15-19 March 2010

This is Break Week for the Spring 2010 offering of the DataStreme Earth Climate Studies course. This Weekly Climate News contains new information items and historical data, but the Concept of the Week is repeated from Week 6.

ITEMS OF INTEREST

• Time change does not affect climate records-- Daylight Saving Time went into effect this past Sunday morning for essentially the entire nation -- the exceptions include Arizona, Hawaii, Puerto Rico and about 18 counties in Indiana. These changes have been mandated by the U.S. Congress in the Energy Policy Act of 2005, which extended Daylight Saving Time across the nation, with the start on the second Sunday in March (11 March 2010) and end on the first Sunday in November (7 November 2010). In other words, following the old adage of "spring ahead, fall behind", you will need to turn your clocks ahead by one hour to conform with the local time observance.
  What does this time change mean to you (other than later sunsets)? Contrary to a popular belief that has surfaced at times, the change from Standard to Daylight Saving Time does not add an extra hour of daylight to the day nor does it affect climate record keeping. The daily high and low temperatures, along with the 24-hour precipitation taken by essentially all stations across the nation are based upon local Standard time, not Daylight time; therefore, the daily entries in the Preliminary Local Climate Data (CF6) for Reagan National Airport appearing on the Washington/Baltimore National Weather Service Forecast Office's climate webpage will end at 1 AM EDT (or midnight EST). Furthermore, weather charts produced by the National Weather Service operate on "Z time" (variously called Greenwich Mean Time or Universal Coordinated Time) which does not observe Daylight Saving Time.
• Notice the Vernal Equinox --
The vernal equinox, which marks the commencement of astronomical spring, will occur Saturday 20 March 2010 (officially at 1:32 PM EDT, 12:32 PM CDT, and so forth). If you checked the sunrise and sunset times in your local newspaper or from the climate page at your local National Weather Service Office, you would probably find that by midweek, the sun should have been above the horizon for at least 12 hours at most locations. The effects of atmospheric refraction (bending of light rays by the varying density of the atmosphere) along with a relatively large diameter of the sun contribute to several additional minutes that the sun appears above the horizon at sunrise and sunset.
• "Earth-Sun Day"--
Since Saturday 20 March 2010 is the vernal equinox, the day has been declared Earth-Sun Day, which is includes a series of programs and events that occur throughout the year culminating with a celebration on the Spring Equinox. This year's theme is Magnetic Storms, which are disturbances in the Earth's magnetic field associated by solar activity. NASA will have a live Sun-Earth Day Webcast from the exhibit floor of the National Science Teachers Association (NSTA) conference in Philadelphia, PA.
• Flood Safety Awareness --
Many locations around the nation experience spring floods. Therefore, the National Weather Service has designated that this coming week of 15-19 March 2010 is Flood Safety Awareness Week. Check the website http://www.floodsafety.noaa.gov/ for information concerning flooding caused by excessive rain events, rapid snowmelt, ice jams and debris flow, along with useful flood safety and mitigation measures. At least one half of the 50 states are also observing this week with special activities. Iowa is observing the entire month of March as Flood Awareness Month.

CURRENT CLIMATE STATUS

• Review of weather and climate for February 2010 and the 2009-10 winter --
  Based upon preliminary data, scientists at NOAA's National Climatic Data Center reported that temperatures across the coterminous US for February 2010 and the recently-concluded meteorological winter season (December 2009 through February 2010) were below the long-term average for the period of record that commenced in 1895. Nearly two-thirds of the nation experienced below normal winter temperatures, while Maine had the third warmest winter on record. Washington State and Oregon had above average winter temperatures. The states across the Mid-South and Southeast experienced February temperatures that ranged from the fourth to eighth coldest in the 116-year period of record. While winter precipitation across much of the nation was above average, February precipitation was slightly below average. The South generally had above average winter precipitation, while sections of the Midwest and the northern Rockies had much below average precipitation. [NOAA News]
  While much of the continental US experienced below average temperatures for winter, much of Canada had a warmer than normal winter, with only sections of the Prairie Provinces having below average temperatures. The national average temperature for the three months of December 2009 through February 2010 being the highest since nationwide temperature averages began in 1948. Nationwide, Canada also experienced its driest winter in the last 63 winters. [Environment Canada]

