Weekly Ocean News

DATASTREME OCEAN SPRING BREAK WEEK: 10-14 March 2014

This is Break Week for the Spring 2014 offering of the DataStreme Ocean course. This Weekly Ocean News contains new information items and historical data, but the Concept of the Week is repeated from Week 6.

For Your Information

Time change -- Daylight Saving Time went into effect this past Sunday morning for essentially the entire nation -- the exceptions include Arizona, Hawaii, Puerto Rico and about 18 counties in Indiana. These changes have been mandated by the U.S. Congress in the Energy Policy Act of 2005, which extended Daylight Saving Time across the nation, with the start on the second Sunday in March (9 March 2014) and end on the first Sunday in November (2 November 2014). In other words, following the old adage of "spring ahead, fall behind", you will need to turn your clocks ahead by one hour to conform with the local time observance. Most of Canada also observes Daylight Saving Time changes at the same time [National Research Council Canada].
What does this time change mean to you (other than later sunsets)? Contrary to a popular belief that has surfaced at times, the change from Standard to Daylight Saving Time does not add an extra hour of daylight to the day nor does it affect weather patterns. While the weather will not change because of the time change, the times when you will be able to obtain weather charts will now be one hour later. The reason is that the National Weather Service operates on "Z time" (variously called Greenwich Mean Time or Universal Coordinated Time) which does not observe Daylight Saving Time, and the charts are still produced and transmitted at the same Z time.
While many people want additional daylight after work, some health experts say that the change to Daylight Saving Time is hard on human health, as it affects the natural sleep cycle and circadian rhythms. Increases in heart attacks, traffic accidents and sleep disorders have been seen during the first several days after the time change in spring. Economic costs involving the time change are also incurred. [Business Insider]
Biomixing in ocean motion -- If you would like information on recent findings that indicate marine organisms contribute to motion in the ocean, please read this week's Supplemental Information…In Greater Depth.

