Precipitation declines in Pacific Northwest mountains

Dec 03, 2013

Recent Forest Service studies on high-elevation climate trends in the Pacific Northwest United States show that streamflow declines tie directly to decreases and changes in winter winds that bring precipitation across the region. Scientists believe the driving factors behind this finding relates to natural climate variations and man-made climate change.

Research Hydrologist Charlie Luce, with the Rocky Mountain Research Station's Aquatic Sciences Laboratory in Boise, Idaho, along with cooperators at the University of Idaho and the US Forest Service Northern Region, reflect on the decline of precipitation in the region's mountains for 60 years. Increasing wildfire area and earlier and lower streamflows have generally been attributed to warming temperatures.

"Our research," says Luce, "suggests that an alternative mechanism – decreases in winter winds leading to decreased precipitation – may compound the changes expected from warming alone. This is important because mountains are a primary source for the region. Less precipitation leads to reduced runoff for communities, industry and agriculture. Decreased precipitation also exacerbates early snowmelt tied to warming temperatures.

Acknowledging the effects of decreasing precipitation requires changes in how resource specialists approach adaptation for water resources and forest management compared to preparing for increased temperature alone," he said. According to Luce, this may present important implications for changes in mountain and future water availability for other areas as well.

The American Association for the Advancement of Science is publishing the study, The Missing Mountain Water; Slower Westerlies Decrease Orographic Enhancement in the Pacific Northwest USA, in their Science journal, available on Nov. 28, 2013.

Explore further: Rising temperatures challenge Salt Lake City's water supply

add to favorites email to friend print save as pdf

Related Stories

Rising temperatures challenge Salt Lake City's water supply

Nov 01, 2013

In an example of the challenges water-strapped Western cities will face in a warming world, new research shows that every degree Fahrenheit of warming in the Salt Lake City region could mean a 1.8 to 6.5 percent drop in the ...

Statistically linking extreme precipitation to global warming

Sep 24, 2013

Extreme rainfall can have serious effects on societies and ecosystems. Increases in extreme precipitation events are predicted to occur as Earth's climate warms, in part because warmer air has greater capacity to hold moisture, ...

Valley networks suggest ancient snowfall on Mars

Jul 23, 2013

Researchers at Brown University have shown that some Martian valleys appear to have been caused by runoff from orographic precipitation—moisture carried part of the way up a mountain and deposited on the ...

Recommended for you

Tropical Storm Rachel dwarfed by developing system 90E

2 hours ago

Tropical Storm Rachel is spinning down west of Mexico's Baja California, and another tropical low pressure area developing off the coast of southwestern Mexico dwarfs the tropical storm. NOAA's GOES-West ...

NASA ocean data shows 'climate dance' of plankton

5 hours ago

The greens and blues of the ocean color from NASA satellite data have provided new insights into how climate and ecosystem processes affect the growth cycles of phytoplankton—microscopic aquatic plants ...

Glaciers in the grand canyon of Mars?

7 hours ago

For decades, planetary geologists have speculated that glaciers might once have crept through Valles Marineris, the 2000-mile-long chasm that constitutes the Grand Canyon of Mars. Using satellite images, ...

NASA support key to glacier mapping efforts

7 hours ago

Thanks in part to support from NASA and the National Science Foundation, scientists have produced the first-ever detailed maps of bedrock beneath glaciers in Greenland and Antarctica. This new data will help ...

User comments : 0