CURRENT CLIMATE MONITORING

• Satellite instruments are readied for ionospheric study -- Three instruments that will be a part of the FASTSAT-HSV01 (Fast, Affordable, Science and Technology Satellite, Huntsville) satellite are being readied at NASA's Goddard Space Flight Center and at Marshall Space Flight Center for launch in May 2010. These instruments, which will detect the environment of the Earth's ionosphere are the MINI-ME (Miniature Imager for Neutral Ionospheric atoms and Magnetospheric Electrons), PISA (Plasma Impedance Spectrum Analyzer) and TTI (Thermospheric Temperature Imager). [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

• "Outsourcing" of carbon emissions made to developing countries -- Scientists at the Carnegie Institution recently released a new study that finds over a third of carbon dioxide emissions associated with consumption of goods and services in many developed countries in western Europe, Japan, and North America are actually emitted elsewhere, especially in developing countries where the goods are produced. For example, some European countries "outsource" over half of their carbon dioxide emissions, primarily to developing countries, especially China. [EurekAlert!]
• Sea salt is spread high and wide --
Based upon air samples taken in the air above Boulder, CO, atmospheric scientists from the University of Washington, NOAA's Earth Systems Research Laboratory in Boulder, CO and from NOAA facilities in Seattle, WA have found that sodium chloride from sea salt can be carried more than one mile above and as far as 900 miles from the nearest large saltwater body. The researchers believe that chemical reactions could form chloride compounds that could contribute to smog formation. [EurekAlert!]
• Hypoxic waters could contribute to climate change --
An oceanographer from the University of Maryland warns that the increasing number and intensity of hypoxic waters, which are oxygen-deprived "dead zones" in the coastal waters, could adversely impact environmental conditions with the large amounts of nitrous oxide, a greenhouse gas, produced in these waters, thereby resulting in elevated global temperatures. The nitrous oxide release could also be detrimental to stratospheric ozone levels. [EurekAlert!]

CLIMATE IMPACTS ON THE BIOSPHERE

• Amazon rainforest myths are debunked -- Researchers from Boston University and colleagues have used data collected from the MODIS instruments on NASA's Aqua and Terra satellites to find few significant differences between the greenness level of the Amazon rainforests in drought and non-drought years, which appears to debunk the myth that the rainforests had been severely affected by the major 2005 drought in the Amazon Valley. [EurekAlert!]

CLIMATE AND SOCIETY

• Prehistoric response to Arctic climate changes studied -- An anthropologist from the University at Buffalo along with colleagues from other institutions has been attempting using archaeological and paleoenvironmental data to determine how ancient societies living in the Arctic regions of Quebec, Finland and Russia's Kamchatka Peninsula approximately 4000 to 6000 years ago responded to changes in the climate of the region. [University at Buffalo News Center]
• 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.

This Concept of the Week is repeated from Week 6.

Concept of the Week: Tropospheric westerly winds, north and south

The theoretical existence of upper tropospheric jet stream winds were not confirmed until being encountered by World War II bomber pilots when heading west into strong headwinds at altitudes of approximately 30,000 feet (10,000 m). Wind speeds sometimes exceeded 170 mph causing their relatively slow, heavily laden aircraft to almost stand still. Subsequently, westerly jet stream winds were found to encircle the planet in midlatitudes of both hemispheres above regions of strong temperature contrasts.

The explanation for these winds involves atmospheric mass distributions and forces on a rotating planet. Air in tropical latitudes is warmed, rises and then flows poleward, both north and south. On a rotating planet, moving air is deflected by the Coriolis effect, to the right in the Northern Hemisphere (and left in the Southern). The greater the temperature differences between warm lower and cold higher latitudes, the stronger the air motions and the faster the jet streams. The vertical temperature patterns result in the highest wind speeds near the top of the troposphere.