Ocean in the News

Eye on the tropics --- Meteorological autumn in the Southern Hemisphere (December, January and February) commenced early last week. Topical cyclone activity was reported during the last week in the following basins:
- In the western South Pacific basin, Tropical Cyclone Kofi lost its tropical characteristics and became an extratropical cyclone (or midlatitude storm) at the start of last week to the southeast of Fiji. This tropical cyclone had tropical-storm-force winds (maximum sustained winds ranging between 39 and 74 mph). Additional information for Tropical Cyclone Kofi along with satellite images can be found on the NASA Hurricane Page.
  Another tropical storm, identified as Tropical Cyclone Gillian, formed early this past weekend from a tropical low pressure system (98P) over the northern Gulf of Carpentaria, a large shallow sea to the north of Australia. Gillian moved to the south-southeast over the past weekend toward Australia's Cape York Peninsula. Forecasts early Monday (local time) indicate that this system could be forced westward across the southern Gulf of Carpentaria before making landfall early this upcoming week. The NASA Hurricane Page has information on System 98P prior to intensification to Cyclone Gillian.
- In the western North Pacific basin, Tropical Storm Faxai intensified to become a category 1 typhoon on the Saffir-Simpson Scale early last week as it traveled toward the north and north-northeast over the open waters of the western North Pacific east of the Northern Mariana Islands. By late in the week Faxai had weakened to a tropical storm and then dissipated to the northwest of Wake Island. The NASA Hurricane Page has additional information and satellite imagery on Typhoon Faxai.
Ocean gliders used to listen for reef fish -- During this current month, scientists from NOAA and their partners are using two autonomous ocean gliders in the waters of the western North Atlantic off the Southeastern United States and in the US waters of the Caribbean off Puerto Rico to detect reef fish activity around marine protected areas. Once these gliders are retrieved at the end of March, the sound recordings will be analyzed and combined with water temperature and ocean current data to increase understanding of reef spawning aggregations and habitat. [NOAA National Ocean Service News]
New web portal helps map climate change in the oceans -- Scientists from NOAA's Earth System Research Laboratory and NOAA Fisheries Service have created a new Ocean Climate Change Web Portal designed to assess the vulnerability of various fish stocks to climate change. Global maps of climate data such as ocean temperature and salinity will be available on this web portal. [NOAA News]
Dolphins exposed to Deepwater Horizon oil spill experience more health problems -- Scientists with NOAA's Centers for Coastal Ocean Science have found that those bottlenose dolphins in Louisiana's Barataria Bay exposed to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico appear to be suffering lower weight, more lung disease and adrenal problems than those that were not exposed to the oil contamination. [The Washington Post]
Colored lobster ropes could prevent right whale entanglements -- A whale researcher from the New England Aquarium claims that changing the color of the rope used in lobster gear to make them more visible to endangered northern right whales could prevent these whales from becoming entangled in this lobster gear. [WBZ CBS Boston]
Warm river discharges contribute to Arctic sea ice melt -- Using sea surface temperature data collected by the MODIS instrument on NASA's Aqua and Terra satellites, researchers from NASA's Jet Propulsion Laboratory have found that warm river water draining into the Arctic Ocean contributes to the melting of Arctic sea ice each summer. One of the areas they studied was the Beaufort Sea where discharges from Canada's Mackenzie River discharges into the Arctic Ocean resulted in increased sea surface temperatures. [NASA Jet Propulsion Laboratory] [NASA Earth Observatory]
Ice cover on Great Lakes near a record -- Late last week, NOAA's Great Lakes Environmental Research Laboratory (GLERL) reported that the ice cover on the Great Lakes reached 92.2 percent of the total area of all the lakes. [Weather Underground] This areal coverage was slightly less than the maximum ice extent of 94.7 percent set in 1979. Plots of historical ice cover on each of the Great Lakes are available for the period of satellite surveillance from 1973-2013. [NOAA/GREL Great Lakes Ice Cover]
On Saturday (8 March 2014), GLERL reported that the ice concentration on Lake Michigan had reached 93.29 percent, which set a new record ice cover on Lake Michigan exceeding the previous record of 93.1 percent set in 1977. [Milwaukee/Sullivan National Weather Service Forecast Office]
The US Coast Guard recently began breaking ice on Lake Superior in an attempt to begin opening traffic on that lake by 17 March. [Wisconsin Public Radio]
Understanding Great Lakes water level changes -- Scientists at NOAA's Great Lakes Environmental Research Laboratory (GLERL) have been attempting to determine about the factors that force the changes in the water levels on North America's Great Lakes and how water resource management planning decisions can be improved. The research is pressing as several of the Lakes had been at near record low levels during the last several years have been adversely impacting the economies around the Great Lakes basin. During the last week, GLERL and the US Army Corps of Engineers made a forecast that Great Lakes water levels should approach levels close to normal over the next six months on nearly all the Lakes due in part to the reduced winter evaporation over the lake surfaces because of the near-record ice cover. [NOAA Office of Oceanic and Atmospheric Research News]
African dust sweeps out across tropical Atlantic Ocean -- A true-color satellite image made from the MODIS sensor onboard NASA's Terra satellite at the end of February shows airborne dust particles being carried westward across the Cape Verde Islands in the tropical North Atlantic Ocean from West Africa. Subsequently, the dust veil reached the Caribbean in early March. The yellow dust that appears on the satellite image had been lifted into the atmosphere by a harmattan, or a desert wind that typically develops across the northwestern Sahara Desert between November and March. [NASA Earth Observatory]
UNESCO World Heritage sites threatened by global sea-level rise -- A recent study warns that many of the 720 sites currently on the list of UNESCO World Heritage sites could be inundated and lost to rising sea levels if current trends in global temperature change were maintained over the next two millennia. [Institute of Physics]
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]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

This Concept of the Week is repeated from Week 6.

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

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

Historical Events

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)
15 March 1493...Christopher Columbus returned to Spain after his first voyage to the New World. (Wikipedia)
15 March 1778...Nootka Sound, Vancouver Island was discovered by Captain James Cook.
15 March 1946...For the first time, U.S. Coast Guard aircraft supplemented the work of the Coast Guard patrol vessels of the International Ice Patrol, scouting for ice and determining the limits of the ice fields from the air. (USCG Historian's Office)
15 March 1960...Key Largo Coral Reef Preserve in the Florida Keys was established as the nation's first underwater park. This preserve currently includes John Pennekamp Coral Reef State Park and the adjacent Florida Keys National Marine Sanctuary.
16 March 1521...Portuguese navigator Ferdinand Magellan reached the Philippines. He was killed the next month by natives.
16 March 1834...The HMS Beagle anchored at Berkeley Sound, Falkland Islands.
16 March 1889...A war between the U.S. and Germany was likely averted as a hurricane sank all three U.S. and three German warships in the harbor at Apia, Samoa. Joint U.S., German and Samoan rescue cooperation led to the Treaty of Berlin (1889) that later settled the dispute. (Accord's Weather Calendar)