WEEKLY CLIMATE NEWS

SPRING BREAK WEEK: 10-14 March 2014

This is Break Week for the Spring 2014 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 (10 March 2013) and end on the first Sunday in November (3 November 2013). Most of Canada also observes changes to Daylight Saving Time at the same time [National Research Council Canada]. 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 any of the more than 200 cities around the nation will remain on Standard time throughout the year.
While many people want additional daylight after work, some health experts say that the change to Daylight Saving Time is hard on human health, as it affects the natural sleep cycle and circadian rhythms. Increases in heart attacks, traffic accidents and sleep disorders have been seen during the first several days after the time change in spring. Economic costs involving the time change are also incurred. [Business Insider]
Viewing atmospheric circulation in three-dimensions -- Read this week's Supplemental Information.. In Greater Depth for information concerning the average circulation in the lower and upper troposphere.

CURRENT CLIMATE MONITORING

Ice cover on Great Lakes near a record -- Late last week, NOAA's Great Lakes Environmental Research Laboratory (GLERL) reported that the ice cover on the Great Lakes reached 92.2 percent of the total area of all the lakes. [Weather Underground] This areal coverage was slightly less than the maximum ice extent of 94.7 percent set in 1979. Plots of historical ice cover on each of the Great Lakes are available for the period of satellite surveillance from 1973-2013. [NOAA/GREL Great Lakes Ice Cover]
On Saturday (8 March 2014), GLERL reported that the ice concentration on Lake Michigan had reached 93.29 percent, which set a new record ice cover on Lake Michigan exceeding the previous record of 93.1 percent set in 1977. [Milwaukee/Sullivan National Weather Service Forecast Office]
The US Coast Guard recently began breaking ice on Lake Superior in an attempt to begin opening traffic on that lake by 17 March. [Wisconsin Public Radio]
Southern Patagonia Ice Field viewed from Space Station -- A digital photograph made by an astronaut on the International Space Station nearly one month ago shows a panoramic view of South America's Southern Patagonia Ice Field in the Andes Mountains on a relatively clear day. This ice field, which is the largest temperate ice sheet in the Southern Hemisphere, has shown shrinkage in the last several decades because of increased global air temperatures. [NASA Earth Observatory]
Painting forests red on satellite images -- An explanation is provided as to why some satellite images made over forests on Earth appear red rather than green, which would be seen on more familiar "true-color" imagery. These reddish colored images use near-infrared radiation reflected from the leaves of plants to assess health of the vegetation. [NASA Earth Observatory]
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]

CLIMATE FORCING

African dust sweeps out across tropical Atlantic Ocean -- A true-color satellite image made from the MODIS sensor onboard NASA's Terra satellite at the end of February shows airborne dust particles being carried westward across the Cape Verde Islands in the tropical North Atlantic Ocean from West Africa. Subsequently, the dust veil reached the Caribbean in early March. The yellow dust that appears on the satellite image had been lifted into the atmosphere by a harmattan, or a desert wind that typically develops across the northwestern Sahara Desert between November and March. [NASA Earth Observatory]
Understanding Great Lakes water level changes -- Scientists at NOAA's Great Lakes Environmental Research Laboratory (GLERL) have been attempting to determine about the factors that force the changes in the water levels on North America's Great Lakes and how water resource management planning decisions can be improved. The research is pressing as several of the Lakes had been at near record low levels during the last several years have been adversely impacting the economies around the Great Lakes basin. During the last week, GLERL and the US Army Corps of Engineers made a forecast that Great Lakes water levels should approach levels close to normal over the next six months on nearly all the Lakes due in part to the reduced winter evaporation over the lake surfaces because of the near-record ice cover. [NOAA Office of Oceanic and Atmospheric Research News]
Warm river discharges contribute to Arctic sea ice melt -- Using sea surface temperature data collected by the MODIS instrument on NASA's Aqua and Terra satellites, researchers from NASA's Jet Propulsion Laboratory have found that warm river water draining into the Arctic Ocean contributes to the melting of Arctic sea ice each summer. One of the areas they studied was the Beaufort Sea where discharges from Canada's Mackenzie River discharges into the Arctic Ocean resulted in increased sea surface temperatures. [NASA Jet Propulsion Laboratory] [NASA Earth Observatory]

CLIMATE AND THE BIOSPHERE

New web portal helps map climate change in the oceans -- Scientists from NOAA's Earth System Research Laboratory and NOAA Fisheries Service have created a new Ocean Climate Change Web Portal designed to assess the vulnerability of various fish stocks to climate change. Global maps of climate data such as ocean temperature and salinity will be available on this web portal. [NOAA News]

CLIMATE AND HUMANS

Agricultural fires across Indochina monitored from space -- A natural-color image was produced from data collected late last week from the MODIS sensor onboard NASA's Aqua satellite that shows numerous agricultural fires still burning across Indochina; the exact locations obtained from thermal bands were also highlighted. Farmers across Indochina burn large areas of croplands for weed and pest control and as a means for removing excess crop residue in the preparation of the fields for planting. However, vast quantities of smoke from these fires are produced, reducing air quality across the region. [NASA Goddard Space Flight Center]

