Saturday, February 16, 2019

Vortex Redux

As the frenzy concerning the January stratospheric polar vortex abates, we could not resist treating the subject in at least one more post. The polar vortex has become a catch word and buzz phrase. One feels more meteorologically literate when this term rolls off the tongue during conversation. We do not intend to disparage the importance of an event having such a great negative impact on so many residents. In our area, the vortex was embedded in an unprecedented sequence of school cancellations (10) and late openings or early closings (7) since January 14. Only two of those cancelled days were directly related to the polar vortex. The remaining days were linked to an unusual stretch of dangerous icy and snowy conditions causing havoc with local educational continuity and athletic team schedules.

In an ironic twist, many climate change proponents claim that global warming phenomena are related to, and may contribute to climate disasters such as hurricanes, tornadoes, floods, droughts, blizzards, and even the recent stratospheric polar vortex cold outbreak. Tropospheric polar vortexes are common and coincide with almost all winter weather in heavily populated mid-latitudes of Planet Earth. In our previous 2-7-19 post we distinguished between rare stratospheric and common tropospheric vortexes:

Today’s societal frenzy over climate change connects with the recent embrace of the “Green New Deal” promoted by many politicians with future presidential ambitions. On the assumption that CO2 emissions from burning of fossil fuels causes destructive climate warming, proponents of the “Green New Deal” would prohibit fossil fuels by 2030. This would result in phasing out of airplane travel, not to mention a substantial revision of our national economy and lifestyle. Consumption of fossil fuels would be “net zero.” China currently emits more CO2 than the US and the European Union combined but would be immune from the US Green New Deal if enacted. CO2 emissions have generally leveled off in the industrialized world. This includes China. In the US and the European Union, CO2 emissions have actually decreased since 2007. 

Returning to the lively discussion of how climate change relates to the stratospheric polar vortex which chilled us with near record low temperatures in much of the Midwest, we cite a PBS News Hour program from 1/30/19. A climate scientist from Woods Hole Research Center, Dr. Jennifer Francis, was questioned on her view of the relationship between the late January polar vortex and climate change. The News Hour scheduled Dr. Francis only one day after the worst cold snap in years. The questioner, Amna Nawaz, seemed intent on evoking a climate change connection to the polar vortex event.

Climate scientists on both sides of the anthropocentric climate warming question agree that climate is changing. The questions remain—How much? How fast? What are the causes? And will the results be beneficial or harmful? Many scientists and politicians of today are predicting future disaster on many fronts. The questions are not close to being settled.

On the News Hour program, Dr. Francis made the point that Arctic warming has occurred significantly faster than warming at middle latitudes. Could this be the result of melting of polar ice in the Arctic? Scientists agree that sea ice in the Arctic has declined about 40% since 1970. Warmer liquid oceans could eventually warm the air over higher latitude regions and disrupt the polar vortex, causing it to break apart and send pockets of intense cold air to lower latitudes. Francis also states that water vapor in the Earth’s atmosphere has increased 5 or 6% since 1900 causing warming and more erratic behavior of the jet stream. Her newest hypothesis, however, is related to reduced sea ice in Arctic regions.

Dr. Francis concluded her presentation with a comment about the gradual climate change that we are experiencing: “…We know why: It’s all because of human activities increasing the greenhouse gases in the atmosphere that trap a lot more heat down by the surface.” We suggest that partly should replace all in Dr. Francis’ statement.   

Another noted climate scientist is Dr. Kevin Trenberth from National Center for Atmospheric Research (NCAR). He agrees that the climate is undergoing significant warming and has impressive graphics to prove his point. Trenberth disagrees with Francis on the cause of the polar vortex and its connection with reduced sea ice. One of the worst stratospheric polar vortex events in 1985 did not correlate with an open ocean. Francis countered that other factors such as more water vapor in Earth’s atmosphere also could have an effect on the onset of polar vortexes. Trenberth posits that changes in ocean temperature such as those brought about by the El Nino event are as important as CO2 emissions from fossil fuels.

Our short post cannot begin to deal with the complex causes and effects of climate change. Some causes and effects are natural; some are man-made. Our God has created a wonderful planet and desires that humanity would exercise wise care for it. Earth is a wonderful, robust but intricate system. We offer thanks to the Creator who entrusts it to humanity’s care.                       

Thursday, February 7, 2019

Vanishing Vortex

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 “ 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.