There has been a lot of debate on the record heat and humidity in the northern hemisphere this summer, especially the humidity levels in the conus (continental U.S.). Whether this is due to green house gases or is a anomaly in the cycle of multi century climatology (which is my stand) it is my belief though we do have an effect on the climate due to the aspiration of corn and other crops we are seeing another cycle in the big picture of the ups and downs through the millennium. Our records cover around a century of data, we would also have to look at the effect of such things as solar and volcanic activity, fires and other forces which nature has on our climate.
With the exception of China we have cleaned up our act in regards to air pollution compared to the 60s and 70s when industry was spewing out smoke and other pollutants into the air (and rivers). We had three paper mills in the Otsego/Plainwell area which put out a lot of toxic chemicals in the water and smoke into the air back when I was younger – some summers it was so bad it would peel the paint off the houses. Over the past couple years they have been dredging the Kalamazoo river and removing dams bringing back the natural flow of the river.
I believe the heat and record humidity this summer has been an anomaly which was set up by blocking in the Arctic and Ontario (and other contributing factors). There are no tropical cyclones or hurricanes in the Pacific or Atlantic today which has been the case quite often this summer to help mess with the weather or move tropical moisture and disturbances into the great lakes region as has been the case over the past few years. Without the steering currents we can have stagnant air masses set up. High pressure centers have set up over the state to bring a lot of warm and sunny days which in turn has steered the low pressure areas around us rather than over us.
As a disclaimer I am not a certified meteorologist or hold a degree in earth sciences, my opinions come from observation rather than a college education though I have studied the weather as a hobby. I still believe we have cycles which can go through multiple decades and even centuries.
As I mentioned earlier in this post we do have a lot of farmland which cultivates hundreds of thousands of acres of corn and soybeans which aspirate moisture into the air, plus the fact we had a very wet spring and early summer which gave us a lot of soil moisture which can add to the heat and humidity which we saw in July. I have read articles which say cattle have an effect on the lower atmosphere, including gases (farts) emitted from cows, so there are a lot of variables which affect our climate.
For another view this is an excerpt from Judah Cohen’s posting this week from Atmospheric and Environmental Research.
The pattern of strong warming in Europe, cooling or lack of a trend in Western Russia with more amplified warming in Siberia is not unique to this summer but has been a multi-annual trend. Why the long-term trend should manifest in this pattern is curious to me. I did see a recent paper that does provide a possible physical explanation. According to Sato and Nakamura (2019) it could be related to increased snowfall in Western Asia in winter that leads to increased soil moisture in the spring and early summer that then favors troughing in the region with ridging on either end across Europe and Siberia. It is an interesting idea and provides another impact of Arctic amplification or accelerated Arctic warming not only in the winter season but in summer as well and links the two together. My own research has focused on the possibility that accelerated Arctic warming and low sea ice are contributing to increased snowfall across Eurasia primarily in the fall and together the low sea ice and more extensive snow cover in the fall contribute to colder temperatures and heavier snowfall in winter across the continents of the NH. According to this study that impact of heavier snowfall is not confined to winter but extends into the summer with a strong influence on European summer temperatures.
I do want to express that I have been spooked by what I have seen this summer. There is an article in today’s Washington Post on July’s record heat. There is one line that really resonates with me “This is not your grandfather’s summer” by UN Secretary General Antonio Guterres. I was fortunate enough to visit Paris for a number of summers in the 1980’s and early 1990’s. On none of those trips did I anticipate or pack for hot temperatures. Over that decade the warmest weather that I encountered was in April during a fluke one off day with temperatures in the 90’s. I am having a hard time juxtapositioning the summers in Paris from my memories of cool, cloudy and damp weather and the Paris of 2019 with a high temperature of 109°F; to me it is mind boggling. I never would have guessed that in my lifetime Paris would fall short of 110°F by just one degree. And it is not just one or two hot days in Paris, as there are always flukes. There have been many all-time records set this summer across Europe and in many cases by unusually wide margins. Here in Boston we did not see any all-time record highs but we did just experience our warmest month ever.
And the heat is not simply confined to the mid-latitudes but includes the Arctic as well. There have been many headlines about the melting of the Greenland ice sheet, and it is looking like 2019 will give 2012 a run for the lowest Arctic sea ice minimum in the satellite era. In August 2012 sea ice loss was unprecedented that may be hard to match in 2019, but 2019 at least second place looks like a lock.
With so many all-time record high temperatures from daily to monthly and from local to global scale, melting glacial and sea ice and widespread Arctic fires it does seem we have numerous highly anomalous weather and climate events all occurring simultaneously. More than ever I feel that we have entered a “new normal.” Attribution of an event, a series of events in space and time and collectively across the globe is difficult but the best explanation that I can come up with is increasing greenhouse gases. And if the theory is correct, or maybe more likely without unforeseen negative feedbacks, the extreme weather of 2019 will only become exacerbated in the years to come. For me this is very sobering.
To read the whole post go to the AER website…
We have a beautiful weekend setting up with comfortable temps near 80° and cool nights which will give us slightly below normal temps. There is a small chance of rain Saturday night into Sunday (20%). A better chance of rain will be in the Monday/Tuesday time frame. Temps will be near to slightly below normal over the next week.
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