PALEOCLIMATE RECONSTRUCTION

Ancient Greek plays used to help reconstruct Europe's past climate -- Researchers from Greece's National and Kapodestrian University of Athens have been reconstructing the Mediterranean climate during the 5th and 4th centuries BC by exploring the weather conditions that would have enabled Athenians of the classical era to watch theater performances in open theatres during the midwinter (between 15 January and 15 February). "Halcyon days" of clear, sunny theater friendly weather in mid-winter were identified from historical observations from artwork and plays. [Science Daily]

CLIMATE FORECASTS

UNESCO World Heritage sites threatened by global sea-level rise -- A recent study warns that many of the 720 sites currently on the list of UNESCO World Heritage sites could be inundated and lost to rising sea levels if current trends in global temperature change were maintained over the next two millennia. [Institute of Physics]

CLIMATE AND SOCIETY

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.)

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.
In the Southern Hemisphere, the jet stream winds to be directed generally toward the [(south), (east), (west)].

Historical Events:

10 March 1912...The barometric pressure reached 990.9 millibars (29.26 inches) at Los Angeles, CA, and 997.7 millibars (29.46 inches) at San Diego, CA, setting all-time records for those two locations. (David Ludlum)
10 March 1922...Dodge City, KS reported an all-time record 24-hour total of 17.5 inches of snow. (The Weather Channel)
10-11 March 1972, The temperature at Chicago, IL rose from 15 degrees on the 10th to 73 degrees on the 11th. The 58-Fahrenheit degree temperature rise tied the largest day-to-day rise on record. The city experienced a similar jump in temperature in February 1887. (The Weather Doctor)
11 March 1911...Tamarack, CA reported 451 inches of snow on the ground, a record for the U.S. (David Ludlum)
11 March 1948...Record cold followed in the wake of a Kansas blizzard. Lows of 25 degrees below zero at Oberlin, Healy, and Quinter established a state record for the month of March. Lows of 15 degrees below zero at Dodge City, 11 degrees below zero at Concordia, and 3 degrees below zero at Wichita were records for March at these locations. The low of 3 degrees below zero at Kansas City, MO was their latest subzero reading of record. (The Weather Channel) (Intellicast)
11 March 2006...The record run for dry days in Phoenix, AZ finally ended at 143 at 12:07 AM MST. The last measured rain in the city fell on 18 October 2005. The last time the region had significant precipitation was 2 August when 0.59 inch (15 mm) fell. Not only did the rain break the dry spell, the 1.40-inch total was a record amount for the date: The previous consecutive dry-day mark, set in 1998-99, was 101 days. (The Weather Doctor)
12-13 March 1907...A storm produced a record 5.22 inches of rain in 24 hours at Cincinnati, OH. (The Weather Channel)
12 March 1923...The record low air pressure of 971.9 millibars (28.70 inches) for Chicago, IL was set during a storm that produced heavy snow, a thick glaze, gales, and much rain that caused $800,000 damage. (Intellicast)
13-15 March 1952...The world's 5-day rainfall record was set when a tropical cyclone produced 151.73 inches of rain at Cilos, Reunion Island in the Indian Ocean. The 73.62 inches that fell in a 24-hour period (15^th-16^th) set the world's 24-hour rainfall record. (Accord's Weather Guide Calendar)
13 March 1993...The "Great Blizzard of '93" clobbered the eastern US and produced perhaps the largest swath of heavy snow ever recorded. Heavy snow was driven to the Gulf Coast with 3 inches falling at Mobile, AL and up to 5 inches reported in the Florida Panhandle, the greatest single snowfall in the state's history. Thirteen inches blanketed Birmingham, AL to set not only a new 24-hour snowfall record for any month, but also set a record for maximum snow depth, maximum snow for a single storm, and maximum snow for a single month. Tremendous snowfall amounts occurred in the Appalachians. Mount Leconte in Tennessee recorded an incredible 60 inches. Mount Mitchell in North Carolina was not far behind with 50 inches. Practically every official weather station in West Virginia set a new 24-hour record snowfall. Farther to the north, Pittsburgh, PA measured 25 inches, Albany, NY checked in with 27 inches, and Syracuse, NY was buried under 43 inches. The major population corridor from Washington, DC to Boston, MA was not spared this time as all the big cities got about a foot of snow before a changeover to rain. A rather large amount of thunderstorm activity accompanied the heavy snow. Winds to hurricane force in gusts were widespread. Boston recorded a gust to 81 mph, the highest wind gust at that location since hurricane Edna in 1954. Numerous cities in the south and mid Atlantic states recorded their lowest barometric pressure ever as the storm bottomed out at 960 millibars (28.35 inches of mercury) over Chesapeake Bay. Some 208 people were killed by the storm and total damage was estimated at $6 billion-- the costliest extratropical storm in history. (Intellicast)
14 March 1944...A single storm brought a record 21.6 inches of snow to Salt Lake City UT. (The Weather Channel)
14 March 1984...A coastal storm dumped very heavy snow over northern New England. Caribou, ME received 28.6 inches of snow in 24 hours, by far its greatest 24-hour snowfall on record. (Intellicast)
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)

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