WEEKLY OCEAN NEWS

DATASTREME OCEAN WEEK SIX: 8-12 March 2010

Item of Interest

• Internship Opportunities --
The National Council for Science and the Environment provides college students and recent graduates paid Climate Change Internships with federal agencies, non-profit organizations and businesses. These internships involve science-based research, resource conservation, data collection, monitoring, communication, policy development, sustainable operations, and other projects to support adaptation to and mitigation of the effects of climate change on lands administered by the National Park Service. For further details and how to apply, visit http://www.ncseonline.org/CampustoCareers/.
• Regional climate science center planned for Alaska --
The Secretary of the US Department of Interior recently announced that the University of Alaska-Anchorage had been selected as the site for his Department's eight planned regional climate science centers around the nation that will provide science about climate change impacts, help land managers adapt to the impacts and engage the public through education initiatives. The focus of the Alaska center would be on the thawing of the permafrost and the loss of sea ice in the Arctic basin. [US Dept. of Interior] [Anchorage Daily News]

Ocean in the News

• Eye on the tropics ---
At the start of last week, a tropical cyclone 17P intensified to become Tropical Storm Sarah over the waters of the South Pacific, but dissipated near the Cook Islands. For more information and satellite imagery concerning Tropical Storm Sarah see NASA Hurricane Page
• Giant iceberg collides with Antarctic ice tongue --
In early February 2010, Iceberg B-09B, the size of Luxembourg collided with the Mertz Glacier Tongue in Eastern Antarctica to form a new iceberg the size of Rhode Island. Scientists with Australia's Antarctic Climate and Ecosystems Cooperative Research Centre (ACECRC) warned that this newly formed floating ice could affect ocean circulation, which could also affect the planetary climate. [National Geographic Daily News] A series of three images obtained from the MODIS sensor on NASA's Aqua satellite during the first half of February 2010 also shows this collision. [NASA GSFC] [Editor's Note: Special thanks are extended to Roy Chambers a LIT Leader from Portland, OR for forwarding this article. EJH]
• Ships stuck in Baltic Sea ice --
Between 30 and 40 ships, including several passenger ferries, were stuck last week in the ice that covered the Baltic Sea off Sweden. The below average temperatures across southern sections of the Baltic Sea contributed to the sea ice. By the end of the week, most of the ships had been freed by icebreakers. [CNN News]
• Giant waves on Mediterranean are killers --
A set of three giant waves that were 26 feet high struck the cruise ship Louis Majesty in the Mediterranean Sea off the northeast coast of Spain last Wednesday, killing two passengers. The investigation continued into this incident on Friday after the cruise ship docked at the port of Barcelona. Strong winds appeared to contribute to the large waves that may have interacted with astronomical tides. [CNN News]
• Daylength could be shortened by Chilean earthquake --
A research scientist at NASA's Jet Propulsion Laboratory has computed that recent magnitude 8.8 earthquake in Chile has affected the Earth's rotation, shortening the length of each Earth day by approximately 1.26 microseconds. [NASA JPL]
• Passing of a weather science legend --
Dr. Joanne Simpson, Chief Scientist Emeritus for Meteorology, Earth Sun Exploration Division, at NASA's Goddard Space Flight Center, died last Thursday in Washington, DC at the age of 86. Dr. Simpson, who was the first woman to obtain a doctorate in meteorology in the US, was involved with the study of hurricanes, tropical meteorology and cloud physics. She received numerous scientific awards and was a past President of the American Meteorological Society. Joanne was married to Robert H. Simpson, who helped devise the Saffir-Simpson Hurricane Scale. [NASA]
• Agreement reached in illegal fishing cases --
Early last week, NOAA and Gloucester Fish Exchange, Inc., a Massachusetts company that owns the Gloucester Seafood Display Auction, reached an agreement to settle three cases involving allegations that the Auction handled illegally caught fish and maintained false records. [NOAA News]
• New England groundfish fishery receives monetary support --
The assistant administrator for NOAA’s Fisheries Service recently announced that an additional $10 million was being provided to four New England states to preserve fishing opportunities for the New England fishing industry and continue the development of a new sector program in the groundfish fishery. [NOAA News]
