Month: February 2013

Urban heat islands – why is it warmer in the city?

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Summer in the city can be especially hot and sticky, because urban heat islands exacerbate the warm weather. Researchers at Berkeley Lab are testing materials that battle that effect, making pavements cooler and safer.

Causes

The properties of urban roofs and pavements, as well as human activity, contribute to the formation of summer urban heat islands:

  • Urban surface properties. Roofs and pavements can constitute about 60% of the surface area of a U.S. city. These surfaces are typically dark in color and thus absorb at least 80% of sunlight, causing them to get warmer than lighter colored surfaces.1 These warm roofs and pavements then emit heat and make the outside air warmer.
  • Human activity. Air conditioning, manufacturing, transportation, and other human activities discharge heat into our urban environments.

Consequences

Urban heat islands can negatively affect the urban community and the environment.

  • Increased energy use. Warm temperatures in cities increase the need for air conditioning (A/C) to cool buildings. This elevated demand can strain the electrical grid on a hot summer afternoon, making it more susceptible to brown-outs and black-outs.
  • Impaired air quality. Warmer air accelerates the formation of smog (ozone) from airborne pollutants like nitrogen oxides and volatile organic compounds. Elevated demand for cooling energy in the form of A/C use can also increase the emission of air pollutants and greenhouse gases from fossil-fuel power plants.
  • Illness. Higher air temperatures and lower air quality can aggravate heat-related and respiratory illnesses, and also reduce productivity.

Learn more →

(Source: heatisland.lbl.gov)

The algorithm that won an Oscar

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Hollywood likes a good explosion.  Now, with the help of an open source algorithm called Wavelet Turbulence, filmmakers can digitally create pyrotechnics that were formerly time-consuming and difficult to control.

UCSB’s Theodore Kim (along with three collaborators) picked up the Academy Award in Technical Achievement for Wavelet Turbulence.

So far, it has been used in over 26 major hollywood productions including Avatar, Sherlock Holmes, Hugo, and Super 8 (pictured above).

Read the full story →

Is that really red snapper on your plate?

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tumblr_mil8vjJulj1rjatglo2_250A recent survey done by Oceana says that fish found at the market are not always correctly labeled.  So, scientists are working on a genetic sequence technique called fish barcoding that can positively identify fish species.

Marine biologist Ron Burton of UCSD’s Scripps Institution of Oceanography says it’s important for the public to make sure they’re getting what they think they’re getting:

“In a market like red snapper, we can be seeing red snapper at many fish markets and that would lead somebody to believe that the fish is very common, when in fact what’s being sold is a diversity of species – some of which are common, some of which aren’t. And so it can lead to a false impression about the abundance of species to the public.”

Read more stories on Science Today →

The science behind breaking up

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If your Valentine’s Day was less than ideal, don’t worry — hopefully this comic inspired by UCSF’s Dr. Lewis’ “A General Theory of Love” can boost your spirits!

“Long before science existed, sharp-eyed men and women told each other stories about how people are, stories that have never lost their power to enchant and instruct. The purpose of using science to investigate human nature is not to replace those stories but to augment and deepen them. Robert Frost once wrote that too many poets delude themselves by thinking the mind is dangerous and must be left out. That principle is mirrored in the study of the brain, where too many experts, out of plain fear, avoid mentioning love.”

— from A General Theory of Love by Thomas Lewis, MD, Fari Amini, MD, and Richard Lannon, MD

Check out the full comic here →

 

The urban heat island effect and how cool pavement can help

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On sweltering days you can fry an egg on them. But, now, Lawrence Berkeley Lab and UC Davis researchers are testing surfaces designed to make them cooler and safer.

“Cool pavements are paved surfaces that are more effective at reflecting sunlight. So, by reflecting more sunlight than traditional paved surfaces, they’re able to absorb less heat from the sun and keep cities and communities cooler.  We’ve teamed with industry partners and we’re hopeful that this can get the ball rolling on some local government action for cool pavement.”
– Ben Mandel, Heat Island Group, LBNL