So Northern Hemisphere air headed northward, deflected to the right ends up headed east, a "westerly wind." In the Southern Hemisphere, southward moving air, deflected left will also go east, as a westerly wind. These "rivers" of strong upper-level winds steer surface weather systems as they move generally eastward across midlatitudes. They also provide boosts for jet aircraft headed eastward with them, but need to be avoided for going west! Of course, the full story is complex as land (especially mountains) and water surfaces interact with the heating of the air and eddies form in the turbulent flows, so jet streams wander. And with them go the storms and the weather patterns that form our short-term climate.

Concept of the Week: Questions

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

1. The Northern Hemisphere jet stream winds would be directed such that cold air is [(to the left),(to the right),(directly ahead)] of their forward motion.
2. In the Southern Hemisphere, the jet stream winds to be directed generally toward the [(south), (east), (west)].

Historical Events:

• 15 March 1892...A winter storm in southwestern and central Tennessee produced 26 inches of snow at Riddleton, and 18.5 inches at Memphis, resulting in the deepest snow of record for those areas. (David Ludlum)
• 15 March 1906...The temperature at Snake River, WY dipped to 50 degrees below zero, a record for the U.S. for the month of March. (Sandra and TI Richard Sanders -1987)
• 15 March 1952...Over 72 (73.62) inches of rain fell on Cilaos, Reunion Island in the western Indian Ocean, the greatest global 24-hour total rainfall. (The Weather Doctor)
• 15 March 2004…Rain at Brownsville, TX broke a century-old precipitation record for the greatest daily rainfall accumulation for March with 3.23 inches . (The Weather Doctor)
• 16 March 1975...A single storm brought 119 inches of snow to Crater Lake OR establishing a state record. (The Weather Channel)
• 16-17 March 2002…A snowstorm dumped 28.7 inches of snow on Anchorage, AK breaking the old daily record of 15.6 inches. Snow amounts ranged from 24 to 29 inches at lower elevations. (The Weather Doctor)
• 17 March 1906...The temperature at Snake River, WY dipped to 50 degrees below zero, a record for the coterminous U.S. for the month of March. (Sandra and TI Richard Sanders -1987)
• 17 March 1998...Calgary, Alberta experienced its worst March snowstorm in 113 years, measuring 13 inches of snow at the airport and from 15 to 18 inches in other parts of the city. (The Weather Doctor)
• 17-24 March 1999…Intense Tropical Cyclone Vance (Category 5) moved across portions of Western Australia. A record wind gust for the Australian mainland of 167 mph was recorded at the Learmonth Meteorological Office. (The Weather Doctor)
• 18 March 1914...San Francisco, CA reached its highest temperature ever recorded in March. The mercury rose to 86 degrees. (Intellicast)
• 18 March 1925...The great "Tri-State Tornado" occurred, the most deadly tornado in U.S. history. The tornado, which claimed 695 lives (including 234 at Murphysboro, IL and 148 at West Frankfort, IL), cut a swath of destruction 219 miles long and as much as a mile wide from east central Missouri to southern Indiana between 1 PM and 4 PM. (David Ludlum) (Intellicast)
• 18 March 2002…A snowstorm over coastal British Columbia produced the latest and heaviest single-day snowfall on record for the city of Vancouver of 2.55 inches. (The Weather Doctor)
• 19 March 1950...Timberline Lodge on Mount Hood reported 246 inches of snow on the ground, a record for the state of Oregon. (The Weather Channel)
• 19 March 1964...Up to 39 inches of snow fell at Cape Whittle for Quebec's greatest one-day snow total. (The Weather Doctor)
• 20-21 March 1948…Juneau, AK received 31.0 inches of snow, to set a 24-hour snowfall record for Alaska's capital. This snowfall record pales compared to the state's 24-hour snowfall record of 62.0 inches set at Thompson Pass on 28-29 December 1955. (Accord's Weather Guide Calendar)
• 20 March 1986…A wind gust of 173 mph was recorded in the Cairngorm Mountains, Scotland, the highest ever recorded in the United Kingdom. (The Weather Doctor)

Return to DataStreme ECS website

Prepared by Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2010, The American Meteorological Society.