WEEKLY CLIMATE NEWS

DataStreme ECS WEEK 7: 15-19 October 2012

ITEMS OF INTEREST

• Linking weather and climate -- Read this week's Supplemental Information.. In Greater Depth for a description the distinction between atmospheric conditions that can be considered as weather events, which may last for time spans of up to a week, from those events with longer time spans of a month to three months that can be considered within the ream of climate analysis or forecasting.
• Celebrate Earth Science Week 2012 -- The National Oceanic and Atmospheric Administration, including the National Weather Service, along with NASA, the US Geological Survey and several professional scientific organizations such as the American Geological Institute have recognized next week (14-20 October 2012) as Earth Science Week 2012 to help the public gain a better understanding and appreciation for the earth sciences and to encourage stewardship of the Earth. This year's theme for the 15th annual Earth Science Week is " Discovering Careers in the Earth Sciences", designed to "engage young people and the public in learning how geoscientists gather and interpret data about the Earth and other planets." [American Geological Institute]
  Starting on the 14th, students will be invited to connect with NASA Earth explores on virtual trips to Antarctica, the Peruvian Amazon, the mangrove forests of Africa and many other places around the world to inspire them to pursue science, technology, engineering and math (STEM) careers. [NASA GSFC]

CURRENT CLIMATE STATUS

• US weather and climate reviewed for September 2012 -- Basing their report on preliminary data, scientists at NOAA's National Climatic Data Center indicate that the average temperature across the coterminous United States for September 2012 was approximately 1.4 Fahrenheit degrees above the 20th-Century (1901-2000) nationwide temperature. The statewide temperatures across the five Western States of California, Nevada, Utah, Idaho and Wyoming were among the ten highest for September since sufficiently reliable climate records began in 1895. Above average temperatures were also recorded across other states from the western Plains to the Pacific Coast. On the other hand, six states across the Midwest along with Alabama reported below average temperatures in September. Nationwide precipitation for September 2012 was slightly below the 20th-century average. The northern tier of states, extending from the Pacific Northwest to the Great Lakes had much below average precipitation, with Montana, the Dakotas and Minnesota experiencing their driest September in 118 years. On the other hand, states in the Ohio and Tennessee Valleys had much above average rainfall. Drought and wildfires remained a problem across many areas of the West. [NOAA/NCDC State of the Climate]
• Sea ice around Antarctica expands to record size -- The National Snow and Ice Center recently reported that analysis of satellite images obtained from the Special Sensor Microwave/Imagers onboard the Defense Meteorological Satellite Program (DMSP) satellites shows that in late September 2012 the sea ice surrounding Antarctica grew to its greatest annual winter maximum extent since satellite surveillance began in 1979. Note that this record expanse of Antarctic sea ice occurred approximately two weeks after the sea ice covering the Arctic Ocean had shrunk to the smallest annual summer extent in the satellite record. Sea ice scientists at NASA's Goddard Space Flight Center claim that changes in the atmospheric circulation has contributed to the increased Antarctic sea ice. [NASA Earth Observatory]

