DataStreme ECS WEEK THREE: 7-11 February 2011

CURRENT CLIMATE STATUS

• Annual drought report -- The National Climate Data Center has posted its 2010 annual drought report online. This report describes how the areas experiencing drought and wet conditions changed throughout the calendar year. Using the Palmer Drought Severity Index, approximately four percent of the United States experienced severe to extreme drought conditions in January 2010, while 42 percent of the area had severely to extremely wet conditions. By the end of December, the size of the severe to extreme drought had was at 16 percent of the area of the United States, while the severely to extremely wet conditions covered 36 percent of the area.

CURRENT CLIMATE MONITORING

• Animation of global snow cover produced -- An animation of monthly global maps of snow cover collected from February 2000 through December 2010 has been produced by the Earth Observatory mission at NASA's Goddard Space Flight Center. The monthly maps were obtained from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. [NASA Earth Observatory]
• Satellites monitor three decades of Antarctic "ozone hole" changes --
A series of images made from data collected by NASA's Total Ozone Mapping Spectrometer (TOMS) and the Royal Netherlands Meteorological Institute (KNMI) Ozone Monitoring Instrument (OMI) shows the distribution of ozone across the Southern Hemisphere on the date of maximum depletion in four different years since 1979. The images show the total amount of ozone through an atmospheric column, expressed in Dobson Units. The region over Antarctica with the smallest amount of stratospheric ozone has often been dubbed the "ozone hole." Changes in ozone are being monitored to ascertain the effectiveness of the Montreal Protocol banning the use of ozone-destroying chlorofluorocarbons. [NASA Earth Observatory]
• Rain in Spain declined over last 60 years --
Scientists at Spain's University of Zaragoza, the Czech Hydrometeorological Institute and the Italy's Institute of Atmospheric and Climate Science of Bologna recently reported on their analysis of precipitation trends in Spain's ten hydrological basins between 1946 and 2005. They found that precipitation has declined overall between the months of March and June, reducing the length of the rainy season. However, they also found October rains to be heavier in northwestern Spain. [EurekAlert!]
• An All-Hazards Monitor --
This Web portal provides the user information from NOAA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [NOAAWatch]
• Global and US Hazards/Climate Extremes --
A review and analysis of the global impacts of various weather-related events, including drought, floods and storms during the current month. [NCDC]

CLIMATE FORCING

• Recent Amazon droughts alarm scientists --
  A team of scientists from the United Kingdom and Brazil claim that two severe droughts across Amazonia within five years are having a devastating effect on the river basin's rainforests. They calculated that the 2010 drought appears more serious than the 2005 drought, which had been billed as a one-in-100 year event. They warn that the adverse effect of these droughts on the rainforests would result in the release of large amounts of carbon dioxide into the atmosphere. [EurekAlert!]

• Changing climate could threaten wolverine population --
A study conducted involving computer model simulations made at the National Center for Atmospheric Research indicates that projected changes in the climate across the northwestern United States could adversely affect the wolverine population, which normally live in boreal forests and tundra regions of the Northern Hemisphere. A warmer climate could reduce the springtime snow cover needed to protect the newborn and the increased August temperatures could be higher than what the species would tolerate. [NCAR/UCAR News]
• Climate is one of the factors affecting turtle populations --
Researchers at the USDA Forest Service's Pacific Northwest Research Station and colleagues report that turtle populations across the nation are becoming decimated by a combination of factors involving climate change habitat loss, road kill, mortality from farm equipment, and overexploitation (for pets). The scientists are attempting to determine how increases in global temperature may affect turtle reproduction. To bring attention to issues affecting turtles, 2011 has been designed as the Year of the Turtle. [US Forest Service Pacific Northwest Research Station]

