Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 30 November-4 December 2009

Ocean in the News:

Eye on the tropics --- With the end of the official hurricane seasons in both the North Atlantic and eastern North Pacific basins, neither basin experienced tropical cyclone activity during the last week. However:
- In the western North Pacific, Typhoon Nida formed at the start of last week south of Guam and moved northward. By late in the week, this typhoon had intensified into a supertyphoon and was rated as a category 5 typhoon on the Saffir-Simpson Scale, when maximum sustained surface winds reached 172 mph and gusts to 207 mph as it moved past the Mariannas. Some of the wind driven waves reached 44 feet in height. As of Sunday, this system remained a supertyphoon as it continued to travel northward. As of late Sunday (local time), Typhoon Nida remained a powerful category 4 typhoon as it continued northward. Satellite imagery and more information on Supertyphoon Nida can be obtained from the NASA Hurricane Page.
  A tropical depression, identified as Tropical Depression 27W formed over the waters east of Mindanao early last week. After one day, this depression dissipated. The NASA Hurricane Page has additional information on Tropical Depression 27W.
- In the South Indian Ocean basin, Tropical Cyclone Bongani formed to the northeast of Madagascar at the start of last week and traveled to the southwest, approaching the northern coast of Madagascar by midweek. This cyclone, which had the strength of a tropical storm, dissipated over the Mozambique Channel before making landfall, but produced heavy rain and wind-driven seas. See the NASA Hurricane Page for additional information and satellite images on Tropical Cyclone Bongani.
The 2009 hurricane seasons reviewed -- With the end of the official 2009 hurricane season in both the North Atlantic and North Pacific on Monday, 30 November 2009, a quick review of this year's tropical cyclone statistics for official 2009 hurricane season has been made for both basins. [AMS DataStreme Atmosphere]
Tropical cyclone climatologies of North Atlantic and the eastern North Pacific released -- The National Hurricane Center (NHC) recently released an updated and revised edition of its "Tropical Cyclones of the North Atlantic Ocean, 1851-2006." While a paper copy of this book is available for a cost from NHC, a 243-pg pdf file of this edition can be downloaded for free. NHC also released the first edition of "Tropical Cyclones of the Eastern North Pacific Ocean, 1949-2006." In addition to a paper copy is available for sale, a free 164-page pdf file is available. Both of these climatologies have numerous graphics that show long-term changes in tropical cyclone frequency in the two basins.
Attempts made to fix ailing QuikSCAT satellite -- During the last week, engineers and mission managers at NASA's Jet Propulsion Laboratory are assessing possible options for continuing operations of the agency's 10-year old QuikSCAT satellite because of a failure in the antenna mechanism that permits transmission of ocean surface wind data obtained by the mission's scatterometer instrument. [NASA JPL]
Southern islands produce wave cloud patterns -- An image obtained from the MODIS instrument on NASA's Terra satellite early last week shows an interesting interference pattern in the cloud deck caused by winds passing over and around the peaks in the South Sandwich Island chain in the South Atlantic Ocean. [NASA Earth Observatory]
An official position made on a Columbia River court hearing -- Dr. Jane Lubchenco, Under Secretary of Commerce for Oceans and Atmosphere and NOAA Administrator, recently issued a statement on the Federal Columbia River Power System Biological Opinion following a federal court hearing. [NOAA News]
Slower absorption of carbon dioxide by oceans seen -- Using atmospheric carbon dioxide data collected from three observing stations over the last 50 years, a geophysicist at Yale University has determined that the interannual lag between global temperature and atmospheric carbon dioxide has increased, meaning that the oceans may have lost some of their ability to absorb carbon dioxide. He claims that the oceans currently absorb approximately 40 percent of the carbon dioxide emitted into the atmosphere by human activity. [Yale University] In a related investigation, scientists with the Woods Hole Oceanographic Institution and their colleagues who are participating in the Global Carbon Project have developed ocean-model simulations for estimating the annual fluxes of carbon dioxide between the atmospheric and oceanic reservoirs. These researchers have found that carbon dioxide emissions have increased by more 3 .4 percent per year since 2000. [Woods Hole Oceanographic Institution]
Dynamic ocean crust formation found -- Following a high-resolution seismic study in the Gulf of California, scientists at Brown University and the University of Rhode Island have found centers of dynamic upwelling in the shallow mantle beneath spreading centers on the seafloor, providing evidence that geological processes can lead to the formation of oceanic crust. [Brown University]
Marine census includes creatures of the dark ocean depths -- With slightly less than one year remaining in the 10-year Census of Marine Life project, marine scientists have inventoried and catalogued approximately 17,650 ocean species in the oceans between the edge of darkness and black abyss, with some species living at the depths approaching 3 miles below the ocean surface. [EurekAlert!]
Regional warm and cold intervals of the past appear driven by climate phenomena -- Using a variety of climate proxy indicators, researchers from Penn State University, Roger Williams University, the University of Massachusetts, the University of Arizona, NASA's and the National Center for Atmospheric Research have reconstructed spatial patterns of ocean and land surface temperature over the last 1500 years. These researchers have found that regional patterns of temperature change appear related to natural phenomena such as El Niño/La Niña events and the "North Atlantic Oscillation." [EurekAlert!]
Evidence of an ancient Martian ocean found -- Scientists from Northern Illinois University and the Lunar and Planetary Institute in Houston have produced a new and more detailed global map of the valley networks on Mars, which revealed pattern providing added evidence for an ocean covering much of Mars' northern hemisphere and a past climate with sufficient precipitation. [EurekAlert!]
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: 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:

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 Guide 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 Guide 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 houses 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 Guide 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 Guide Calendar)
5 December 1872...A British brigantine, the DeGratia, discovered the American ship Mary Celeste derelict and boarded her. The Mary Celeste, a brigantine had set sail from New York harbor for Genoa, Italy, on 5 November 1872. Everyone aboard the Mary Celeste had vanished-her captain, his family, and its 14-man crew. The ship, which appeared to have been abandoned for approximately nine days, was in perfect order with ample supplies and there was no sign of violence or trouble. The fate of the crew remains unknown. (Infoplease.com) (Wikipedia)
5 December 1492...The explorer Christopher Columbus became the first European to set foot on the island of Hispaniola, which now contains the countries of Haiti and the Dominican Republic. (Wikipedia)
5 December 1949...A typhoon struck fishing fleet off Korea; several thousand men reported dead. (Infoplease.com)
6 December 1830...The US Naval Observatory, the first U.S. national observatory, established as the Depot of Charts and Instruments in Washington, DC, under commander of Lieutenant Louis Malesherbes Goldsborough. Its primary mission was to care for the U.S. Navy's chronometers, charts and other navigational equipment. (Naval Historical Center)