Patterns of changing surface climate variability from the Last Glacial Maximum to present in transient model simulations
As of 2023, global mean temperature has risen by about 1.45 ± 0.12 °C with respect to the 1850–1900 pre-industrial baseline according to the World Meteorological Organization. This rise constitutes the first period of substantial global warming since the Last Deglaciation, when global temperatures r...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Copernicus Publications
2024
|
| Subjects: | |
| Online Access: | https://doi.org/10.5194/egusphere-2024-1396 https://noa.gwlb.de/receive/cop_mods_00073919 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00072052/egusphere-2024-1396.pdf https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1396/egusphere-2024-1396.pdf |
| Summary: | As of 2023, global mean temperature has risen by about 1.45 ± 0.12 °C with respect to the 1850–1900 pre-industrial baseline according to the World Meteorological Organization. This rise constitutes the first period of substantial global warming since the Last Deglaciation, when global temperatures rose over several millennia by about 4.0–7.0 °C according to proxy reconstructions. Similar levels of warming could be reached in the coming centuries considering current and possible future emissions. Such warming causes widespread changes in the climate system of which the mean state provides only an incomplete picture. Indeed, climate’s variability and the distributions of climate variables change with warming, impacting for example ecosystems and the frequency and intensity of extremes. However, climate variability during transition periods like the Last Deglaciation remains largely unexplored. Therefore, we investigate changes of climate variability on annual to millennial timescales in fifteen transient climate model simulations of the Last Deglaciation. This ensemble consists of models of varying complexity, from an energy balance model to Earth System Models and includes sensitivity experiments, which differ only in terms of their underlying ice sheet reconstruction, meltwater protocol, or consideration of volcanic forcing. While the ensemble simulates an increase of global mean temperature of 3.0–6.6 °C between the Last Glacial Maximum and Holocene, we examine whether common patterns of variability emerge in the ensemble. To this end, we compare the variability of surface climate during the Last Glacial Maximum, Deglaciation and Holocene by estimating and analyzing the distributions and power spectra of surface temperature and precipitation. For analyzing the distribution shapes, we turn to the higher order moments of variance, skewness and kurtosis. These show that the distributions cannot be assumed to be normal, a precondition for commonly used statistical methods. During the LGM and Holocene, they further ... |
|---|