carl A.;Wentz, Frank J.
通讯作者：
Wentz, Frank J.