WEEKLY WATER NEWS

DataStreme WES Week Nine: 30 October-3 November 2006

Water in the News:

(Thurs.) Esperanza fire view -- NASA's MODIS instrument captured a view of the smoke from the deadly Esperanza fire in California that was aided by the dry conditions. [NASA Earth Observing Mission]
(Thurs.) Historic pre-incident surveys of coastal shoreline is launched -- Officials with the NOAA Office of Response and Restoration and the U.S. Navy recently announced that they have been collaborating in the first surveys of potential threats to coastal shorelines due to hazardous material leaks or spills. Pearl Harbor in Hawaii was the first site for the survey. [NOAA News]
(Thurs.) Australian drought conditions are monitored from space -- An image made from vegetation greenness data collected by the MODIS instrument onboard NASA's Terra satellite over a two-week interval shows the development of a severe to extreme drought across southern Australia. [NASA Earth Observatory]
(Thurs.) A new coastal mapping vessel to be built -- NOAA officials recently announced that a Pascagoula, MS shipbuilder will build a new Small Waterplane Area Twin Hull Coastal Mapping Vessel or (SWATH CMV) with sophisticated sonar that will collect depth data from the full seafloor in coastal waters for production of new nautical charts. [NOAA News]
(Thurs.) Wind component added to coral bleaching warning system -- The NOAA Coral Reef Watch now has an experimental near-surface wind forecast product based the satellite-based wind observations from the QuickSCAT scatterometer instrument onboard NASA and NOAA satellites. [NOAA News]
(Thurs.) An Amazon River had a reversed flow -- Geologists at the University of North Carolina in Chapel Hill claim that their analysis of zircon crystals buried in the Amazon Valley indicates that the Amazon River once flowed to the west, but reversed course and currently flows from west to east following the creation of the Atlantic Ocean during the Cretaceous Period (65-145 million years ago) and the subsequent building of the Andes. [EurekAlert!]
(Thurs.) Moorings to monitor the "pump" -- British scientists are leading a project that places an array of subsurface monitors across the Atlantic Ocean to check on the temperature and salinity of the waters. The data will hopefully provide an early warning of weakening of the Meridional Overturning Circulation (MOC), sometimes called the thermohaline circulation. Changes of the MOC would lead to major climate impacts for Europe. [BBC News]
(Tues.) World's most intense thunderstorms identified by satellites -- Scientists have been using data from the NASA Tropical Rainfall Measuring Mission (TRMM) satellite to determine the global distribution of thunderstorms, primarily the most intense thunderstorms, which were found to occur frequently east of the Andes Mountains in Argentina and the Plains of the US east of the Rockies, as well as along the southern edge of Africa's Sahara Desert, northern Australia and sections of the Indian subcontinent. [NASA Earth Observatory] Additional information and images can be found on the Goddard Space Flight Center webpage. [NASA GSFC]
(Tues.) Lightning research gets grant -- A scientist at Florida Tech has received a grant from the National Science Foundation to continue and expand his research into lightning, primarily on runaway breakdown with electrons gaining enormous amounts of energy. Previously, he and his team determined that laboratory-generated sparks also make X-rays. [EurekAlert!]
(Tues.) A water finding technique leads to finding ancient tombs -- Penn State University researchers have been applying a forty-year old method for finding water that utilizes analyses of geological fractures to help locate and protect the ancient tombs and other burial sites in Egypt. [EurekAlert!]
(Tues.) Tibet water diversion is claimed not to be feasible -- The top Chinese water resources minister recently stated that the plan to channel water through a series of tunnels along a 190-mile route from Tibet to the Yellow River in western China is not feasible and is not necessary. [ENN]