• White House unveils its Gulf Coast restoration plan --
Last week, President Obama's administration outlined a plan designed to support coastal restoration of the Gulf Coast from damage wrought by major hurricanes during the last four years including in the restoration of barrier islands and wetlands in Mississippi and Louisiana. The catastrophic dangers from future hurricanes, rising sea levels and erosion from the Gulf Coast would also be addressed. [USA Today]
• Reductions in marine life found to accompany current El Niño event --
Using data collected from satellites, buoys and robotic submersible gliders, Researchers with the California Cooperative Oceanic Fisheries Investigations at Scripps Institution of Oceanography and NOAA's Southwest Fisheries Science Center report that the northward spread of warm Pacific ocean water farther northward than normal along the Southern California coast has led to a high sea-level event in January and the low abundance of plankton and pelagic fish. They report that these conditions, which are affecting ecosystems in the North Pacific Ocean, are consistent with the currently occurring El Niño event, an anomalous but cyclic atmospheric and oceanic circulation episode. [Scripps Institution of Oceanography]
• Sources of mercury in ocean fish explored --
Researchers at the University of Michigan, Harvard School of Public Health, the Louisiana Universities Marine Consortium and Norway's National Institute of Nutrition and Seafood Research recently reported on their study on how mercury enters the oceanic food chain and accumulates in various open-ocean fish species including tuna as methylmercury, a highly toxic contaminant, which ultimately poisons humans who consume the fish. Norway. [University of Michigan News Service]
• Ocean sensors indicate accelerated changes in global hydrological cycle --
An oceanographer at Scripps Institution of Oceanography and his colleagues from other research institutions have found that data collected by the Argo network of ocean-observing sensors indicate increased salinity associated with increased evaporation from surface waters of the world's oceans because of increased global temperatures. Consequently, they argue that climate change is accelerating the world's hydrological cycle. [Explorations, Scripps Institution of Oceanography]
• New estimates of Alaska's glacier melt rate are presented --
Researchers from Northern Arizona University, the University of British Columbia, the University of Northern British Columbia and France's Université de Toulouse recently claimed that their study of the glacier melt in Alaska from 1962 through 2006 using satellite imagery indicates a slower glacial retreat rate that contributed approximately one-third less to sea level rise than previously estimated. [Northern Arizona University]
• Evidence of hydrothermal vents located off Antarctica --
After their analysis of large quantities of oceanographic measurements, scientists from Columbia University’s Lamont-Doherty Earth Observatory recently found evidence of hydrothermal vents along the Pacific Antarctic Ridge, a geologic feature on the seafloor near Antarctica. These hydrothermal vents, which spew volcanically heated seawater from the mid-ocean ridge system, also provided chemicals dissolved in those vents that influence ocean chemistry and biological activity. [The Earth Institute Columbia University]
• Fossil corals may provide hope for current reefs --
A researcher at the Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies and The University of Queensland claims that eight fossil reefs in Papua New Guinea’s Huon Gulf region survived record low ocean levels and could provide hope that coral reefs may be able to survive the stresses due to human activity. [Coral Reef Studies]
• 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 --
Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Abyssal Storms

Until recently, ocean scientists thought of the deep ocean abyss as a dark and cold, but serene place where small particles rained gently onto the ocean floor. However, instruments lowered to the sea floor to measure ocean motion or currents and resulting mobilization of bottom sediments detected a much more active environment. Scientists found that bottom currents and abyssal storms occasionally scour the ocean bottom, generating moving clouds of suspended sediment. A surface current of 5 knots (250 cm/sec) is considered relatively strong. A bottom current of 1 knot (50 cm/sec) is ripping. Although this may be called an abyssal storm, the water motion pales by comparison to wind speeds in atmospheric storms.

