Earth Gauge » Atmosphere

Climate Number: One Inch per Year

kraus — Mon, 30 Jan 2012 15:15:42 +0000

The extent of the Arctic sea ice, which is usually gauged by its annual minimum extent in September, has been declining by 11.2 percent per decade since 1979. Large-scale effects of this decline impact Earth’s climate, primarily through increased absorption of sunlight by the open oceans. Local effects have also been documented. As ice has melted, the number of open water days along the coasts of the Beaufort and Chukchi Seas around Alaska increased from an average of 45 days in the late 1970’s to about 95 days in recent years. This increased melt means there is less ice protecting and stabilizing the sea cliffs in the region, which has caused increased cliff erosion along these coasts. The sea cliffs are now retreating at a rate of 45 feet per year. Decreased Arctic sea ice has also made the waters in the Chukchi Sea and Pacific-Arctic Ocean choppier. Less ice means that there is a larger area in which waves can develop and a longer ice-free season, allowing for late fall and early winter storms to move over water instead of ice. These developments mean that the average surface wave heights are growing over the Chukchi Sea at a rate of 0.8 inches per year and over the Pacific-Arctic at a rate of one inch per year. In the Chukchi Sea, there were five events in the 2000s when surface wave heights exceeded 13 feet; during the 1990s, only two of these events occurred.

For comparison: Global sea level is rising at about 2.1 millimeters per year, or a little over one-sixteenth of an inch.

Seasons: Winter, Spring, Summer, Fall

Sources: Overeem, I et al. “Sea ice loss enhances wave action at the Arctic coast.” Geophysical Research Letters 38 (2011): L17503 and National Snow and Ice Data Center: Arctic Sea Ice News and Analysis. Accessed Online 28 January 2011 and Francis, OP et al. “Ocean wave conditions in the Chukchi Sea from satellite and in situ observations.” Geophysical Research Letters 38 (2011): L24610.

AO, ENSO and Your Winter Weather

kraus — Fri, 13 Jan 2012 21:02:24 +0000

Two large scale circulation patterns, the Arctic Oscillation and the El Niño-Southern Oscillation, have proven useful for predicting winter weather in different areas of the United States.

AO: The Arctic Oscillation (AO) is the difference in atmospheric pressure between the Arctic and the mid-latitudes of the Northern Hemisphere. Upper-atmospheric westerly winds and mid-latitude winter storms are stronger during “positive phases” of the AO (when the pressure difference is greater), and these stronger winds serve as a “blocking” mechanism that keeps the frigid Arctic air in the Arctic instead of invading many midlatitude areas, particularly the Eastern United States, leading to milder winter temperatures there. Negative phases work the opposite way, with less blocking and a colder eastern United States.

So far, the Arctic Oscillation has favored mild winter temperatures in the Eastern United States (http://www.climatewatch.noaa.gov/image/2011/so-far-arctic-oscillation-favoring-mild-winter-for-eastern-u-s)

Useful Climate Analogy: The Arctic Oscillation and Your Refrigerator Door.

http://www.earthgauge.net/2011/analogies-of-basic-physical-principles#arctic The El Niño-Southern Oscillation (ENSO) is a periodic shift in tropical Pacific sea surface temperature distributions. During cool La Niña phases, the northern hemisphere storm track tends to move farther north, leading to a wetter northern tier of the United States – particularly a wetter Northwest – and a drier southern tier. El Niño phases bring relatively the opposite conditions.

NOAA’s Winter Weather Outlook (http://www.climatewatch.noaa.gov/image/2011/2011-2012-winter-outlook) gives different regional probabilities for warmer/colder or wetter/drier conditions. Variation in this outlook is driven largely by differences in the state of the El Niño-Southern Oscillation.

Regional Outlooks:

Albany, Georgia Winter Outlook: The Albany area has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a 40 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Albuquerque, New Mexico Winter Outlook: The Albuquerque area has equal chances of experiencing well above or well below normal winter temperatures and has a 33 to 40 percent chance of receiving below average precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Anchorage, Alaska Winter Outlook: The Anchorage region has equal chances of experiencing well above or well below normal winter temperatures and an equal chance of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Arizona Winter Outlook: Most of Arizona has equal chances of experiencing well above and well below normal winter temperatures and a 33 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Asheville, North Carolina Winter Outlook: The Asheville region has a 40 to 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Atlanta, Georgia Winter Outlook: The Atlanta area has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Bismarck Winter Outlook: The Bismarck area has a greater than 40 percent chance of experiencing well below normal winter temperatures and a 40 to 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