(Tues.) Could galactic cosmic rays affect terrestrial clouds and climate? -- An international team of scientists using a high energy physics accelerator have begun an experiment called CLOUD (Cosmics Leaving OUtdoor Droplets) designed to investigate the possible influence of galactic cosmic rays on Earth's clouds and climate. [CERN]
Eye on the tropics --
- In the eastern Pacific, former Hurricane Paul made landfall early Thursday morning along the western Mexican coast as a tropical depression. At the start of last week, an image from the MODIS sensor (Moderate Resolution Imaging Spectroradiometer) on NASA’s Terra satellite captured the spiral bands of clouds and the eye of Paul south of Baja California. [NASA Earth Observatory]
  Tropical Depression 18-E formed last Thursday and moved westward across the eastern North Pacific. A visible image made by sensors on NOAA's GOES-11 satellite captures clouds from Tropical Depression 18-E. [NOAA OSEI]
- In the western North Pacific, Supertyphoon Cimaron formed late Friday east of Luzon in the Philippines and moved westward to become a category 5 typhoon on the Saffir-Simpson Scale on Sunday. By late Sunday this typhoon, with maximum sustained winds of over 143 mph made landfall in the northern Philippines as one of the most intense storms to ever hit the country. [USA Today] A visible image from Japan's MTSAT-1 satellite shows Supertyphoon Cimaron hours prior to landfall on Luzon. [NOAA OSEI]
What has happened to the Atlantic hurricane season? -- While coastal residents are relieved that the pre-hurricane season forecasts of much above average hurricane activity in the North Atlantic have not come true so far this season, researchers at the National Hurricane Center and Colorado State University are attempting to determine how the effects of a developing El Niño episode and upper tropospheric wind patterns have had on reducing the actual number of hurricanes below the earlier forecasts. [USA Today]
New York City could be at risk from hurricanes and sea level rise -- A team of scientists with the Goddard Institute for Space Studies have been collaborating with colleagues at New York City's Department of Environmental Protection to determine the impact that future rises in sea level, along with the approach of hurricanes, would have upon residents of New York City based upon the output from a variety of computer models. [NASA Earth Observatory] Additional information and images are available from a NASA website. [NASA]
First images obtained from an international weather satellite -- Some of the first images were obtained from the NOAA Advanced Very High Resolution Radiometer (AVHRR) that is onboard the recently launched MetOp-A, the European polar-orbiting satellite that is part of the U.S.-European Initial Joint Polar System. [NOAA News]
Seasonal Drought Outlook released -- Scientists at the Climate Prediction Center recently released their updated US Seasonal Drought Outlook through January 2007 that indicates improvement in drought conditions across the southern Plains and the Southeast due to a projected continuation of the El Niño event through at least early next year. Improvement was also anticipated in the Pacific Northwest, while only limited improvement is foreseen across the Southwest and the western northern Plains. However, drought conditions could persist across other regions of the Plains, the mid-Mississippi Valley and northern Rockies. Drought conditions could develop across the interior sections of the Pacific Northwest. [NOAA CPC]
Coastal flood events not new to Gulf Coast -- An oceanographer at Rice University recently reported that his research of the Gulf Coast over the last 10,000 years indicates every bay along the Texas and Louisiana Gulf coast is vulnerable to significant flooding and expansion due to rising sea levels and a reduction in sill flowing from dammed rivers. He warns that these rapid flooding events have occurred before. [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: Seiche

