WEEKLY WATER NEWS

DataStreme WES Week Four: 13-17 February 2006

Water in the News

(Thurs.) A space-aged portrait of a historic island -- NASA recently posted an image taken from the orbiting International Space Station of Cuba's Cayo Largo del Sur, an island reported to have been visited by Christopher Columbus on his second voyage in 1494 and Sir Francis Drake in his circumnavigation of the globe nearly one century later. [NASA]
(Thurs.) Bolivian water claim dropped -- Bechtel, the US construction and engineering giant, has dropped its $25 million claim against the Bolivian government for canceling a water contract in which the company would maintain the water and sewage utilities in Cochabamba, Bolivia's third largest city. [US Water Online]
(Thurs.) New desalination techniques unveiled -- A chemical engineer with the New Jersey Institute of Technology who is the leader of a team of researchers recently reported on the team's progress in the new membrane distillation method for desalinating water from brine with high salt concentrations. [EurekAlert!]
(Thurs.) Declining snowpack reduces CO₂ emissions from forest soils -- Scientists from the University of Colorado-Boulder, San Diego State University and the National Center for Atmospheric Research report that their monitoring of the winter CO₂ emissions from the forest soils in the high country of Colorado indicates that reduced snowpack has reduced the emissions, as well as a picture of declining health for the mountain forests. [EurekAlert!]
(Tues.) Northeast digging out from record snows -- The nor'easter storm brought unprecedented snowfall totals from New York City to New England. Widespread power outages and travel strandings accompanied the storm's passage.[NOAA News]
(Tues.) Another view of the developing La Niña event -- NASA recently released a map showing the sea surface anomalies (differences between observed and long-term average temperatures) observed from the orbiting Advanced Microwave Scanning Radiometer for EOS during the last week of January, confirming the forecast made by scientists at NOAA's Climate Prediction Center several weeks earlier. [NASA Earth Observatory]
(Tues.) Trading on snow futures -- The Chicago Mercantile Exchange will soon begin electronically trading snowfall futures and options contracts, which should help municipalities and large companies primarily in the New York-Boston corridor manage the risk associated with significant snowfall accumulations. [USA Today]
(Tues.) Katrina's exact toll may never be known -- Officials along the Gulf coast are indicating that the exact death toll due to Hurricane Katrina may never be known exactly as many bodies may never be recovered. A recent count indicates that more than 1300 bodies have been found. [USA Today]
Another view of the 2005 Atlantic hurricane season -- The NASA Goddard Space Flight Center has posted several animated images featuring several hurricanes and tropical storms that helped make the 2005 North Atlantic hurricane season historic. These images were obtained from the NASA fleet of orbiting satellites. [NASA GSFC]
Arizona could be experiencing a disastrous drought -- Arizona's governor has assembled a drought response team and charged them with helping residents of the Grand Canyon State to cope with what could be one of the driest winter seasons in over one hundred years. [USA Today]
Drought becomes a Texas crisis -- The worsening drought across many areas of Texas could result in an economic catastrophe for the Lone Star State according to experts who note that currently drought-related losses are at an estimated $1.5 billion and climbing. [Bryan-College Station Eagle]
An acidified lake shows recovery -- Ecologists report that a well known trout lake in Upstate New York's Adirondack Mountains that had been declared a "dead" lake in the 1980s due to acid precipitation appears to have shown signs of recovery at a rate faster than previously hoped. [US Water Online]
Uganda draining Lake Victoria -- Uganda has been ignoring a half-century old international agreement designed to protect the waters of Lake Victoria in east Africa by secretly draining water to maintain its hydroelectric generating capability. [The New Scientist]
Growing risk for water shortages and flooding foreseen for California -- Scientists at Lawrence Livermore National Laboratory have cautioned that higher global temperatures could increase the risk that California could experience a greater risk of summer water shortages and winter flooding that could even occur during the same year, especially during those years when an El Niño event was occurring. [Lawrence Livermore National Laboratory]
Detailed analysis of ice cloud crystals made -- An international team of atmospheric scientists have been studying the high resolution images of ice crystals in high-altitude tropical clouds taken by a sophisticated instrument flown onboard an instrumented aircraft flying at altitudes of up to 11 miles over Australia. This research is part of the Tropical Warm Pool International Cloud Experiment. [EurekAlert!]
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: Controlling Indoor Humidity

In public buildings as well as individual homes, it is sometimes desirable to alter extremes of relative humidity so that living spaces are more comfortable. For human comfort, optimum relative humidity is between about 30% and 50%. When indoor air is exceptionally dry, a humidifier may be used to add water vapor to the air, but when indoor air is excessively muggy, a dehumidifier may be used to remove water vapor from the air.