California Winter Outlook: Most of California has a greater than 40 percent chance of experiencing well below normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Carbondale, Illinois Winter Outlook: The Carbondale area has a 33 to 40 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Central Mississippi Winter Outlook: Central Mississippi has a greater than 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well below and well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Central North Carolina Winter Outlook: The Central North Carolina region has a 33 to 40 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Central Oklahoma Winter Outlook: Central Oklahoma has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a 40 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Colorado Springs Winter Outlook: The Colorado Springs region has equal chances of experiencing well above and well below normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Dallas, Georgia Winter Outlook: The Dallas region has a 40 to 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well below and well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Dayton, Ohio Winter Outlook: The Dayton region has equal chances of experiencing well above and well below normal winter temperatures and a greater than 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Eastern Nebraska Winter Outlook: The Eastern Nebraska region has equal chances of experiencing well above and well below normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Eastern Tennessee Winter Outlook: Eastern Tennessee has a 40 to 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Fairbanks, Alaska Winter Outlook: The Fairbanks region has a greater than 40 percent chance of experiencing well below normal winter temperatures and a 33 to 40 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Fallon, Nevada Winter Outlook: The Fallon region has a 33 to 40 percent chance of experiencing well below normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Florida Panhandle Winter Outlook: The Florida Panhandle region has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a 40 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Grand Forks, North Dakota Winter Outlook: The Grand Forks area has a greater than 40 percent chance of experiencing well below normal winter temperatures and a 40 to 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Iowa Winter Outlook: Most of Iowa has equal chances of experiencing well above or well below normal winter temperatures and equal chances of receiving well above or well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period. A predominately positive Arctic Oscillation has so far favored mild winter temperatures in the region.

Kansas Winter Outlook: Most of Kansas has a 33 to 40 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Little Rock, Arkansas Winter Outlook: The Little Rock region has a 40 to 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Louisiana Winter Outlook: Most of Louisiana has a greater than 50 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Lubbock Winter Outlook: The Lubbock area has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a greater than 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Memphis, Tennessee Winter Outlook: Memphis has a 40 to 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Minnesota Winter Outlook: Most of Minnesota has a 33 to 40 percent chance of experiencing well below normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Missoula, Montana Winter Outlook: The Missoula region has a 33 to 40 percent chance of experiencing well below normal winter temperatures and a greater than 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Missouri Winter Outlook: The State of Missouri region has a 33 to 40 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well below and well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Mobile, Alabama Winter Outlook: The Mobile area has a greater than 50 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Nashville, Tennessee Winter Outlook: The Nashville area has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Northeast Winter Outlook: The Northeast has equal chances of experiencing well above or well below normal winter temperatures and an equal chance of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period. A predominately positive Arctic Oscillation has so far favored mild winter temperatures in the region.

Northern Alabama Winter Outlook: Northern Alabama has a greater than 40 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well below or well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Northern California Winter Outlook: Northern California has a greater than 40 percent chance of experiencing well below normal winter temperatures and 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Northern Colorado Winter Outlook: The Northern Colorado region has equal chances of experiencing well above and well below normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Northern Florida Winter Outlook: The Northern Florida region has a 33 to 40 percent chance of experiencing well above normal winter temperatures and a greater than 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Northern Mississippi Winter Outlook: Northern Mississippi has a 40 to 50 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well below and well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Ohio Winter Outlook: Most of Ohio has equal chances of experiencing well above and well below normal winter temperatures and a greater than 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Ohio Valley Winter Outlook: The Ohio Valley region has a 33 to 40 percent chance of experiencing well above normal winter temperatures and a greater than 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Plentywood Winter Outlook: The Plentywood region has a greater than 40 percent chance of experiencing well below normal winter temperatures and a greater than 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Pocatello-Idaho Falls Winter Outlook: The Pocatello-Idaho Falls region has equal chances of experiencing well above and well below normal winter temperatures and around a 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Portland, Oregon Winter Outlook: The Portland region has a greater than 40 percent chance of experiencing well below normal winter temperatures and around a 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Rapid City, South Dakota Winter Outlook: The Rapid City region has equal chances of experiencing well above and well below normal winter temperatures and a 40 to 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Reno, Nevada Winter Outlook: The Reno area has a greater than 40 percent chance of experiencing well below normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Salt Lake City Winter Outlook: The Salt Lake City region has equal chances of experiencing well above and well below normal winter temperatures and around a 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

San Diego, California Winter Outlook: The San Diego region has a 33 to 40 percent chance of experiencing well below normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Sandpoint Winter Outlook: The Sandpoint region has a greater than 40 percent chance of experiencing well below normal winter temperatures and a greater than 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Santa Fe Winter Outlook: The Santa Fe region has equal chances of experiencing well above or well below normal winter temperatures and has a 33 to 40 percent chance of receiving below average precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Savannah, Georgia Winter Outlook: The Savannah area has a 33 to 40 percent chance of experiencing well above normal winter temperatures and a 40 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Socorro, New Mexico Winter Outlook: The Socorro region has equal chances of experiencing well above or well below normal winter temperatures and has a 40 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

South Carolina Winter Outlook: Most of South Carolina has a 33 to 40 percent chance of experiencing well above normal winter temperatures and a 40 to 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

South Florida Winter Outlook: The South Florida region has equal chances of experiencing well above and well below normal winter temperatures and a greater than 60 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Spartanburg, South Carolina Winter Outlook: The Spartanburg region has a 40 to 50 percent chance of experiencing well above normal winter temperatures and a 33 to 40 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Springfield-Eugene, Oregon Winter Outlook: Most of Oregon has a greater than 40 percent chance of experiencing well below normal winter temperatures and a 40 to 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Texas Winter Outlook: Most of Texas has a greater than 50 percent chance of experiencing well above normal winter temperatures and a greater than 50 percent chance of receiving well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Twin Falls, Idaho Winter Outlook: The Twin Falls region has a 33 to 40 percent chance of experiencing well below normal winter temperatures and a 40 to 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Upper Midwest Winter Outlook: The Upper Midwest has equal chances of experiencing well above and well below normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Virginia Winter Outlook: Most of Virginia has a 33 to 40 percent chance of experiencing well above normal winter temperatures and equal chances of receiving well above and well below normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

Washington State Winter Outlook: Most of Washington State has a greater than 40 percent chance of experiencing well below normal winter temperatures and a greater than 50 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period.