You probably remember as a child agitating the bath water so that it sloshed back and forth in the tub. (If you never did this as a child, there's still time.) You produced a seiche, a phenomenon first studied in Lake Geneva, Switzerland in the 1700s. A seiche (pronounced "say-sh") is a rhythmic oscillation of water in an enclosed basin (e.g., bathtub, lake, or reservoir) or a partially enclosed coastal inlet (e.g., bay, harbor, or estuary). With this oscillation, the water level rises at one end of a basin while simultaneously dropping at the other end. A seiche episode may last from a few minutes to a few days.

A seiche is a standing wave. Whereas wind-driven waves (pages 181-182 in your DataStreme WES textbook) are progressive in that they propagate through a body of water, standing waves are stationary. With progressive waves, crests and troughs travel along the water surface but with standing waves, crests alternate vertically with troughs at fixed locations. For both progressive and standing waves, the restoring force is gravity.

With a typical seiche in an enclosed basin, the water level near the center does not change at all although that is where the water exhibits its greatest horizontal movement; this is the location of a node. At either end of an enclosed basin, vertical motion of the water surface is greatest (with minimal horizontal movement of water); these are locations of antinodes. The motion of the water surface during a seiche is somewhat like that of a seesaw: The balance point of the seesaw does not move up or down (analogous to a node) while people seated at either end of the seesaw move up and down (analogous to an antinode).

Go to the University of Delaware's Seiche Calculator at http://www.coastal.udel.edu/faculty/rad/seiche.html. Set the "Modal Number" to 1 and then press "Calculate" for a graphical simulation of a seiche in an enclosed basin.

Partially enclosed basins usually have a node located at the mouth (rather than near the center) and an antinode at the landward end. Go to the Seiche Calculator, set the "Modal Number" to 0.5 and then press "Calculate" for a simulation of a seiche in a basin open to the right. Furthermore, some basins are complex and have multiple nodes and antinodes; these can be simulated on the Seiche Calculator by selecting different values of "Modal Number" greater than one.

A seiche can be induced by wind, regional differences in air pressure, earthquakes, or tidal forces. For example, wind blowing persistently in the same direction down the long axis of a bay causes water to pile up at the downwind end of the bay. When the wind slackens, the water oscillates (as a seiche) back-and-forth from one end of the bay to the other until eventually the water calms to a horizontal surface. A line of thunderstorms moving eastward from Wisconsin in late May 1998 produced a seiche in Lake Michigan that killed several people by drowning at the southern end of the lake. Previous seiches have produced 8 to 10 ft waves on Lake Michigan. A tsunami generated a seiche in the harbor of Hilo, HI following a major earthquake in the Aleutian Islands on 1 April 1946.

The natural period of a seiche depends on the length and depth of the basin and generally ranges from minutes to hours: The period is directly proportional to basin length. For example, the natural period of a seiche in a small pond is considerably shorter than its period in a large coastal inlet. In addition, for the same basin, the natural period is inversely proportional to water depth; that is, the period shortens as water deepens. Using the Seiche Calculator, you may wish to experiment with different values of basin length and depth. Conversely, one can estimate the average depth of a lake by determining the period of the seiche and the length of the lake.

Usually a seiche in a lake or harbor is of little concern because the changes in water level are minor--often only a few centimeters. Under certain circumstances, however, a seiche may grow to great heights with serious consequences including flooding and damage to moored vessels. A seiche grows as a consequence of resonance, that is, when the period of the disturbance (e.g., wind, earthquake) matches the natural oscillation period of a specific basin. Recall again your youthful bathtub experience. By timing your rhythmic disturbance of the water to match the natural period of the tub (about one second), you were able to cause the seiche to build until the water splashed out of the tub and onto the floor. Through resonance, vibrations from the 1994 Northridge, CA earthquake caused swimming pools to overflow throughout Southern California. In bays open to the ocean, if the period of tidal forcing matches the natural period of the bay, resonance can greatly increase the tidal range.

Concept of the Week: Questions

Seiches are [(standing) (progressive)] waves.
The natural period of a seiche [(depends on) (is independent of)] the size of an enclosed basin.

Historical Events:

