I was so busy ranting about AGW lawsuits yesterday that I forgot to mention the U.S. Drought Monitor. The great news is that the drought in Wisconsin has improved since last week. This is the first time this year (I am fairly sure) that we do not have any severe drought in the state. The severe drought category that was present in the far northeast part of the state last week has now diminished to moderate status. I would expect that this improving trend would continue except for the fact that this week has been dry and no rain is expected until the middle of next week. Therefore the drought situation should remain stable.
Perhaps you came across this news perusing science and weather news over the last couple of days: Brazilian scientist proposes to generate electricity from air. This is not a proposal to capture the electricity from lightning strikes – something I have thought of before – it is a method to extract minute amounts of electricity from water droplets. Humid air would be the best target. While this sounds interesting in theory and probably works as described, I have my doubts that this method could ever generate any substantial amount of electricity at a competitive cost. The amount of of charge collected from each water droplet is very minuscule. It might take a massive installation in order to generate a usable current. So how does nature create such dramatic and large displays of electricity (lightning)? Through thunderstorms. Thunderstorms move truly massive amounts of air and separate positive and negative charges in the process. So how does lightning begin? Some researchers are looking at terrestrial gamma ray flashes as the “spark” of lightning.
Lightning is also an interesting subject in hurricane research. Lightning intensity and frequency change as a hurricane changes in strength. Researchers want to know how direct is the relationship in order to help with forecasting. To study lightning in hurricanes NASA is using autonomous drones - specifically the Global Hawk. For the latest on Danielle, Earl, and other tropical disturbances be sure to check the National Hurricane Center website.
Finishing up on the hurricane topic, there was an article recently that suggested major cities can attract hurricanes. Now this is not some magical force that cities exert from hundreds of miles away, it is only something that has shown up in computer simulations of hurricane movement when they get close to landfall. It turns out (according to the models) that “rougher” land surfaces make hurricanes change course a bit. The hurricanes move toward the land surfaces with more friction or roughness. In some coastal areas, large cities with big buildings produce more roughness than the surrounding landscape and thus could cause a hurricane path to shift a bit toward the city.
Have a good Friday! Meteorologist Justin Loew.
This post was written by jloew on August 27, 2010