Cold in the East:

Cold in the East:

I generally don’t enter into the rhetoric on climate change that percolates up in the mix of journalism and entertainment that is broadcast and blogged. Last week I caught on Lou Dobbs a discussion about climate change and the recent cold, especially in the upper Midwest and East of the U.S. ( Lou Dobbs Video). There was a reprise in the discussion of the arrogance of scientists to imagine that we humans could impact the climate of the Earth. Since then, I have seen prayers thankful that the global warming myth has been set to rest and Mother Earth can return to taking care of herself, having wrested herself from the stranglehold of scientists. (My take on the arrogance argument is here: Arrogance and Arrogance Redux)

Gavin Schmidt at Realclimate.org is much better at responding to stories like Lou Dobbs than I am. Here is his response: cnn-is-spun-right-round-baby-right-round.

This weekend I have been in the Rocky Mountain National Park. Today in Estes Park, Colorado the high was near 50 F. In Colorado, along the Front Range, many of the towns had highs above 60 F. As Jeff Masters talked about in his blog, along with very cold temperatures in the eastern U.S. and Canada there have been very warm temperatures in Alaska and the U.S. West. In his previous blog Jeff talked about the incorrect if not deceitful averaging together of the northern and southern hemisphere sea ice. I suspect that Lou Dobbs could collect together three panelists from California, British Columbia, and Alaska, and they could provide counterpoint to his show last week. It would be just as bogus.

I want to add a point or two to Jeff’s blog on the sea ice in the northern and southern hemisphere. First, I did a series of blogs on sea ice in October 2007. ( Sea Ice North and South, Sea Ice Arctic, and Sea Ice North (The End)). The point of these blogs was that the northern and southern hemispheres really are different in terms of how ice is formed and melted. This difference is strongly influenced by many things, including the distribution of fresh water. The end result of it all was that in the northern hemisphere, the sea ice was formed at the bottom and melted at the top. The processes of formation and melting in the northern and southern hemisphere are different. There is no reason to expect symmetry.

Second, I occasionally see statements of incredulity that the northern and southern hemispheres are different. It is a question I pose in both my dynamics class and my climate change class. It is one of those simple physics questions suitable for Ph.D. qual exams. Why are the poles so different? It lies in the basic structure of the Earth. At the South Pole is a large continent, Antarctica. Antarctica is of very high altitude. The North Pole is ocean, and on the Atlantic side the Arctic Ocean is open to transport of heat from the Gulf Stream. The Gulf Stream: The geometry of the continents is different in the northern and southern hemispheres. There are warm ocean currents on the western sides of oceans. In the southern hemisphere the ocean is open between the tip of South America, the tip of Africa and Antarctica. The continents in the southern hemisphere do not steer the warm water to the poles. With the configuration of the continents, Antarctica sitting over the pole, with an altitude of greater than 2 km the South Pole is very different than the North Pole.

Tomorrow it will be 65 F in Boulder, 18 F in Ann Arbor. That’s a strong wave.

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Figure 1: Here is a map of ocean currents made in 1943. It is from one of my favorite maps places the Perry-Castañeda Library Map Collection at the University of Texas Note in the north, the “Permanent Polar Ice Cap.” It is immediately evident the difference in how the oceans heat the poles. Note specifically the role of the Gulf Stream. Here is a larger version of the map; one you can read.