The impact of large-scale orography on northern hemisphere winter synoptic temperature variability
Name
jcli-d-19-0129.1.pdf
Description
Published version
Size
11.97 MB
Format
Adobe PDF
Checksum (MD5)
829a88af9c284033cbace380e973408e
Author(s)
Lutsko, Nicholas J.
Baldwin, Jane Wilson
Cronin, Timothy Wallace
Date Issued
September 2019
Journal
Journal of climate
Publisher
American Meteorological Society
Citation
Lutsko, Nicholas J., Jane Wilson Baldwin, and Timothy W. Cronin, "The impact of large-scale orography on northern hemisphere winter synoptic temperature variability." Journal of Climate 32, 18 (September 2019): p. 5799-814 doi 10.1175/JCLI-D-19-0129.1 ©2019 Author(s)
Version
Final published version
Abstract
The impact of large-scale orography on wintertime near-surface (850 hPa) temperature variability on daily and synoptic time scales (from days to weeks) in the Northern Hemisphere is investigated. Using a combination of theory, idealized modeling work, and simulations with a comprehensive climate model, it is shown that large-scale orography reduces upstream temperature gradients, in turn reducing upstream temperature variability, and enhances downstream temperature gradients, enhancing downstream temperature variability. Hence, the presence of the Rockies on the western edge of the North American continent increases temperature gradients over North America and, consequently, increases North American temperature variability. By contrast, the presence of the Tibetan Plateau and the Himalayas on the eastern edge of the Eurasian continent damps temperature variability over most of Eurasia. However, Tibet and the Himalayas also interfere with the downstream development of storms in the North Pacific storm track, and thus damp temperature variability over North America, by approximately as much as the Rockies enhance it. Large-scale orography is also shown to impact the skewness of downstream temperature distributions, as temperatures to the north of the enhanced temperature gradients are more positively skewed while temperatures to the south are more negatively skewed. This effect is most clearly seen in the northwest Pacific, off the east coast of Japan. ©2019
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1175/JCLI-D-19-0129.1
