Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 17-21 April 2006

Ocean in the News:

(Thurs.) New satellite system launched that will help monitor Earth's environment -- Six tiny satellites that will form a low orbit and globe-spanning constellation were successfully launched from Vandenberg AFB in California last Friday. Orbiting at an altitude of 500 miles, this fleet of satellites, called COSMIC (the Constellation Observing System for Meteorology, Ionosphere, and Climate) in the US represents a joint US-Taiwan venture designed to use the bending of GPS signals passing through the Earth's atmosphere (radio occultation) to generate vertical temperature and water vapor profiles of the atmosphere that can then be used track hurricanes and other storm systems, as well as to monitor changes in climate. [UCAR]
(Thurs.) Using a vacuum on algae -- Marine researchers with the University of Hawaii have been using a modified dredging device as an underwater vacuum to suck invasive algae from some of the bays along the coast of the Aloha State. [ENN]
(Thurs.) Trawling for origins of European sea fishing -- Archaeologists at the University of York have been using fish bones from archaeological sites in Great Britain, Belgium, Denmark, Germany and Poland to investigate the beginning and development of sea fishing across northern Europe approximately 1000 years ago. [University of York]
(Thurs.) Satellite technology used to measure sea level and predict ENSO events -- American and French scientists recently described how radar altimetry devices onboard orbiting satellites are used to measure global sea level and to predict the occurrence of El Niño and La Niña events. [Underwater Times]
(Tues.) Water mold could result in large fish lesion events -- NOAA scientists from the Center for Coastal Fisheries and Habitat Research, along with colleagues from academia and state environmental agencies, reported that water mold appears to be a pathogen that could produce seasonal outbreaks of lesions and skin ulcers in a variety of estuarine fish along the East Coast. [NOAA News]
(Tues.) Satellite-derived maps used to monitor urban development along Chesapeake Bay -- Scientists at Woods Hole Oceanographic Institution have been using a set of high resolution images (with a spatial resolution of 30 square meters) obtained from satellites to develop maps of the land use around Chesapeake Bay in an attempt to monitor and mitigate the effects of large impervious surfaces affecting the water quality in the nation's largest estuary. [EurekAlert!]
(Tues.) Melting Arctic ice strands walrus calves -- Researchers with Woods Hole Oceanographic Institution along with colleagues from other academic institutions conclude that rapidly melting sea ice in the Arctic Ocean have caused walrus mothers to abandon their pups. [Woods Hole Oceanographic Institution]
(Tues.) Coastal plates on the move -- Using underwater data obtained from various sources, including that from naval hydrophones, a researcher with Oregon State University claims that the three major tectonic plates (the Juan de Fuca, the North American and the Pacific plates) off the coast of the Pacific Northwest are converging into a "triple junction", which also appears to be moving slowly. [EurekAlert!]
(Tues.) Damaged interstate highway bridge to become a giant reef -- The 2.5-mile long I-10 bridge across Florida's Escambia Bay near Pensacola that was damaged by Hurricane Ivan in 2004 will become an artificial reef for fish and other marine life when a replacement bridge is completed. [Ledger-Enquirer]
Using school milk cartons to promote ocean science -- As part of a K-12 education and outreach effort, NOAA, in cooperation with a local dairy, is putting ocean science awareness messages on the side panels of school milk cartons distributed in the St. Louis, MO area next week. [NOAA News]
Add another named storm to 2005 list -- Upon reviewing of data obtained from an unnamed subtropical storm that formed in early October off the Azores during last year's record hurricane season in the North Atlantic basin (including the Caribbean and Gulf of Mexico), scientists at the National Hurricane Center added this system as the 28th named system (including tropical storms and hurricanes) to the season's list. [USA Today] An official report of this unnamed subtropical storm from the National Hurricane Center appears in pdf format. [NHC]
The 2005 hurricane seasons reviewed -- The 2005 hurricane season in the North Atlantic was historic as numerous long-standing records were been broken by the most active hurricane season in the North Atlantic in over 150 years of record keeping. In addition to a review of this season in this basin, a review of the eastern North Pacific hurricane season was also made. [AMS DataStreme Atmosphere] [NOAA News]
Coral bleaching and disease are attacking Caribbean reefs -- Scientists with NOAA and the National Park Service report that a combination of coral bleaching that may be due to higher water temperatures and deadly diseases have been attacking the coral reefs in the Caribbean Sea. [ENN]
Whale sharks studied -- Researchers have been attempting to study the behavior and migration patterns of whale sharks, the world's largest fish, in the offshore waters of Western Australia. [Natural History Magazine]
"Moat of death" accompanies an emerging oceanic volcano -- Researchers using submersible vehicles to explore the Vailulu'u Seamount, an undersea volcano off the Samoan archipelago, have found that the volcano has developed a 1000-foot cone that has a cavity of turbid and toxic waters dubbed the "moat of death", which can be fatal for some fish. [Fox News]
Sewage spilled into a Virgin Islands harbor -- Millions of gallons of raw sewage spilled into the harbor near Christiansted on the north side of St. Croix in the US Virgin Islands over one week ago, leading officials to warn local residents and tourists to stay away from the beach and water. [ENN]
Record ocean waves documented -- Measuring instruments onboard the British Royal Research Ship Discovery indicate that the ship encountered record-setting waves reaching heights of nearly 98 feet during a scientific expedition in the North Atlantic off Scotland in February 2000. [M&C Science and Nature]
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: Climate Feedback Processes

