Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK SEVEN: 16-20 March 2015

Items of Interest:

Notice the Equinox -- The vernal equinox, which marks the commencement of astronomical spring, will occur this Friday (officially at 2245Z on 20 March 2015 or 6:45 PM EDT, 5:45 PM CDT, etc.). If you checked the sunrise and sunset times in your local newspaper or from the climate page at your local National Weather Service Office, you would probably find that by midweek, the sun should have been above the horizon for at least 12 hours at most locations. As discussed previously, the effects of atmospheric refraction (bending of light rays by the varying density of the atmosphere) along with a relatively large diameter of the sun contribute to several additional minutes that the sun appears above the horizon at sunrise and sunset.
International observances -- Several days during this upcoming week have been designated as special days that are intended to focus public attention on the environment and earth science:

"World Water Day" -- Sunday, 22 March 2015, has been designated by the United Nations (UN) as the annual World Water Day. The theme for this year's World Water Day 2015 is "Water and Sustainable development." [UN-Water]
"World Meteorology Day" -- A celebration will be held on Monday, 23 March 2015 for World Meteorology Day. This day is designated to celebrate the anniversary of the establishment of the World Meteorological Organization (WMO) on 23 March 1950. The WMO is an agency within the United Nations. This year's theme for World Meteorological Day 2015 is “Climate knowledge for climate action."

Worldwide GLOBE at Night 2015 Campaign is underway -- The third in the series of GLOBE at Night citizen-science campaigns for 2015 will continue a 10-night campaign that runs through Friday 20 March. GLOBE at Night is a worldwide, hands-on science and education program designed to encourage citizen-scientists worldwide to record the brightness of their night sky by matching the appearance of a constellation (Orion in the Northern Hemisphere and Crux in the Southern Hemisphere) with the seven magnitude/star charts of progressively fainter stars. Activity guides are also available. The GLOBE at night program is intended to raise public awareness of the impact of light pollution. In addition to the 11-20 March campaign, the other three GLOBE at Night campaigns during the first half of 2015 are on 9-18 April, 9-18 May and 8-17 June. [GLOBE at Night]
Oceanographic expeditions that made an impact -- This week's Supplemental Information ... In Greater Depth provides a historical perspective of some of the oceanographic expeditions that made an impact upon science, especially in terms of oceanography.

Ocean in the News:

