DataStreme ECS WEEK 7: 17-21 October 2011

• September drought report -- The National Climate Data Center has posted its September 2011 drought report online. Using the Palmer Drought Severity Index, approximately 24 percent of the coterminous United States experienced severe to extreme drought conditions at the end of September, while 24 percent of the area had severely to extremely wet conditions.
• Review of September 2011 global temperatures -- Preliminary data analyzed by scientists at NOAA's National Climatic Data Center indicated that the global combined land and ocean average surface temperature for the September 2011 was 0.95 Fahrenheit degrees above the 20th century average (1901-2000) for the month. Therefore, last month's global temperature was the eighth highest September temperature since global temperature records began in 1880. When considered separately, the monthly temperatures of the land surface for this recently concluded month resulted in the fourth highest September land surface temperature on record, while September monthly average temperature over the global oceans was the 14th highest September ocean temperature in 132 years. La Niña conditions were strengthening during September, which may have reduced the September ocean temperatures. Furthermore, when considering the combined land-ocean global temperature for the year to date, this temperature was the eleventh highest nine-month global temperature since 1880.
  Arctic sea ice coverage after the end of the first week of September reached its annual minimum, which was the second smallest annual extent since satellite surveillance began in 1979. On the other hand, the areal extent of the Antarctic sea ice cover during September was slightly above the long-term average, ranking as the 14th largest since 1979. [NOAA News] Additional information is available on the monitoring of this past summer's minimum in Arctic sea ice by satellite. [NASA's Earth Science News Team]

• Counting down to launch of new polar-orbiting environmental satellite -- NASA scientists and engineers are preparing for the launch within ten days of a new polar-orbiting environmental satellite called the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) that is intended to measure both global climate changes and key weather variables, which should ultimately enable NOAA to improve weather forecasting accuracy. NPP instruments will include a "Visible Infrared Imaging Radiometer Suite" to monitor the surface characteristics of the land and ocean; an "Ozone Mapper Profiler Suite" to measure the concentration of ozone in the atmosphere; a "Clouds and Earth's Radiant Energy System" to monitor the amount of energy entering and exiting the top of the atmosphere; a "Cross-track Infrared Sounder" that measures atmospheric temperature profiles; and an "Advanced Technology Microwave Sounder" that generates detailed vertical profiles of atmospheric pressure, heat and humidity. [NOAA NESDIS] [NASA]
• Critical survey of Antarctica's changing ice continues -- During the last week, scientists participating in NASA's Operation IceBridge began this mission's third year of surveys on the changing ice of Antarctica. This Operation IceBridge mission, represents the largest airborne research campaign flown over this polar cap, is designed to collect critical ice sheet measurements that can be used to determine how this major ice sheet could contribute to an anticipated global sea level rise. [NASA GSFC]
• 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]

• Insoluble dust particles can form cloud droplets that affect climate -- Scientists at Georgia Tech have shown that insoluble dust particles can help form cloud droplets. These scientists claim that their research should help improve the accuracy of both regional and global climate models, especially in areas of the world that have significant amounts of mineral aerosols in the atmosphere. [Georgia Tech Research News]
• Baltic Sea adds to atmospheric carbon dioxide -- Scientists at Sweden's University of Gothenburg have found that the Baltic Sea emits more carbon dioxide to the overlying atmosphere than it sequesters in its waters. From their analysis of 15 years of seawater data, they found large differences in the flux of carbon dioxide between atmosphere and the seawater between seasons, between years and between regions. [EurekAlert!]

• Permanent ecosystem destruction can be caused by severe drought -- Scientists at Oregon State University have found that some aquatic desert ecosystems have been driven into irreversible "catastrophic regime change" by increasingly frequent and severe drought, dropping water tables and dried-up springs. [Oregon State University]
• Developing plants that accommodate climate change is progressing -- Scientists at Brown University and colleagues have been studying the genetic bases of plant adaptations to local climate in an effort to develop plant strains that would be able to thrive in multiple types of climates and, hence, survive climate change. [NSF News]
• Future forests may sequester more carbon dioxide to help buffer climate change -- Researchers from the University of Michigan, the US Forest Service and Michigan Technological University claim that North American forests appear to have a greater capacity to assimilate atmospheric carbon dioxide gas than researchers had previously anticipated, which would help slow the pace of human-caused climate warming. They based their findings on a 12-year study in an experimental forest in northeastern Wisconsin. [University of Michigan News Service]

• Future changes in Hawaiian rainfall patterns foreseen -- Using rainfall data from across Hawaii's Oahu Island, a statistical model and projected temperature trends from the Intergovernmental Panel on Climate Change (IPCC), scientists at University of Hawaii - Manoa have projected changes in the frequency and intensity across Oahu over the next 30 years. They predicted an increased frequency of heavy rainfall events, but a decrease in rainfall intensity over the next three decades for the southern shoreline of Oahu. [School of Ocean and Earth Science and Technology University of Hawaii – Manoa] [NOTE: This link requires the Adobe Acrobat Reader; see below]