West Virginia, Western New York and Western Pennsylvania Winter Outlook: The Western Pennsylvania and Western New York region has equal chances of experiencing well above or well below normal winter temperatures and a 33 to 40 percent chance of receiving well above normal precipitation levels. “Well above” and “well below” normal are defined by NOAA as conditions falling into the top or bottom third of climate conditions observed during the 1980 to 2010 period. A predominately positive Arctic Oscillation has so far favored mild winter temperatures in the region.

Climate Fact: Finches on the Move (East)

kraus — Wed, 07 Dec 2011 15:17:13 +0000

In Brief: Warmer winter temperatures are allowing the Purple Finch to winter 433 miles farther north than it did in the 1960s.

Observers during recent annual Audubon Christmas Bird Counts are noticing different birds in their local areas during the winter months than observers did in the 1960s. Between 1966 and 2005, significant northward movement of 177 out of 305 observed species was documented. Not all species moved north and a few may be wintering a little farther south, but the general trend has been an average northward movement of 35 miles. More than 60 species are now wintering at least 100 miles farther north than they did in the 1960s. General trends of species movement toward or away from the poles happen during periods of climate warming and cooling, as species seek their preferred conditions. The average temperature in January in the lower 48 states rose by over five degrees Fahrenheit from 1966-2005. This means that temperatures are now more tolerable in more northerly areas, letting birds stop their southerly migrations sooner and remain closer to the north pole during winter. In the eastern United States, the range of the Purple Finch has advanced by 433 miles over the past 40 years. This is about the distance from the Virginia-North Carolina border to southern Connecticut.

Want to help scientists collect more data about winter bird ranges? Participate in the Christmas Bird Count from December 14, 2011 to January 5, 2012.

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Purple Finch (click for image download from U.S. Fish and Wildlife Service)

Photo courtesy of Dr. Thomas T. Barnes, U.S. FWS

Source: The Audubon Society. “Birds and Climate Change: Ecological Disruption in Motion.” February 2009. Accessed Online 2 December 2011 < http://birdsandclimate.audubon.org/>

Climate Fact: Finches on the Move (Midwest)

kraus — Wed, 07 Dec 2011 15:15:15 +0000

In Brief: Warmer winter temperatures are allowing the American Goldfinch to winter 250 miles farther north than it did in the 1960s.

Observers during recent annual Audubon Christmas Bird Counts are noticing different birds in their local areas during the winter months than observers did in the 1960s. Between 1966 and 2005, significant northward movement of 177 out of 305 observed species was documented. Not all species moved north and a few may be wintering a little farther south, but the general trend has been an average northward movement of 35 miles. More than 60 species are now wintering at least 100 miles farther north than they did in the 1960s. General trends of species movement toward or away from the poles happen during periods of climate warming and cooling, as species seek their preferred conditions. The average temperature in January in the lower 48 states rose by over five degrees Fahrenheit from 1966-2005. This means that temperatures are now more tolerable in more northerly areas, letting birds stop their southerly migrations sooner and remain closer to the North Pole during winter. In the Midwest United States, the range of the American Goldfinch has advanced by 250 miles over the past 40 years. This is about the distance from the southern to northern border of Missouri.

Want to help scientists collect more data about winter bird ranges? Participate in the Christmas Bird Count from December 14, 2011 to January 5, 2012.

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Goldfinch (click for image download from U.S. Fish and Wildlife Service)

Photo courtesy of David Brezinski, U.S. FWS

Source: The Audubon Society. “Birds and Climate Change: Ecological Disruption in Motion.” February 2009. Accessed Online 2 December 2011 < http://birdsandclimate.audubon.org/>

Climate Fact: Finches on the Move (West)

kraus — Wed, 07 Dec 2011 15:11:22 +0000

In Brief: Warmer winter temperatures are allowing the House Finch to winter 270 miles farther north than it did in the 1960s.

Observers during recent annual Audubon Christmas Bird Counts are noticing different birds in their local areas during the winter months than observers did in the 1960s. Between 1966 and 2005, significant northward movement of 177 out of 305 observed species was documented. Not all species moved north and a few may be wintering a little farther south, but the general trend has been an average northward movement of 35 miles. More than 60 species are now wintering at least 100 miles farther north than they did in the 1960s. General trends of species movement toward or away from the poles happen during periods of climate warming and cooling, as species seek their preferred conditions. The average temperature in January in the lower 48 states rose by over five degrees Fahrenheit from 1966-2005. This means that temperatures are now more tolerable in more northerly areas, letting birds stop their southerly migrations sooner and remain closer to the north pole during winter. In the western United States, the range of the House Finch has advanced by 270 miles over the past 40 years. This is about the distance from Fresno, California to the California-Oregon border.

Want to help scientists collect more data about winter bird ranges? Participate in the Christmas Bird Count from December 14, 2011 to January 5, 2012.

