WEEKLY OCEAN NEWS

WEEK SIX: 29 February-4 March 2016

For Your Information

• A change in meteorological seasons -- Monday, 29 February 2016, marks the end of meteorological winter in the Northern Hemisphere, which by convention, is the three-month interval of December, January and February. The following day (1 March 2016) represents the beginning of boreal meteorological spring, the three month interval of March, April and May. At the same time, summer in the Southern Hemisphere ends and autumn begins.
• Leap years and calendars -- This year (2016) is a leap year with 366 days, one more than the "normal" year with 365 days. Since the Earth completes one orbit around the Sun in 365.2422 days, calendars based upon integer days must be adjusted every few years so that recognizable events, such as the occurrence of the vernal equinox, do not progress through the year. In the first century BC the Julian calendar was developed by Julius Caesar who decreed a calendrical reform with a 365-day year that involved the inclusion of an extra day to the end of February (the last month of the old Roman year). However, an additional reform was instituted by Pope Gregory XIII in 1572 that included the requirement that only those centurial years divisible evenly by 400 would be leap years, while the other centurial years (e.g., 1800 and 1900) would not.
  The National Centers for Environmental Information (formerly National Climatic Data Center) recommends that the climate normals for 28 February be used also for 29 February in a leap year.
• Worldwide GLOBE at Night 2016 Campaign resumes -- The third in a series of GLOBE at Night citizen-science campaigns for 2016 will commence on Tuesday (1 March) and continue through 10 March. GLOBE at Night is a worldwide, hands-on science and education program designed to encourage citizen-scientists worldwide to record the brightness of their night sky by matching the appearance of a constellation (Orion in the Northern Hemisphere and Crux in the Southern Hemisphere) with the seven magnitude/star charts of progressively fainter stars. Activity guides are also available. The GLOBE at night program is intended to raise public awareness of the impact of light pollution. The next series in the 2016 campaign is scheduled for 30 March-8 April 2016. [GLOBE at Night]
• 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.
• A Reminder -- Next week (beginning Monday, 7 March 2016) is Spring vacation week for DataStreme Ocean. All the familiar DataStreme Ocean products will be available throughout the week. The Investigation and Supplemental Information files from this week will remain on the DataStreme Ocean's RealTime Ocean Portal and the Concept of the Week will be repeated for those who are on spring break. If you have questions, check with your mentor.

