WEEKLY WATER NEWS

DataStreme WES Week Five: 19-23 February 2007

Water in the News

(Thurs.) Higher temperatures could lead to drought -- Using historical records and a numerical climate model, NASA scientists at the Goddard Institute for Space Studies claim that a projected warmer climate in the future could increase the frequency and intensity of droughts across some areas of the world, including the Southwestern US. [NASA Earth Observatory]
(Thurs.) A Peruvian glacier could vanish in the near future -- Noted glaciologist Lonnie Thompson from Ohio State University recently predicted that the observed retreat in the ice tongues on the Quelccaya Ice Cap in the Peruvian Andes could signal an eventual disappearance of this famed high altitude tropical glacier within five years. [Ohio State University News]
(Thurs.) A new computer visualization tool to assist water policy makers -- Researchers at Arizona State University have developed a computer visualization program called WaterSim that they claim would allow water policy makers to see how changes in population, climate and land use can affect the water supply in the Phoenix, AZ metropolitan area. [EurekAlert!]
(Tues.) A view of the Antarctic Peninsula from space -- A recent image made by the MODIS instrument on one of NASA's satellites shows the Antarctic Peninsula with an assortment of features that include mountains, glaciers and the large ice shelf, along with a large semi-circular bay that had been occupied for at least 400 years by the Larsen B Ice Shelf that collapsed and disintegrated within the last five years. [NASA Earth Observatory]
(Tues.) Nation's water supply could be affected by weather and aging infrastructure -- A water researcher from Michigan State University warned that better ways are needed to monitor drinking water safety as more variable and extreme weather events along with an aging infrastructure could result in outbreaks of waterborne illness, even in the Great Lakes region. [EurekAlert!]
(Tues.) Little significant change in coastal contamination concentrations due to 9-11 is found -- Based upon their recent analysis of selected sites in the New York City metropolitan area's Hudson-Raritan Estuary, NOAA Mussel Watch Project scientists have found no significant change in the concentration of polycyclic aromatic hydrocarbons and polychlorinated biphenyls with sediment and mussels as a consequence of the collapse of the World Trade Center on 11 September 2001. [NOAA News]
(Tues.) Role of aerosols on clouds could be a key to climate change -- Using the predictive capabilities of several climate models as an example, an atmospheric scientist at the University of Michigan reported that climate models must be able to handle the effects of aerosols upon clouds in order to better simulate climate and predict future climate change. [EurekAlert!]
More lakes found under Antarctic ice -- Using data collected from NASA's Aqua satellite and the Ice Cloud and land Elevation Satellite (ICESat), scientists from Scripps Institution of Oceanography and Goddard Space Flight Center have discovered and monitored a network of more than 100 lakes under the West Antarctic ice sheet that fill and empty with rapidly flowing water in a ice stream. The researchers claim that their analysis could help improve their forecasts of the worldwide changes in ocean level. [NASA Earth Observatory]
Name that ship! The NOAA administrator recently invited students in the sixth through the twelfth grade across the six New England States to name the first Small Waterplane Area Twin Hull Coast Mapping Vessel, which will map the seafloor along the Atlantic and Gulf coasts, along with the Caribbean and the Great Lakes. This contest will continue through 30 March 2007. [NOAA News]
A review of January 2007 temperature trends across the US and the globe -- Scientists at the NOAA National Climatic Data Center recently reported that their analysis of global surface temperatures (combined land and ocean) for January 2007 indicates a January monthly record of 55.1 degrees Fahrenheit for the 128-year instrumental period of record. This reading was approximately 1.5 Fahrenheit degrees above the 20th century average. However, they found that the January temperature across the continental US was slightly less than one Fahrenheit degree below the 20th century average. The scientists point to a moderate El Niño circulation regime in the atmosphere and ocean that began to weaken by midmonth along with the continued increase in global temperatures as being responsible for the record global monthly temperature. The West, along with the Upper Mississippi Valley, the western Great Lakes and the Southeast experienced a January that was drier than average, while the southern Plains had much above average precipitation for the month. [NOAA News]
Avalanches become a problem in the West -- An avalanche in the Rocky Mountains of Colorado west of Denver closed Berthoud Pass on US Highway 40 early Saturday, while a massive snowslide that had been dislodged by an avalanche blocked I-70 for those motorists heading for Aspen and Vail. [USA Today] An avalanche in the mountains near Helena, MT claimed the lives of two snowmobilers early Sunday. [USA Today]
Ski industry in the Northeast attempts a comeback -- Following a disastrous start to the winter ski season due to a lack of snow through mid-January, several recent snowstorms along with unseasonably cold weather has been beneficial to many winter resorts across the Northeast from West Virginia northward to New England that feature skiing. [USA Today]
New York City increases security of its water system -- Following the recent discovery of pipe bombs along the California Aqueduct, New York City's Department of Environmental Protection has increased its surveillance at critical points in its water system. [US Water News Online]
A call is made for a national drought policy -- Faced with a continuing western drought, scientists from Oregon State University, the University of Washington and other institutions across the Western States recently called for the development of a national drought policy that would achieve sustainable usable water for human consumption, agriculture and fisheries, thereby averting a potential national catastrophe. [EurekAlert!]
Worldwide comprehensive research network needed to assess Arctic change -- An Ohio State geologist called for the consolidation of data collected by scientists in the Arctic basin within a global observation network that would better help in the assessment of the environmental changes that are occurring across that basin. [Ohio State University News]
Evidence of Martian water is found -- A researcher with the University of Arizona and colleagues claimed that new images made by NASA's Mars Reconnaissance Orbiter of a canyon on Mars are evidence that underground water flow occurred for a long time near the Martian surface. [ENN]
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]
Global Water News Watch -- Other water news sources can be obtained through the SAHRA Project at the University of Arizona [SAHRA Project]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Artificial Snow