PALEOCLIMATE RECONSTRUCTION

• Ice cores help provide past climate record --
  A research team funded by the National Science Foundation recently reached a milestone as it completed drilling a bore hole in ice sheet at the West Antarctic Ice Sheet Divide. This team has collected a main ice core reaching to a depth of 3,331 meters (10,928 feet), which is the deepest ice core drilled by the United States. This core will be analyzed to ascertain the last 100,000 years of Earth's climate history, focusing on how changes in the atmospheric concentration of greenhouse gases have influenced the Earth's climate over time. [NSF]
• New drought records help investigate ancient Mesoamerican civilizations --
A research team from the University of Arkansas, Fayetteville, Southern Illinois University, NOAA's National Climatic Data Center and several Mexican research institutions have reconstructed a detailed 12-century long record of rainfall fluctuations in ancient Mexico and Central America (Mesoamerica) from a 1,238-year-long tree-ring chronology. They claim that this record provides the accurate timing of four ancient megadroughts that may have played a role in the fall of pre-Hispanic civilizations in the region. [American Geophysical Union]
• Climate models improved by new discoveries --
Scientists from the US Geological Survey and their colleagues from the United Kingdom reported on their study of the influence of the Greenland-Scotland Ridge under the surface of the North Atlantic and Arctic Oceans upon the surface water temperature over the last three million years, back to the mid-Pliocene warm period. They argue that their discovery of how underwater ridges impact ocean circulation will help improve climate projections run using climate models. [USGS Newsroom]

CLIMATE AND SOCIETY

• Website for human dimensions of climate change -- An interagency effort within the US federal government that included NOAA, the Bureau of Land Management and the US Forest Service, has resulted in a website called HD.gov (for HumanDimensions.gov) that provides users, such as natural resource managers, with information on the human dimensions on a variety of topics of interest such as climate change. [HD.gov]
• Earthweek --
Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Climate sensitivity is a relatively new and powerful concept in climate science. It is a measure of how responsive the temperature of Earth’s climate system is to a change in radiative forcing due to increases in atmospheric carbon dioxide, an important greenhouse gas, combined with the contributions of feedbacks within the system. Specifically, the term is defined as how much the global mean surface temperature will increase if there is a doubling of atmospheric greenhouse gases (in terms of equivalent CO₂), once the planet has had a chance to settle into a new equilibrium after the increase occurs. In other words, it’s an assessment of how Earth’s climate will respond to that doubling.

According to NASA climate scientist James Hansen, the concept of climate sensitivity has its origins in a request made by President Jimmy Carter in 1979 for the National Academy of Sciences (NAS) to report on the potential impact on climate of the increasing atmospheric concentration of carbon dioxide. Jule G. Charney (1917-1981) of the Massachusetts Institute of Technology (MIT) led the Academy investigation team. He designed a now classic experiment where computer models of Earth’s climate system had the atmospheric concentration of CO₂ doubled while all other variables (except temperature) were held constant.

The addition of CO₂ makes the atmosphere more opaque for outgoing infrared radiation (heat), warming the lower atmosphere and cooling the upper atmosphere. Applying basic radiation laws, Charney found that doubling the atmospheric CO₂ concentration would reduce the net radiative flux (from Earth to space) at the tropopause by a global average of about 4 watts per square meter (W/m²). How much warmer would Earth’s surface become as a consequence of this enhanced greenhouse effect? According to the Stefan-Boltzmann law, the radiation emitted by an object is directly proportional to the fourth power of the object’s absolute temperature. To reestablish radiative equilibrium following a doubling of atmospheric CO₂, Earth must radiate to space an additional 4 W/m², brought about by a global warming of 1.2 Celsius degrees (or 0.3 Celsius degrees per W/m²).

Charney’s initial experiment accounted for the effect of a forcing agent (i.e., atmospheric CO₂) on global climate but not the influence of feedbacks. As noted in the Concept of the Week for Week 2, forcing agents and mechanisms drive climate change, while feedbacks determine the magnitude of climate change. Hence, Charney’s "no-feedback" experiment significantly underestimates the amount of global warming likely to accompany a doubling of atmospheric CO₂. With inclusion of feedbacks, the 1979 Academy study indicated that global warming could range from 2 to 3.5 Celsius degrees. The most recent IPCC report (AR4) estimates the magnitude of warming with feedbacks incorporated as 3 Celsius degrees with a range of uncertainty of 2 to 4.5 Celsius degrees. This greater sensitivity depends primarily on all the different feedbacks, both positive and negative, that either amplify or diminish the greenhouse effect. The three primary feedbacks involve clouds, sea ice, and water vapor.

In summary, climate sensitivity is usually expressed in terms of the equilibrium change in global mean annual surface temperature caused by an increment in downward infrared radiative flux that would result from sustained doubling of atmospheric CO₂ concentration compared to its pre-industrial level (taken to be 280 ppmv).

Concept of the Week: Questions

1. All other factors being equal, the addition of CO₂ to the atmosphere [(increases) (decreases)(has no effect upon)] the flux of infrared radiation from Earth’s surface to space.
2. Charney’s initial estimate of the amount of global warming that would accompany a doubling of atmospheric CO₂ [(did)(did not)] account for the temperature change(s) likely to accompany feedbacks in Earth’s climate system.