Ocean in the News

• Eye on the tropics --- As meteorological summer in the Southern Hemisphere (December, January and February) draws to a close, tropical cyclone activity was limited to the western South Pacific Ocean basin during the last week. After devastating Fiji over the previous weekend, Cyclone Winston turned toward the south at the start of last week. As it traveled southward it weakened and also lost its tropical characteristics by the second half of last week as it approached Australia's Norfolk Island. At its peak, Cyclone Winston was one of the strongest tropical cyclones in the Southern Hemisphere, rated a category 5 tropical cyclone on the Saffir-Simpson Scale as maximum sustained surface winds reached 185 mph with gusts to nearly 200 mph. Winston was expected to turn to the south and weaken to a tropical storm midweek. The NASA Hurricane Page has additional information and satellite images on Cyclone Winston.
  Tropical Storm Yalo formed late last week nearly 400 miles to the west-southwest of Papeete, Tahiti. Traveling to the southeast, Yalo was torn apart by strong wind shear (large changes in wind speed and/or direction) and then dissipated less than 48 hours after formation. Satellite images and additional information Tropical Storm Yalo are available from the NASA Hurricane Page.
• More historic statistics on Tropical Cyclone Winston -- During the previous weekend, Tropical Cyclone Winston, a category 5 tropical cyclone (on the Saffir-Simpson Scale), devastated the island nation of Fiji in the South Pacific. With maximum sustained surface winds reaching 185 mph, Winston was one of the strongest storms ever measured in the Southern Hemisphere and was one of the strongest tropical cyclones to make landfall anywhere on earth since the modern era of global records began in 1970. Damage estimates and final death toll are yet to be determined from this storm. [NOAA Climate.gov News]
• Assessing the current El Niño event -- With some areas of the nation, notably California, not receiving the precipitation anticipated during a typical El Niño winter, questions have been raised about the current status of this much heralded event and how it compares with the famous 1997-1998 El Niño One of the staff at NOAA's Climate Prediction Center posted a blog that attempts to answer these questions and provide some insight into how one should interpret the CPC outlook. [NOAA News]
  NASA's Scientific Visualization Studio has produced an animated visualization using computer models that shows the current El Niño develop across the Pacific Ocean in 2015, with sea surface temperatures creating different patterns than those seen in the 1997-1998 El Niño. [NOAA News]
• NOAA's Okeanos Explorer 2016 field season commences in Pacific basin -- During the past week, the NOAA Ship Okeanos Explorer departed Pearl Harbor, HI on its 2016 spring and summer field season that involves a series of expeditions of the nation's marine protected areas across the central and western Pacific Ocean basins. Equipped with unmanned remotely operated vehicles (ROV), the scientists onboard the Okeanos Explorer will make televised dives to depths of 3.7 miles below the ocean surface that will provide the public with views of the real-time exploration of deep sea corals, sponges and possibly a World War II aircraft carrier that was lost in the Battle of Midway in 1942. [NOAA News]
• Access to 40 years of ocean environmental data is upgraded -- During the last week NOAA officials announced that their agency's "Digital Coast" geospatial data discovery and access tool will host the "Environmental Studies Program Information System", which has been upgraded by the US Department of Interior's Bureau of Ocean Energy Management. As a result, users from a variety of sectors such as the shipping and fishing industries, ocean conservation and offshore energy interests will be able to access more than 40 years of ocean environmental data. [NOAA News] or [NOAA National Ocean Service News]
• "Red tide" forecasts issued for Florida -- NOAA and partners have been monitoring the bloom of Karenia brevis a marine dinoflagellate common in Gulf of Mexico waters responsible for the Florida harmful algal bloom or "red tide" that has been persisting in the coastal waters off Southwest Florida. Based upon these observations, NOAA issued Red Tide forecasts that are designed to help the public, coastal community officials and public health managers make decisions concerning the possible health effects from these blooms. [NOAA National Ocean Service News]
• Public input solicited for national bycatch strategy -- In its commitment to minimize the bycatch in US Fisheries, NOAA Fisheries is inviting public comment on a draft of the agency's "National Bycatch Reduction Strategy." Bycatch occurs when fishing operations discard fish or interact with marine mammals, seabirds, or sea turtles. Six broad program areas are addressed. Informational webinars will be held this Tuesday and Wednesday(1 and 2 March). Public feedback will be accepted through early June. [NOAA Fisheries News]
• Allocated "catch shares" appear to reduce risky fishing -- A recently released NOAA Fisheries study reports that the allocation of "catch shares" appears to reduce the risky "rush-to-fish" behaviors of fishermen during a time limited season. Focusing upon West Coast fixed-gear fishermen, a 79 percent reduction occurred in the average annual number of fishing trips taken on high-wind days. [NOAA News]
• Coral reef growth being slowed by ocean acidification -- An international team of scientists recently reported on their experiment where they manipulated seawater chemistry in a natural coral-reef community in a lagoon on Australia's southern Great Barrier Reef in order to determine the effect that excess carbon dioxide released by human activity is having on coral reefs. By controlling the alkalinity of the seawater, they were able to examine how fast the reef is growing currently and compare this growth with growth rates in less acidic conditions that existed prior to the Industrial Revolution. They found that ocean acidification is already causing reefs to grow more slowly than they did a century ago. [Rice University News]
• Salt marshes should persist despite rising seas -- A professor at the Virginia Institute of Marine Science and colleagues foresee that salt marshes should persist despite rising sea levels. They reanalyzed 179 previously published records of marsh elevation change from sites in North America and Europe. The researchers argued that traditional assessment methods overestimate the vulnerability of salt marshes to sea-level rise because they do not fully account for processes that allow the marshes to grow vertically and migrate landward as water levels increase. [Virginia Institute of Marine Science News]
• Global sea level rise during 20th century was most rapid in three millennia -- Scientists from research institutions in the United States, the United Kingdom and Germany have found that global sea level rose at a faster rate than in the last 3000 years. These scientists developed a new database of geological sea-level indicators from marshes, coral atolls and archaeological sites from 24 locations around the globe that spanned these past three millennia, along with 66 tide-gauge records from the last 300 years. The study found that global sea level declined by approximately three inches from 1000 to 1400, a period when the planet cooled by about 0.4 Fahrenheit degrees. They also found that if increases in global temperature attributed to human activity would not have occurred during the 20th century, the sea level would have risen at less than half the observed rate or may have even dropped. [Rutgers University News]
• New prediction tool could increase warning time of rogue waves -- Engineers at the Massachusetts Institute of Technology (MIT) have developed a new prediction tool that could provide sailors with a two- to three-minute warning of a dangerous approaching rogue or freak wave, a wall of water that may be as much as eight times higher than surrounding waters and appears with virtually no warning. This new tool is a computer algorithm that sifts through data from surrounding waves to spot clusters of waves that may develop into a rogue wave. Using a wave group's length and height as input information, the algorithm computes a probability that the group will turn into a rogue wave within the next few minutes. [MIT News]
• Satellites help rescue 250 people in 2015 -- During last year (2015), 250 people were rescued from life-threatening situations throughout the US and on its surrounding waters in part because of the role that NOAA’s fleet of operational satellites played. More than half of those rescued (55%) involved waterborne rescues. Detecting distress signals from emergency beacons and from hand-held Personal Locator Beacons (PLBs), these NOAA satellites helped pinpoint the location of these people and relay this information to first responders who perform the actual rescue. NOAA's geosynchronous and polar-orbiting satellites are part of the international COSPAS-SARSAT (COSPAS a Russian abbreviation for "Space System for the Search of Vessels in Distress" and SARSAT "Search and Rescue Satellite Aided Tracking") system. [NOAA News]
• An All-Hazards Monitor -- This Web portal provides the user information from NOAA's National Weather Service, FAA and FEMA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [NOAA/NWS Daily Briefing]
• Earthweek -- Diary of the Planet [earthweek.com]

