Weekly Ocean News

WEEKLY OCEAN NEWS

DATASTREME OCEAN WEEK SIX: 25 February-1 March 2013

For Your Information

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 change in meteorological seasons -- Thursday, 28 February 2013, 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 2013) 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 (2013) is considered a "normal" year with 365 days, while last year was a "leap" year with 366 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 Climatic Data Center recommends that the climate normals for 28 February be used also for 29 February in a leap year.
Becoming AWARE -- Commencing next Sunday (3 March 2013), NOAA's National Weather Service and its partner, the Federal Emergency Management Agency (FEMA) will be observing "National Severe Weather Preparedness Week" that will run through the following Saturday (9 March). The theme for this year's National Severe Weather Preparedness Week is "Be a Force of Nature." The NOAA "Weather-Ready Nation" website (http://www.nws.noaa.gov/com/weatherreadynation/force.html), contains links that allow the public to "Be a Force of Nature" in their communities through Tweet, a blog post, or a presentation. Other stations throughout the nation have either conducted or will conduct their Severe Weather Awareness Weeks in the next several months as the spring season for severe thunderstorms unfolds.

Ocean in the News

Eye on the tropics --- As austral summer continued to wane, some tropical cyclone activity was reported last week across the tropical ocean basins in both the Southern and Northern Hemispheres:
- In the South Indian basin, a tropical storm intensified to become Tropical Cyclone Haruna during the first half of last week over the waters of the Mozambique Channel between Madagascar and Africa. Initially, the tropical storm traveled southward before curving toward the east and intensifying into major category 3 tropical cyclone on the Saffir-Simpson Scale just before making landfall on the southwestern coast of Madagascar last Friday. Maximum sustained surface winds reached 115 mph, causing sea waves to reach heights of up to 25 feet. Although Haruna weakened to a tropical storm as it traveled across southern Madagascar, the system brought heavy rains and strong winds to this island nation. Tropical Storm Haruna was expected to continue traveling toward the southeast across the Southern Indian Ocean and weaken on Sunday and Monday. Additional information along with satellite imagery on Cyclone Haruna can be found on the NASA Hurricane Page.
  At the start of the new week (local time), Tropical Storm Rusty formed over the waters north of Australia. This tropical storm was forecast to travel south toward the coast, intensifying to either a category 1 or 2 tropical cyclone during the first half of this week.
- In the western North Pacific basin, a tropical depression formed early last week to the southeast of the Philippine island of Mindanao. This system, identified as Tropical Depression 2, traveled to the west-northwest across the islands of the southern Philippines before dissipating over the South China Sea two days after formation.
Managing and protecting Monitor National Marine Sanctuary planned -- Officials with NOAA's National Marine Sanctuaries recently released their final management plan and environment assessment for the Monitor National Marine Sanctuary, which is located off the coast of North Carolina coast and protects the sunken wreck of the Civil War ironclad, USS Monitor. The plan, which outlines the operation of the sanctuary for the next five years, will provide a framework for a variety of programs that include conservation and restoration of the ship's artifacts. [NOAA National Marine Sanctuaries]
Review of global weather and climate for January 2013 -- Using preliminary data collected from the global network of surface weather stations, scientists at NOAA's National Climatic Data Center have determined that the combined global land and ocean surface temperature for January 2013 was 54.57 degrees Fahrenheit (or 12.54 degrees Celsius), which tied January 1995 for the ninth highest global temperature for any January since global climate records began in 1880. The average global ocean surface temperature for January was the eighth highest on record, while the global land surface temperature for January 2013 was thirteenth highest. The scientists also noted that January 2013 was also the 335th consecutive month with a combined global temperature that exceeded the 20th century average (1901-2000). They also noted that neither El Niño or La Niña conditions were found across the equatorial Pacific Ocean, which resulted in slightly below average sea surface temperatures across the equatorial surface waters of the eastern half of the Pacific.
The extent of the Northern Hemisphere snow cover during January 2013 was the sixth highest for the period of record that started in 1967, while January Arctic sea ice extent was the sixth smallest monthly extent since satellite surveillance began in 1979. On the other hand, Antarctic sea ice extent was the seventh largest January sea ice extent on record. [NOAA/NCDC State of the Climate/NCDC]
Shark conservation will be the focus for 2013 -- In one week the 16th meeting of the Conference of Parties (CoP) will be held in Bangkok, Thailand to review, discuss and negotiate changes to the implementation of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), a multilateral treaty that is aimed to ensure that international trade in specimens of wild animals and plants does not threaten the survival of the species in the wild. The United States is a CITES party and works closely with international partners in CITES to advance the conservation of marine species. One of the focuses for 2013 will be shark conservation based on concerns that over-exploitation for the international fin trade is negatively impacting the population status of this shark species. [US Fish and Wildlife Service]
Biodiversity in marine organisms seen at extreme ocean depths -- Scientists from Scripps Institution of Oceanography have recently shown the results obtained from video made by a submersible vehicles during several deep ocean dives made last year in the Pacific Ocean as part of the DEEPSEA CHALLENGE expedition. Dives included those to 11 km (6.8 mi) below the ocean surface to the Mariana Trench and to the New Britain Trench and Ulithi. These researchers have found a vibrant and diverse mix of marine organisms at each trench. [Scripps Institution of Oceanography News]
Rate of cloud droplet formation not affected by pollution -- Researchers at the Georgia Institute of Technology who were studying the wide range of airborne particles including those that were hydrocarbon-rich particles produced by the 2010 Deepwater Horizon oil spill in the Gulf of Mexico report that oily, organic coatings on particles do not appear to significantly affect the rate at which cloud droplets form. The researchers claim that their findings may help reduce the uncertainty of climate model predictions, as scientists had thought that organic and viscous oily coatings on aerosols produced by combusted biomass and petroleum would slow the condensation rate during the formation of cloud droplets. [Georgia Tech]
Earthquake catastrophes and fatalities predicted to rise during 21st century -- Engineering geologists with the US Geological Survey (USGS) warn that as the world's population is projected to increase during the 21st century, the number of fatalities due to earthquakes and associated tsunamis would increase. They found that the number of catastrophic earthquakes that have claimed at least 50,000 lives each has increased from 1500 AD to the present, along with the increased global population. Using new 21st-century population projections by the United Nations they projected that approximately 21 catastrophic earthquakes would occur in the 21st century, triple the number in the 20th century and that the total deaths in the century could more than double to approximately 3.5 million people. Four catastrophic earthquakes have already occurred since so far this century, including the 2004 Sumatra-Andaman earthquake (and tsunami) and 2010 Haiti earthquake that each may have killed over 200,000 people. [USGS Newsroom]
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

