Changing features of the Northern Hemisphere 500-hPa circumpolar vortex

Nazla Bushra; Robert V Rohli; Chunyan Li; Paul W Miller; Rubayet Bin Mostafiz

doi:10.3389/fdata.2022.1009158

Changing features of the Northern Hemisphere 500-hPa circumpolar vortex

Front Big Data. 2023 Jan 9:5:1009158. doi: 10.3389/fdata.2022.1009158. eCollection 2022.

Authors

Nazla Bushra^{1

2}, Robert V Rohli^{1

2}, Chunyan Li^{1

2}, Paul W Miller^{1

2}, Rubayet Bin Mostafiz^{1

2}

Affiliations

¹ Department of Oceanography and Coastal Sciences, College of the Coast and Environment, Louisiana State University, Baton Rouge, LA, United States.
² Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, United States.

Abstract

The tropospheric circumpolar vortex (CPV), an important signature of processes steering the general atmospheric circulation, surrounds each pole and is linked to the surface weather conditions. The CPV can be characterized by its area and circularity ratio (R _c ), which both vary temporally. This research advances previous work identifying the daily 500-hPa Northern Hemispheric CPV (NHCPV) area, R _c , and temporal trends in its centroid by examining linear trends and periodic cycles in NHCPV area and R _c (1979-2017). Results suggest that NHCPV area has increased linearly over time. However, a more representative signal of the planetary warming may be the temporally weakening gradient which has blurred NHCPV distinctiveness-perhaps a new indicator of Arctic amplification. R _c displays opposing trends in subperiods and an insignificant overall trend. Distinct annual and semiannual cycles exist for area and R _c over all subperiods. These features of NHCPV change over time may impact surface weather/climate.

Keywords: 500-mb flow patterns; breakpoint analysis; climate change; fast Fourier transform; steering atmospheric circulation; tropospheric circumpolar vortex.

Grants and funding

The authors are grateful for funding from Louisiana State University's Economic Development Assistantship and Dissertation Year Fellowship programs. The publication of this article is subsidized by the LSU Libraries Open Access Author Fund.