It seems counterintuitive that clouds over the Southern Ocean, which circles Antarctica, would cause rain in Zambia or the tropical island of Java. But new research finds that one of the most persistent biases in global climate models – a phantom band of rainfall just south of the equator that does not occur in reality – is caused by poor simulation of the cloud cover thousands of miles farther to the south.
University of Washington atmospheric scientists hope their results help explain why global climate models mistakenly duplicate the inter-tropical convergence zone, a band of heavy rainfall in the northern tropics, on the other side of the equator. The study appears this week in the Proceedings of the National Academy of Sciences. (more…)
Regional cloud changes, such as those that result in less rain during monsoons in India and those that indicate a widening of the tropics, may be as important to watch as the overall amount of cloud cover, new University of Washington research indicates.
Authors of the paper, led by Ryan Eastman, a UW research scientist in atmospheric sciences, set out to examine observations collected from weather stations around the world as a way to study the distribution of clouds. The research was recently published in the American Meteorological Society’s Journal of Climate. (more…)
Research May Also Help Determine Effects of Global Warming in the Region
With more than 40 million people living under exceptional drought conditions in East Africa, the ability to make accurate predictions of drought has never been more important. In the aftermath of widespread famine and a humanitarian crisis caused by the 2010-2011 drought in the Horn of Africa—possibly the worst drought in 60 years— researchers are striving to determine whether drying trends will continue.
While it is clear that El Niño can affect precipitation in this region of East Africa, very little is known about the drivers of long-term shifts in rainfall. However, new research described in the journal Nature helps explain the mechanisms at work behind historical patterns of aridity in Eastern Africa over many decades, and the findings may help improve future predictions of drought and food security in the region. (more…)
Plant and animal species are shifting their geographic ranges and the timing of their life events – such as flowering, laying eggs or migrating – at faster rates than researchers documented just a few years ago, according to a technical report on biodiversity and ecosystems used as scientific input for the 2013 Third National Climate Assessment.
The report, Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services, synthesizes the scientific understanding of the way climate change is affecting ecosystems, ecosystem services and the diversity of species, as well as what strategies might be used by natural resource practitioners to decrease current and future risks. More than 60 federal, academic and other scientists, including the lead authors from the U.S. Geological Survey, the National Wildlife Federation and Arizona State University in Tempe, authored the assessment. (more…)
PASADENA, Calif. – Scientists with NASA’s Cassini mission have spotted what appears to be a miniature, extraterrestrial likeness of Earth’s Nile River: a river valley on Saturn’s moon Titan that stretches more than 200 miles (400 kilometers) from its “headwaters” to a large sea. It is the first time images have revealed a river system this vast and in such high resolution anywhere other than Earth.
Scientists deduce that the river, which is in Titan’s north polar region, is filled with liquid hydrocarbons because it appears dark along its entire length in the high-resolution radar image, indicating a smooth surface. (more…)
There’s an old adage (with several variations) that California has four seasons: earthquake, fire, flood and drought. While Californians happily cede the title of Hurricane Capital of America to U.S. East and Gulf coasters, every once in a while, Mother Nature sends a reminder to Southern Californians that they are not completely immune to the whims of tropical cyclones. Typically, this takes the form of rainfall from the remnants of a tropical cyclone in the eastern Pacific, as happened recently when the remnants of Hurricane John brought rain and thunderstorms to parts of Southern California. But could a hurricane ever make landfall in Southern California?
The answer, as it turns out, is yes, and no. While there has never been a documented case of a hurricane making landfall in California, the Golden State has had its share of run-ins and close calls with tropical cyclones. In fact, California has been affected by at least a few tropical cyclones in every decade since 1900. Over that timeframe, three of those storms brought gale-force winds to California: an unnamed California tropical storm in 1939, Kathleen in 1976 and Nora in 1997. But the primary threat from California tropical cyclones isn’t winds or storm surge. It’s rainfall — sometimes torrential — which has led to flooding, damage and, occasionally, casualties. (more…)
Students use tornado-chasing technology to research rain’s impact on stream
COLUMBIA, Mo. – With advances in meteorology technology, predicting storms is becoming easier than in the past. While most meteorology students learn about these new technologies in the classroom and don’t get a chance to use sophisticated equipment until they are on the job, a group of University of Missouri students were able to test a mobile weather tracking device, Doppler on Wheels (DOW), made famous by shows such as Discovery Channel’s Storm Chasers.
The DOW visiting MU is one of a fleet of radar trucks maintained by the Center for Severe Storm Research. Each radar truck is mounted with a Doppler weather radar dish. The fleet also consists of a support vehicle and three trucks that deploy instruments to track weather patterns in tornadoes and hurricanes. One of the radar trucks was brought to MU so that students could learn about the technology first-hand. (more…)
A NASA-sponsored expedition is set to sail to the North Atlantic’s saltiest spot to get a detailed, 3-D picture of how salt content fluctuates in the ocean’s upper layers and how these variations are related to shifts in rainfall patterns around the planet.
The research voyage is part of a multi-year mission, dubbed the Salinity Processes in the Upper Ocean Regional Study (SPURS), which will deploy multiple instruments in different regions of the ocean. The new data also will help calibrate the salinity measurements NASA’s Aquarius instrument has been collecting from space since August 2011. (more…)
