DataStreme WES Week Eight: 21-25 March 2005

• Flood Awareness Week announced -- The National Weather Service has announced that this coming week of 21-25 March 2005 has been declared Flood Safety Awareness Week across the nation in an attempt to raise the public's attention to the dangers of flooding, as well as the suggested means to protect life and property. [NOAA News] [Editor's note: A website for flood safety has also been posted at http://www.floodsafety.noaa.gov/ EJH]
• Spring outlook provides some optimism for drought relief -- Scientists with the Climate Prediction Center unveiled the official 2005 Spring Outlook last week, which shows that during the next three months (April through June) the severity of the drought across the Southwest could be significantly reduced. However, the Pacific Northwest should expect little drought relief. Spring flooding could be a problem in the Southwest, Texas and the Northeast. [NOAA News] [USA Today] [ENN]
• No relief foreseen for the Pacific Northwest -- Using an analysis scheme that they developed, researchers at Oregon State University and the US Forest Service indicate that the dry weather should continue across the Pacific Northwest, resulting in significant wildfires across the region's forests and range land. [EurekAlert!]
• Drought emergency declared in Washington State -- The governor of Washington State, Christine Gregoire, recently declared a statewide drought emergency in response to the worst drought in the Pacific Northwest in over two decades. [US Water News Online]
• River levels rise across Poland -- Recent heavy rains along with melting snow have caused rivers to reach flood levels across Poland and forced emergency officials to take action. [ENN]
• Illinois water use forecasts focus on the countywide scale -- The Illinois State Water Survey recently released the results from two new studies that indicate that water use in some of the counties near Chicago would grow faster than the population during the next 20 years. One of the forecast reports is for Illinois, focusing on seven water use sectors, while the other analyzes water use across the Midwest (Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin). [EurekAlert!]
• Movement of massive iceberg monitored -- Radar images obtained from the European Space Agency's Envisat satellite indicate that iceberg B-15A, the world's largest floating object, was once again drifting across the McMurdo Sound, but could pass very close to the Drygalski ice tongue. [ESA]
• Silver found in North Pacific waters -- Researchers from the University of California, Santa Cruz found high levels of silver in water collected two years ago from the North Pacific that were fifty times higher than the natural background level. While below levels considered toxic to marine life, the silver contamination appears to be from atmospheric depositions of aerosols from coal burning in Asia. [EurekAlert!]
• Solar-powered water circulating machines to help lakes--The city of Madison, WI may install and test five solar-powered machines in one of its four lakes that will circulate lake water in an effort to reduce algae blooms during this upcoming summer. [Wisconsin State Journal]
• Interdisciplinary water symposium planned -- A three-day symposium entitled "The Place of Water in the World: Ritual, Beauty and the Environment" is scheduled for Mount Holyoke College in Massachusetts at the end of the month. The political, environmental and cultural meanings of water will be explored by a variety of international scientists, artists, writers and scholars. [EurekAlert!]
• Rare shrimp species discovered -- A biologist with the Idaho National Guard discovered a new species of fairy shrimp in the desert lakes of southwestern Idaho. [CNN]
• A rise in sea level foreseen for this century -- A team of numerical climate modelers at the National Center for Atmospheric Research recently reported that their models indicate that global sea level could rise another 4 inches during this century from thermal expansion due to higher global temperatures even if concentrations of several greenhouse gases remained at current levels. [EurekAlert!]
• New hurricane probability map unveiled -- The National Hurricane Center recently reported that it will post a new type of hurricane probability map during the upcoming North Atlantic hurricane season on its website that is intended to provide the public with a better sense of the probability of the probability of the track of a tropical weather system. These maps would also attempt to project the approaching system's size and strength. [USA Today]
• 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: Chesapeake Bay Ecosystem

Chesapeake Bay is the nation's largest estuarine ecosystem; it is more than 300 km (185 mi) long, 65 km (40 mi) at its broadest, and averages about 20 m (66 ft) deep. The estuary was formed by the post-glacial rise in sea level that flooded the valley of the ancient Susquehanna River. The Bay receives about half its water input from the Atlantic Ocean and the other half from the more than 150 rivers and streams draining a 166,000 square kilometer land area encompassing parts of New York, Pennsylvania, West Virginia, Delaware, Maryland, Virginia, and the District of Columbia. Major rivers emptying into Chesapeake Bay include the Potomac, Susquehanna, York, and James.

An estuary is a complex and highly productive ecosystem formed where seawater and fresh runoff meet. In Chesapeake Bay, more-dense seawater creeps northward along the bottom of the estuary, moving under the less-dense fresh water flowing in the opposite direction. This circulation combined with wind-driven water motions causes salinity to decrease upstream in the Bay, from values typical of seawater at its mouth to freshwater values at its northern margin.

As in all ecosystems, organisms living in estuaries depend on one another and their physical environment for food energy and habitat. This interdependency is evident in food chains, pathways along which energy flows and materials cycle. Phytoplankton and submerged aquatic vegetation (e.g., marsh grass) are the primary producers in estuarine food webs. (Producers acquire energy from solar radiation through photosynthesis and are at the bottom of food chains.) Consumers in food webs are organisms that derive their energy by eating producers or other consumers. Chesapeake Bay consumers include zooplankton, finfish, shellfish, birds, and humans. Through cellular respiration, producers and consumers convert energy to a form that the organism can use for growth and reproduction.

