WEEKLY CLIMATE NEWS

DataStreme ECS WEEK 9: 29 October-2 November 2012

ITEMS OF INTEREST

• Reconstructing past climates -- Scientists from many disciplines have developed a variety of methods that use proxy indicators such as tree rings, ice cores and ocean cores to reconstruct past climates, some extending back thousands of years. For more details on paleoclimatology, or the study of past climates, and available data sets, please read this week's Supplemental Information...In Greater Depth.

CURRENT CLIMATE STATUS

• High-quality maps of November temperature and precipitation normals across US available -- The PRISM Climate Group at Oregon State University has prepared high-resolution maps depicting November's normal maximum temperature, minimum temperature and precipitation totals across the 48 coterminous United States for the current 1981-2010 climate normals interval. These maps, with a 800-meter resolution, were produced using the PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate mapping system.
• Second smallest Antarctic "ozone hole" in two decades -- According to measurements obtained from instruments onboard NASA and NOAA satellites, the size of the so-called "ozone hole" over Antarctica during the current austral spring reached a maximum size of only 8.2 million square miles on 22 September 2012, which was the second smallest seasonal ozone hole in the last 20 years. The "ozone hole" is a region of depleted ozone amounts in the stratosphere. In September, the areal size was roughly equivalent to the combined size of the United States, Canada and Mexico; for comparison, the largest ozone hole extent so far recorded to date was 11.5 million square miles in 2000. [NOAA News] NASA's Goddard Space Flight Center has assembled an animation that includes daily images of the ozone hole over Antarctica from 1 July to 19 October 2012. [NASA Earth]
  A nearly 6-minute long video has been prepared by NASA's Goddard Space Flight Center describing the chain of events that commenced with the discovery of the depleted stratospheric ozone layer over Antarctica in the mid-1980s that progressed to the signing of the initial 1987 Montreal Protocol, which is an international treaty designed to protect this ozone layer through the regulation of chlorofluorocarbons (CFCs). [NASA GSFC]
• Polar ice appear to behave oppositely in two hemispheres -- A new NASA study produced by climate scientists from NASA's Goddard Space Flight Center has shown that the sea ice cover over the Arctic Ocean in the Northern Hemisphere has been decreasing during the last three decades since satellite surveillance began in 1979, while the total extent of sea ice in the Southern Ocean surrounding Antarctica in the Southern Hemisphere has been increasing. The scientists describe what they consider to be the reasons for the opposite behaviors of the sea ice in the two hemispheres that include different geographies and the effects of absorbed solar radiation and the atmospheric circulation regimes. Comparative satellite-derived images for September 2012 are included that show the record minimal extent of the summer sea ice in the Arctic and the record maximum wintertime sea ice around Antarctica. [NASA Earth Science News Team]

CURRENT CLIMATE MONITORING

• 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]

• Malaria transmission may peak at lower temperatures -- Researchers from the US Geological Survey and other research universities across the nation including the University of California-Santa Barbara used a mathematical model to determine that the air temperature for malaria transmission from mosquitoes to humans by the parasite, Plasmodium falciparum, should peak at approximately 25 degrees Celsius (11 degrees Fahrenheit), nearly 6 Celsius degrees (11 Fahrenheit degrees) lower than what was previously considered an optimal temperature. In addition, they found that the transmission dramatically decreases above 28 degrees Celsius (82 degrees Fahrenheit). These findings are important in understanding how the deadly malaria, especially prevalent in Africa, is sensitive to climate. [USGS Newsroom]

CLIMATE FORCING

• Permafrost appears not so permanent -- US Geological Survey scientists and their colleagues from the US, Canada and Sweden recently reported that projected thawing of the arctic permafrost over the next century would release as much as 44 billion tons of nitrogen and 850 billion tons of carbon into the atmospheric and hydrospheric environment that had been stored in this permafrost, or frozen ground. They claim that the release of both nitrogen and carbon from the permafrost could exacerbate the increases in global temperature and also would impact water systems on land and offshore. [USGS Newsroom]

