Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 20-24 April 2009

Ocean in the News:

Eye on the Tropics -- The first tropical cyclone of the season in the North Indian Ocean basin, Tropical Cyclone Bijli, formed early last week in the Bay of Bengal. By this past Saturday (local time), this cyclone that had tropical storm force winds made landfall on the coast of southeast Bangladesh, producing heavy rainfall. A MODIS image obtained from NASA's Terra satellite shows the clouds surrounding Tropical Storm Bijli before it made landfall.[NASA Earth Observatory] More information concerning Tropical Cyclone Bijli can be found on the NASA Hurricane Page.
The 2008 hurricane season reviewed -- The 2008 hurricane season in both the North Atlantic and North Pacific is reviewed and compared to the more than 150 years of record keeping in the North Atlantic and the 40 years in the eastern North Pacific. [AMS DataStreme Atmosphere]
New instrumented ocean buoys coming to Hawaii -- The National Weather Service Office in Honolulu announced that three new instrumented buoys will be deployed within the next weeks in the waters of the North Pacific to the north of the Hawaiian Islands to assist in accurate wave and surf forecasts for the north shores of the Aloha State. [NWS Honolulu]
Improved Indian Ocean tropical cyclone forecasts could save lives -- Researchers at NASA's Goddard Space Flight Center and colleagues have used NASA satellite data and a new modeling approach that could improve weather forecasts across the northern Indian Ocean where tropical cyclones form that result in nearly 80 percent of the world's cyclone related deaths. [NASA Earth Science News Team]
Educator selected for 2009 NOAA Teacher at Sea Program -- NOAA has selected Taylor Parker, the Education Director for southern California's Friends of the Colorado Lagoon, to join scientists aboard the 224-foot research vessel, NOAA Ship Oscar Elton Sette, as part of this year's Teacher at Sea program designed to bridge science and education. [NOAA News]
New Chesapeake Bay research vessel is christened -- NOAA recently christened a new research vessel, R/V Bay Hydro II, that will collect oceanographic data in the Chesapeake Bay region using state of the art instrumentation. [NOAA News]
New learning center opened at Hawaiian marine sanctuary -- NOAA and state officials recently opened the Sanctuary Learning Center for the Hawaiian Islands Humpback Whale National Marine Sanctuary at Kihei, Maui, which is designed to facilitate the sanctuary’s education, research and ocean protection efforts. [NOAA News]
Empire State's objections to natural gas terminal in Long Island Sound upheld -- Last week, the US Department of Commerce issued a decision that upheld the objection made by State of New York under the Coastal Zone Management Act to a proposed floating liquefied natural gas terminal and connecting 21-mile subsea pipeline that would be built and operated in the state waters of Long Island Sound. The state had argued that the proposed project would have an adverse impact on the Sound and the coast. [NOAA News]
Global temperatures for March 2009 -- Based upon analysis of preliminary monthly climate data, scientists at NOAA’s National Climatic Data Center report that the monthly global combined land and ocean surface average temperature for the concluded month of March 2009 indicates this past month was the tenth warmest March since climate records began in 1880. [NOAA News]
Mangroves saved lives in super cyclone -- Researchers from Duke University and India's University of Dehli claim that a study of storm-related deaths attributed to a category 5 tropical cyclone (on the Saffir-Simpson scale) that hit India's eastern coast in October 1999 indicates villages shielded by mangrove forests from the storm surge had fewer deaths than in less protected villages. [EurekAlert!]
Rapid evolution of marine species studied -- Research conducted at the University of Gothenburg and Stockholm University on a species of seaweed collected from the Baltic Sea indicates unexpectedly rapid formation and evolution. [EurekAlert!]
Microbes found in water under Antarctic glacier -- A team of researchers from six research universities have discovered microbes in briny water under Antarctica's Taylor Glacier that appear to have survived for several million years consuming leached iron compounds and that are similar to modern marine species. [EurekAlert!] [EurekAlert!]
Greenhouse gas emission cuts could save Arctic sea ice -- Scientists at the National Center for Atmospheric Research and their colleagues at other institutions claim that their analysis of experiments run of the center's Community Climate System Model indicates that if nations cut emissions of greenhouse gases by 70 percent during this century, the threat of massive loss of Arctic sea ice and permafrost leading to significant sea level rise could be partially avoided even though global temperatures would continue to rise. [NCAR/UCAR]
Mathematics applied to sea ice and climate change -- A mathematician at the University of Utah has developed a mathematical model of percolation that simulates the physical process by which water moves through porous sea ice in an attempt to improve modeling efforts involving polar climate dynamics. [EurekAlert!] Editor's Note: The American Mathematical Society, the American Statistical Association, the Mathematical Association of America, and the Society for Industrial and Applied Mathematics have made Mathematics and Climate the theme for Mathematics Awareness Month, April 2009. EJH
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:

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 collided 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)
24 April 1884...USS Thetis, Bear, and Alert sailed from New York to search for Greeley expedition lost in the Arctic. (Naval Historical Center)
24 April 1928...The fathometer was patented by Herbert Grove Dorsey (No. 1,667,540). The invention measured underwater depths by using a series of electrical sounds and light signals. (Today in Science History)