30 October-1 November 1991...After absorbing Hurricane Grace on the 29^th, an intense ocean storm took an unusual course and moved westward along 40 degrees north latitude and battered eastern New England with high winds and tides. Winds had already been gusting over 50 mph along the coast 2 days before, so seas and tides were very high. Major coastal flooding and beach erosion occurred all along the New England, New York, and New Jersey coastlines. Over 1000 homes were damaged or destroyed with tides 4 to 7 ft above normal. Wind gusts reached 78 mph at Chatham, MA and 74 mph at Gloucester, MA. One ship east of New England reported a 63-ft wave. Total damage from the storm was $200 million. On 1 November this ocean storm underwent a remarkable transformation. Convection developed and rapidly wound around the storm center and an eye became visible on satellite imagery. Air Force reconnaissance aircraft found a small but intense circulation with maximum winds of 75 mph. This evolution from a large extratropical low to a small hurricane is rare but not unprecedented. (Intellicast)
31 October 1876...A 10 to 50 ft storm surge ahead of the Backergunge cyclone flooded the eastern Ganges Delta in India (now Bangladesh). Over 100,000 people drowned. (The Weather Doctor)
31 October 1846...Eighty-seven pioneers were trapped by early snows in the Sierra Nevada Mountains that piled five feet deep, with 30 to 40 ft drifts. Just 47 persons survived the "Donner Pass Tragedy." (The Weather Channel)
31 October 1874...A waterspout (a tornado-like vortex that travels over water) formed over Lake Erie and reached the lakeshore approximately 0.5 mi west of Buffalo, MY. Upon reaching the shore, it dissipated, scattering sand in all directions. (Accord Weather Calendar)
31 October 1965...Fort Lauderdale, FL was deluged with 13.81 inches of rain over a two-day period (30^th-31^st), the second heavy rainfall in two weeks. This brought their rainfall total for the month of October to an all-time record of 42.43 inches. More road and street damage occurred and some homes were flooded for the second time. (David Ludlum) (The Weather Channel) (Intellicast)
31 October 1984...An exceptional thunderstorm at Al Wajh on the Red Sea coast of northern Saudi Arabia produced 4.81 inches of rain, which was more than the total rainfall there in the previous ten years. At Tabuk 150 miles to the north, 0.49 inches of rain fell to set a daily October rainfall record at that location. (Accord Weather Calendar)
1-6 November 1570...The All Saints Day Floods killed an estimated 400,000 people in Western Europe. (The Weather Doctor)
1 November 1861...A hurricane near Cape Hatteras, NC battered a Union fleet of ships attacking Carolina ports, and produced high tides and high winds in New York State and New England. (David Ludlum)
2 November 1946...A heavy wet snow began to cover the Southern Rockies. Up to three feet of snow blanketed the mountains of New Mexico, and a three-day snowstorm began at Denver, CO. By the time it ended, this storm had dropped 31 inches, making it the second greatest snowfall ever in city history and causing roofs to collapse. (David Ludlum)
2-4 November 1927...The "Great Vermont Flood" occurred as a two-day rain event totaling up to 15 inches at the higher elevations. The deluge put rivers in western New England over their banks and caused the worst flooding in the history of Vermont. Somerset, VT received 8.77 inches of rain to establish a 24-hour record for the state. (3^rd-4^th) The Winooski Valley was devastated. Eighty-four died in the Vermont town of Vernon. Flooding left up to eight to ten feet of water in downtown Montpelier. Across New England the flooding claimed 200 lives, caused $40 million in damage and halted traffic for days. (The Weather Channel) (Intellicast) (David Ludlum)
4-5 November 1966...The River Arno surged above flood stage and caused irreparable damage to much of the architectural and art treasure of Florence, Italy. Millions of historical library volumes were either damaged or destroyed. More than 15,000 vehicles were also destroyed. Roughly two-thirds of Florence was flooded, 113 people died and 30,000 were made homeless by the flooding on both the Arno and Po rivers. (Accord Weather Calendar) (Wikipedia)
5 November 1977...A slow moving storm produced five to nine inch rains across northern Georgia causing the Toccoa Dam to burst. As the earthen dam collapsed, the waters rushed through the Toccoa Falls Bible College killing three persons in the dorms. Thirty-eight persons perished at a trailer park along the stream. Eighteen bridges were washed out in Madison County. (David Ludlum)
5 November 1987...Heavy rains in California's Death Valley National Park washed out many park roads. As much as 1.20 in. of rain fell at Scotty's Castle, compared with the annual rainfall average of 2.28 in. Up to 8000 people attending a recreational encampment were stranded. (Accord Weather Calendar)