Weekly Ocean News

WEEK SEVEN: 20-24 October 2008

Ocean in the News

Eye on the tropics --- During the last week:
- In North Atlantic -- Omar developed over Caribbean at the start of last week and rapidly intensified into the seventh hurricane in the North Atlantic this current season as it massed close to Puerto Rico and the Virgin Islands, reaching a category 3 status on the Saffir-Simpson Scale. By the first part of the weekend, Hurricane Omar had weakened to a tropical storm as it traveled to the northeast over the central North Atlantic. An image obtained from the MODIS instrument on NASA's Aqua satellite shows the clouds surrounding Hurricane Omar. [NASA Earth Observatory] Additional information concerning Omar can be obtained from the NASA Hurricane Page.
  Tropical depression 16 formed in the western Caribbean off the Honduras coast early in the week, but made landfall before intensifying. More information can be found on the NASA Hurricane Page
  Early in the week, Tropical Storm Nana weakened and dissipated over the eastern tropical Atlantic after three days. The NASA Hurricane Page has images and additional information on Nana.
- In western North Pacific Tropical Depression 22 formed over the Gulf of Tonkin early in the week and intensified into a tropical storm before making landfall along the coast of Viet Nam.
  Tropical Storm Bavi formed over the western Pacific over the weekend and was curving toward the northeast, passing well to the east of Japan.
- Tropical Cyclone 1S formed in the Southern Indian Ocean late last week, which is somewhat rare for this time of year in that ocean basin. As Sunday, this cyclone was traveling to the southwest.
Conservation internship program is taken to the coasts -- NOAA and the national organization of interns and volunteers called the Student Conservation Association recently signed a memorandum of agreement that would result in a program in which would talented high school and college students would serve as conservation interns who would be helping marine scientists protect some of the coastal natural resources. [NOAA News]
Ocean acidification studied by undersea lab -- Geoscientists from NOAA and several universities across the Southeast are more than midway through their 10-day mission in NOAA's Aquarius Mission, the world's only undersea research station located in the waters of the Florida Keys, in which they will study the effect of ocean acidification on coral reef ecosystems. [NOAA News]
Public comments invited -- NOAA’s Fisheries Service is seeking comments from the public through mid November involving the measures designed to protect marine mammals as part of the proposed authorization of training exercises to be conducted by the US Navy. One NOAA proposal is involved with the planned use of sonar in naval training exercise off the southern California coast [NOAA News], while another separate proposal involves sonar operations in naval exercises in the offshore waters along the Atlantic and Gulf of Mexico coastlines. [NOAA News]
Marine forecast model an aid to sport fishers -- A computer model that has been developed at Oregon State University with the support of NOAA to predict ocean water temperatures with lead times of up to 48 hours has been helping sport fishers along the West Coast predict the best location for catching tuna, while conserving fuel. [NOAA News]
Alaskan beluga whales are declared endangered -- NOAA’s Fisheries Service recently announced that the beluga whale population that is found in Alaska's Cook Inlet near Anchorage is now considered an endangered species, in danger of extinction. [NOAA News]
Review of September global temperatures -- Preliminary data analyzed by scientists at NOAA’s National Climatic Data Center indicated that the global average temperature for September 2008 was the ninth highest September temperature since global temperature records began in 1880. The monthly temperature of the land surface was the eleventh highest, while the ocean surface temperature for the month was the seventh highest on record. [NOAA News]
Annual Arctic Report Card for 2008 is issued -- NOAA’s Climate Program Office recently issued its annual Arctic Report Card that tracks the recent environmental changes across the Arctic, focusing upon the region's atmosphere, oceans, sea ice, Greenland's ice sheet and the biology for this year. The report card notes continued temperature increases, a near-record loss of summer sea ice and a melting of surface ice in Greenland. [NOAA News]
Changes in underwater data communications are suggested -- A professor at the New Jersey Institute of Technology has discovered new acoustic particle velocity channels in underwater environments and invented a technique to communicate data through these channels, allowing for faster and more reliable communications between multiple users. [EurekAlert!]
Coastal dead zones could benefit some species -- An ecologist at Brown University claims that some of the low-oxygen areas in coastal waters that are commonly called "dead zones" may contain life and could benefit some species, such as the commercially valuable quahog clam thrives in hypoxic waters in Rhode Island's Narragansett Bay. [Brown University]
"Swimways" needed to protect endangered turtles and sharks -- A resolution was adopted by the International Union for the Conservation of Nature at its World Conservation Congress recently that urged nations to create marine protected areas to protect the endangered Pacific leatherback sea turtle and the hammerhead sharks. [EurekAlert!]
Genetics of Antarctic "antifreeze fish" studied -- Biologists at the University of Illinois and at the Chinese Academy of Sciences have been studying the genetics of several types of notothenioid fish, dubbed "antifreeze fish" that inhabit the cold waters of the Southern Ocean offshore of Antarctica in an attempt to learn how these fish survive in such extreme environmental conditions. [EurekAlert!]
Research into diatom's ability to trap carbon in oceans -- An international team of researchers has been analyzing the genome of a diatom species in order to understand how these microscopic algae have the capability to capture and trap excess atmospheric carbon compounds in the world oceans. [EurekAlert!]
Mental health issues studied as part of recovery from Ike disaster -- Researchers from Dartmouth University who are associated with the National Center for Disaster Mental Health Research will conduct a field mission in early November to the area around Galveston, TX to study the lingering impact of Hurricane Ike upon the mental health of the residents along the upper Texas Gulf Coast following the hurricane's landfall in September. [Dartmouth University]
Termites may have helped Katrina destroy floodwalls -- Researchers at Louisiana State University report that the Formosan subterranean termites they discovered in the seams of the floodwalls protecting New Orleans, LA five years before Hurricane Katrina struck may have contributed to the floodwall breaks that resulted in the inundation of that city following the hurricane's landfall in 2005. [Entomological Society of America]
An All-Hazards Monitor -- This Web portal provides the user information from NOAA on current environmental events that may pose as hazards such as tropical weather, marine weather, tsunamis, rip currents, Harmful Algal Blooms (HABs) and coral bleaching. [NOAAWatch]
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.