Download image in high resolution
(1280 x 720)

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(640 x 360)

House Finch (click for image download from U.S. Fish and Wildlife Service)

Photo courtesy of Dave Menke, U.S. FWS

Source: The Audubon Society. “Birds and Climate Change: Ecological Disruption in Motion.” February 2009. Accessed Online 2 December 2011 < http://birdsandclimate.audubon.org/>

Climate Number: 195 Kelvin (-108.67 degrees Fahrenheit)

kraus — Mon, 31 Oct 2011 15:30:29 +0000

Commercial airline flights spend most the time in the lower reaches of the stratosphere, which is the second layer of the atmosphere beginning at five to six miles up in the air. The air in the stratosphere is thin and cold, making it inhospitable, but it is also less turbulent than the air in the troposphere near the Earth’s surface, which is part of the reason pilots like to fly there. The stratosphere is also where a protective layer of ozone sits. While ozone near the Earth’s surface poses a health hazard to people, ozone in the stratosphere has been protecting life for billions of years. Depletion of stratospheric ozone happens during the respective winters at both poles, as temperatures dip below 195 Kelvin allowing polar stratospheric clouds to form. Within these clouds, conditions are just right for a series of chemical reactions to take place, with the result being the destruction of ozone molecules. This ozone destruction process is more intense around Antarctica, leading to the formation of the famous “ozone hole” around that continent. Ozone concentrations reach their minimum during the Southern Hemisphere spring (September to December), following the peak (June through August) winter ozone destruction season. The same process happens in the Arctic, but not to the same extent. This past winter of 2010-2011, however, featured the lowest ever recorded stratospheric ozone values in the Arctic, although these values are higher than the values regularly experienced over Antarctica during its ozone minimum season. Temperatures at 12.5 miles in altitude over the Arctic remained below 195 Kelvin from mid-December 2010 through the end of March 2011. One climatic trend that may have influenced this first “Arctic ozone hole” is the cooling of the lower stratosphere by 0.5 Kelvin per decade and the cooling of the upper stratosphere by 1.0 Kelvin since 1979. This cooling is related to the warming of the troposphere that occurred during the same period.

For comparison: If 195 Kelvin (-108.67 degrees Fahrenheit) sounds cold, it is! Water boils at 373.16 Kelvin (212 degrees Fahrenheit) and freezes at 273.16 Kelvin (32 degrees Fahrenheit). It is not quite as cold, however, as the lowest surface temperature ever recorded, which was 184.0 Kelvin (-128.6 degrees Fahrenheit) at Antarctica’s Russian Vostok Station in July of 1983.

Seasons: Winter, Spring, Summer, Fall

Sources: Garcia, RR. “An Arctic ozone hole?” Nature 478 (2011): 462-463 and Manney, GL et al. “Unprecedented Arctic ozone loss in 2011.” Nature 478 (2011): 469-475.

Climate Fact: African Smoke and Dust over the Amazon

kraus — Mon, 24 Oct 2011 14:15:57 +0000

In Brief: African aerosols are transported across the Atlantic, affecting the climate of the Amazon rainforest.

Dust suspended in the air and smoke from fires make up most of the aerosol concentrations found in the air around us. Aerosols affect how much sunlight reaches the Earth’s surface and how clouds form, which means they can have a strong influence over regional precipitation. Aerosols also link different parts of the world: winds can carry aerosols from fires and dust storms far away, even across oceans, affecting the climates of remote regions. This is particularly true for the Amazon rainforest. Dust storms in the Sahara Desert, combined with the smoke that is generated during Central Africa’s dry season when fires are common, are carried by northeasterly trade winds across the Atlantic to the Amazon. This transport is most common from January to May and takes approximately ten days to reach South America from Africa. The January through May period is the wet season in most of the Amazon, when there are few fires and dust generation is at a minimum. During this time, aerosols from Africa impact air in the Amazon – they are present in about one-third of aerosol measurements taken across the Amazon region. Aerosols are considered a wild card in Amazonian weather and climate prediction. Variations in aerosol concentrations can make the difference between rainfall occurring or not. Generally, higher aerosol concentrations mean less rainfall. African dust does, however, provide a fertilizer for the soils of the Amazon, helping plant growth.

Seasons: Winter, Spring, Summer, Fall

Source: Baars, H. et al. “Further evidence for significant smoke transport from Africa to Amazonia.” Geophysical Research Letters 38 (2011): L20802.

Climate Fact: Stratospheric Aerosol Trends

kraus — Mon, 17 Oct 2011 14:33:40 +0000

In Brief: Periods of increased stratospheric aerosol content over the past 50 years likely dampened the warming trend.

Volcanic eruptions can cool the Earth by injecting sulfur up into the stratosphere, the second layer of the atmosphere between five and 30 miles in altitude. The volcanoes increase stratospheric levels of tiny droplets of sulfuric acid, which work to reflect incoming sunlight. Volcanoes in the tropics, such as Pinatubo in the Philippines, which erupted in 1991 and Tambora in Indonesia, which erupted in 1815, are particularly good at cooling the planet because their emissions travel into both hemispheres. Even smaller volcanic eruptions, such as the 2006 Soufriére Hills (located in the Caribbean) and Tavurvur (Papua New Guinea, South Pacific) eruptions, are clearly noticeable to scientists taking measurements of the aerosol content of the stratosphere. These measurements show significant variability in stratospheric aerosol content. Overall aerosol loads increased by between five and nine percent each year from the 1960s through the 1980s, and then declined during the 1990s. They have been rebounding since 2000. The causes behind these trends are not entirely understood, although rises and declines in aerosol levels following volcanic eruptions are evident and relatively predictable. The Earth’s warming trend experienced since the 1960s would likely have been more pronounced without the accompanying trend of increased stratospheric aerosol content.

