While it may be fair to say global warming is an issue many people are informed about, it may be just as fair to say most could not give a detailed explanation of why it is happening, and how it effects weather around the world, even here in central New York. That explanation is exactly what Syracuse meteorologist Dave Eichorn offered at the most recent Cazenovia Forum lecture, held on Friday, November 22nd at the Catherine Cummings Theatre.
Approximately 250 people listened to Eichorn deliver his 60-minute talk titled, “Climate Change Through A Meteorological Perspective.” Eichorn got their full attention with his opening remark: “Your area will receive lake effect snow later this weekend,” he said, with a wry smile on his face, almost as if saying “Gotcha,” the audience chuckling. “I’m not here to try and convince anyone to take a certain position on global warming. I just want to provide the meteorological facts of climate change.”
Eichorn focused his talk on the Arctic region, because for the past two decades, the Arctic has warmed more than any other place on the planet, and because that change is driving weather patterns around the world. Whole regions in the Arctic have shifted and melted as a result of these changing surface and air temperatures. The Muir Glacier in Alaska, for example, retreated more that seven miles and thinned over 2,600 feet between 1941 and 2004. “So not only is the ice becoming less but that which remains is getting thinner,” Eichorn noted.
But what does the warming in the Arctic have to do with central New York? As Eichorn explained it- everything. With a slide show presentation, Eichorn explained the sun heats the Equator more than the poles, and as a result, the atmospheric pressure is greater at the Equator. That difference in pressure drives the winds in the upper atmosphere. “These winds, which are responsible for creating the weather, are very important,” Eichorn said. He described how an atmospheric high-pressure pocket over Greenland, and decreased upper atmosphere wind speeds—both the result of a warmer Arctic– act together as a roadblock of sorts and force the jet stream southward – down to the mid-latitudes. The jet stream pulls cold air down from the Arctic and across the Great Lakes, then drops that air right into our lap. It’s not only upstate New York that feels the freeze. This pattern has also caused unseasonable weather all the way down to Florida and even across Europe over the past few years. “It’s like someone left the refrigerator door open and all that air comes sweeping in over the Northeast.” Eichorn said. The air results in thigh high snowfalls that homeowners have to fire up the snow blower to remove in order to get the car out of the driveway.
Eichorn also cited differences in oceanic circulation, increased air –pollution and increased humidity as three of the many and complex reasons for global warming.“ Increased humidity means more moisture in the air, which means the earth doesn’t cool as much. And pollution keeps the Sun’s heat from escaping the earth in both the warm and cool seasons.”
Eichorn wrapped up his talk with a Q & A. Global warming will surely be discussed for years to come. Some will agree and, probably, some won’t. But if Eichorn’s comments are as accurate as his prediction of our own lake effect snow, then he’s probably not too far off the mark. The morning after his Friday evening lecture, a good two inches of fresh snow had fallen and spread out across Central New York, including Cazenovia.
The Cazenovia Forum series will continue in the spring with CNN’s Syria analyst Rick Francona.