Arctic Warming Can Trigger Extreme Cold Waves
A very severe cold wave struck large arctic areas of North America in February 2021. It occurred amid rapidly rising global temperatures. 10 million people were without power. Texas was the worst affect, with more than 125 people dying. It was the coldest February in the United States in over 30 years. This cold wave the most expensive winter storm ever record in the United States.
The freezing temperatures were cause by a dip in the jet stream. This is a band of strong winds that hovers eight miles above Earth’s surface. And serves as the boundary between warmer and colder air. Although the jet stream flows west to east, they are not the only directions in which atmospheric waves can move. They can also move up or down over large distances. This can be use to link weather and climate conditions in one region. The Arctic with other regions, such as Texas.
You can see ripples when you place a rock into a pond. Although ripples in a pond may be a different kind of wave from dips in a jet stream. Both can transmit the disturbance’s effects to distant areas. The atmospheric waves carried the Arctic’s climate change influence to other parts of North America, Asia and North America. We present how this happen in a Science study that was publish Sept. 2, 2021. And how global warming can make events such as the February cold waves more likely.
The Arctic Is Not A Place That Stays The Same
The Arctic is heating faster than any other region and at twice the global average rate. This is causing major changes in the climate of the region. Including melting sea ice and, in late fall, an increase in snow cover over Siberia.
The reflective properties of snow and ice provide an insulating layer. They also alter the amount and velocity of energy and water between the Earth’s surface and the atmosphere. Because the atmosphere is sensitive to changes of energy and moisture, substantial changes can provide a kick. Which causes upward-moving waves to rippling from the area.
These waves travel upwards into the stratosphere to disrupt the stratospheric Polar Vortex, another band that moves closer around the pole at the middle of the stratosphere, about 18 miles above. The vortex responds by weakening and stretching.
The waves can alter the stratospheric Vortex. However, the vortex can also affect how waves move. Because waves are affect by wind and temperature fields, the vortex is responsible for determining those winds and temperatures. A vortex stretching event is different from larger vortex disruptions because upward-moving waves reflect back to the surface and can have an impact on weather patterns at lower altitudes.
These downward-moving waves gather at lower altitudes in North America and cause a dip in the jet stream to the south, which brings colder air south. The Arctic can be link to other regions by the upward and down movement of atmospheric waves, which travel long distances in the same way as ripples across a pond.
Test Cause And Effect Arctic
Two different approaches use to identify and examine these relationships. We first used machine learning. This is a technique where a computer learns to group similar events using historical data. Then, we analysis the events of the stretched vortex to find a pattern. First, surface temperature changes in Arctic followed by changes in the stratospheric Polar Vortex. Finally, cold waves in North America, Asia, and vertically moving waves provided the connections over the period of a few months. The Arctic’s surface temperature changes are similar to those that are associate with melting sea ice, increasing Siberian snow covers and Arctic climate change.
The computer model was use to assess cause and effect, and to test the response of the atmosphere to Arctic changes. The model accurately reproduced the sequence of events observed. Two independent lines of evidence support a pathway of influence. From Arctic climate changes at the surface, to changes in the stratospheric winds and back down to cold waves and Arctic climate change in North America and other parts of Asia.
These Results Have Implications
Our research confirms two important lessons about climate change. First, it doesn’t need to happen in your backyard for it to have an impact on you. Unexpected consequences can have very serious consequences poker pelangi.
Large changes in the Arctic may not only be a concern for one region, but can have wide-reaching impacts on North America and other parts of Asia. These impacts can be quite different from what people expect. These results show that there are two things to do: reduce greenhouse gas emissions quickly and develop better strategies to manage extreme weather events (hot and cold).