• Using luminous sand grains to date historic storm flood -- Scientists at Delft University of Technology in the Netherlands and their colleagues have used to optical stimulated luminescence of sand grains to match a layer of sediment from the dunes near Heemskerk to a severe storm flood that occurred in either 1775 or 1776. [Delft University of Technology]
• Investigating how life may have survived "snowball Earth" -- Researchers at the University of Washington propose that simple photosynthetic algae life forms could have survived "snowball Earth", episodes of global glaciation between 800 million and 550 million years ago in a narrow body of water with characteristics similar to the present-day Red Sea. [University of Washington]

• Higher heating bills foreseen for upcoming winter -- Officials with the US Department of Energy recently reported that based upon their analysis of NOAA seasonal forecasts, households across the Northeast should pay more for heating this winter due to a combination of rising fuel prices and colder weather conditions across the region than last year. [USA Today]

• 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]

• Reconstructing past Martian temperatures -- Researchers at the California Institute of Technology (Caltech) have analyzed a meteorite discovered in 1984 in the Allan Hills of Antarctica and identified as ALH84001 that originated just below the surface of Mars approximately 16 million years ago. From this meteorite, they have directly determined the surface temperature of early Mars, which helps provide evidence that Mars had a warmer and wetter past. [Cal Tech News]
• Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: End of the Growing Season

As we move through autumn, we often contemplate the end of the growing season as daylight shortens and temperatures begin to fall across many areas of the nation. The length of the growing season depends upon the plant species, as well as the climate of the locale, meaning that several ways can be used to define the growing season.

Many crops, especially vegetables and fruits, are sensitive to relatively low air temperatures. In spring, when many crops are emerging and in various stages of development they are more vulnerable to air temperatures near 32 degrees Fahrenheit. But by fall, many of these plants have become hardy. Generally speaking, a killing frost would occur when the temperature around the plant would fall to a point that would kill all but the hardiest vegetation. Sometimes, other terminology is used. When air temperatures fall between 29 and 32 degrees Fahrenheit, a so-called "light freeze" occurs. While tender plants such as tomatoes, peppers, corn and cucumbers would be killed when temperatures fall to around 29 degrees, these conditions would have little destructive effect on other hardier vegetation. A "moderate freeze" typically occurs between 25 and 28 degrees, which would have a widely destructive effect upon most vegetation. For temperatures of 24 degrees or lower, a condition called a "severe freeze", heavy damage would occur with most plants that are not dormant. Apples are damaged when the temperature drops below 20 degrees. Under these conditions, the soil would have frozen solid to a depth dependent upon the duration of the freeze, as well as the soil type and soil moisture.

In most mid latitude climates, the growing season is often used synonymously with the frost-free season, loosely defined as the length of time between the last killing frost in spring and the first killing frost in the autumn. The National Climatic Data Center has produced climatological tables that identify those median dates (a 50 percent occurrence) during spring and fall when the temperature at a station falls to 36, 32, 28, 24 or 20 degrees Fahrenheit for the last time in spring or the first time in autumn. While the exact time span that a plant survives would vary by plant type, the growing season for climatological purposes is often related to the interval when the daily minimum temperature remains above 32 degrees.

Across the continental U.S. the typical lengths of the frost free regions range from about 120 days along the Canadian border to about 220 days in Oklahoma and north Texas and over 320 days in southern sections of Florida and California. Mountainous areas provide a complex pattern, with some higher elevations having lengths that are less than 100 days. By accessing the NOWData (NOAA Online Weather Data) feature on the Climate page of your local National Weather Service, you can find the "first/last dates" for various climate reporting stations around your area.

Concept of the Week: Questions

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

1. Many vegetable crops would succumb when autumn air temperatures fall to [(36),(33),(28)] degrees.
2. The frost-free season in states bordering Canada would probably be less than [(60),(90),(120)] days.

Historical Events:

• 17-18 October 2005...Heavy rain fell on Las Vegas, NV over the two-day period, with a rainfall total of 1.42 inches, which broke the full month record for October set in 1992. (The Weather Doctor)
• 17-19 October 2007...According to NOAA's Storm Prediction Center, 87 tornadoes were reported in the United States on these three days -- a new record outbreak for the month. With the outbreak, the monthly total of confirmed tornado reached 105, the second highest for October, behind the 117 in October 2001 since records began in 1950. Over 300 reports of severe weather were filed on 18 October across the lower and mid-Mississippi Valleys. (The Weather Doctor)
• 18 October 1984...Heavy snow began falling late on the 17^th at Salt Lake City and when it ended, 18.4 inches fell, setting a new 24-hour snowfall record. (Intellicast)
• 20 October 2004...Rain at two stations in Nevada broke the state's previous 24-hour maximum precipitation record of 7.13 inches set previously at Mt. Rose Highway Station (31 January 1963). The new state record of 9.78 inches was established at Mt. Charleston, while Kyle Canyon also broke the old record with 8.75 inches. (Accord Weather Guide Calendar)
• 21 October 1996...Portland, ME received 13.32 inches of rain to set a 24-hour maximum precipitation record for the Pine Tree State. (NCDC)
• 22 October 1987...Yakutat, AK surpassed their previous all-time yearly precipitation total of 190 inches. Monthly records were set in June with 17 inches, in September with 70 inches, and in October with more than 40 inches. (Sandra and TI Richard Sanders - 1987)

Return to DataStreme Earth Climate Systems website

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