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

• 29 February 1504...Christopher Columbus used his knowledge of a lunar eclipse that night to convince Native Americans to provide him with supplies. (Wikipedia)
• 1 March 1498...The Portuguese explorer, Vasco de Gama, landed at what is now Mozambique on his way to India.
• 1 March 1854...The SS City of Glasgow left Liverpool harbor for Philadelphia and was never seen again with 480 people on board.
• 1 March 1902...The first regular light stations in Alaska were established at Southeast Five Finger Island and at Sentinel Island--both on the main Inside Passage between Wrangell Strait and Skagway. (USCG Historian's Office)
• 1 March 1905...The first regular light stations in Alaska were established. (USCG Historian's Office)
• 1 March 1927...A system of broadcasting weather reports by radio on four lightships on the Pacific Coast was put into effect. (USCG Historian's Office)
• 1 March 1970...US commercial whale hunting was ended.
• 1 March 1977...The United States extended its territorial waters to 200 miles.
• 1 March 1983...A ferocious storm battered the Pacific coast. The storm produced heavy rain and gale force winds resulting in flooding and beach erosion and in the mountains produced up to seven feet of snow in five days. An F2 tornado hit Los Angeles. Thirty people were injured and 100 homes were damaged. (The Weather Channel) (Intellicast)
• 2 March 1982...Half of Tonga in the South Pacific was rendered homeless by Tropical Cyclone Isaac after winds of 112 mph caused heavy damage. (National Weather Service files)
  
• 3 March 1873...US Army Signal Corps established storm signal service for benefit of seafaring men, at several life-saving stations and constructed telegraph lines as original means of communication. (USCG Historian's Office)
• 3 March 1960...The submarine USS Sargo returned to Hawaii from an Arctic cruise of 11,000 miles, of which 6,003 miles were under the polar ice, reaching the North Pole on 9 February. This cruise marked the first time that a submarine explored the Arctic in winter. (Naval Historical Center)
• 4-5 March 1899...Tropical Cyclone Mahina (the Bathurst Bay Hurricane) crossed Australia's Great Barrier Reef and generated produced the highest storm surge ever recorded: 13-14.6 m (42.6-47.8 ft) surge in Bathurst Bay. The Australian pearling fleet was destroyed, over 100 shipwrecks reported and 307 people killed, making Mahina the largest death toll of any natural disaster in Australian history. Minimum central pressure barometric pressure fell to an unofficial reading of estimated at 914 millibars (26.90 inches of mercury). (Accord's Weather Calendar) (The Weather Doctor) (National Weather Service files)
  
• 5 March 1914...The Spanish ship the Principe de Asturias enroute from Barcelona to Buenos Aires sank with the loss of 445 of the 588 passengers and crew members when it struck the jagged reefs along the Brazilian coast at Ponta Boi in dense fog.
• 5-6 March 1962...The Great Atlantic Coast Storm of 1962 caused more than $200 million in property damage from Florida to New England. Winds along the Middle Atlantic Coast reached 70 mph raising 40-ft waves, and 42 inches of snow fell at Big Meadows, in the mountains of Virginia--a state record. The storm caused greater alteration of the coastline from Cape Hatteras, NC to Long Island than any previous storm, including hurricanes. A new inlet was cut through Hatteras Island and more than 10 miles of Outer Banks barrier dunes were obliterated. The Virginia shoreline was rearranged by historic tidal flooding caused by the combination of the long stretch of strong onshore winds and the spring tides. A 3-mile long boardwalk in Ocean City, MD was wiped out. (David Ludlum) (Intellicast)
• 6 March 1521...The Portuguese explorer Ferdinand Magellan reached Guam in his around the world voyage. (Wikipedia)
• 6 March 1987...The British ferry Herald of Free Enterprise capsized in the English Channel off the coast of Belgium with the loss of 189 people.

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Prepared by DS Ocean Central Staff and Edward J. Hopkins, Ph.D.,
email hopkins@aos.wisc.edu
© Copyright, 2016, The American Meteorological Society.