Snow is the essential ingredient for many winter recreational activities including downhill and cross-country skiing, snow boarding, and snowmobiling. No natural snow cover means no cross-country skiing or snowmobiling. But downhill ski hill operators have another option if weather conditions do not provide adequate snow cover--they can generate their own snow. Artificial snow is used to build a base for skiing, refresh snow surfaces, and make skiing possible even during a snow drought, significantly lengthening the ski season. Some ski areas have the equipment to spread artificial snow over 80% or more of their terrain. Whereas snowmaking offers many recreational and economic advantages, some drawbacks stem from altering the local water budget.

Artificial snow actually consists of tiny particles of ice. Snow makers use specially designed snow guns into which flexible hoses feed compressed air and water separately. A jet of compressed air breaks the stream of water into a fine mist of tiny droplets, which if conditions are favorable, freezes into ice crystals. Expansional cooling of the compressed air as it is emitted through the nozzle of the snow gun and into the atmosphere chills the water droplets. Artificial "snowflakes" settle onto the slopes and mechanized snow groomers then till and spread the accumulated artificial snow evenly over the ski slopes.

Many snowmakers add a special protein (commercially known as Snowmax) to the air/water mix to improve both the quality and quantity of artificial snow. A non-toxic and non-pathogenic strain of a bacterium produces the protein that attracts water and promotes ice crystal formation. Snowmax increases the amount of artificial snow produced at higher temperatures and snowflakes tend to be drier and lighter than other artificial snowflakes.

Ideal weather for snowmaking consists of low air temperature, light winds, and low humidity. Snowmaking is possible even when the air temperature is above 0ºC provided that the relative humidity is sufficiently low that the wet-bulb temperature is below 0ºC. Recall from pages 65-66 in your DataStreme WES Textbook that the wet-bulb temperature is the reading obtained through evaporative cooling when water vaporizes from the wetted bulb of a liquid-in-glass thermometer. Some droplets in the fine water spray (produced by the snow gun) evaporate, tapping latent heat from the air. With sufficient evaporative cooling, the air temperature drops to the wet-bulb reading, that is, to freezing or below, and subsequent water droplets freeze to ice crystals.