Eye on the tropics --- As meteorological autumn continued across the Southern Hemisphere, most of last week's tropical cyclone activity was limited to the ocean basins to the south of the equator:
- In the South Indian Ocean, Tropical Storm Haliba dissipated early last week to the south of La Reunion after moving to the southeast and then south across the waters of the western South Indian Ocean.
  Cyclone Olwyn formed as a tropical storm several hundred miles north of Western Australia's town of Exmouth on the tip of the North West Cape at midweek. Moving to the south-southwest, Olwyn strengthened to become a category 2 tropical cyclone on the Saffir-Simpson Scale before making landfall near Cape Cuvier in Western Australia early last Friday (local time). After bringing heavy rains and strong winds to coastal sections of Western Australia, Olwyn continued traveling south before dissipating by Sunday. For additional information and satellite imagery on Cyclone Olwyn, consult the NASA Hurricane Page .
- In South Pacific basin, Tropical Storm Pam formed early last week over the waters in the Solomon Islands. During the week, Pam intensified to become a major category 5 tropical cyclone as it traveled toward the south, passing near New Caledonia. Maximum sustained surface winds reached at least 160 mph and the winds generated ocean waves that had heights ranging between 45 and 50 feet. The strong winds and the torrential rain devastated the Pacific Island nation of Vanuatu on Saturday. Although the official death toll on Vanuatu was eight, these numbers were expected to increase. [CNN] On Sunday Cyclone Pam traveled toward the south-southeast and was forecast to pass near New Zealand's North Island. See the NASA Hurricane Page for additional information and satellite images on Cyclone Pam.
  Tropical Storm Nathan formed early last week to the east of Australia's Cape York Peninsula. Initially, Nathan traveled westward toward the eastern coast of Queensland before reversing course in the Coral Sea and then traveling toward the east. Forecasts indicate that Nathan would turn toward the south and continue for the next several days well off the coast of Australia. Satellite images and additional information on Tropical Storm Nathan are available on the NASA Hurricane Page.
- In western North Pacific a tropical depression formed during midweek slightly more than 100 miles to the south of Kwajalein in the Marshall Islands. This system intensified quickly to become a tropical storm and then to a category 1 typhoon (on the Saffir-Simpson Scale) as it traveled to the west-northwest near Guam and then west during the late week. Current forecasts indicate that Bavi should weaken to a tropical storm and then a tropical depression as it would continue traveling across the Philippine Sea toward the Philippine Islands during the first few days of this new week. The NASA Hurricane Center has satellite images and additional information on Typhoon Bavi.
- In South Atlantic basin, a rare subtropical storm formed last week east of the Brazilian state of Rio Grande do Sul. This subtropical storm, which was identified as 90Q, was only the third subtropical or tropical storm to have formed since 2004. Approximately 24 hours later, this rare storm system had moved toward the east and then dissipated. Additional information and satellite images on 90Q can be found on the NASA Hurricane Page.
- An image obtained from the Japanese Meteorological Agency's (JMA) geosynchronously orbiting MTSAT-2 satellite last Wednesday provided a simultaneous view of four tropical cyclones over four seas: Tropical cyclones Olwyn, Nathan, and Pam in the South Hemisphere and the tropical depression that became Typhoon Bavi in the Northern Hemisphere. [NOAA Environmental Visualization Laboratory]
National marine sanctuaries expanded off northern California coast -- Late last week NOAA officials released a final rule authorizing the expansion of the Cordell Bank and Gulf of the Farallones National Marine Sanctuaries off the coast of northern California. This expansion, which would more than double the size of each of the two existing sanctuaries, is intended to help protect the region's marine and coastal habitats, biological resources and special ecological features. [NOAA National Marine Sanctuaries News]
Aid provided for conservation and management of whales, dolphins and porpoises -- A group of researchers have identified 131 "Biologically Important Areas" (BIAs) within US waters that should be considered biologically important when making management and regulatory decisions about human activities that could affect whales, dolphins and porpoises. Each BIA includes a written narrative, a map, a list of references, and a table of data that details the type and quantity of information used to define the BIA. [NOAA Fisheries Northeast Fisheries Science Center Newsroom]
Sea Grant agent and Arctic communities study bowhead whales -- A NOAA Sea Grant extension agent from the University of Alaska Fairbanks has been assisting Alaskan Native tribes and other Arctic communities in Alaska study the health of bowhead whales, a protected species that resides in the waters of the northern Bering Sea and in the Bering Strait. [NOAA Oceanic and Atmospheric Research News]
New spacecraft planned to study ocean color, aerosols and clouds -- NASA scientists and engineers have started work on the Pre-Aerosol Clouds and ocean Ecosystem (PACE) mission, a new satellite designed to extend critical climate measurements of Earth's oceans and atmosphere that would also serve to advance studies of the impact of environmental changes on ocean health, fisheries and the carbon cycle. PACE is scheduled to be launched in 2022. An ocean color instrument on PACE would provide a view of the colors of the ocean, from the ultraviolet to near infrared, which would result in more accurate measurements of biological and chemical ocean properties, such as the biomass and composition of phytoplankton communities. PACE will measure clouds and aerosols in the atmosphere to supplement measurements from existing NASA satellite missions. An aerosol/cloud polarimeter instrument onboard this mission would be used to assess the role of clouds and aerosols has in affecting the planetary climate.[NASA Headquarters]
Predicting those African storms that could make landfall on North American coast as hurricanes -- Using satellite-derived temperatures of cloud tops over West Africa for the Atlantic hurricane seasons (June through November) between 2005 and 2010, researchers at Israel's Tel Aviv University have found that approximately 85 percent of the most intense hurricanes affecting the coasts of the United States and Canada started as intense thunderstorms over western Africa. They compared these data with hurricane statistics for the same seasons obtained from the National Hurricane Center's database. Apparently, larger areas covered by cold clouds that form into tropical waves leaving the western coast of tropical Africa have a higher chance of developing into hurricanes within the next one to two weeks. [American Friends of Tel Aviv University Newsroom]
Navy aircraft carrier delayed from deployment by Bryozoans -- The US Navy's aircraft carrier USS Theodore Roosevelt was forced to remain docked in Norfolk, VA at the beginning of last week after Bryozoa, a tiny marine organism clogged the ship's intake before its scheduled deployment. [Wavy.com] (Special thanks to Terri Kirby Hathaway, LIT Leader and Marine Education Specialist with North Carolina Sea Grant from Manteo, NC for forwarding this item.)
A sick leatherback turtle washes upon on Outer Banks beach -- A week ago last Friday a giant female leatherback sea turtle was found along a beach of North Carolina's Outer Banks. Since the turtle was sick and in a weakened state, scientists decided to euthanize her. Apparently, the turtle had ingested plastic. [WITN.com News] (Special thanks to Terri Kirby Hathaway, LIT Leader and Marine Education Specialist with North Carolina Sea Grant from Manteo, NC for forwarding this item.)
An All-Hazards Monitor -- This Web portal provides the user information from NOAA's National Weather Service, FAA and FEMA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [NOAA/NWS Daily Briefing]
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 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:

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)
20 March 1866...The immigrant ship Monarch of the Seas left Liverpool, England, but was never seen again. The ship with 738 people was officially declared "lost" after 130 days. A message in a bottle was found at Plymouth, supposedly sent by a passenger. In July, wreckage was found around the Dingle coast in Southern Ireland.
20 March 2000...A large iceberg measuring approximately 170 mi by 25 mi calved off Antarctica's Ross Ice Shelf near Roosevelt Island. The iceberg was approximately 2.5 times the size of New York's Long Island. (Accord's Weather Guide Calendar)
22 March 1778...Captain James Cook of the British Royal Navy sighted Cape Flattery, in present day Washington State.
22 March 1999...Tropical Cyclone Vance produced Australia's highest measured wind speed of 166 mph at Learmonth, West Australia. Gusts reaching 185 mph were estimated in the eyewall in the Exmouth Gulf. All homes in the village of Exmouth were either damaged or destroyed. (Accord's Weather Guide Calendar)