Abstract
Since the 1980s, the subtropical jet stream has generally moved poleward, but its behavior varies by region and season. Here we examine the interannual variability and trends in the latitudinal position of the spring subtropical jet over the Himalayas. During the modern period (1948 to 2018), the spring (March-April-May) jet is typically anchored immediately south of the Himalayas but has rarely (in 1956, 1971, 1984, and 1999) moved poleward to pass over Kyrgyzstan and northwest China. A tree-ring reconstruction of the jet's latitude indicates that such poleward excursions may have become more frequent after 1950, but it is not clear whether that behavior is unprecedented within the past four centuries. These insights into the behavior of the Himalayan subtropical jet may improve seasonal weather forecasts for the region and provide a target for climate simulations to test whether the recent spate of excursions is unusual and due to anthropogenic warming.
| Original language | English (US) |
|---|---|
| Article number | e2020GL089631 |
| Journal | Geophysical Research Letters |
| Volume | 47 |
| Issue number | 22 |
| DOIs | |
| State | Published - Nov 28 2020 |
Bibliographical note
Funding Information:Support for this work was provided by fellowships to Uday K. Thapa from the University of Minnesota's Graduate School and Department of Geography, Environment, and Society and the Bell Museum of Natural History. U. K. T. also acknowledges NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by UCAR's Cooperative Programs for the Advancement of Earth System Science (CPAESS) under award NA18NWS4620043B. This work also benefited from a Talle Family Research Award from the University of Minnesota's College of Liberal Arts. V. T. acknowledges funding from the National Science Foundation (CAREER grant AGS-1349942). We thank the two anonymous reviewers for their constructive comments that greatly improved the quality of our manuscript. The reconstructed Himalayan jet latitude and tree-ring chronologies used in reconstruction are archived in the National Oceanic and Atmospheric Administration/National Centers for Environmental Information's Paleoclimatology Data center.
Funding Information:
Support for this work was provided by fellowships to Uday K. Thapa from the University of Minnesota's Graduate School and Department of Geography, Environment, and Society and the Bell Museum of Natural History. U. K. T. also acknowledges NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by UCAR's Cooperative Programs for the Advancement of Earth System Science (CPAESS) under award NA18NWS4620043B. This work also benefited from a Talle Family Research Award from the University of Minnesota's College of Liberal Arts. V. T. acknowledges funding from the National Science Foundation (CAREER grant AGS‐1349942). We thank the two anonymous reviewers for their constructive comments that greatly improved the quality of our manuscript. The reconstructed Himalayan jet latitude and tree‐ring chronologies used in reconstruction are archived in the National Oceanic and Atmospheric Administration/National Centers for Environmental Information's Paleoclimatology Data center.
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