Arctic Warming and the Climate Crisis are to Blame for the Polar Vortex

The official National Weather Service temperature forecast map for February 18, 2021. Note the polar vortex dip chilling the entire continental United States and Canada. Photo: National Weather Service

This week what is known as a “polar vortex” took hold of the North American continent, with most states experiencing temperatures below freezing and some with extended power outages for various reasons.

In places extending to the southern border of the United States, a deep freeze caused power lines to collapse and water systems to fail as pipes froze in areas not used to such low temperatures. The cold weather often brought with it powerful ice storms, sleet, and heavy snow, making travel impossible as roads were covered in layers of sheet ice.

According to a just-released National Weather Service alert, even a place as far south as Austin/San Antonio, Texas, was bracing for “ice accumulations of 0.25 inches to 0.75 inches“ along the northern parts of the Interstate 10 highway tonight. The NWS warning said the ice formation would likely cause additional “major power outages and tree damage”, as “the worst of all the winter events over the past week” took hold.

In Dallas, Fort Worth, the NWS announced yesterday morning to expect ice that had melted the night before would be frozen solid on most major highways in the area. When the new storms which are heading for that area make their appearance, the roadways in that metropolitan area are expected to see another 0.25 inches of ice buildup on their roads.

The electrical power outages which have resulted from the storms have caused over 4 million in Texas to be without power now for days on end. As of late yesterday, the Electric Reliability Council of Texas, the organization which regulates the state’s power distribution, said that their emergency crews had only just been able to restore power to some 700,000 people. The Council also reported that over 3.4 million people in the state were still without power.

Where lines have stayed up or been repaired by emergency crews, the surging need for power has caused the state to begin to implement rolling power blackouts.

Natural gas usage has also roared upwards quickly, so much so that natural gas prices have soared and state suppliers are having problems meeting demand. This is behind why Governor Greg Abbott signed an executive order on February 17 which restricts natural gas providers from selling natural gas outside of the state. He had previously signed an order prioritizing gas sales to meet human needs.

Without sufficient electrical power or natural gas, many in their homes are struggling to stay warm. While blankets and other emergency supplies have been distributed to help wherever possible, there is simply no way for many to do anything more than just huddle together. State authorities are bracing for a horrifying death count when the storm is over.

At least 31 have died so far, with that count covering a mix of those killed in car accidents and those who attempted to generate heat within their homes without adequate ventilation.

Those seeking answers to why this is happening made the quick guess that this was proof of some sort that the climate crisis everybody was talking about was not all that serious.

The facts tell a different story. Climate scientists say this deep freeze can be directly blamed on continued high temperatures the Arctic has been experiencing throughout much of the last twelve months.

For much of 2020, the Arctic has suffered from far hotter temperatures than normal. As Trillions reported in its summary of the National Oceanic and Atmospheric Administration’s (NOAA) Arctic Report Card for last year, “For the 12-month period between October 2019 and September 2020, the Arctic logged the second-warmest average annual land-surface air temperature ever, beating all but one other record set since temperatures in this region were first tracked in 1900.”

The article noted that “Arctic warming [was] running at rates of over 2X that of the warming rate of the entire planet averaged since 2000.” That included multiple regions in Siberia recording temperatures at 5° C (9° F) over their typical average levels for the first half of the year. In June, the highest ever temperature recorded above the Arctic Circle was measured at Verkhoyansk, where thermometers peaked at 38° C (100.4° F).

Prior to such warming, the formerly extreme cold “vortex” of air surrounding the Arctic Circle stayed more or less in place. On a seasonal basis, as temperatures fluctuated, that polar vortex might occasionally float downwards, driven by jet stream conditions.

Evolution of the sudden stratospheric warming (SSW) in the stratospheric circulation. Top figures show 10 millibar (mb) geopotential heights for (left) December 26, 2020 as the polar vortex began to weaken, (middle) on January 5, 2021 when the stratospheric winds reversed sign and (right) on January 15, 2021 during the warming event. Bottom figure shows the evolution of the 100mb zonal mean winds (blue line; units in m/s) at 60°N and 10mb polar cap temperatures (red line; units in Kelvin) from December 15, 2020 through January 18, 2021. Figure courtesy of Lara Ciasto (NOAA CPC). Data from NCEP/NCAR Reanalysis. Photo: NOAA's Climate.gov website

As to the specifics of the current situation, NOAA reported on its Climate.gov site on January 28 that what scientists call a “sudden stratospheric warming” (SSW) event which launched on January 5, 2021, is the current culprit to blame. The polar stratosphere had warmed quickly at that time, triggered in part by global heating conditions tied to the many factors which made the Arctic summer and fall so much hotter than normal. As the report notes, the SSW caused the tropospheric jet stream to weaken just above the polar cap. When that happened, the extreme cold bubble of air in the polar cap pushed down into the middle latitudes of the United States, as well as into parts of Asia and Europe.

What is happening now is something which may become far more common now. With temperatures having been raised for such a long time at the north polar region, the air systems and entire air masses are now floating down into the U.S. more often. The Arctic warming has caused an overall weakening of the jet stream, a major wind pattern which in the past has caused the winter polar air to stay trapped in the north but is now no longer able to do that.

As an analogy, consider something else also happening in the Arctic region because of its extreme hot temperatures. The oceans there are now much warmer than in the past. That has blocked the normal fast-moving ocean currents which used to take the much hotter equatorial waters and move them quickly into the Arctic. In transit those currents cooled along the way, of course, but the whole process was something physicists understand well, that heat always moves towards cold. With the Arctic waters now much hotter, the natural thermodynamic systems which would ordinarily bring the waters north just do not function the same way any longer.

This pattern in the Arctic oceans is also an explanation for something happening in Europe of a similar nature. As the oceans continue to warm further north as global heating continues, such as around the coast of Europe and up into the waters surrounding the United Kingdom, the Gulf Stream will begin to slow. That used to drive strong currents of warmer equatorial waters, again powered by simple physics and the laws of thermodynamics. As the Gulf Stream slows, the paradox of global heating is that the UK will see average temperature drops initially because of this. The southern parts of the country will suffer from snow and ice storms and freezing conditions happening well into the spring.

For now, the south-central United States is going to be in for some of the coldest temperatures recorded in recent decades. It will cease as the jet stream re-stabilizes over the Arctic circle again. Based on what has already happened, however, and the continued much-higher-than-normal Arctic temperatures which created havoc in 2020, Texas and all regions above could be in for more waves like the current polar vortex until spring breaks out a couple of months from now.