Human activity has greatly modified Chesapeake Bay with consequences for the functioning of its ecosystem. Much of the original forests that covered its drainage basin were converted to farmland, roads, cities, and suburban developments. These modifications accelerated the influx of nutrients (i.e., compounds of phosphorous and nitrogen), sediment, pesticides, and other pollutants. More nutrients spur growth of algal populations and when these organisms die (in mid-summer), their remains sink to the bottom. Decomposition of their remains reduces dissolved oxygen levels in the Chesapeake's bottom water. More sediment makes the water cloudy, reducing sunlight penetration for photosynthesis.

One casualty of human modification of the Chesapeake Bay ecosystem was marsh grass--reduced by 90% from historical levels. Marsh grass anchors sediment and dampens wave action thereby controlling erosion and turbidity. Marsh grass is a food source for many organisms including waterfowl and small mammals and serves as a primary nursery ground for crabs and many species of fish. Reduction of this habitat along with over-fishing has been implicated in the decline of populations of blue crabs, a mainstay of the Bay fishery for more than a century. Over the past decade, the number of adult female crabs has plunged by 80%. Without adequate protection by marsh grass, the blue crab is more vulnerable to predation by striped bass (i.e., rockfish). Striped bass turned to blue crabs as a food source when fishing reduced the numbers of menhaden, their preferred food. Menhaden is a marine fish in the herring family and the Bay's top fishery by weight.

Concept of the Week: Questions

1. Within the waters of Chesapeake Bay, salinity [(is relatively uniform)(varies greatly)].
2. Marsh grass is a [(producer)(consumer)] in the Chesapeake Bay ecosystem.

• 21 March 1876...More than 40 inches of snow stopped traffic in Montreal, Quebec. Trains were delayed and mail carriers resorted to snowshoes. (The Weather Doctor)
• 22 March 1941...Grand Coulee Dam along the Columbia River in Washington State began to generate electricity. At the time, this dam was the largest in the world. (Wikipedia)
• 24 March 1888...Snowflakes measuring 3.75 in. in diameter and 0.25 in. thick reportedly fell "like plates" on Chepstow, England. The flakes fell for approximately 2 minutes and covered the ground to a depth of 2 in. The liquid content of 0.33 in. would give a liquid accumulation rate of 9.90 in. per hour. (Accord's Weather Guide Calendar)
• 24 March 1989...The tanker Exxon Valdez grounded on a reef in Prince William Sound, AK, spilling 10.1 million gallons of crude oil, resulting in the worst oil spill in U.S. history. Coast Guard units responded and prevented the entire cargo from spilling, cleaned up the oil which did spill, and conducted an investigation into the causes of the accident. The spill provided the impetus for the passage of the Oil Protection Act in 1990. (US Coast Guard Historians Office)
• 25 March 1961...The fifth major snowstorm of the month prompted the provincial government of Prince Edward Island to declare a state of emergency. Snowdrifts of at least 33 feet reached overhead power lines. (The Weather Doctor)
• 25 March 2000...A rouge wave near Shelter Cove, CA swept a lady from a Canadian school group into the ocean. Four members of the group tried to rescue her, but ere overcome by the waves and currents. A fishing vessel and the US Coast Guard rescued two of the rescuers. (Accord's Weather Guide Calendar)
• 26 March 1913...The Ohio River Basin flood reached a peak. Ten-inch rains over a wide area of the Ohio River Basin inundated cities in Ohio, drowning 467 persons, and causing $47 million in damage. The Miami River at Dayton reached a level 8 feet higher than ever before. The flood, caused by warm weather and heavy rains, was the second mostly deadly on record for the nation. (David Ludlum)
• 26 March 1997...Mudslide wiped out 164 feet of Canadian National rails in Fraser Canyon, British Columbia causing an eastbound freight train to plunge from the tracks. Two crewmen died and fears of chemical spill abound. (The Weather Doctor)
• 27 March 1980...Waves to 20 ft and winds to 58 mph in the North Sea southwest of Stavanger, Norway led to the collapse of an oil rig accommodation platform. The deaths of 123 of the 212 people on the platform represents the world's worst drilling catastrophe. (Accord's Weather Guide Calendar)
• 28 March 1902...McMinnville, TN (elevation 900 ft) received 11.00 in. of precipitation, setting a 24-hour precipitation record for the Volunteer State. (National Climate Data Center).
• 28 March 1964...A tsunami generated by an earthquake (which rated 9.2 on the Richter scale) in Prince William Sound, AK produced a major surge wave that was approximately 100 ft above low tide and caused major damage to Whittier (where 13 died) and other coastal communities in Alaska. The death toll from the earthquake and associated tsunami waves was at least 122, with 108 in Alaska. The earthquake and tsunami caused $311 million in property damage. The first wave took more than 5 hours to reach the Hawaiian Islands where a 10-foot wave was detected, while a wave that was 14.8 feet above high tide level traveled along portions of the West Coast, reaching northern California 4 hours after the earthquake. Nearly 10,000 people jammed beaches at San Francisco to view the possible tsunami, but no high-amplitude waves hit those beaches. (The University of Washington) (Accord's Weather Guide Calendar) (US Coast Guard Historians Office)
• 28 March 1980...Although springtime was starting in the Rocky Mountains, the snow just kept on coming! One foot or more of snow fell over portions of eastern Colorado, southwest Nebraska, northwest Kansas and southeastern Wyoming. Winds reached 40 mph and Valentine, NE received 13 in. of snow. North Platte, NE checked in with 15 in. (Intellicast)
• 28 March 1998...Three Boy Scout troop members died when their sport utility vehicle was swept away as they tried to cross a running wash just north of Sunflower, AZ. (Accord's Weather Guide Calendar)

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Prepared by AMS WES Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2005, The American Meteorological Society.