Seasons: Winter, Spring, Summer, Fall

Source: Solomon, S et al. “The Persistently Variable ‘Background’ Stratospheric Aerosol Layer and Global Climate Change.” Science 333 (2011): 866-869.

Climate Fact: Plants Help Persist Prevailing Precipitation Patterns

kraus — Mon, 17 Oct 2011 14:31:43 +0000

In Brief: Plants, particularly in the Amazon, influence their climate by moving moisture from the soil into the atmosphere – less when the soil is dry and more when the soil is wet. This helps to maintain both wet and dry rainfall regimes.

Every place in the world has its own climate with its own average temperature and precipitation levels. Some places around the world, such as most equatorial rainforests, experience little seasonal variation and are hot and wet throughout the year. Locations closer to the poles have more seasonal climates. The Northeast United States, for example, has rainfall evenly spread throughout the year, but the summer months are much warmer than the winter months. In some locations in the tropics, temperatures don’t change much throughout the year, but there are defined wet and dry seasons. Similarly, from year to year some places have little rainfall variance while other locations can be considerably wetter or drier. Such inter-annual variability in rainfall can be particularly pronounced in parts of Amazon. Inter-annual rainfall variability in the Amazon is driven by surface temperature shifts every few years in the waters of the equatorial Pacific Ocean, and shifts on longer time scales in the tropical and subtropical Atlantic Ocean. These water temperature shifts move winds, affecting rainfall patterns on land. If it was not for the plants of the Amazon, however, this variability would be even greater. Wetter years, or years with wetter wet seasons and/or shorter dry seasons, are years when vegetation flourishes. More vegetation means more evapotranspiration, the movement of moisture from the soil through plants to the atmosphere. More evapotranspiration means more rainfall. This increase in rainfall helps to keep the wet conditions going into the next year, even if other factors would favor drier conditions. Drier years tend to stress vegetation, leading to less evapotranspiration and less rainfall, which perpetuates these dry conditions into the following year. This means that years following severe droughts, such as the “once-in-a-century” 2010 Amazon drought, may be more susceptible to further droughts. It also means that there is more year-to-year continuity of rainfall levels than there would otherwise be.

Seasons: Winter, Spring, Summer, Fall

Source: Wang, G et al. “Vegetation dynamics contributes to the multi-decadal variability of precipitation in the Amazon region.” Geophysical Research Letters 38 (2011): L19703.

Climate Fact: Mountains Drive Ocean Circulation Patterns

kraus — Mon, 26 Sep 2011 15:18:55 +0000

In Brief: Earth’s ocean circulation patterns and climate would be much different without the presence of the Rocky and Andes Mountains, and without the Antarctic Ice Sheet.

A system of big warm and cool water ocean currents, which dwarf the flow of even the largest rivers, work to mix heat and nutrients around the globe. This circulation is ultimately driven by two things: differences in heat and salt content in the water, and prevailing winds, which can generate currents as they move across the ocean surface. One crucial process for the whole system, the Atlantic Meridional Overturning Circulation (AMOC), happens in the far North Atlantic near Greenland. A flow of warm and very salty water from the south cools as it moves towards the pole. Once it becomes sufficiently cool and salty, and thus sufficiently dense, it sinks and becomes a cool deep water current heading south. Why does this same process not happen in the Pacific Ocean? The presence of the Rocky Mountains in North America and the Andes Mountains in South America block the westerly winds blowing moisture from the Pacific towards the Atlantic, reducing the amount of rainfall and freshwater the Atlantic gets. On the other hand, the Atlantic’s trade winds, which move over the mountain gaps of the thin Central American Isthmus, do bring moisture to the Pacific. This unequal exchange means the Pacific Ocean is dominated by a freshwater surface layer sitting on top of dense salty water, as opposed to in the Atlantic, where there is mobile salty surface water. Without the presence of these mountains, our oceans and climate would function quite differently.

Source: Schmittner, A et al. “Effects of Mountains and Ice Sheets on Global Ocean Circulation.” Journal of Climate 24 (2011): 2814-2829.

Climate Trivia: Bacteria and Rainfall

kraus — Sat, 27 Aug 2011 21:24:38 +0000

Trivia Question: True or False: Bacteria can cause rainfall.

The correct answer is true. Bacteria are single-celled organisms that are found on every continent, at the bottom of the ocean and as high as 50 miles in the atmosphere. Each year, between 90 million and four billion pounds of bacteria travel from the Earth’s surface into the air around us. While most of these bacteria sink down to the surface within days or weeks, winds sometimes carry them into circulation patterns that keep them aloft for years. Many bacteria return to Earth during rainfall, with both living and dead bacteria serving as cloud condensation nuclei (CCN). CCN are tiny particles that even smaller water vapor droplets cling to as raindrops form. Once enough water vapor droplets gather on the nuclei, raindrops fall. This is a critical part of Earth’s water cycle, which moves water from the oceans to the land, making freshwater and life on land possible. Without the nuclei, water vapor would not collect and fall as raindrops. Other types of condensation nuclei include mineral dust particles, salt from the ocean and sulfate from volcanic activity.

