Tech Tuesday

Global Temperature Report Offers Contrast

World has warm tropical October even as U.S. saw cold, rethinking the wind farm and airborne nitrogen could be a new challenge.

Farmers trying to finish their harvest will love this. Scientists at the Earth System Science Center at the University of Alabama in Huntsville note that the El Nino Pacific Ocean warming event caused the second warmest tropical October in 31 years. At the same time, the United States saw its second coldest October in the same time period.

Here's a quick recap of those October numbers for the U.S.: the average temperature over the 48 contiguous states was 1.45 C (about 2.61 degrees Fahrenheit) cooler than seasonal norms for October. The coldest October in the past 31 was in 2002, when average temperatures dropped 1.48 C (about 2.66 degrees Fahrenheit) below normal. By comparison, the next coldest October was in 2006, when temperatures in the continental U.S. were only 0.8 C cooler than normal.

A New Kind of Wind Farm. The familiar propeller farms popping up across the Midwest could be a thing of the past as scientists work on ways to make these power generators even more efficient. Researchers at the California Institute of Technology have developed a potentially more efficient design that also maximizes land use - and in part it gets its main design idea from schooling fish.

When fish swim, they shed tiny vortices - or currents - in their wake, according to the researchers. By schooling together, they can potentially help each other swim by transferring energy between one another through these vortices. Since wind turbines work in an atmospheric environment that has similar properties - air movement can be quantified like water movement - the researchers applied the principles to wind farm design.

Using turbines that work on a vertical-axis (more like a cylinder than a big propeller) they could group each tower closer to its neighbor. Using this arrangement - with the turbines closely spaced - each is turned by the wind to extract energy, and each helps direct wind flow to other turbines in the group.

Based on a computer model using this method, the researchers predict that the power per acre from a single wind farm could be increased as much as a hundred times over the familiar "propeller" approach. Their next step is to build a test field with real turbines to make actual energy measurements. It's another example of the further refinements of new-tech tools in the renewable energy world.

Nitrogen as a Pollutant? The burning of fossil fuels releases nitrogen into the air; use of nitrogen fertilizers can also boost the atmospheric content of the element. Turns out researchers now say this higher level of nitrogen content in the environment is impacting alpine lakes around the world. Studying alpine and subalpine lakes in Colorado, Sweden and Norway, scientists from Arizona State University have found ecological shifts in lake biology based on higher nitrogen availability.

The researchers acknowledge that the impact of this higher atmospheric nitrogen level isn't completely known since not a lot is known about the impact of nitrogen deposition on aquatic systems. However, concerns over the balance of nitrogen in the atmosphere is a topic to watch in the future. The researchers are already taking a closer look at China, which has a high concentration of atmospheric nitrogen.

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