Archive for March, 2012


Global Warming and Whipsaw Weather

Perhaps you’ve noticed that we’ve had a record-shattering heat wave across much of North America in recent months, whereas Europe and Asia have experienced an unusually cold winter. That’s to be expected according to a new report on extreme weather published by the Intergovernmental Panel on Climate Change. The report points out that it’s “very likely” that we’ve seen an overall increase in both cold and warm days (and nights) since 1950 due to global warming. Another recent study, published in Nature Climate Change, came to a similar conclusion, noting that the evidence for global warming as the cause of increases in heat waves and precipitation extremes is particularly robust.

Raise Your Glass to Water
March 22nd was World Water Day. Where is the world’s water? You’ve likely heard that  oceans hold 97 percent of it. That’s true, but the numbers get even more interesting when you start to consider some of the less voluminous places where water resides. As this story noted, swamps hold four times as much water as the world’s rivers (0.0008 percent versus 0.0002 percent); and the atmosphere holds more than both (0.001 percent). Want to learn about the blue stuff? A new 30-second animation based on data from the GRACE satellites is on display at Times Square through April 22nd. And though Gothamist suspects it may actually be a Van Gogh painting, NASA’s Goddard’s Scientific Visualization Studio has a new visualization (below) of the ocean’s surface currents that’s going viral.

What’s Causing Lake Poyang to Dry?
Poyang Lake in China has seen better days. Once China’s largest lake, it shrunk to just a fraction of its usual size this winter. Scientists are working to understand exactly what’s causing the decline in water levels, but an ongoing drought has surely played a role. The Three Gorges Dam, which is upriver, has likely contributed to the drawdown as well. Remote Sensing of the Environment recently published a study of data from the MODIS instrument that documents the dramatic fluctuation in lake levels between 2000 and 2010. The authors conclude Poyang Lake covered 3,163 square kilometers (1,220 square miles) in August of 2010, but only 714 kilometers (275 square miles) in October of 2010. (In recent months, the size of the lake has dipped to less than 200 square kilometers (77 square miles.) Overall, the scientists found the size of the lake has declined by about 30 square kilometers (12 square miles) a year.

When it Rains it Pours
Xin Lin
and Arthur Hou, scientists based at NASA’s Goddard Space Flight Center, recently published a study detailing seasonal and geographical variations in rainfall across the continental United States. By analyzing data from ground radars and rain gauges, they found that although heavy rain events (greater than 10 millimeters (0.4 inches) of rain per hour) only make up up 2.6 percent of total events, they represented 27 percent of the total volume that fell between 2002 and 2009.  Light rain events, in contrast, accounted for 65 percent of rain events and 15 percent of the total rain volume.

A Grandfather Speaks Up
James Hansen is sometimes called the grandfather of climate change science, but he also happens to be the grandfather of a pair of youngsters named Sophie and Conner. In the TED talk below, he explains how their birth helped spur him—a self-described “reticent midwestern scientist”—to speak out about the science he’d been studying for decades.

 

Taking Science to the People: Climate Forum in Maryland

March 20th, 2012 by Mike Carlowicz

Ernie Hilsenrath spent more than 40 years working for NASA, and though he officially retired a few years ago, he is still a great advocate for his employer and for science. The longtime atmospheric chemist is both amazed and troubled by how few people know that NASA works in Earth science. He is equally troubled by all of the misinformation and misunderstanding in the public discourse about our planet.

“I have met many educated people who did not know that NASA runs Earth-observing missions,” said Hilsenrath, who served as deputy project scientist and program scientist for the Aura satellite mission. “They know about going to the Moon and Hubble and astronauts and Mars rovers. But many don’t know that NASA is out there watching this planet, gathering important data about Earth systems and the quality of our environment.”

He decided to do something about it. Working with his nearby county college, local civic groups in Maryland, and several NASA colleagues, Hilsenrath has organized two public science events for this week. During “Observations from Space: Earth and Climate Change,” NASA scientists will present the latest data and images from Earth-observing satellites and then have an interactive discussion about climate change.

The first event will take place from 7 to 9 p.m. on Wednesday, March 21, and it will be geared toward students from Howard Community College and local high schools. The second forum is open to the public and will be held from 9 a.m. to noon on Saturday, March 24. Both free events will be held at Howard Community College, which is sponsoring the event along with the Climate Change Initiative of Howard County, Howard County’s Office of Environmental Sustainability, and NASA.

“In recent years, people have drifted away from seeing our environment and climate as a priority,” Hilsenrath noted. “I would like to raise some awareness and nudge people back to caring about it. There are some uncertainties and unknowns, but there is a lot more convincing data — non-partisan data — about real and measurable changes.”

If you cannot make it in person, both events will be shown via webcast. Visit http://aura.gsfc.nasa.gov/20120321hcc.html for more information.