Seasons: Winter, Spring, Summer, Fall

Source: Smith, DJ et al. “The High Life: Transport of Microbes in the Atmosphere.” Eos 92 (2011): 249-250.

Climate Number: 5.7 x 1017 joules

kraus — Sat, 27 Aug 2011 21:23:00 +0000

Changes in climate are fundamentally about changes in the amount of energy in the air and water circulating around us. While most discussions of climate trends focus on the air temperature taken at the Earth’s surface, this is only one measure of the amount of energy in the air, let alone the climate system as a whole. The total amount of energy in a parcel of air above the land surface can be broken down into three variables: the kinetic energy, or how much wind is happening inside the parcel; the enthalpy of the air, which is closely related to the temperature measured with a thermometer; and the latent heat, or the energy associated with evaporation and moisture in the air. Generally, the warmest and wettest air parcels are the most energetic. Since at least the early 1970s, the air masses above Earth’s land surface have been gaining energy. There has been a slight “stilling” of winds, meaning a slight decrease in the kinetic energy variable, but this loss has been more than offset by large gains in enthalpy and latent heat content. On average, the surface air (the bottom 6.5 feet of the atmosphere) over Earth’s land surface gained 5.7 x 10¹⁷ joules between 1973 and 2003. In warmer regions, such as the tropics, the largest energy gains have been in latent heat, whereas at the higher latitudes, trends in enthalpy dominated as reflected by the larger temperature increases experienced there.

For comparison: The amount of energy it takes to power the global economy is about 474 exajoules, or 830 times the 5.7 x 10¹⁷ joules the bottom 6.5 feet of the atmosphere over land gained between 1973 to 2003. The amount of energy the top 6.5 feet of the oceans have gained over this same period is about 370 exajoules, about the same as annual global energy use, and the top 2,300 meters of the oceans have gained is 4.2 x 10²² joules worth of energy, or about 90 times annual global energy use.

Seasons: Winter, Spring, Summer, Fall

Source: Peterson, TC et al. “Observed changes in surface atmospheric energy over land.” Geophysical Research Letters 38 (2011): L16707.

Climate Number: 15 Million Pounds

kraus — Sun, 21 Aug 2011 16:34:40 +0000

In the air around you are organic aerosols – substances based on carbon-hydrogen bonds that are light enough to be suspended in the atmosphere for days or weeks. How much organic aerosol mass is in the air has direct implications for air quality and human health, as well as for climate and weather. Organic aerosols can help to seed clouds, which can affect how much of the Sun’s energy reaches the surface, and ultimately surface temperatures, rainfall levels and potentially even larger scale circulation patterns. Climate and weather conditions also drive atmospheric aerosol levels, with higher temperatures leading to higher organic aerosol emissions from plants, particularly conifers. In the loblolly pine forests of the Southeast, which cover about 116,000 square miles across 12 states, estimates of emissions of a certain type of volatile organic compound that is particularly important for atmospheric chemistry, sesquiterpenes, are in the range of 15 million pounds for the warm month of September. The amount of sequiterpene emissions increases exponentially with temperature and because organic sources such as pine trees account for as much as 50 percent of fine aerosol concentrations in mid-latitude regions like the southeast, this variance has significant implications for weather and climate variability.

For comparison: 15 million pounds is about the same weight as 80 fully loaded Boeing 737-800s.

Seasons: Summer, Fall

Sources: Horvath, E et al. “Microscopic fungi as significant sesquiterpene emission souces.” Journal of Geophysical Research: Atmospheres 116 (2011): D16301 and Helmig, D et al. “Sesquiterpene emissions from loblolly pine and their potential contribution to biogenic aerosol formation in the Southeastern US.” Environmental Sciences 40 (2006): 4150-4157.

Climate Fact: Positive Evaporation/Precipitation Feedback

kraus — Mon, 18 Jul 2011 14:36:12 +0000

In Brief: In the eastern United States, afternoon summertime rainfall events are more probable in areas where soil moisture levels are high.

Afternoon summertime precipitation in the wet, humid and heavily vegetated eastern United States is related to the evaporation that happens in the morning. Lots of soil moisture can stimulate lots of evaporation, which can push cloud development over the threshold where precipitation happens. This positive land-atmosphere feedback means that soil moisture conditions are self-reinforcing. Dry soils mean less evaporation and less plant-nurturing rainfall, while wet soils mean more evaporation that can enhance the probability of a rainfall event by up to 25 percent. Soil moisture conditions do not appear to be particularly influential regarding rainfall intensity, however, with other factors such as large-scale convergence largely controlling how much rain falls during a given summertime afternoon event. This coupling of processes at the land surface and the atmosphere helps to explain the persistence of droughts, as dry soil conditions make the atmosphere less conducive to drought-mitigating rainfall. It also explains the persistence of wet periods where ample soil moisture stimulates the precipitation that keeps it moist.

Seasons: Summer

Source: Findell, KL et al. “Probability of afternoon precipitation in eastern United States and Mexico enhanced by high evaporation.” Nature Geoscience 4 (2011): 434-439.