PALEOCLIMATE RECONSTRUCTION

• Old Weather-Arctic citizen science project to Reconstruct historical climate of the Arctic -- NOAA, the National Archives and Records Administration, the citizen science web portal called Zooniverse and other partners are seeking volunteers to transcribe a newly digitized set of ship logs from US Navy, US Coast Guard and Revenue Cutter voyages in the Arctic between 1850 and the World War II era. The project is called the Old Weather-Arctic citizen science project. These logs, which have been preserved by NARA, could provide a wealth of weather data for climate scientists from around the world. [NOAA News]
• Early history of atmospheric and oceanic oxygen investigated -- Geochemists from the University of California-Riverside, the University of Manitoba and the University of Johannesburg have used isotope analysis to study the changes in oxygen levels in both the atmosphere and oceans of early planet Earth. They found that a dramatic increase in oxygen levels within both the atmosphere and ocean occurred in what is called the "Great Oxidation Event" at approximately 2.4 billion years ago was followed a major drop in oxygen approximately 200 million years later. [University of California, Riverside Today]

CLIMATE AND SOCIETY

• Collaborative research projects funded to help coastal communities manage effects of climate change -- Recently, NOAA and the University of New Hampshire have announced that more than $4.9 million has been awarded through NOAA's National Estuarine Research Reserve System Science Collaborative to fund nine collaborative research projects aimed at making coastal communities and environments more resilient to rising sea levels, changing weather patterns, extreme storms, and ocean warming and acidification. [NOAA News]
• 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.

Concept of the Week: Extending the Historical North American Drought Record

Through history, drought has been a major concern for many people as the lack of adequate water can adversely affect agriculture, and in the extreme case, the availability of potable (drinkable) water. The Case in Point for Chapter 9 describes the migration of ancient peoples across the semiarid Southwest due to what may have been major drought conditions. During the last century, the "Dust Bowl" era drought in the 1930s created many problems in this country. The effects of this seven-year long drought were made worse by poor agricultural techniques and land management. The effect of the drought on the nation was also exacerbated by the coincident Great Depression. Drought remains a problem today across Texas and the West Coast as we can see from inspection of the current weekly US National Drought Monitor produced by the National Drought Mitigation Center.

How do the current drought events compare with earlier droughts? A time series of computed Palmer Drought Severity Index (PDSI) values began in 1895 when a sufficiently dense climate network was established. During the 20th century, several episodes of drought have had a major national impact. The exceptional drought that developed in the early 1930s extended across much of the nation resulting in the "Dust Bowl" era. The PDSI time series shows that the 1930s drought was the worst in the last century, with nearly 80 percent of the nation experiencing moderate to extreme drought in 1934. During the 1950s, the southern Plains and the Southwest also experienced a major drought, when 50 to 60 percent of the nation was under drought conditions.

What about farther back in history? Sophisticated tree-ring analysis techniques allow researchers to extend the drought record across a large section of North America farther into the past. In 1998, Edward R. Cook at Columbia University's Lamont-Doherty Earth Observatory along with colleagues at Arizona and Arkansas reconstructed past drought conditions across the nation based upon annual tree-ring data obtained from a network of 388 climatically sensitive tree-ring sites. From these data, time series of annual summertime (June-August) PDSI values were determined back to 1700 at 155 grid points across the nation. These gridded tree-ring chronologies were calibrated with PDSI chronologies generated by instrumental records at selected Historical Climate Network stations commencing in the late 19th century. The researchers found that the 1930s drought was the most severe drought to hit the nation since 1700.

By 2004, the series was expanded to 835 tree-ring sites, primarily across the West, where exactly dated annual tree-ring chronologies were obtained. The new grid covered most of North America with a latitude-longitude spacing of 2.5 degrees. In addition to the 286 grid point PDSI time series, annual contour maps of PDSI were constructed that span much of the continent. This work permitted extension of the spatial and temporal coverage of the drought reconstruction not only into Canada and Mexico, but back 2000 years. From this more recent data set they produced an online "North American Drought Atlas." They found several "megadroughts" in North America were even more severe than the 1930s drought. In addition to being more severe, some droughts extended over several decades, considerably longer than those of the 20th century. One such megadrought was in the 16th century, an event that along with another megadrought into the early 17th century has been implicated by some researchers in the hardships encountered by British settlers in the Virginia area, such as the disappearance of the Roanoke Colony.

