WEEKLY OCEAN NEWS

DATASTREME OCEAN WEEK TWELVE: 28 November-2 December 2005

Ocean in the News:

• (Thurs.) Official hurricane season reviews -- NOAA officials held a press conference on Tuesday where the provided a list of records set during the 2005 official North Atlantic hurricane season that ended on Wednesday. They attributed the increased hurricane activity in the North Atlantic basin during the last several years to "naturally occurring multi-decadal climate variability." [NOAA News] and [NOAA Magazine]
• (Thurs.) Oceanic conveyor may be weakening -- British measurements of deep water currents in the Atlantic suggest the conveyor flow at depth is weakening. Models expect this to mean colder temperatures in Europe. [CNN]
• (Thurs.) Expect more drought in Sahel -- Two NOAA climate modeling groups predicted that the Sahel and southern Africa will become progressively drier over the century. Atlantic Ocean temperatures are expected to affect the regional rainfall patterns. [BBC News]
• (Thurs.) Island growth monitored -- Researchers from the British Antarctic Survey and the Hawaii Institute of Geophysics and Planetology have been using satellite imagery to monitor the expansion of Montagu Island in the South Atlantic's South Sandwich Islands because of fast forming lava flows from the Mount Belinda Volcano. The island's size has increased by 50 acres within a month. [EurekAlert!]
• (Thurs.) Singing icebergs? -- A geophysicist from the Alfred Wegener Institute for Polar and Marine Research reported detecting regularly oscillating signals that apparently were emanating from icebergs when she and her colleagues were monitoring earthquakes in Antarctica. [The New Scientist]
• (Tues.) Improvements in hurricane forecasting foreseen -- Officials with the National Hurricane Center, NOAA's Hurricane Research Division and the National Weather Service's Environmental Modeling Center recently announced that a new higher resolution hurricane forecast model will be put into operation during the next hurricane season. This model, along with additional improvements in data acquisition and computer processing during subsequent seasons are hoped to result in improved hurricane forecasts. [USA Today]
• (Tues.) Pollution of the Baltic Sea addressed -- Representatives from countries surrounding the Baltic Sea area met in Stockholm, Sweden to discuss plans aimed at fighting marine pollution that has contaminated the Baltic Sea. [ENN]
• (Tues.) Cetaceans threatened by sonar and naval maneuvers -- A UN report claims that the capabilities for communication, navigation and hunting by as many as 71 types of cetaceans, or marine mammals such as whales, dolphins and porpoises, appear to be threatened by the increased naval maneuvers along with use of underwater sonar. [ENN]
• (Tues.) New Great Lakes restoration plan appears scuttled -- A report by the US Environmental Protection Agency recommends that the $20 billion plan to restore coastal wetlands, reduce pollution and combat invasive species that was proposed by President Bush should not be funded until existing programs are analyzed. [ENN]
• (Tues.) Ice core shows coupling of atmospheric constituents and ancient climate record -- Two studies of the gases trapped in a 3270-m long ice core obtained by the European Project for Ice Coring in Antarctica (EPICA) team at Antarctica's Ice Dome Concordia extends the record of atmospheric composition to approximately 650,000 years ago. One study was made of the relationship between climate and the carbon cycle during the Pleistocene, while the second study was made of the levels of atmospheric methane and nitrous oxide over the same period. Some of the researchers indicate that current atmospheric carbon dioxide levels appear to be at the highest levels. [EurekAlert!]
• Racing teams aided by NOAA collaboration -- -- Sailing teams participating in the currently-running Volvo Ocean Race off the coast of the Iberian Peninsula and northwest India have been receiving information on ocean currents and other marine observations for the first time, made available online through the cooperation between NOAA's Coast Watch Program and the Atlantic Oceanographic and Meteorological Laboratory. [NOAA News]
• Recent tropical storm updates:
  • The second tropical storm within the last week, Tropical Storm Delta, the 25th named tropical cyclone of the Atlantic hurricane season, formed over the central Atlantic Ocean southwest of the Azores on Wednesday evening. By Sunday morning, the system was accelerating to the northeast and could affect the Canary Islands. [USA Today]
  • Tropical Storm Gamma, the 24th named tropical cyclone that formed over the Caribbean on 16 November 2005, finally dissipated late Sunday, 18 November, but not before bringing torrential rain to Central America, which resulted in the loss of at least 32 lives. [USA Today] Imagery from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite indicated that more than 20 inches of rain fell across the north coast of Honduras between 14-21 November 2005. [NASA Earth Observatory]
• Documenting Hurricane Katrina destruction -- A NOAA helicopter pilot, Lt. Phil Eastman of the NOAA Corps, took several hundred pictures from low altitudes while surveying the damage along the Gulf Coast following the landfall of Hurricane Katrina in late August. [NOAA News]
• NOAA Fisheries Service director to chair international fisheries commission -- Dr. William T. Hogarth, he director of the NOAA Fisheries Service was recently elected by member nations of the International Commission for the Conservation of Atlantic Tunas to chair the commission for a two-year term. [NOAA News]
• The 2005 hurricane seasons reviewed -- Although tropical storms and hurricanes could continue to form, the official 2005 hurricane season in both the North Atlantic and North Pacific will end this upcoming Wednesday, 30 November 2005. Numerous long-standing records have been broken by the most active hurricane season in the North Atlantic in over 150 years of record keeping. [AMS DataStreme Atmosphere]
• Ocean levels appear to be rising at faster rates -- Based upon drilling studies along the New Jersey coast that encompass the last 100 million years and a variety of recent measurements from tidal gauges and satellites, scientists from Rutgers University and five other institutions recently reported that the global ocean level is currently rising at nearly two millimeters per year, or roughly twice the rate during the previous several thousand years. These scientists point to increased concentrations of greenhouse gases during the last century due to human activity as being a major factor in the accelerated rise in sea levels. [EurekAlert!]
• Farm-bred salmon could threaten wild Atlantic stock -- Owners of a salmon farm in the Canadian Province of New Brunswick report that the actions of saboteurs have caused the release of thousands of farm-bred salmon at a time when wild Atlantic salmon are beginning to spawn. Some scientists claim that interbreeding of the two types of fish could signal then demise of wild salmon. [The New Scientist]
• Public looks to Internet for hurricane news -- An official at the Pew Internet and American Life Project released the results of a survey indicating that more than half the Internet users across the US visited the websites of traditional American news organizations for news and information on Hurricanes Katrina and Rita; the pollsters were surprised that a relatively large (14 percent) of American users went to websites maintained by international news organizations for their hurricane news. [USA Today]
• Mask designed to mimic fish gills -- A Massachusetts engineering company is collaborating with Case Western Reserve University in developing a set of artificial gills that involve a polymer membrane mask to obtain dissolved oxygen in water in much the same way as fish breathe, thereby permitting to swim underwater for extended time intervals. [US Water News Online]
• Seawater could help save Venice from flooding -- A team of engineers and geologists are considering a plan that would inject seawater nearly 2300 feet into the ground under Venice, Italy to raise the city by at least one foot, thereby reducing the flooding and tidal action in the historic city. [US Water News Online]
• 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

