Isentropic analysis of polar cold air outbreaks

By IARC Communications | June 9, 2017
A wide, horizontal cropped view of a 3D meteorological visualization of Earth's Northern Hemisphere. The curved surface of the planet shows a highly detailed stream of colorful, flowing lines representing atmospheric currents or jet streams. The stream shifts in color from deep red and orange at the bottom-center, indicating high intensity or velocity, to yellow, green, and blue as it snakes across the globe. Below the currents, the faint contours of northern landmasses, including North America, are visible against a light blue background.

Friday, June 16, 2017 | 2pm, 417 Akasofu

Toshiki Iwasaki, Tohuku University

Polar cold air outbreaks are studied with a definition of cold air mass
below a threshold potential temperature of 280K.  It allows us to treat the
cold air mass as an adiabatically conservative material localized in the
extratropical troposphere.  There are two distinct cold streams in the
northern hemispheric winter, namely, the East Asian and North American streams.
The equatorward cold air mass flux consists of outbreak events that intermittently
occur under favorable synoptic situations.  In East Asia, cold air outbreaks
show interannual variability associated with the El Niño and the Southern Oscillation.

For more information, contact Nate Bauer (nbauer3@alaska.edu).