Can rain clean the atmosphere?
August 28, 2015 02:31 PM - MIT News
As a raindrop falls through the atmosphere, it can attract tens to hundreds of tiny aerosol particles to its surface before hitting the ground. The process by which droplets and aerosols attract is coagulation, a natural phenomenon that can act to clear the air of pollutants like soot, sulfates, and organic particles. Atmospheric chemists at MIT have now determined just how effective rain is in cleaning the atmosphere.
NASA's latest satellite data reveals global sea level rise
August 27, 2015 08:49 AM - ClickGreen Staff, ClickGreen
Global sea levels have risen nearly 3 inches in less than 25 years, with some locations around the world rising more than 9 inches, according to NASA’s latest satellite data. An intensive research effort now underway, aided by NASA observations and analysis, points to an unavoidable rise of several feet in the future.
The Fingerprints of Sea Level Rise
August 26, 2015 02:49 PM - NASA Jet Propulsion Laboratory
When you fill a sink, the water rises at the same rate to the same height in every corner. That's not the way it works with our rising seas.
According to the 23-year record of satellite data from NASA and its partners, the sea level is rising a few millimeters a year -- a fraction of an inch. If you live on the U.S. East Coast, though, your sea level is rising two or three times faster than average. If you live in Scandinavia, it's falling. Residents of China's Yellow River delta are swamped by sea level rise of more than nine inches (25 centimeters) a year.
These regional differences in sea level change will become even more apparent in the future, as ice sheets melt. For instance, when the Amundsen Sea sector of the West Antarctic Ice Sheet is totally gone, the average global sea level will rise four feet. But the East Coast of the United States will see an additional 14 to 15 inches above that average.
Cellphone location data shown to help track infectious disease
August 22, 2015 07:22 AM - B. Rose Huber, Woodrow Wilson School of Public and International Affairs, Princeton University
Tracking mobile phone data is often associated with privacy issues, but these vast datasets could be the key to understanding how infectious diseases are spread seasonally, according to a study published in the Proceedings of the National Academy of Sciences.
Princeton University and Harvard University researchers used anonymous mobile phone records for more than 15 million people to track the spread of rubella in Kenya and were able to quantitatively show for the first time that mobile phone data can predict seasonal disease patterns.
Harnessing mobile phone data in this way could help policymakers guide and evaluate health interventions like the timing of vaccinations and school closings, the researchers said. The researchers' methodology also could apply to a number of seasonally transmitted diseases such as the flu and measles.
Is the California Drought Causing Land to Sink?
August 21, 2015 08:56 AM - Jet Propulsion Laboratory
As Californians continue pumping groundwater in response to the historic drought, the California Department of Water Resources today released a new NASA report showing land in the San Joaquin Valley is sinking faster than ever before, nearly 2 inches (5 centimeters) per month in some locations.
MIT analysis improves estimates of global mercury pollution
August 21, 2015 07:26 AM - MIT News
Once mercury is emitted into the atmosphere from the smokestacks of power plants, the pollutant has a complicated trajectory; even after it settles onto land and sinks into oceans, mercury can be re-emitted back into the atmosphere repeatedly. This so-called “grasshopper effect” keeps the highly toxic substance circulating as “legacy emissions” that, combined with new smokestack emissions, can extend the environmental effects of mercury for decades.
Now an international team led by MIT researchers has conducted a new analysis that provides more accurate estimates of sources of mercury emissions around the world. The analysis pairs measured air concentrations of mercury with a global simulation to calculate the fraction of mercury that is either re-emitted or that originates from power plants and other anthropogenic activities. The result of this work, researchers say, could improve estimates of mercury pollution, and help refine pollution-control strategies around the world.
Sunspot variation not causing climate change
August 8, 2015 06:22 AM - INTERNATIONAL ASTRONOMICAL UNION via EurekAlert
The Maunder Minimum, between 1645 and 1715, when sunspots were scarce and the winters harsh, strongly suggests a link between solar activity and climate change. Until now there was a general consensus that solar activity has been trending upwards over the past 300 years (since the end of the Maunder Minimum), peaking in the late 20th century -- called the Modern Grand Maximum by some .
This trend has led some to conclude that the Sun has played a significant role in modern climate change. However, a discrepancy between two parallel series of sunspot number counts has been a contentious issue among scientists for some time.
4 million years at Africa's salad bar
August 5, 2015 09:18 AM - University of Utah
As grasses grew more common in Africa, most major mammal groups tried grazing on them at times during the past 4 million years, but some of the animals went extinct or switched back to browsing on trees and shrubs, according to a study led by the University of Utah.
Ice cores show volcanic eruptions and cold climate strongly linked
August 4, 2015 07:31 AM -
Researchers find new evidence that large eruptions were responsible for cold temperature extremes recorded since early Roman times
It is well known that large volcanic eruptions contribute to climate variability. However, quantifying these contributions has proven challenging due to inconsistencies in both historic atmospheric data observed in polar ice cores and corresponding temperature variations seen in climate indicators such as tree rings.
How Corn Became King
July 28, 2015 09:12 AM - Kelly April Tyrrell, University of Wisconsin-Madison
Ten thousand years ago, a golden grain got naked, brought people together and grew to become one of the top agricultural commodities on the planet.
Now, University of Wisconsin-Madison researchers have found that just a single letter change in the genetic script of corn's ancestor, teosinte, helped make it all possible.
Publishing in the journal Genetics this month, UW-Madison genetics Professor John Doebley and a team of researchers describe how, during the domestication of corn, a single nucleotide change in the teosinte glume architectural gene (tga1) stripped away the hard, inedible casing of this wild grass, ultimately exposing the edible golden kernel.