Abyssal currents and storms apparently derive their energy from surface ocean currents. Wind-driven surface ocean currents flow about the margins of the ocean basins as gyres centered near 30 degrees latitude. (Refer to Figure 6.6, page 152, in your textbook.) Viewed from above, these subtropical gyres rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. For reasons given in Chapter 6 of your textbook and this week's Supplemental Information, surface currents flow faster, are narrower, and extend to greater depths on the western arm of the gyres. These are known as western boundary currents and include, for example, the Gulf Stream of the North Atlantic basin. Abyssal currents are also most vigorous on the western side of the ocean basins, moving along the base of the continental rise, which is on the order of several kilometers deep.

Abyssal storms may be linked to or may actually be eddies (rings) that occasionally break off from the main current of the Gulf Stream (and other western boundary currents). During an abyssal storm, the eddy or ring may actually reach to the bottom of the ocean where the velocity of a bottom current increases ten-fold to about 1.5 km (1 mi) per hr. While that is an unimpressive wind speed, water is much denser than air so that its erosive and sediment-transport capacity is significant even at 1.5 km per hr. At this higher speed, the suspended sediment load in the bottom current increases by a factor of ten. Abyssal storms scour the sea floor leaving behind long furrows in the sediment. After a few days to a few weeks, the current weakens or the eddy (ring) is reabsorbed into the main surface circulation and the suspended load settles to the ocean floor. In this way, abyssal storms can transport tons of sediment long distances, disrupting the orderly sequence of layers of deep-sea sediments. Scientists must take this disruption into account when interpreting the environmental significance of deep-sea sediment cores.

Concept of the Week: Questions

1. In the subtropical ocean gyres, boundary currents flow faster on the [(western)(eastern)] side of an ocean basin.
2. Currents in an abyssal storm erode, transport, and redeposit sediments that have accumulated on the [(continental shelf)(deep ocean bottom)].

Historical Events

• 9 March 1454...Amerigo Vespucci, the Italian navigator, was born in Florence, Italy. The North and South American continents were named in his honor by Matthias Ringmann, a German mapmaker.
• 9 March 1995...The Canadian Navy arrested a Spanish trawler for illegally fishing off Newfoundland.
• 10 March 1496...Christopher Columbus concluded his second visit to the Western Hemisphere when he left Hispaniola for Spain. (Wikipedia)
• 10 March 1849...Abraham Lincoln applied for a patent for a device to lift vessels over shoals by means of inflated cylinders.
• 11 March 2002...The National Ice Center reported that satellite images indicated that an iceberg with an area larger than the state of Delaware had calved from the Thwaites Ice Tongue, a region of snow and glacial ice extending from the Antarctic mainland into the South Amundsen Sea (Accord's Weather Guide Calendar)
• 13-15 March 1952...The world's 5-day rainfall record was set when a tropical cyclone produced 151.73 inches rain at Cilos, Reunion Island in the Indian Ocean. The 73.62 inches that fell in a 24-hour period (15^th-16^th) set the world's 24-hour rainfall record. (Accord's Weather Calendar)
• 14 March 1891...The submarine Monarch laid telephone cable along the bottom of the English Channel to prepare for the first telephone links across the Channel.
• 14 March 1903...President Theodore Roosevelt issued an executive order making Pelican Island near Sebastian Florida a "preserve and breeding ground for native birds," including pelicans and herons, marking the birth of the National Wildlife Refuge System. (Wikipedia)
• 14 March 1918...The first US concrete seagoing ship was launched at Redwood City, CA. (Today in Science History)

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Prepared by DS Ocean Central Staff and Edward J. Hopkins, Ph.D.,
email hopkins@meteor.wisc.edu
© Copyright, 2010, The American Meteorological Society.