Vanishing Vortex
Published 2-7-2019
Our post title is meant to be humorous and provocative. There are two types of polar vortexes: tropospheric and stratospheric. Both vortexes consist of air circulating west to east, but differ in their size. Earth’s troposphere is the zone of Earth’s atmosphere where virtually all weather occurs. It hugs the Earth’s surface, ascending to various heights—highest at the equator (12 mi) but not as high at the poles (4 mi). Earth’s stratosphere rests atop the troposphere. Its temperature begins to rise as altitude increases. On occasion, various phenomena contribute to SSW (sudden stratospheric warming) at high latitudes around the poles. As a result the stratospheric polar vortex weakens, sending intensely cold air masses southward. The weaker the stratospheric polar vortex, the more likely we will receive a heavy dose of uncommon and intense cold. Truly intense stratospheric polar vortexes strike the US rarely, perhaps every few years.
The polar vortex may also refer to the circumpolar tropospheric vortex. This is a much larger, constant pattern of circulation generally outlined by the jet stream in middle latitudes. Undulations in the jet stream direct air masses to different areas and are frequently the source of diverse weather systems ranging from fair to adverse. A 2017 essay by Darryn Waugh, Adam Sobel, and Lorenzo Polvani in the American Meteorogical Society journal states, “…cold air outbreaks are fundamentally tropospheric events.” With reference to the mounting popularity of the term polar vortex, the authors continue, “…the term has become rapidly ingrained into the vocabulary of popular weather journalism and appears to be more common in the science literature of extreme weather.”
Our recent polar vortex event “vanished” quickly. The historic stratospheric polar vortex outbreak in late January 2019 is now a distant memory. Not only were cold records set or nearly set, but the subsequent sudden warm-up following the event was highly unusual. Many areas rapidly warmed up from -25ºF or -30ºF to +45ºF or +50ºF in only one or two days. From recent official Accuweather records in Dubuque IA, we report daily highs/lows from Monday 1/28/19 through Monday 2/4/19: 14/1; 1/-21; -16/-28; -4/-31; 11/-8; 40/11; 42/37; and 43/14—a swing of 74 degrees! As we study the planet’s weather events, such a phenomenon is unusual, but not unheard of. Hardly any weather phenomenon is unique.
After the intensely cold winter of 2013/14, we submitted posts using the term polar vortex only once. During that year our midwestern region had 43 daily below zero readings, a truly protracted polar vortex. It was then that the term polar vortex became popular—not because the phenomenon had never occurred before, but because media consumers hunger for explanations replete with nomenclature. Al Roker has been a familiar television weather reporter in the New York City area since 1983. In response to skeptics who proposed that weather terms such as the polar vortex were created to explain phenomena such as the ever popular current fixation on climate change, Roker once trotted out a meteorology textbook from 1959 with an accurate description of the phenomenon which, no doubt, has been a characteristic of our planet for thousands or even millions of years.
In past posts we have referred to fascinating characteristics of our “dynamic” Earth. Weather events, sometimes even extreme weather events, are ultimately life sustaining, contrary to popular belief. We must consider these extremes in the context of totality. We explain: The polar vortex is actually a constant feature of our planet, not only a feature of northern or southern hemisphere winters. On rare occasions the symmetric polar vortex supplies Earth dwellers with harsh outcomes. We may question, “May good result from a vicious cold snap?” This year’s polar vortex was ushered in with uncommonly severe blasts of “polar” air. In less intense winter conditions in any season, meteorologists would call such cold air intrusions “cold fronts.”
Weather has been variously described as a chaotic and dynamic system—the day to day state of the atmosphere. Climate is a more stable and predictable average of weather when measured over time. Our discussion has highlighted the wondrous complexity and variety of our weather and climate. Many of these issues are frequently the subject of discontent and sometimes scorn if our comfort is threatened. We recall many discussions about weather where friends complained about uncomfortably cold, hot, humid, windy, rainy, or dry conditions . We have enjoyed powerful references to the power of cold in the words of Elihu (Job 37:9-10) and God Himself (Job 38:29-30). Both passages speak of ice. Elihu says it “..is made from the breath of God.” When the Lord speaks, He inquires “…from whose womb comes the ice?” and reminds Job that He has given birth to the “frost of heaven.” We hold to our previous positions in many posts that Earth is “a place to thrive” for Earth’s over seven billion residents.
We dedicate this post to Joseph P. Virkler, my paternal uncle. He was the “last man standing” of my 21 paternal and maternal uncles and aunts. Over many years Uncle Joe and I shared memories of heat waves, cold waves, blizzards, thunderstorms, hurricanes, and droughts. He loved to recount stories of weather events he experienced during his 92 years of life in Central New York. Of many stories he loved to relate, several stand out. When people complained about the intense heat in the summer, he replied, ‘It’s supposed to be hot in summer.” Another favorite was his love of thunderstorms. One of the most memorable questions he ever posed was, “Who authored the laws of nature?” It was evident that he viewed the chaos of unusual meteorological events in the context of the total picture of weather and climate authored by and under the ultimate control and sustenance of God, the Creator.
https://jasscience.blogspot.com/2019/02/vanishing-vortex.html
