Weekly Ocean News

DATASTREME OCEAN WEEK SEVEN: 12-16 March 2007

Ocean in the News:

(Thurs.) Increased atmospheric carbon dioxide could pose additional threats to marine life -- Scientists at the University of Illinois and the Carnegie Institution claim that increased levels of atmospheric carbon dioxide would adversely affect marine life because of not only projected higher global temperatures, but also increased acidification of the ocean, which would cause the hard shells of many marine organisms to dissolve. [EurekAlert!]
(Thurs.) Changes in chemical processes in ocean could affect climate -- Scientists at New Mexico Tech, the University of Bergen, the University of New Hampshire, the University of Kiel, and University of California at Irvine have conducted a month-long field experiment that indicates increased levels of ocean acidity and carbon dioxide concentrations result in changes in phytoplankton and marked changes in oceanic chemical processes, which could lead to an increased understanding how these marine chemical processes could help regulate Earth's climate. [EurekAlert!]
(Tues.) New federal research plan for hurricane forecasting outlined -- The Federal agencies involved with hurricane research, including NOAA, have outlined their view of the future of hurricane forecasting capabilities in a publication drafted by the Office of the Federal Coordinator for Meteorological Services and Supporting Research entitled "Interagency Strategic Research Plan for Tropical Cyclones: The Way Ahead." [NOAA News]
(Tues.) Investigating hurricanes -- Using aircraft and satellites, scientists from several countries participated in the NASA African Monsoon Multidisciplinary Analyses off the African west coast last year to study the environment where Atlantic hurricanes often develop. [NASA Earth Observatory]
(Tues.) French scientists identify climate - ocean feedback -- Scientists at the CEREGE research center has noted the positive feedback loop between the water cycle in Central America and the salinity of the Atlantic Basin. Climate changes are predicted to affect this water vapor cycle. [EurekAlert!]
Did you remember NOAA Weather Radio during time change?- The Director of the National Weather Service encourages the public to place fresh batteries in their smoke detectors and NOAA Weather Radio All Hazards receivers when they change their clocks to Daylight Saving Time on Sunday morning, 11 March 2007. [NOAA News]
Tropical cyclones hit Australia -- Two tropical cyclones, the Indian Ocean counterparts of hurricanes in the North Atlantic, developed over the Indian Ocean off the northwest coast of Australia last week. One low-pressure system, Tropical Cyclone George, which became at least a category 3 cyclone on the Saffir-Simpson Intensity Scale, hit along the coast causing damage and killing at least one person and injuring 20 others. [USA Today] Another system, Tropical Cyclone Jacob, a category 1 cyclone, was approaching the coast as of Sunday. An image of Tropical Cyclone George taken late last week by the Japanese MTSAT satellite shows the tropical cyclone after it made landfall near Port Hedland, Australia. Tropical Cyclone Jacob is also seen farther to the northwest over the Indian Ocean. [NOAA OSEI]
A research aircraft serves as a learning experience -- A meteorology professor at the University of Utah who was participating in the NASA African Monsoon Multidisciplinary Analysis field campaign was able to teach his graduate-level tropical meteorology course using a high tech package called the "Real Time Mission Monitor" that allowed the students to participate in the monitoring of data collection onboard NASA's DC-8 Airborne Laboratory. [NASA Earth Observatory]
Celebrating 200 years of national science, service and stewardship -- The NOAA Magazine has highlighted NOAA's 200th Celebration currently underway that commemorates the creation of one of its predecessors, the United States Survey of the Coast in 1807. [NOAA Magazine]
A call is made for a worldwide public warning of mercury contaminated fish -- Scientists who attended the Eighth International Conference on Mercury as a Global Pollutant in Madison, WI last August have released a set of findings that appears in "The Madison Declaration on Mercury Pollution," which calls for a worldwide general warning to the public concerning the health risks posed by mercury contaminated fish, especially for children and women of childbearing age. [EurekAlert!]
Farmed salmon could pose a problem -- A fish biologist with the Pacific Northwest Research Station/Forest Service claims that farmed salmon could escape from their marine net pens and become an invasive species in the forest streams of Alaska, British Columbia and Washington State. [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]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

REPORT FROM THE FIELD -- Marsha Rich, a DataStreme LIT Leader from New Hampshire, reported that the cold and windy weather on top of Mount Washington last week forced the cancellation of a trip to the observatory at the summit that she was to conduct with teachers. She said that the temperature at the observatory fell to 37 degrees below zero and a peak wind gust of 117 mph was recorded. However, those observers that remain on the mountain demonstrated a little experiment with turning boiling water to snow, which they posted to the Internet.

Concept of the Week: Seiche Model

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. (Refer to pages 156-157 in your textbook for more on seiches.)

With a typical seiche in an enclosed basin, the water level near the center does not change at all but 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.

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 less than its period in a large coastal inlet. Also, 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 basin lengths and depths. Conversely, one can determine the average depth of a lake by determining the period of the seiche and the length of the lake.

Concept of the Week: Questions

In an enclosed basin the node of a seiche is located [(at either end) (near the center)] of the basin.
The natural period of a seiche [(depends on) (is independent of)] the size of an enclosed basin.

Historical Events:

13-15 March 1952...The world's 5-day rainfall record was set when a tropical cyclone produced 151.73 inches 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 Calendar)
14 March 1891...The submarine Monarch laid telephone cable along the bottom of the English Channel to prepare for the first telephone links across the Channel.
14 March 1903...President Theodore Roosevelt issued an executive order making Pelican Island near Sebastian Florida a "preserve and breeding ground for native birds," including pelicans and herons, marking the birth of the National Wildlife Refuge System. (Wikipedia)
14 March 1918...The first US concrete seagoing ship was launched at Redwood City, CA. (Today in Science)
15 March 1493...Christopher Columbus returned to Spain after his first voyage to the New World. (Wikipedia)
15 March 1778...Nootka Sound, Vancouver Island was discovered by Captain James Cook.
15 March 1946...For the first time, U.S. Coast Guard aircraft supplemented the work of the Coast Guard patrol vessels of the International Ice Patrol, scouting for ice and determining the limits of the ice fields from the air. (USCG Historian's Office)
15 March 1960...Key Largo Coral Reef Preserve in the Florida Keys was established as the nation's first underwater park. This preserve currently includes John Pennekamp Coral Reef State Park and the adjacent Florida Keys National Marine Sanctuary.
16 March 1521...Portuguese navigator Ferdinand Magellan reached the Philippines. He was killed the next month by natives.
16 March 1834...The HMS Beagle anchored at Berkeley Sound, Falkland Islands.
16 March 1889...A war between the U.S. and Germany was likely averted as a hurricane sank all three U.S. and three German warships in the harbor at Apia, Samoa. Joint U.S., German and Samoan rescue cooperation led to the Treaty of Berlin (1889) that later settled the dispute. (Accord's Weather Calendar)
17 March 1891...The British steamer SS Utopia sank off the coast of Gibraltar, killing 574 people. (Wikipedia)
17 March 1898...The USS Holland, the first practical submarine, was demonstrated by John Holland as it made its first dive in the waters off Staten Island, New York for one hour and 40 minutes. (Naval Historical Center)
17 March 1941...USCGC Cayuga left Boston with the South Greenland Survey Expedition onboard to locate airfields, seaplane bases, radio and meteorological stations, and aids to navigation in Greenland. (USCG Historian's Office)
17 March 1959...The submarine USS Skate (SSN-578) surfaced at the North Pole. (Naval Historical Center)