CURRENT CLIMATE MONITORING

• Operation IceBridge flights resumed over Antarctica -- Late last week, scientists and flight crew members began the first science flight of this year's Operation IceBridge campaign when they flew on NASA's DC-8 research aircraft from Chile to the region around Thwaites Glacier in west Antarctica. In its fourth year, Operation IceBridge is NASA's airborne mission to study Earth's changing polar ice. [NASA Ice Bridge - Antarctica 2012]
• Astronauts connect with oceanographers -- An physical oceanographer from NASA and colleagues who were out at sea on the Research Vessel Knorr recently communicated in a long-distance telephone call with the astronauts orbiting onboard the International Space Station. The oceanographers had nearly completed a six-week SPURS (Salinity Processes in the Upper ocean Regional Study) cruise designed to obtain a detailed, 3-D picture of how salt content fluctuates in the ocean's upper layers and how these variations are related to shifts in rainfall patterns around the planet. The data collected from this cruise was also meant to help calibrate the salinity measurements collected by the orbiting NASA's Aquarius instrument. [NASA Headquarters]
• Summertime wind shift in Arctic could affect sea ice loss and weather across North America and Europe -- A research team from NOAA's Pacific Marine Environmental Laboratory reported that changing upper air wind patterns over the Arctic Basin between 2007 and 2012 may affect weather across North America and Europe because the shift in winds in summer appear to be linked to the recent dramatic loss in Arctic sea ice. The prevailing winds across the basin shifted from a west to east flow to a more undulating north-south wavelike pattern, which permitted warmer air to be transported north to the Arctic during summer, while more cold air was brought southward to mid-latitudes over North America and Europe. [NOAA News]
• Decrease in frequency of Hawaii's northeast trade winds documented -- Scientists at the University of Hawaii's School of Ocean and Earth Science and Technology analyzed 37 years of wind data (speed and direction) from Honolulu's International Airport along with area sea level pressure data and found a reduction in the frequency of days with northeast trade winds, but with a corresponding increase in easterly trade wind days over this length of record. The Hawaii State Climatologist claims that reduction in the frequency of humid trade winds from the northeast appear to cause a change in Hawaii's climate, including more frequent drought across the Aloha State. [ School of Ocean and Earth Science and Technology, University of Hawaii at Manoa]
• New products can measure heat available for hurricanes -- Researchers at the University of Miami have developed a new Ocean Heat Content product suite that is now being implemented at NOAA to predict hurricane intensification based upon the thermal energy contained in the near surface waters of the Atlantic Ocean. This product used data obtained from NOAA National Oceanographic Data Center's "World Ocean Atlas" along with sea surface height measurements from the NOAA/NASA Jason satellites. [NOAA Environmental Visualization Lab]
• Backup weather satellite serves as worthy replacement -- NOAA's GOES-13 satellite, identified as GOES-East since April 2010, began experiencing sensor problems in mid-September. This satellite was identified as GOES-East because it was the nation's environmental satellite in geosynchronous orbit that monitored the weather across eastern North America. Within a day, NOAA engineers were able to replace GOES-13 with GOES-14, a spare satellite that was a spare satellite since it was launched in June 2009. [NASA Earth Observatory]

CLIMATE FORCING

• Increased carbon dioxide levels cause glaciers to crack -- Researchers at the Massachusetts Institute for Technology have found that the strength and fracture toughness of ice decrease significantly as the concentration of carbon dioxide molecules increases. They claim that their finding indicates that with higher atmospheric carbon dioxide levels, ice caps and glaciers would become more vulnerable to cracking and splitting. [Institute of Physics]

CLIMATE AND SOCIETY

• Climate science funding announced -- The Secretary of the US Department of Interior, Ken Salazar, recently announced that funding has been awarded by his agency's eight regional Climate Science Centers to universities or other partners for 69 research studies designed to guide managers of parks, refuges and other resources in planning how to help species and ecosystems adapt to climate change. This funding amounts to more than $10 million. [USGS NewsRoom]
• Street level visualization software shows greenhouse gas emissions for US cities -- Researchers at Arizona State University and Purdue University have developed a new software program called "Hestia" that estimates and displays the greenhouse gas emissions down to roads and individual buildings. These high-resolution maps can be used by policy makers to identify carbon dioxide emissions from buildings. [Arizona State University 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: 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. Check the map showing the median date of occurrence of the first 32-degree Fahrenheit temperature across the 48 coterminous United States. (The median date means that half of the occurrences of a 32-degree reading over the 30-year normal occur prior to this date, while the other half occur after this date.)

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.

(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:

• 15-17 October 2005...The summit of Mount Washington, NH, the highest peak in the Northeast received 34 inches of snow between Saturday and Monday. The 24-hour record for the most snowfall was broken when 25.5 inches of snow piles up between noon Sunday and noon Monday. (The Weather Doctor)
• 16 October 1913...The temperature in Downtown San Francisco soared to 101 degrees to equal their record for October. (The Weather Channel)
• 16 October 1988...The afternoon high temperature of 100 degrees at Red Bluff, CA was the latest such reading of record for so late in the autumn season. (The National Weather Summary) (Storm Data)
• 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)

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