Concept of the Week: Questions

(Place your responses on the Chapter Progress Response Form provided in the Study Guide.)

1. The 1930's Dust Bowl era drought [(does), (does not)] appear to be the most intense across the nation of any in the last two thousand years.
2. The "North American Drought Atlas" is based on 835 sites where trees in climatically sensitive areas produce [(monthly),(annual),(biennial)] growth rings.

Historical Events:

• 29 October 1917...The temperature at Soda Butte, WY the mercury plunged to 33 degrees below zero, an U.S. record for the month of October. (David Ludlum)
• 29 October 1991...Bismarck, ND received 15.9 inches of snow on the 28^th and 29^th. This brought the October snowfall total to 23.5 inches, a new record. (Intellicast)
• 30 October 1925...Nashville, TN was blanketed with an inch of snow, their earliest measurable snow of record. (The Weather Channel)
• 31 October 1987...Yakima, WA reported measurable rainfall for the first time since 18 July. The 103-day long dry spell was their longest of record. (The National Weather Summary) (Storm Data)
• 31 October 1991...A severe winter storm dubbed the "Great Halloween Mega Storm" struck the upper Midwest. Minnesota bore the brunt of the storm. By the time the storm finally ended on 2 November, Duluth received 37 inches of snow and Minneapolis 28 inches, which were new all time records for single storm totals. These two cities received nearly half their normal seasonal snows in this one storm. In Wisconsin, 35 inches of snow was reported at Superior and 30 inches at Iron River. (Intellicast)
• 31 October 1993...Corpus Christi, TX dropped to 28 degrees to set the October (and November) record. Brownsville dropped to a monthly record 35 degrees. (Intellicast)
• 2 November 1946...A heavy wet snow began to cover the Southern Rockies. Up to three feet of snow blanketed the mountains of New Mexico, and a three-day snowstorm began at Denver, CO. By the time it ended, this storm had dropped 31 inches, making it the second greatest snowfall ever in city history and causing roofs to collapse. (David Ludlum)
• 2 November 1961...The temperature at Atlanta, GA reached 84 degrees to establish a record for November. (The Weather Channel)
• 2 November 1966...A storm brought 18 inches of snow to Celia, KY in 24 hours. It tied the state 24-hour snowfall record first established at Bowling Green. (The Weather Channel)
• 2 November 1988...A very intense low pressure system brought heavy rain, snow, and high winds, to parts of the northeastern U.S. Portland, ME established a record for November with 4.52 inches of rain in 24 hours, and winds along the coast of Maine gusted to 74 mph at Southwest Harbor. (The National Weather Summary) (Storm Data)
• 3 November 1890...The temperature at Los Angeles, CA reached 96 degrees, a November record for 76 years. (David Ludlum)
• 3 November 1927...The "Great Vermont Flood" began as a two-day rain of up to 9 inches put rivers in western New England over their banks. Somerset, VT was deluged with 8.77 inches of rain to establish a 24-hour record for the state. (3^rd-4^th) (The Weather Channel) (Intellicast)
• 3 November 1989...Cold weather prevailed in the central U.S. The low of 7 above zero at Marquette, MI was their lowest reading of record for so early in the season. (The National Weather Summary)
• 4 November 1983...The temperature at Billings, MT soared to 77 degrees, a new record for the data and month. (Intellicast)
• 4-5 November 1966...The River Arno surged above flood stage and caused irreparable damage to much of the architectural and art treasure of Florence, Italy. Millions of historical library volumes were either damaged or destroyed. More than 15,000 vehicles were also destroyed. Roughly two-thirds of Florence was flooded, 113 people died and 30,000 were made homeless by the flooding on both the Arno and Po rivers. (Accord Weather Calendar) (Wikipedia)

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Prepared by Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2012, The American Meteorological Society.