As cold, dry winter air is drawn indoors and heated by a furnace, its relative humidity declines--sometimes to uncomfortably low levels. Suppose, for example, that outdoor air has a temperature of -20 ºC (-5 ºF) and relative humidity of 50%. If that air were brought indoors and heated to 21 ºC (70 ºF), its relative humidity drops to about 2% -- well below the optimal winter indoor relative humidity of 30% to 50%. At such very low relative humidity values, people often feel discomfort caused by dry skin and irritation of the mucus membranes in their nose and throat. Also, wood furniture dries out and may crack and become unjointed. Discharge of static electricity (e.g., after walking across a carpet and touching a metal doorknob) can be a nuisance in dry rooms.

One remedy for excessively low indoor relative humidity is a device known as a humidifier. A humidifier elevates the relative humidity of indoor air to more comfortable levels by evaporating water into the air (increasing the vapor pressure). A common humidifier design consists of a wheel that continually rotates a porous belt (or pads) into and out of a reservoir of water. A fan blows air through the wetted belt, water evaporates into the air stream, and the more humid air circulates through the dwelling.

On the other hand, a dehumidifier may be desirable during warm muggy summer days. In addition to discomfort caused by reduced evaporative cooling, high values of indoor humidity can increase the incidence of mold and mites. A dehumidifier lowers the relative humidity of indoor air to more comfortable levels by inducing condensation of water vapor (decreasing the vapor pressure). In a standard dehumidifier, a fan draws humid air past a cold refrigerated coil. Air in contact with the coil is chilled to saturation, water vapor condenses on the coils and liquid water drips from the coils into a collection reservoir or through a hose into a drain. Most dehumidifiers function best when the air temperature is at or above 18 ºC (65 ºF).

Click on forecast map for locations across the country where today's indoor relative humidity is expected to be too high or too low in the absence of any controls on indoor humidity. For an interactive applet (from the University of Wisconsin-Madison) that explores the relationships among temperature, dewpoint, and relative humidity, go to http://profhorn.meteor.wisc.edu/wxwise/museum/a7/a7exercise1.html. Follow instructions and note how the indoor relative humidity changes with changes in outdoor conditions.

Concept of the Week: Questions

A humidifier elevates the relative humidity by causing [(evaporation)(condensation)].
A dehumidifier reduces the relative humidity by causing [(evaporation)(condensation)].

Historical Events

13 February 1784...Ice floes blocked the Mississippi River at New Orleans, then passed into the Gulf of Mexico. The only other time this occurred was during the "Great Arctic Outbreak" of 1899. (David Ludlum)
13 February 1885...The "Friday the 13th" avalanche at Alva, UT killed sixteen persons, and left thirteen others buried for twelve hours before they were rescued. (David Ludlum)
13 February 1989...Showers and thunderstorms produced locally heavy rain and flash flooding from central Texas to western Pennsylvania. Up to ten inches of rain deluged western Kentucky in two days, with five-day totals ranging up to 13.16 inches at Gilbertsville Dam, KY. Flooding caused tens of millions of dollars damage, including $18 million damage at Frankfort, KY. (The National Weather Summary) (Storm Data)
13 February 1997...Ocean swells generated by a storm well to the northwest of the Hawaiian Islands generated surf with heights to 20 feet and some sets to 25 feet along the northern shores of the islands. A professional surfer was killed by 25-foot surf at Alligator Rock on Oahu's North Shore. Lifeguards aided more than thirty people. (Accord's Weather Guide Calendar)
14 February 1954...A waterspout was observed two miles east of Baranof, AK, an unusual occurrence for Alaska, particularly in winter. Just prior to the formation of the waterspout, a "terrific wind from the south out of a bay inside Warm Springs Bay" lifted water 20 feet and looked "as if it were boiling". (Accord's Weather Guide Calendar)
15 February 1982...An intense cyclone (low pressure system) off the Atlantic coast of Newfoundland capsized the Ocean Ranger, a drilling rig, killing 84 persons, and sank a Soviet freighter resulting in 33 more deaths. The cyclone produced 80-mph winds that whipped the water into waves fifty feet high. (David Ludlum)
15 February 1998...A "rogue" wave from the Pacific Ocean swept into the harbor at Port Arena, CA. This wave continued through a harbor parking lot, depositing sand, debris and logs, as well as moving thirty parked vehicles. No injuries were sustained. (Accord's Weather Guide Calendar)
16 February 1966...Heavy rain fell in Whenuapai, New Zealand, with 4.2 inches of rain falling in one hour, a new record for that time in New Zealand. (The Weather Doctor)
18 February 1967…Thirty-five members of several ski patrols gathered at Idaho's Skyline Ski Area southeast of Pocatello to study avalanche control. Unfortunately, an afternoon snowslide killed two people at the ski area while the class was being held. (Accord's Weather Guide Calendar)
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)