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:

20 October 1892...After ten years of difficult and costly construction, the St. George Reef Lighthouse, built on a rock lying six miles off the northern coast of California, midway between Capes Mendocino and Bianco, was first lighted. (USCG Historian's Office)
20 October 1956...A German physician, Dr. Hannes Lindemann, began a voyage on which he would become the first person to cross the Atlantic in the smallest craft. Using a double-seat folding kayak that was 17 feet in length and outfitted with an outrigger and sail, he made the trip from Las Palmas in the Canary Islands to St. Thomas in the US Virgin Islands in 72 days. He had made a prior crossing in a 23-foot African dugout canoe. He later wrote a book, Alone at Sea, describing his experiences. (Today in Science History)
20 October 1984...The Monterey Bay Aquarium opened on Cannery Row in Monterey, CA as the largest artificial environment for marine life, housing 500 marine animals from at least 525 species. The aquarium also supports active research and conservation programs. (Today in Science History)
21 October 1797...The USS Constitution was launched at the Charlestown Navy Yard in Boston, MA. The ship, nicknamed "Old Ironsides," is now the oldest commissioned ship in the U.S. Navy. (Naval Historical Center)
21 October 1580...Portuguese navigator Ferdinand Magellan on his famous circumnavigation voyage of the globe reached Cape Virgenes and the strait at the tip of South America that now bears his name. Only three ships entered the 373-mile long passage separating Tierra del Fuego (land of fire) and the continental mainland. Navigating the treacherous strait in 38 days, the expedition entered the South Pacific Ocean, which Magellan named "Mar Pacifico" for the relatively tranquil seas that he found. However, one ship had been wrecked and another deserted. (The History Channel)
21-26 October 1998...Hurricane Mitch, a category 5 hurricane (on the Saffir-Simpson Scale), developed as a tropical depression over the southwestern Caribbean Sea about 360 mi south of Kingston, Jamaica on the 21^st. It would intensify over the next few days to become the second deadliest Atlantic hurricane on record, on the 24^th. By the 26^th, Mitch finally dissipated after remaining a category 5 hurricane for 33 hours. Estimated rainfall totals of up to 75 in. caused devastating flooding and mudslides in Honduras and Nicaragua for days. Estimated death toll from this hurricane was more than 11,000, the worst since 1780. (The Weather Doctor) (Accord Weather Calendar)
22 October 1988...A "nor'easter" swept across the coast of New England. Winds gusted to 75 mph, and large waves and high tides caused extensive shoreline flooding. (The National Weather Summary) (Storm Data)
23-24 October 1918...The Canadian steamship Princess Sophia carrying miners from the Yukon and Alaska became stranded on Vanderbilt Reef along coastal British Columbia. A strong northerly gale hampered rescue attempts, and the next day, the ship sank with the loss of the 268 passengers and 75 crewmen onboard. (The Weather Doctor)
25 October 1859...The Royal Charter Storm, named after the loss of the fully rigged ship Royal Charter off the coast of Anglesey, England, drowned about 500 people, along with the loss of gold bullion. The ship was one of over 200 vessels wrecked between 21 October and 2 November, with the loss of around 800 lives. This tragedy led to the introduction of gale warnings in June 1860. (The Weather Doctor)
25 October 1941...South Greenland Patrol expanded to include three cutters of the Northeast Greenland Patrol and form the Greenland Patrol. (USCG Historian's Office)
25-26 October 1980...The combination of unusually high tides and southeasterly winds gusting to 75 mph generated waves with heights to 25 ft, resulting in serious flooding, beach erosion and sea wall damage along the Maine coast. Wind damage was considerable and as many as 100,000 homes were without power for up to 40 hrs. (Accord Weather Guide Calendar)