Jon White – From the President’s Office: 02-04-2019

2019-02-05T09:50:04+00:00 February 4, 2019|

A tempest about a teapot: Why record cold weather (even a polar vortex) actually supports climate change theories, including global ocean and atmospheric warming

As an oscillation of the (tropospheric) polar vortex brought frigid temperatures across the Midwest and Northeast, NOAA found itself in hot water with some, thanks to this educational tweet. The innocuous cartoon illustrates one explanation for why we see more winter snow in warmer climates: more evaporation occurs when temperatures are higher, which leads to a wetter atmosphere, which in turn increases our wintery precipitation. The tweet was considered by some to be a rebuke to the president’s tweet calling global warming into question in light of record-setting freezing temperatures around the country; he wasn’t the only one asking that question, and the answer is even more complex than a single illustration.

There is a continuous, counter-clockwise circulation of air near the Earth’s surface in the Arctic (a polar vortex). This is caused by larger, complex atmospheric circulations (such as the jet stream), which are in turn caused by differences in temperature – the Earth and ocean are warmer closer to the equator and colder closer to the poles. The overall, ongoing warming of the global atmosphere and ocean, which has been measured over many years, has led (for several reasons) to warming of the Arctic region faster than any other region on the planet, reducing the average temperature difference between the Arctic and regions to the south, including the mid-latitudes (where most people in the U.S. live) and the tropics.  Reducing the temperature difference has caused significant changes in the larger atmospheric circulation patterns, which have allowed the Arctic polar vortex to move around more than it did before we started to see the overall warming of the atmosphere and ocean. As the polar vortex wanders to the south, especially in the winter when the Arctic is darkest and coldest, it pushes some of that really cold air with it, which can leave us with record-breaking cold and rapid changes in temperatures over just a few days as it heads back to the north. So that’s how a warming planet that heats faster at the poles will, over time, likely experience more temperature extremes as features like the polar vortex behave differently than they used to. Still with me? My explanation is really an over simplification, and I suggest you search the web for articles like this for a more accurate description and discussion of the complex phenomena associated with this tweety, steaming cauldron.

It’s important to remember that climate science, which really includes parts of all Earth sciences (or geoscience) – meteorology, oceanography, geology, hydrology, cryospherics, etc., – is a very complex and not yet fully understood science, but scientists around the world are constantly learning new things about our climate to help us better understand and predict its changes. Therefore, we must continue to ask questions, test hypotheses, find answers, refine our knowledge in these areas, and do what we can to predict, mitigate, and adapt to future climate changes. Some of these changes will likely have dire consequences for us, including more record temperature extremes, increased floods, droughts, storms and fires, sea-level rise, ecosystem changes, and more.  These are the real tempests that are brewing in our planetary teapot, and they are also why I believe that ocean science, and really all geoscience, is certainly not science for science’s sake but science with survival at stake!

Waters West Of Europe Drive Ocean Overturning, Key For Regulating Climate
A new international study finds that the Atlantic meridional overturning circulation (MOC), a deep-ocean process that plays a key role in regulating Earth’s climate, is primarily driven by cooling waters west of Europe. In a departure from the prevailing scientific view, the study, which includes scientists from Duke University, Woods Hole Oceanographic Institution, and University of Miami, shows that most of the overturning and variability is occurring not in the Labrador Sea off Canada, as past modeling studies have suggested, but in regions between Greenland and Scotland.

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