Climate Fact: Tropical Hydrological Cycle Changes: The Hadley Circulation

kraus — Mon, 23 May 2011 14:47:35 +0000

In Brief: The boundaries of the Hadley circulation have expanded over the past 30 years, with the most pronounced expansions occurring during the summer months.

Earth’s weather is driven largely by the behavior of two large scale tropical circulation systems: the Hadley circulation and the Walker circulation. The Hadley circulation develops as large columns of warm, moist air rise over the equatorial regions, where the sun’s radiation is most intense (the “rising” regions are between 17.5 degrees North and South). These air columns then travel towards the poles, dropping rainfall along the way. Once this air has literally “run out of steam,” it becomes dry, sinking air that creates areas of divergence on the Earth’s surface, promoting deserts between the latitudes of 17.5 and about 40 degrees in the Northern Hemisphere and 17.5 and 35 degrees in the Southern Hemisphere (the “sinking” regions). Over the last 30 years, this cycle has intensified, with increasing precipitation over the rising regions and decreasing precipitation over the sinking regions. In other words, wet regions are getting wetter and dry regions drier. In the Northern Hemisphere during this 30 year period, the average boundary of the Hadley circulation ? defined as the point where the dry subsidence regions end and wetter climates begin – has been moving poleward in all seasons except spring. The trend is most pronounced during the summer months, where the boundary is now about six degrees farther north than it was in the late 1970s. Similar but weaker trends exist for the Southern Hemisphere, with only one to two degrees latitude shift during the summer and fall months. This trend suggests that Earth’s subtropical desert regions may be growing.

Seasons: Winter, Spring, Summer, Fall

Source: Zhou, ZP et al. “Recent trends of the tropical hydrologic cycle inferred from Global Precipitation Climatology Project and International Satellite Cloud Climatology Project data.” Journal of Geophysical Research: Atmospheres 116 (2011): D09101.

Climate Fact: Tropical Hydrological Cycle Changes: The Walker Circulation

kraus — Mon, 23 May 2011 14:45:43 +0000

In Brief: Earth’s Walker circulations have strengthened over the last 30 years, with wet regions of the circulations getting wetter and dry regions getting drier.

Earth’s weather is driven largely by the behavior of two large scale tropical circulation systems: the Hadley circulation and the Walker circulation. The Walker circulation can be broken down into three different systems? the Indian, Pacific and Atlantic Walker circulations ? each having a region of rising air and a region of sinking air. The best known Walker circulation is the system where warm, moist air rises over the western tropical Pacific Ocean between 120 and 180 degrees East (from the eastern tip of Borneo east to Fiji) and travels east, dropping rainfall along the way. By the time this air approaches the West Coast of South America, it descends as dry air to the surface. This sinking air creates a zone of divergence which keeps the weather off the West Coast of equatorial South America very dry and the skies clear. Clear skies allow lots of sunlight to hit the waters off Peru, which along with a frequent upwelling of cold, nutrient rich water, creates one of the richest fishing grounds on Earth. Variations in the strength of this Walker circulation drive the El Niño-Southern Oscillation, which influences weather around the world. The two other Walker circulations operate in a similar manner, with rising regions in the western tropical Indian and Atlantic Oceans, and sinking regions in the eastern tropical Indian and Atlantic Oceans. All of these circulations appear to have strengthened over the last 30 years. Increasing precipitation in the rising regions and decreasing precipitation in the sinking regions, means that the wet areas of the tropics are getting wetter and the dry areas drier.

Seasons: Winter, Spring, Summer, Fall

Climate Fact: Controls on Annual River Flow Trends

kraus — Mon, 25 Apr 2011 13:40:23 +0000

In Brief: Climate is the dominant force behind changes in river flow on a global scale, despite many other significant contributing factors that must be accounted for when making accurate estimates of water cycle changes.

Regional precipitation and temperature changes, atmospheric composition changes that affect plant growth, land use changes, changes in nitrogen deposition on the soil, and even changes in near-surface ozone concentrations, atmospheric aerosol loading and solar irradiance have all likely contributed to changes in outflow of the world’s major rivers over the past 60 years. There has been an overall decrease of global river flow since the late 1940s, with the world’s major rivers now sending about one less cubic kilometer of freshwater into the oceans each year. This is a rough figure, with a great variation of trends in the world’s rivers. The Amazon River, for example, is putting more water into the Atlantic Ocean every year, due primarily to the impact that higher atmospheric carbon dioxide (CO2) levels are having on plants in its basin. Higher atmospheric CO2 levels mean that less water exits the plants through their stomata, the tiny openings in their leaves that regulate the exchange of gases between the plants and the atmosphere. With less moisture going from the soil to the air through the plant leaves, more water goes into the streams and rivers that lead to the ocean. The Yangtze River in China, on the other hand, has less outflow due largely to land use changes dominated by more agriculture and irrigation. Despite land use, CO2 levels and changes in nitrogen (a plant fertilizer) deposition all playing roles, climatic changes are far and away the dominant factor in water cycle changes on both global and most regional scales. Compared to the late 1940s, the Mississippi River is sending an average two more cubic kilometers of water into the Gulf of Mexico each year, due partly to atmospheric CO2 increases but primarily to increased rainfall the central United States.

Seasons: Winter, Spring, Summer, Fall

Source: Shi, X et al. “The impact of climate, CO2, nitrogen deposition and land use change on simulated contemporary global river flow.” Geophysical Research Letters 38 (2011): L08704.

