DataStreme ECS WEEK 9: 31 October-4 November 2011

• 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.
• Balloon flight experimenters sought -- NASA is currently accepting applications from undergraduate and graduate students at the university level to fly experiments into the exosphere on a scientific balloon as part of a joint project between NASA and the Louisiana Space Consortium (LaSPACE) in Baton Rouge. The next flight opportunity for the LaSPACE maintained High Altitude Student Platform (HASP) facility is targeted for fall 2012. [NASA]

• Successful launch of nation's newest environmental satellite -- Last Friday, the NPOESS Preparatory Project (NPP) spacecraft payload was launched by NASA from Vandenberg Air Force Base, CA and successfully placed into orbit. This polar-orbiting NPP spacecraft features five new instruments that will collect detailed information about Earth's atmosphere, land and oceans. These data will be vital for NOAA's weather and climate forecasting mission. [NOAA News] [NASA] Photos and video of the launch are available. [NASA Earth Observatory]
• Crack seen in an Antarctic glacier ice shelf -- During two recent flights on the NASA DC-8 aircraft, researchers participating in the Operation IceBridge project have found and inspected a crack running across the floating ice shelf of the fast moving Pine Island Glacier along the West Antarctic coast. The rapid thinning of this marine glacier is of concern to scientists because it could contribute to sea level rise. [NASA Blogs] Nearby, scientists from Lamont -Doherty Earth Observatory have been studying the retreat of the fast-flowing Thwaites Glacier, which drains into west Antarctica's Amundsen Sea. The scientists are expecting the melting to accelerate within the next two decades, once the glacier detaches from an underwater ridge. Some of the data from this glacier were collected by NASA's IceBridge campaign in 2009. [Lamont -Doherty Earth Observatory]
• Changing climate devastating to glaciers of southwest China -- Researchers from the Chinese Academy of Sciences report that the annual temperatures at more than 100 stations across regions of southwestern China since 1961 have increased significantly, which have resulted in major retreats in the glaciers in the mountainous regions of the region. These higher temperatures and reduced glaciers appear to have affected natural habitats, tourism and wider economic development. [Institution of Physics]
• 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]

• Human-induced climate change could help increase Mediterranean drought frequency -- In a study of wintertime precipitation patterns from 1902 to 2010 across the Mediterranean basin by NOAA and University of Colorado Boulder scientists, wintertime droughts appear to have become increasingly common. From their analysis of past climatic observational data and output from computer models, these scientists conclude that changes in climate associated with human activity, such as the release of greenhouse gases, appear to be a major factor in the increased drought frequency. [NOAA News]
• Melt cycle on Greenland ice sheet could become self-amplifying--A team of scientists from the City College of New York claim that their research expedition to the Greenland ice sheet indicates that extreme melting of the ice does not necessarily coincide with record high temperatures and that the glaciers could be undergoing a self-amplifying cycle of melting and warming that would be difficult to halt. A combination of relatively warm conditions plus an albedo feedback mechanism appears to have been affecting the ice sheet's mass balance. [City College of New York]
• Floods may change with changes in atmospheric carbon dioxide -- Researchers with the US Geological Survey report that their analysis of flood conditions at 200 stream gauges across the nation over a time span ranging from 85 to 127 years indicates that while a clear pattern does not currently exist, a potential linkage could develop between increased greenhouse gas concentrations in the atmosphere and changes in flood behavior. [USGS Newsroom]

• Seaweed could be affected by ocean warming -- A scientist at the University of Western Australia reports that the herbarium records collected in the waters surrounding Australia since the 1940s reveals that nearly one quarter of the temperate seaweed species in these waters could be headed to extinction because of increased ocean temperatures due to a changing climate. [EurekAlert!]