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

Historical Events:

• 28 November 1520...Portuguese navigator Ferdinand Magellan reached the Pacific Ocean after passing through the treacherous South American strait that now bears his name in a 38-day passage. He was the first European to sail into the Pacific Ocean from the Atlantic to the east. (The History Channel)
• 28 November 1960...A severe storm produced waves 20 to 40 feet high on Lake Superior. Duluth, MN was buried under a foot of snow, and clocked wind gusts to 73 mph. The northern shore of Lake Superior was flooded, and property along the shore was battered. Thousands of cords of pulpwood were washed into Lake Superior, and up to three feet of water flooded the main street of Grand Marais. Thunder accompanied the "nor'easter". (David Ludlum) (The Weather Channel)
• 1 December 1969...Ocean swells generated by a storm more than 1000 miles to the north-northwest of the French Frigate Shoals produced 50-foot high surf along the outer shoals of Tern Island, submerging the 300-foot wide island under two to three feet of water. The 19-member Coast Guard contingent was evacuated, but considerable damage was done to buildings. (Accord Weather Calendar)
• 1 December 1990...Workers from the United Kingdom and France on the Channel Tunnel construction project met approximately 120 feet beneath the English Channel seabed, to establish the first ground connection between the British Isles and mainland Europe since the last Ice Age. (Wikipedia)
• 2 December 1755...The second Eddystone Lighthouse near Plymouth, England was destroyed by fire. This light had replaced an earlier light that had been destroyed in the "Great 1703 Storm." The current structure is the fourth light to be constructed at that site. (Wikipedia)
• 3 December 1952...A remarkable display of sea smoke was seen in Hong Kong harbor. The sea-smoke, induced by a strong surge of arctic air, poured from the water of Kowloon Bay from 8 AM to 9:30 AM. The air temperature near the sea wall was 44 degrees F. (Accord Weather Calendar)
• 3 December 1992...The Greek oil tanker Aegean Sea carrying 80,000 tons of crude oil ran aground in a storm while approaching La Coruña, Spain, spilling much of its cargo. (Wikipedia)
• 3 December 1999...After rowing for 81 days and 2962 miles, Tori Murden became the first woman to cross the Atlantic Ocean by rowboat alone when she reached Guadeloupe after departing from the Canary Islands. (Wikipedia)
• 4 December 1786...The first of two great early December storms began. The storm produced high seas at Nantucket that did great damage. (David Ludlum)
• 4-13 December 1991...Tropical Cyclone Val with gusts to 150 mph caused $700 million damage. Seventeen deaths were reported in American and Western Samoa, with 95 percent of the housed in Savaii either destroyed or badly damaged. Savaii was essentially hit twice by Val as the system completed a loop on the 8^th. (Accord Weather Calendar)
• 4 December 2003...A tropical depression became Tropical Storm Odette in the Caribbean well south of Kingston, Jamaica, becoming the first December tropical storm of record to form in the Caribbean Sea. Odette made landfall on near Cabo Falso, Dominican Republic on 6 December, causing eight deaths and destroying 35 percent of the banana crop. (Accord Weather Calendar)

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Prepared by AMS DS Ocean Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
ã Copyright, 2005, The American Meteorological Society.