Earth's climate system includes many interacting variables. Some variables are external to the Earth-atmosphere system and some are internal. External variables include solar energy output and Earth-sun geometry (i.e., the Milankovitch cycles). Internal variables include properties of the Earth's surface (e.g., albedo, moisture), the concentration of key atmospheric components (e.g., greenhouse gases, sulfurous aerosols), and cloud cover and thickness.

An important consideration in understanding how Earth's climate system responds to some perturbation is feedback. Feedback is defined as a sequence of interactions among variables in a system that determines how the system responds to some initial perturbation in one or more of the variables. Variables in Earth's climate system may interact in such a way as to either amplify (positive feedback) or lessen (negative feedback) a change in climate. An example of positive feedback is the ice-albedo effect described in Chapter 12 of the DataStreme Ocean textbook. Less ice cover in the Arctic greatly reduces the albedo of the Arctic Ocean causing higher sea surface temperatures and accelerated melting of the multiyear pack ice.

Consider an example of negative feedback. Increasing concentrations of atmospheric carbon dioxide enhances the greenhouse effect causing global warming. Global warming in turn raises sea surface temperatures and increases the rate of evaporation. A more humid atmosphere means more persistent and thicker cloud cover but clouds have both a cooling and warming effect on the lower atmosphere. The relatively high albedo of cloud tops causes cooling whereas absorption and emission of infrared radiation by clouds causes warming by contributing to the greenhouse effect. Satellite measurements and numerical models indicate that cooling would dominate.

In general, negative feedback tends to dominate over positive feedback in Earth's climate system, limiting the magnitude of climate change. The great thermal inertia of the ocean is the principal reason for dampening the planetary temperature response.

Concept of the Week: Questions

Feedback in Earth's climate system that amplifies climate change is described as [(positive)(negative)] feedback.
In general, [(negative)(positive)] feedback tends to prevail in Earth's climate system.

Historical Events:

17 April 1492...Spain and the Italian explorer Christopher Columbus signed a contract for him to sail to Asia to obtain spices. (Wikipedia)
17 April 1524...Giovanni Verrazano, a Florentine navigator, onboard the frigate La Dauphine "discovered" New York Bay. (Wikipedia)
18 April 1906...An early morning magnitude 7.8 earthquake along with a subsequent fire devastated much of San Francisco, CA, resulting in one of the worst natural disasters to hit a major US city. As many as 6000 people may have died because of this disaster. The earthquake was along the San Andreas Fault, with an epicenter thought to have been near Mussel Rock along the coast at suburban Daly City. [A series of articles commemorating the 100th anniversary of the San Francisco earthquake has been posted. [San Francisco Chronicle]
18 April 1848...U.S. Navy expedition to explore the Dead Sea and the River Jordan, commanded by LT William F. Lynch, reached the Dead Sea. (Naval Historical Center)
19 April 1770...Captain James Cook discovered New South Wales, Australia. Cook originally named the land Point Hicks.
20 April 1534...Jacques Cartier, a French explorer, set sail from St. Malo, France with two ships to explore the North American coastline in an attempt to find a passage to China. In this first voyage, he explored the Gulf of St. Lawrence.
20 April 1952...The tankers Esso Suez and Esso Greensboro crashed in thick fog off the coast of Morgan City, LA. Only five of the Greensboro's crew survived after the ship burst into flame. (David Ludlum)
21 April 1910...The U.S. Government took over sealing operation of Pribilof Islands in the Bering Sea from private lessees. (USCG Historian's Office)
21 April 1906...Commander Robert Peary, USN, discovered that the supposed Arctic Continent did not exist. (Naval Historical Center)
22 April 1500...Portuguese navigator Pedro Álvares Cabral became the first known European to sight Brazil, claiming it for Portugal. (Wikipedia)
23 April 1924...A tube transmitter for radio fog-signal stations, developed to take the place of the spark transmitters in use, was placed in service on the Ambrose Channel Lightship and proved successful. (USCG Historian's Office)