• New tool improves cloud simulations in climate models -- Scientists at the US Energy Department's Lawrence Livermore National Laboratory and their colleagues have developed the "Cloud-Feedback-Model Intercomparison Project Observation Simulator Package" (COSP), a computational processing tool that permits climate models to more accurately simulate the effect of clouds upon the climate with increased spatial resolution. [Lawrence Livermore National Laboratory]

• Dramatic mass extinction found at end of Permian -- Analysis of numerous animal specimens have led researchers at Brown University and the University of Utah to conclude that the cataclysmic events marking the end of the Permian Period (approximately 252 million years ago) drastically reduced the number of land-based animal species to a few "disaster taxa" that survived. The terrestrial ecosystems had relatively low diversity for the next eight million years during the early Triassic before rebounding due to repopulation and diversification of species, rather than on an external event, such as an amelioration of climate. Fluctuations in the carbon cycle occurring after the extinction event resulted in unstable ecosystems. [Brown University News]
• Prehistoric data from ocean floor could help predict future climate -- Scientists at the University of Missouri, the University of Florida and the United Kingdom's University of Manchester report that their examination of deep ocean temperature and circulation data approximately 70 million years ago during the "greenhouse climate" of the late Cretaceous Epoch provides evidence of a warm and salty water mass in the Atlantic basin moving south. They claim that their research should help in the understanding of the potential consequences of future increases in greenhouse gases. [University of Missouri News Bureau]

• More decisive action needed to stem global warming -- In a comprehensive review of 193 emission scenarios from scientific literature to date, an international group of scientists including a scientist from Australia's University of Melbourne warn that in order to achieve the internationally agreed upon target of a 2 Celsius degree increase by 2020, more action is required to reduce carbon dioxide emissions. This study analyzed feasible emissions scenarios and mitigation actions that ranged from energy efficiency to carbon free technologies such as solar photovoltaic, wind and biomass. [University of Melbourne Newsroom]
• Plans needed for climate-forced migration -- An international consortium of 12 scientists recently warned that governments around the world must plan for mass migrations that would caused by rising global temperatures or face the potential of calamitous results. [University of Florida News]
• Navajo memories help in assessing climate change in Southwest -- A geologist with the US Geological Society has conducted interviews with elders of the Navajo Nation together with other historical research in her decade-long research of the climate changes on the Navajo Nation lands of northeastern Arizona. The interviews help provide an unique perspective of the changing climate from those who have lived on this land that has seen recent drought and sand dune migration. [USGS Newsroom]
• 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.

• 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)
• 5 November 1977...A slow moving storm produced five to nine inch rains across northern Georgia causing the Toccoa Dam to burst. As the earthen dam collapsed, the waters rushed through the Toccoa Falls Bible College killing three persons in the dorms. Thirty-eight persons perished at a trailer park along the stream. Eighteen bridges were washed out in Madison County. (David Ludlum)
• 5 November 1987...Heavy rains in California's Death Valley National Park washed out many park roads. As much as 1.20 in. of rain fell at Scotty's Castle, compared with the annual rainfall average of 2.28 in. Up to 8000 people attending a recreational encampment were stranded. (Accord Weather Calendar)
• 5 November 1991...Elkins, WV dropped to 8 degrees, the coldest so early in the season. Pittsburgh, PA dropped to 11 degrees also the coldest so early. Jackson, KY fell to 17 degrees, a daily record. (Intellicast)
• 6 November 1988...A powerful low-pressure system over the Great Lakes Region continued to produce snow across parts of the Ohio Valley and the Great Lakes Region. Snowfall totals along the shore of Lake Superior reached 24 inches, with three feet of snow reported in the Porcupine Mountain area of Upper Michigan. Marquette, MI established a November record with 17.3 inches of snow in 24 hours. (The National Weather Summary) (Storm Data)
• 6 November 1989...Unseasonably warm weather prevailed in the south central and southeastern U.S. The high temperature of 89 degrees at the Dallas/Fort Worth Airport in Texas equaled their record for November. (Storm Data) (The National Weather Summary)
• 6 November 1994...Downtown San Francisco, CA was drenched with 6.19 inches of rain in 24 hours to set an all-time record for the city.

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