ScienMag] Overwhelming scientific evidence has demonstrated that our planet is getting warmer due to climate change, yet parts of the eastern U.S. are actually getting cooler. According to a Dartmouth-led study in Geophysical Research Letters, the location of this anomaly, known as the "U.S. warming hole," is a moving target.
During the winter and spring, the U.S. warming hole sits over the
Southeast, as the polar vortex allows arctic air to plunge into the
region. This has resulted in persistently cooler temperatures throughout
the Southeast. After spring, the U.S. warming hole moves north and is
located in the Midwest.
The study found that winter temperatures in the U.S. warming hole are
associated with a wavier jet stream, which is linked to natural climate
cycles over the Atlantic and Pacific Oceans, and potentially to climate
change. Previous research has illustrated that warming temperatures and
melting Arctic sea ice set up conditions for a wavier jet stream. The
study revealed that the jet stream over the U.S. became wavier in the
late 1950's, coincident with the start of the warming hole. As such,
since the late 1950's, the polar vortex has been cooling the
southeastern U.S. during the winter. Read More