Climate Number: 1670 Petagrams of Carbon

kraus — Mon, 04 Apr 2011 14:56:31 +0000

The northern circumpolar permafrost region – located mostly above 60 degrees North or the southern tip of Scandinavia – is an area where temperatures are so cold that the soil remains permanently frozen, except for an active surface layer that is as shallow as a few inches deep. Beneath this active layer lie ancient carbon stocks composed of partially decayed plants and animals that have remained frozen for thousands of years. Despite comprising only 16 percent of Earth’s total global soil area, these northern circumpolar zone carbon stocks hold about 1670 petagrams, or 1670 billion tons, of carbon. This is about 50 percent of the planet’s total below-ground carbon pool. It is also about twice the amount of carbon held in the atmosphere. Earth’s recent one degree Fahrenheit warming trend has been particularly pronounced in the Arctic region. The Arctic has been warming at twice the global rate since the 1970s and summer temperatures in the Alaskan and western Canadian Arctic have risen by 2.5 degrees Fahrenheit and winter temperatures by 3.6 degrees Fahrenheit. This has corresponded to thawing of deeper soil layers for longer periods of the year and a disturbance of the formerly locked-away ancient carbon. Emissions of this carbon from the soil into the atmosphere have been increasing, although they have been somewhat counteracted by an increase in surface vegetation, which takes more carbon out of the air. Experimental warming of plots in the Arctic shows that increases in thaw depth persist into the following winter, stimulating respiration that doubles the total amount of carbon released annually into the atmosphere.

For Comparison: 1670 Petagrams is about the same mass as 18 million Nimitz Class Aircraft Carriers or 300,000 Great Pyramids at Giza.

Seasons: Winter, Spring, Summer, Fall

Sources: Schuur, EAG et al. “The effect of permafrost thaw on old carbon release and net carbon exchange from tundra. Nature 459 (2009): 556-559 and Schuur, EAG et al. “Effects of Experimental Warming of the Deep Soil and Permafrost on Ecosystem Carbon Balance in Alaskan Tundra.” American Geophysical Union Fall Meeting 2009, abstract #U44A-03 and Tarnocai, C et al. “Soil organic carbon pools in the northern circumpolar permafrost region.” Global Biogeochemical Cycles 23 (2009): GB2023.

Climate Number: Five Gigatonnes of Carbon per Year

kraus — Fri, 25 Feb 2011 22:44:50 +0000

Commonly known as the biological carbon “pump,” oceans take carbon from out of the atmosphere and deposit it down to the depths. This process is dominated by phytoplankton on the surface taking carbon out of the atmosphere to build their bodies, dying and then falling down to the ocean bottom, where the carbon they originally took out of the atmosphere will stay for potentially millions of years. The oceans are vast, marine biological processes are complicated, sediment accumulates slowly at any given location of the ocean bottom and monitoring the depths is expensive; knowing how much carbon the oceans are storing is thus difficult and estimates for this potentially crucial climatic variable vary greatly. It is believed, however, that about 20 percent of the dissolved organic carbon taken out of the atmosphere that supports ocean life is exported to the depths. This number, as well as new estimates based on the well-known radioactive decay rate of uranium, have led to a new number of five gigatonnes of carbon per year being sequestered on the ocean floor.

For Comparison: About eight gigatonnes of carbon are emitted from human fossil fuel use each year. Five gigatonnes is about the same weight as 900 Great Pyramids at Giza.

Seasons: Winter, Spring, Summer, Fall

Source: Henson, SA et al. “A reduced estimate of the strength of the ocean’s biological carbon pump.” Geophysical Research Letters 38 (2011): L04606.

Climate Number: 150 Teragrams of Carbon

kraus — Mon, 03 Jan 2011 15:22:00 +0000

Tiny particles suspended in the air affect Earth’s temperature by reflecting, absorbing and scattering solar radiation. These tiny particles known as aerosols – generally between ten billionths and 1000 billionths of a meter –are so small that it only takes slight winds to keep them aloft. In addition to affecting solar radiation, aerosols are also critical to key nutrient cycles and even provide surfaces on which raindrops form, making them one type of condensation nuclei. Organic aerosols are a type of aerosol based on carbon and hydrogen bonds. Organic aerosols are produced by combustion (burning), vegetation, oceanic phytoplankton and human industrial activities. Past estimates of the atmosphere’s organic aerosol load have been broad. A recent estimate is 150 teragrams of carbon is emitted from Earth’s land surface each year as part of these organic aerosols. This mass does not include the mass of the hydrogen, oxygen, nitrogen, etc. atoms that are also part of the organic aerosol molecules. These organic aerosols are believed to spend about 21 days in the atmosphere before they fall to the Earth’s surface.

For Comparison: 150 teragrams is about the same weight as 300 fully loaded ultra large crude carrier tanker ships, the largest ocean-going ships in the world.

Seasons: Winter, Spring, Summer, Fall

Sources: Heald, CL et al. “Satellite observations cap the atmospheric organic aerosol budget.” Geophysical Research Letters 37 (2010): L24808 and Ellison, GB et al. “Atmospheric processing of organic aerosols.” Journal of Geophysical Research: Atmospheres 104 (1999): 11633-11641.