Historical Events:

• 7 February 1892…The lowest temperature ever recorded to that time in Asia was reported from Verkhoyansk, Russia with a 90-degree below zero reading. This record was subsequently tied in 1933. (The Weather Doctor)
• 7 February 1989...The low of 43 degrees below zero at Boca, CA was a state record for the month of February. In Utah, lows of -32 degrees at Bryce Canyon, -27 degrees at Delta, -29 degrees at Dugway, and -38 degrees at Vernal were all-time records for those locations. (The National Weather Summary)
• 8 February 1933...The record low temperature for the state of Texas was set at Seminole when the mercury dropped to 23 degrees below zero. (Intellicast)
• 8 February 1936...The temperature at Denver, CO plunged to its all-time record low temperature of 30 degrees below zero. (David Ludlum) (The Weather Channel)
• 9 February 1899...Norway House, Manitoba reported a temperature of 63 degrees below zero to set the province's record for lowest temperature. (The Weather Doctor)
• 9 February 1933...The temperature at Moran, WY, located next to Teton National Park, plunged to 63 degrees below zero to establish a state record. The temperature at the Riverside Ranger Station in Montana near West Yellowstone, MT dipped to 66 below zero to establish a record for the state, and a record for the nation, which stood until 1954. (David Ludlum)
• 9 February 1934...The mercury dipped to 51 degrees below zero at Vanderbilt to establish a record for the state of Michigan. The temperature at Stillwater Reservoir plunged to 52 degrees below zero to establish a record for the state of New York; this record was subsequently tied in February 1979. (David Ludlum) (NCDC)
• 10 February 1899...The record low temperature for the state of Ohio was set at Milligan when the mercury dipped to 39 degrees below zero. The record low temperature for Virginia was also set at Monterey with 29 degrees below zero; this record has been broken in January 1985. (Intellicast) (Sandra and TI Richard Sanders - 1987)
• 11 February 1895...Braemar (Grampian), Scotland reported a temperature of 17 degrees below zero, the lowest temperature ever measured in the United Kingdom. (The Weather Doctor)
• 11 February 1899...Perhaps the greatest of all arctic outbreaks commenced on this date. The record low temperature for Washington, DC was set when the temperature fell to 15 degrees below zero. (David Ludlum) (Intellicast)
• 11 February 1935...Temperature of 11 degrees below zero at Ifrane, Morocco was the lowest temperature ever in Africa. (The Weather Doctor)
• 11 February 1970...Mount Washington, NH, the highest point in New England, recorded 10.38 inches during a 24-hour span (10^th-11^th) to set a statewide 24 hour maximum precipitation record. (NCDC)
• 11 February 1999...Tahtsa Lake, located in the Whitesail Range of the Coast Mountains of British Columbia reported 57 inches of snow, which set a new 24-hour snowfall record for Canada, eclipsing the old record of 46.5 inches of snow that fell at Lakelse, BC on 17 January 1974. This former record replaced a 44.0 inch summertime snowfall on 29 June 1963 at Livingston Ranger Station, AB. (Accord's Weather Guide Calendar) (The Weather Doctor)
• 12 February 1899...Texas and the eastern Great Plains experienced their coldest morning of modern record. The temperature at Camp Clarke, NE plunged to 47 degrees below zero to establish a record for the Cornhusker State; this record has been tied in December 1989. (David Ludlum)
• 13 February 1784...Ice floes blocked the Mississippi River at New Orleans, then passed into the Gulf of Mexico. The only other time this occurred was during the "Great Arctic Outbreak" of 1899. (David Ludlum)
• 13 February 1899...It was the coldest morning of record along the Gulf Coast. The mercury dipped to 2 degrees below zero at Tallahassee, the lowest reading of record for the state of Florida. The record low temperature for the state of Louisiana was set at Minden, when the thermometer fell to 16 degrees below zero. A trace of snow fell at Fort Myers, FL. This was the farthest south snow has ever been observed in the U.S. until 1977 when snow fell in Miami. The lowest temperature ever recorded at Dayton, OH occurred when it dropped to 28 degrees below zero. (David Ludlum) (Intellicast)
• 13 February 1905...Morning lows of 29 degrees below zero at Pond, AR, 40 degrees below at Lebanon, KS, and 40 below at Warsaw, MO established all-time records for those three states. (The Weather Channel)

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Prepared by Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2011, The American Meteorological Society.