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

25 February 1977...An oil tanker explosion west of Honolulu spilled 31 million gallons of oil into the Pacific Ocean.
26 February 1935...Robert Watson-Watt demonstrated RADAR (Radio Detection and Ranging) for the first time, using the BBC shortwave radio transmitter to successfully detect the distance and direction of a flying bomber during the so-called Daventry Experiment.
26 February 1938...The first passenger ship was equipped with radar.
27 February 1949...Aerial ice observation flights by long-range aircraft operated from Argentia, Newfoundland. An International Ice Patrol by vessels was neither required nor established during the 1949 season, and it was the first time that aircraft alone conducted the ice observation service. (USCG Historian's Office)
27 February 1988...A major rain event occurred across Saudi Arabia's Foroson Islands in the Red Sea and on the adjacent mainland around Jizon when 1.15 in. fell. The monthly average rainfall is only 0.02 in. On the following day, flash flooding south of Riyadh killed three children. (Accord's Weather Calendar)
28 February 1849...Regular steamboat service to California from the East Coast via Cape Horn arrived in San Francisco for the first time. The SS California had left New York Harbor on 6 October 1848 on a trip that took 4 months and 21 days. (Wikipedia)
28 February 1964...A world 12-hour rainfall record was set at Belouve, La Reunion Island in the western Indian Ocean when 52.76 inches of rain fell. World records for 9 hours and 18.5 hours were also set with 42.79 and 66.49 inches, respectively. (Accord's Weather Calendar) (The Weather Doctor)
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)
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 the Great Barrier Reef and generated a 48-ft storm surge across Barrow Point, Queensland, Australia. The Australian pearling fleet was destroyed, over 100 shipwrecks reported and 307 people killed. Barometric pressure fell to an unofficial reading of 915 millibars (27 inches of mercury). (Accord's Weather Calendar) (The Weather Doctor)