Decreasing wind speed and weakening latitudinal surface pressure gradients in the Tibetan Plateau

Abstract

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 42:57-64 (2010) - DOI: https://doi.org/10.3354/cr00864 Decreasing wind speed and weakening latitudinal surface pressure gradients in the Tibetan Plateau Qinglong You1,2,6, Shichang Kang1,3,*, Wolfgang-Albert Flügel2, Nick Pepin4, Yuping Yan5, Jie Huang1,6 1Key Laboratory of Tibetan Environmental Change and Land Surface Process, Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), Beijing 100085, China 2Department of Geoinformatics, Friedrich-Schiller University Jena, Jena 07743, Germany 3State Key Laboratory of Cryospheric Science, CAS, Lanzhou 730000, China 4Department of Geography, University of Portsmouth, PO1 3HE, UK 5National Climate Center, Beijing 100081, China 6Graduate University of Chinese Academy of Sciences, Beijing 100049, China *Corresponding author. Email: shichang.kang@itpcas.ac.cn ABSTRACT: The Tibetan Plateau, with an average elevation of over 4000 m above sea level, is the highest and most extensive highland in the world. Between 1980 and 2005, the annual mean temperature has warmed at the rate of 0.38°C decade–1. However, little attention has been paid to the variation of wind speed, the most important factor controlling evapotranspiration in the Tibetan Plateau. Here we used monthly mean wind speed from the Chinese Meteorological Administration data set to examine the spatial and temporal variability of wind speed at 71 stations (with elevations above 2000 m above sea level) in the eastern and central Tibetan Plateau during 1980–2005, and compared wind speed climatology and their trends with NCEP and ERA-40 reanalyses in the same domain. Compared with surface stations, NCEP overestimates wind speed and ERA-40 underestimates it, with mean annual biases of 0.93 m s–1 for NCEP and –0.75 m s–1 for ERA-40. Both surface stations and NCEP reanalysis show significant decreasing trends, at rates of –0.24 and –0.13 m s–1 decade–1, respectively, mainly evident in spring and summer. ERA-40 fails to capture any decrease. The above results indicate that NCEP captures wind speed better than ERA-40. We speculate that the most likely cause of diminishing wind speed are the asymmetrically decreasing latitudinal surface temperature and pressure gradients over the Tibetan Plateau, which may be part of a large-scale atmospheric circulation shift. KEY WORDS: Tibetan Plateau · Wind speed · NCEP · ERA-40 · Pressure gradient Full text in pdf format PreviousNextCite this article as: You Q, Kang S, Flügel WA, Pepin N, Yan Y, Huang J (2010) Decreasing wind speed and weakening latitudinal surface pressure gradients in the Tibetan Plateau. Clim Res 42:57-64. https://doi.org/10.3354/cr00864 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 42, No. 1. Online publication date: May 27, 2010 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2010 Inter-Research.