Sunday, August 28, 2011

Research Roundup: Wandering Storms, Arctic Ozone Loss, and More

What On Earth - Wednesday, August 17, 2011, 17:39

Wandering Storms in a Warming World
Most people know climate change is causing glaciers to retreat in Earth’s polar regions, but that’s hardly the only change warming temperatures can produce. A new study, led by Frida Bender of the Scripps Institute of Oceanography and published in Climate Dynamics, shows that the tracks of mid-latitude storms – the type that drives the weather systems that affect Americans the most – have shifted poleward and narrowed over the last 25 years as a result of climate change. What’s more, as the Jet Propulsion Laboratory’s Graeme Stephens notes in a Nature Climate Change article about the study, Bender’s satellite-based research shows that the cloudiness of the storm tracks has decreased over the same period. That’s important as it suggests the decline may have increased the net flux of radiation at the top of Earth’s atmosphere over storms – a process that could amplify warming over time.

Ocean Temperatures a Factor in Arctic Ozone Loss
In March of 2011, the World Meteorological Organization put out a statement announcing an unprecedented loss of stratospheric ozone over the Arctic. Between the beginning of winter and late March ozone levels declined by 40 percent due to unusually cold temperatures in the Arctic stratosphere. (Cold temperatures hasten ozone destruction by making it possible for a certain type of cloud to form that hosts ozone-depleting chemical reactions). But what caused the cold spell? A new study authored by Megan Hurwitz of Goddard Space Flight Center and published in Atmospheric Chemistry and Physics Discussions points out that unusually warm sea surface temperatures in the North Pacific likely played a key role. The phase of the solar cycle, greenhouse gas emissions, nor El Niño/La Niña oscillations can fully the explain the unusual conditions, she notes.

Can Satellites Help Save the Burrowing Owl?
Burrowing owls, one of the world’s smallest owl species, live in the abandoned tunnels of small mammals such as ground squirrels and prairie dogs. The long-legged birds, which typically weigh just 6 ounces, are losing ground to development and some conservation groups put the number of breeding burrowing owls at a mere 10,000. A new study, published in the Canadian Journal of Remote Sensing, suggests that crop classification imagery from Landsat satellites could be used to evaluate owl demographics and help with conservation plans as agricultural areas experience short-term changes.

Hang Tight, LandSat 5
Speaking of LandSat, Landsat 5, launched in 1984, is still operating more than a quarter of a century later despite having an original design life of three years. However, the reality that LandSat 5’s critical Thematic Mapper instrument, which many agencies around the world rely upon, won’t last indefinitely is becoming increasingly difficult for scientists to ignore as the satellite ages. Since Landscape 6 failed to reach orbit and LandSat 7’s Enhanced Thematic Mapper, which reached orbit in 1999, has a glitch that omits key strips of images, there’s a real possibility that top-tier LandSat images won’t be available until the Landsat Data Continuity Mission launches in December of 2012, a new study in the Canadian Journal or Remote Sensing cautions. The Australian authors of the study tested some of the alternative satellite data products, but none of them quite measured up to LandSat 5 in their view.

DESDynI Takes a Hit. Now What?
Terrestrial ecologists have been eagerly anticipating the development of DESDynI, a mission that aims to measure the 3-D structure of Earth’s vegetation with lidar and active radar instruments. DESDynI is listed as a top priority mission in the Decadal Survey, a National Research Council report published in 2007 that laid out a vision for future earth science missions, so it came as a jolt to ecologists when they learned in February 2011 that funding for DESDynI had been cut. There’s still a possibility that DESDynI’s radar instrument will fly as part of a future mission, but so far there’s no plan B for the lidar instrument, note Forrest Hall of the Goddard Space Flight Center and Sassan Saatchi of the Jet Propulsion Laboratory in an editorial published recently by Remote Sensing of the Environment. There will be a lidar on the upcoming IceSat-2 mission, but that lidar system won’t be tuned to measure vegetation, the scientists point out.

Text by Adam Voiland. Extratropical storm imagery published originally by the Earth Observatory. Burrowing owl imagery published originally by the city of Boulder. DESDynI originally published on JPL’s radar science page.



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