Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 16-20 April 2012

Item of Interest:

Celebrate Earth Day -- Next Sunday (22 April 2012) is the 42nd Earth Day, first proposed by the late Senator Gaylord Nelson of Wisconsin in 1970 as a teach-in to heighten awareness of the environment. The Nelson Institute for Environmental Studies at the University of Wisconsin-Madison has posted a website called "Gaylord Nelson and Earth Day: The Making of the Modern Environmental Movement" that highlights Senator Nelson and his idea became Earth Day. A government website provides links to various activities and resources planned for this week. In the Washington, DC metropolitan area, NASA scientists will conduct activities and have exhibits for three consecutive days (Friday-Sunday) on the National Mall and at NASA's Goddard Space Flight Center in nearby Greenbelt, MD. These activities are designed to show the public the agency's commitment to satellite monitoring and climate modeling. [NASA Earth Mission]
National Park Week -- The US Department of the Interior's National Park Service has designated the week commencing on this coming Saturday (21-29 April 2012) as National Park Week. The focus for this year's observance is "Picture Yourself in a National Park." In observance of this event, free entry can be made to any of the 397 national parks in the system. [National Park Service Fee Free Days]
Centennial of the Titanic tragedy remembered -- In remembrance of the 100th anniversary of the RMS Titanic over this past weekend, NOAA has posted a website that contains descriptions of the agency's participation in the exploration of the wreck site and its role in the site's protection and preservation. [RMS Titanic 100 years later]
A podcast called "Making Waves: Titanic, 100 Years Later (Part I)" was produced that contains an interview with the director of Maritime Heritage with the National Ocean Service's Office of National Marine Sanctuaries made in recognition of the 100th anniversary. This podcast represents the first half of a special two-part Titanic podcast. [NOAA's National Ocean Service]
Geosynchronous environmental satellite retired after 25 years --During the last week, NOAA moved GOES-7, one of NOAA's early geosynchronous environmental satellites, into a higher orbit (or greater distance from Earth) and retired it from service. This GOES (Geostationary Operational Environmental Satellite) spacecraft was launched in 1987 and was used to capture data that could be used to generate images of weather systems across North America. After some of its Earth-observing instruments became degraded, NOAA leased GOES-7 beginning in 1999 to the Pan-Pacific Education and Communication Experiments by Satellite (PEACESAT) program to provide communications for the Pacific islands. Currently, NOAA operates GOES-13 and GOES-15to provide continuous coverage of weather across the United States and the Western Hemisphere. [NOAA News] The last operational image obtained from GOES-7 in 1996 is highlighted. [ NOAA Environmental Visualization Laboratory]
Animated visualization of a perpetually moving ocean system produced -- Using data from a variety of sources, a high-definition scientific animation was recently produced showing the movement of the surface ocean currents around the Earth from June 2005 through December 2007. The data used for this animation were collected from NASA satellites, from direct ocean measurements and from numerical ocean model developed by NASA's Jet Propulsion Laboratory and the Massachusetts Institute of Technology. [NASA JPL]

Ocean in the News:

Eye on the tropics -- No organized tropical cyclones developed over the tropical waters of either the Northern or Southern Hemispheres during the last week.
The 2011 hurricane season reviewed -- The 2011 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]
"Irene" has been retired from Atlantic Basin storm name list -- The World Meteorological Organization's (WMO) hurricane committee recently retired the name Irene from its official list of names used to identify Atlantic Basin tropical storms and hurricanes because of the fatalities and damage that Hurricane Irene caused in August 2011. The replacement name on the list is Irma. [NOAA News]
Public opinion sought on possible expansion of Great Lakes marine sanctuary -- NOAA's Office of National Marine Sanctuaries recently announced that public comment is invited over the next month as a draft of an Environmental Impact Statement is being developed to expand Thunder Bay National Marine Sanctuary in Lake Huron off the Lower Peninsula of Michigan. [NOAA News]
Agreement signed to assess damages in harbor contamination case -- An agreement was recently signed by Port Angeles (Washington) Harbor Natural Resource Trustees, consisting of members from federal, state and tribal governments, to jointly conduct Natural Resource Damage Assessment activities within Port Angeles Harbor that include pollution from a former pulp mill. [NOAA News]
No tsunami follows massive Indonesian earthquakes -- A massive magnitude-8.6 earthquake off the west coast of northern Sumatra, Indonesia was followed by a magnitude-8.2 aftershock caused tsunami warnings to be posted for Indonesia along with a tsunami watch for most of the Indian Ocean. However, these warnings and the watch were lifted after several hours as no signs of a major tsunami were detected. Seismologists reported that since these earthquakes appeared to be along a "strike-slip fault" where the tectonic plates were sliding past one another, they did not produce a massive tsunami as had occurred off Indonesia in December 2004 following a magnitude 9.1 earthquake, when the plates slid against one another. [USA Today]
Adaptive capacity of reef corals to changing climate may be widespread -- Scientists at the University of Miami's Rosenstiel School of Marine & Atmospheric Science claim that many species of reef-building corals appear to be capable of adapting to warming waters by hosting a variety of algal types that exhibit different sensitivities to environmental stress. [ Rosenstiel School of Marine & Atmospheric Science]
Dead Sea has undergone large changes in water level over time -- Based upon their analysis of sediment cores extracted from sediments beneath the floor of the Dead Sea, researchers from Israel's Tel Aviv University and Hebrew University have found that the level of the Dead Sea has risen and fallen by several hundred meters over the last 200,000 years. The Dead Sea level was extremely low during the previous interglacial period approximately 120,000 years ago and near the end of the last Ice Age approximately 13,000 years. [American Friends of Tel Aviv University]
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, drought, floods, 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, to include drought, floods and storms during the current month. [NCDC]
Earthweek --

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:

16 April 1851...The famous "Lighthouse Storm" (a "nor'easter") raged near Boston Harbor. Whole gales and gigantic waves destroyed the 116-ft Minot Ledge Light at Cohasset, MA with the loss of its two keepers still inside. The lighthouse was the first one built in the United States that was exposed to the full force of the ocean. The storm coupled with a spring tide resulted in massive flooding, great shipping losses and coastal erosion. Streets in Boston were flooded to the Custom House. (David Ludlum) (US Coast Guard Historians Office) (Accord's Weather Guide Calendar)
16 April 1854...A furious storm that produced two feet of snow at New Brunswick, NJ also caused approximately 18 shipwrecks along the New Jersey coast. The immigrant ship Powhattan beached 100 yards from the shore. With rescue impossible, 340 people onboard lost their lives. "The shrieks of the drowning creatures were melancholy indeed." (Accord's Weather Guide Calendar)
16 April 1992...The Katina P ran aground off Maputo, Mozambique, causing 60,000 tons of crude oil to spill into the ocean. (Wikipedia)
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 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)