Image caption
Atmospheric conditions in the stratosphere and upper troposphere on January 5, 2025. The shape of the polar vortex (left) has been slightly elongated with lower atmospheric thickness (geopotential heights) extending down over North America, primarily eastern Canada. In the upper troposphere (right), where the jet stream resides, there is also a region of lower thickness anomalies over eastern Canada. The question is: are these regions of low thickness in the stratosphere and the troposphere connected or is it coincidence? NOAA Climate.gov image, based on Global Forecasting System (GFS) analysis data from Laura Ciasto.