Euro-Atlantic Atmospheric Circulation during the Late Maunder Minimum
This paper presents observational evidence of the atmospheric circulation during the Late Maunder Minimum (LMM, 1685–1715) based on daily wind direction observations from ships in the English Channel. Four wind directional indices and 8-point wind roses are derived at monthly scales to characterize...
Published in: | Journal of Climate |
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Main Authors: | , , , , |
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Meteorological Society
2018
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Subjects: | |
Online Access: | http://hdl.handle.net/10261/186794 https://doi.org/10.1175/JCLI-D-17-0261.1 https://doi.org/10.13039/100000192 https://doi.org/10.13039/501100001871 https://doi.org/10.13039/100000015 https://doi.org/10.13039/501100003329 |
Summary: | This paper presents observational evidence of the atmospheric circulation during the Late Maunder Minimum (LMM, 1685–1715) based on daily wind direction observations from ships in the English Channel. Four wind directional indices and 8-point wind roses are derived at monthly scales to characterize the LMM. The results indicate that the LMM was characterized by a pronounced meridional circulation and a marked reduction in the frequency of westerly days all year round, as compared to the present (1981–2010). The winter circulation contributed the most to the cold conditions. Nevertheless, findings indicate that the LMM in Europe was more heterogeneous than previously thought, displaying contrasting spatial patterns in both circulation and temperature, as well as large decadal variability. In particular, there was an increase of northerly winds favoring colder winters in the first half of the LMM, but enhanced southerlies contributing to milder conditions in the second half of the LMM. The analysis of the atmospheric circulation yields a new and complete classification of LMM winters. The temperature inferred from the atmospheric circulation confirms the majority of extremely cold winters well documented in the literature, while uncovering other less documented cold and mild winters. The results also suggest a nonstationarity of the North Atlantic Oscillation (NAO) pattern within the LMM, with extremely cold winters being driven by negative phases of a “high zonal” NAO pattern and “low zonal” NAO patterns dominating during moderately cold winters. Javier M. Cano was supported by the Portuguese Science Foundation (FCT) through the Ph.D. fellowship PD/BD/ 106028/2014. Support for the Twentieth Century Reanalysis Project, version 2c, dataset is provided by the U.S. Department of Energy, Office of Science Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office. . This work was supported by the Spanish Ministry of Economy and Competitiveness ... |
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