Seminar: Is there any evidence of a poleward expansion in the subtropical jet stream in either hemisphere?

Penny Maher (University of Utrecht) The tropics are expanding poleward at about 1 degree per decade in observations. The Hadley cell edge is one common measure of tropical expansion. One alternative method is the trend in the subtropical jet position. Unlike the Hadley cell edge, the observed trends in the subtropical jet position are much smaller and often not significant. This makes us question if current methods adequately identify the subtropical jet position. The “tropopause gradient method” is introduced to... View Article