The water demand for snowmaking may impact the local water budget. In Vermont, for example, snowmaking uses about 2 billion gallons of water per year--equivalent to about one-seventh of the volume of the public water supply. To cover an area measuring 500 m by 60 m with 20 cm (8 in.) of artificial snow requires about 2500 cubic meters (658,000 gallons) of water. Streams are the usual source of water for snowmaking but ski areas are typically located high on hill or mountain slopes where stream flow is normally low, especially in winter. In some cases, dams or holding ponds are constructed to ensure an adequate water supply for snowmaking. Diversion of water for snowmaking may cut the supply of water for users downstream. Water that is stored in the winter snowpack on the ski trails runs off to streams during the spring snowmelt, adding to the normally high spring stream discharge and perhaps increasing the potential for downstream flooding.

Concept of the Week: Questions

If the air temperature were above 0ºC, artificial snow can be made if the wet-bulb temperature were [(above) (below)] the freezing point of water.
When water droplets evaporate while falling through a layer of relatively dry air, the temperature of the surrounding air [(falls) (rises)].

Historical Events

19 February 1972...A vicious coastal storm dumped 10 to 20 inches of snow over interior sections of the mid-Atlantic and Northeast states and caused some of the worst coastal damage of the century in New England. Twenty-three inches of snow fell at McHenry, MD, 23 inches piled up at Williamsport, PA, and Syracuse, NY recorded 20 inches. Twenty-foot drifts were reported in northeastern Pennsylvania. Storm surges up to 4.5 feet and winds gusting over 80 mph along coastal Rhode Island, Massachusetts, New Hampshire, and Maine resulted in extensive property damage and tremendous beach erosion. Twenty-seven houses were destroyed and 3000 damaged in Massachusetts alone. (Intellicast)
20 February 1805...The Potomac River was opened after being closed by ice for a period of two months. (Sandra and TI Richard Sanders - 1987)
20 February 1997...A vast mudslide swept off an Andean mountainside onto two remote villages in southeastern Peru burying up to 300 people. Inhabitants had been evacuated after weekend flooding, but their refuge above the village put them in the path of the mudslide. (The Weather Doctor)
21 February 1992...Today marked the 16^th consecutive day that Sacramento, CA recorded measurable rain, breaking the old record of 15 consecutive days set back in February 1936 and again in November 1970. Total rainfall over the 16-day period was 6.41 inches. (Intellicast)
22 February 1986...A twelve-day siege of heavy rain and snow, which produced widespread flooding and mudslides across northern and central California, finally came to an end. The storm caused more than $400 million in property damage. Bucks Lake, located in the Sierra Nevada Range, received 49.6 in. of rain during the twelve-day period. (Storm Data)
22-26 February 1995...Cyclone Bobby slammed into the Western Australia coast causing widespread flooding. Some areas reported up to 12 in. of rain from the storm. (The Weather Doctor)
23 February 1802...A great snowstorm raged along the New England coast producing 48 inches of snow north of Boston and 54 inches at Epping, NH. Three large (indiamen) ships from Salem were wrecked along Cape Cod by strong winds. (David Ludlum) (Intellicast)
23 February 1991...A black rain fell on eastern Turkey as soot from the Kuwait oil field fires mixed with the precipitation. (The Weather Doctor)
23 February 1998...Another storm in the series of storms during the major El Niño episode pounded southern California with 2 to 3 inches of rain, and 3 to 4 feet of snow in the mountains above 7000 feet. A sinkhole that measured 550 feet in length, 35 feet in width, and 65 feet in depth developed near I-15 in San Diego. (Accord's Weather Guide Calendar)
24 February 1925...A 250,000-ton ice jam on the St. Lawrence River near Waddington, NY was removed using thermit for the first time in the U.S. Thermit is a mixture of finely divided magnesium and red iron oxide that produces hot molten iron when ignited. (Today in Science History)
24 February 1970…Eight people were killed by an avalanche as chalets and hotels were destroyed in near Mont Cenis, France. Earlier, on the 10^th of the month, 39 people were killed as an avalanche struck a chalet at Val d'Isere. On 15 April 1970, a landslide buried a sanatorium at Plateau d'Assy, killing 72 people. (Accord's Weather Guide Calendar)