Tag Archives: climate models

Q&A: Harry Stern discusses historical maps, the Northwest Passage and the future of Arctic Ocean shipping

Harry Stern, a polar scientist at the University of Washington’s Applied Physics Laboratory, has been studying the Arctic Ocean for decades, and sailed part of the Northwest Passage in 2009. Stern’s latest work uses the earliest explorers’ experiences to better understand a maritime environment that still contains many unknowns. A paper published in November in Polar Geography uses Captain James Cook’s records of sea-ice edge, more than two centuries ago, as a way to understand the changes we’re seeing now. UW Today asked him a few questions about the project. (more…)

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Scientists Part the Clouds on How Droplets Form

Berkeley Lab researchers find new mechanism to explain the birth of cloud droplets, could influence climate models

There is enough known about cloud formation that replicating its mechanism has become a staple of the school science project scene. But a new study by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) reveals that much more is going on at the microscopic level of cloud formation than previously thought. (more…)

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Undersea mountains provide crucial piece in climate prediction puzzle

A mystery in the ocean near Antarctica has been solved by researchers who have long puzzled over how deep and mid-depth ocean waters are mixed.

They found that sea water mixes dramatically as it rushes over undersea mountains in Drake Passage – the channel between the southern tip of South America and the Antarctic continent. Mixing of water layers in the oceans is crucial in regulating the Earth’s climate and ocean currents.

The research provides insight for climate models which until now have lacked the detailed information on ocean mixing needed to provide accurate long-term climate projections. The study was carried out by the University of Exeter, the University of East Anglia, the University of Southampton, the Woods Hole Oceanographic Institution, the British Antarctic Survey and the Scottish Association for Marine Science and is published in the journal Nature. (more…)

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Researchers take new look at future Colorado River flows

The Colorado River provides water for more than 30 million people in the U.S. West, so water managers have been eager to understand how climate change will affect the river’s flow. But scientific studies have produced an unsettling range of estimates, from a modest decrease of 6 percent by 2050 to a steep drop of 45 percent by then.

A new paper by researchers at the University of Washington (UW), CIRES, NOAA and other institutions across the West investigates and explains why those estimates differ and summarizes what is known about the future of this iconic Western river—key information for decision makers. (more…)

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UCLA study shows warming in central China greater than most climate models indicated

Temperatures in central China are 10 to 14 degrees Fahrenheit hotter today than they were 20,000 years ago, during the last ice age, UCLA researchers report — an increase two to four times greater than many scientists previously thought.

The findings, published on May 14, 2013, in the early online edition of the journal Proceedings of the National Academy of Sciences, could help researchers develop more accurate models of past climate change and better predict such changes in the future. (more…)

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NASA to Launch Ocean Wind Monitor to Space Station

PASADENA, Calif. – In a clever reuse of hardware originally built to test parts of NASA’s QuikScat satellite, the agency will launch the ISS-RapidScat instrument to the International Space Station in 2014 to measure ocean surface wind speed and direction.

The ISS-RapidScat instrument will help improve weather forecasts, including hurricane monitoring, and understanding of how ocean-atmosphere interactions influence Earth’s climate. (more…)

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Climate Change Study Strengthens Link to Human Activities

Computer Models, Satellite Data Reveal Clearest Evidence Yet of Human Influence on Changing Temperatures

New research shows some of the clearest evidence yet of a discernible human influence on atmospheric temperature.

Published online in the Nov. 29 early edition of the Proceedings of the U.S. National Academy of Sciences, the study compared 20 of the latest climate models against 33 years of satellite data. When human factors were included in the models, they followed the pattern of temperature changes observed by satellite. When the same simulations were run without considering human influences, the results were quite different.

“We can only match the satellite record when we add in human influences on the atmosphere,” said Michael Wehner, a research scientist at Lawrence Berkeley National Laboratory (Berkeley Lab) Computational Research Division and a coauthor of the article, which involved colleagues from 16 other organizations and was led by Benjamin Santer, an atmospheric scientist at Lawrence Livermore National Laboratory (LLNL). (more…)

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International Study Provides More Solid Measure of Shrinking in Polar Ice Sheets

The planet’s two largest ice sheets have been losing ice faster during the past decade, causing widespread confusion and concern. A new international study provides a firmer read on the state of continental ice sheets and how much they are contributing to sea-level rise.

Dozens of climate scientists have reconciled their measurements of ice sheet changes in Antarctica and Greenland during the past two decades. The results, published Nov. 29 in the journal Science, roughly halve the uncertainty and discard some conflicting observations.

“We are just beginning an observational record for ice,” said co-author Ian Joughin, a glaciologist in the University of Washington’s Applied Physics Laboratory who is lead author on an accompanying review article. “This creates a new long-term data set that will increase in importance as new measurements are made.” (more…)

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