WEEKLY OCEAN NEWS

WEEK THREE: 20-24 September 2010

For Your Information

• The Autumnal Equinox --
The Autumnal Equinox will occur late this Wednesday evening (officially at 0309Z, 23 September 2010 or 11:09 PM EDT or 10:09 PM CDT, etc. on 22 September). At that time the noontime sun will appear directly above the equator, representing one of the two times during the year for such an occurrence, with the other being at the vernal equinox in March. The term "equinox" arises from the fact that this time of year represents "equal night" and equal day essentially everywhere. Within the subsequent several days, the length of daylight will become noticeably shorter. This decrease in daylight will continue for another three months to the winter solstice during the early evening of Tuesday, 21 December 2010.
Editor's note: John White, a meteorologist from North Carolina involved with the AMS Education program, reported that the geosynchronous (or geostationary) satellites make an "satellite eclipse" of the sun near the spring and autumnal equinoxes because of their equatorial orbit, such that these satellites pass through the earth's shadow and the satellite is powered down when the solar array does not receive sufficient sunlight. [For more information, consult NWS Southern Region GOES Satellite FAQ] EJH.

Ocean in the News

• Eye on the tropics --
Tropical cyclone activity remained relatively active across the North Atlantic Basin this past week. A somewhat rare event occurred last Thursday when three hurricanes were found simultaneously in the North Atlantic basin. According to the National Hurricane Center, the last time three or more hurricanes were in the North Atlantic at the same time was back in September 1998, when four hurricanes (Georges, Ivan, Jeanne and Karl) were found on one day. Five other simultaneous occurrences of three or more hurricanes were found over the last 115 years.
• Hurricane Igor traveled to the northwest across the North Atlantic through much of the past week as a powerful category 3 or 4 hurricane on the Saffir-Simpson Hurricane Scale. As of Sunday, this hurricane had weakened to a category 1 hurricane as it was taking aim at Bermuda. For more information and satellite imagery, consult the NASA Hurricane Page.
  Hurricane Julia, the fifth hurricane of the 2010 Atlantic hurricane season formed early in the week near the Cape Verde Islands and traveled to the northwest, briefly becoming a category 4 hurricane. At that time, Hurricane Julia joined Hurricane Igor as being category 4 hurricanes, which marked only the second time since 1900 that two category 4 hurricanes were present simultaneously in the North Atlantic according to the National Hurricane Center. As of Sunday, Julia had weakened to a tropical storm as it began curving toward the northeast over the central North Atlantic well away from land. See the NASA Hurricane Page for further details on Hurricane Julia.
  Hurricane Karl, the tenth named tropical cyclone of the 2010 Atlantic season formed as a tropical storm over the western Caribbean sea off the Yucatan Peninsula early last week. After making landfall and cross the Yucatan Peninsula, Karl rapidly intensified into a category 3 hurricane as it traveled westward across the Bay of Campeche before making landfall along the Mexican coast near Veracruz on Friday. The NASA Hurricane Page has additional information on Hurricane Karl. This hurricane was studied by scientists participating in NASA's Genesis and Rapid Intensification Processes (GRIP) mission. [NASA GRIP]
• In the western North Pacific, Typhoon Fanapi developed early last week to the east of Taipei. By this past weekend, Fanapi reached category 3 status on the Saffir-Simpson Hurricane scale prior to making landfall on the eastern coast of Taipei. See the NASA Hurricane Page for additional details.
• Current Atlantic hurricane season meets expectations --
Hurricane experts have noted that the 2010 hurricane season at the statistical midpoint of the North Atlantic hurricane season has been extremely active as had been foreseen by several hurricane forecast groups. As of late last week, eleven named tropical cyclones had formed across the basin, which includes the Caribbean Sea and the Gulf of Mexico, including six hurricanes. Earlier this summer, Bill Gray and Phil Klotzbach of Colorado State University had predicted 15 named cyclones and eight hurricanes, while NOAA forecasters anticipated 14 to 23 named cyclones and eight to 14 hurricanes. On a long-term average, 10 named tropical cyclones and six hurricanes can be expected across the basin. [USA Today]
• This year could be close to warmest in more than a century --
Basing their analysis on preliminary data, scientists at NOAA's National Climatic Data Center recently reported that the first eight months of 2010 tied the same period in 1998 for the highest combined land and ocean surface temperature on record worldwide since widespread reliable climate data became available in 1880. They also stated that the global land-ocean combined temperature for the boreal summer/austral winter (the three months of June, July and August) was the second highest on record. Furthermore, the global average land surface temperature for August 2010 was the second highest on record for August, while the global ocean surface temperature tied with 1997 as the sixth highest for August. In addition, they noted that the Arctic sea ice continued its 14-year decline. [NOAA News]
• Monitoring this summer's Arctic sea ice extent --
Images obtained from the MODIS and the AMSR-E (Advanced Microwave Scanning Radiometer for EOS) sensors on NASA’s Aqua satellite during the last several weeks show shrinkage of the Arctic sea ice to the seasonal minimum in early September. [NASA Earth Observatory] Researchers at the University of Colorado at Boulder's National Snow and Ice Data Center report that as of mid September, the extent of Arctic sea ice appears to have reached a minimum for the 2010 summer season, with an areal extent that supplants 2009 as the third smallest since routine satellite surveillance commenced in 1979. [University of Colorado] [National Snow and Ice Data Center]
• US Virgin Islands serves as a base for hurricane research --
A group of scientists have been using St. Croix in the US Virgin Islands as their base of operations for the six-week PREDICT (Pre-Depression Investigation of Cloud Systems in the Tropics) field experiment designed to study how low pressure depressions develop over tropical waters and then eventually organize into tropical cyclones such as tropical storms and hurricanes in the North Atlantic basin. The researchers collect data from the disturbances using the NCAR (National Center for Atmospheric Research) high-altitude Gulfstream V research aircraft. [Virgin Islands Daily News] [UCAR/NCAR]
• Record year for turtles on North Carolina's Outer Banks --
Officials at the Cape Hatteras National Seashore on North Carolina's Outer Banks have noted that 2010 appears to be a record for the number of sea turtle nests along this section of the Atlantic coast. They believe that the increase in sea turtle nests can be attributed to the abundance of food, as well as to the banning of nighttime driving along the beaches. [Pilot Online] [Editor's note: Special thanks are extended to Terri Kirby Hathaway, an Oceans LIT Leader and Marine Education Specialist for the North Carolina Sea Grant at Manteo, NC. EJH]
• Monetary grant to study Great Lakes water quality --
The National Science Foundation has recently provided a $5 million grant to a team of 27 researchers from research institutions, including the University of Michigan, to study how extreme weather events caused by climate change affect the water quality of the Laurentide Great Lakes. [University of Michigan]
• Coral disease outbreaks linked to warm seawater --
Using sea surface temperature data collected from satellites, scientists from NOAA, the Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University and the Australian Institute of Marine Science have found that a strong relationship exists between warm sea water in summer with outbreaks of coral diseases on Australia's Barrier Reef and in addition, relatively mild seawater during the preceding winter season can be linked also to the disease outbreaks. Their research has also contributed to a new experimental Coral Disease Outbreak Risk Map product that is available online. [NOAA News]
• European marine observation network proposed --
In a recent meeting of the European Science Foundation's Marine Board, more than 100 marine scientists, policy makers and members of industry called for an integrated network of long-term marine observing stations that would monitor the waters surrounding Europe so as to better understand ocean, earth and climate system processes. [EurekAlert!]
• Improvements seen in tsunami detection, but coastal areas remain vulnerable --
In response to a congressional request, the National Research Council issued a report that while the nation's ability to detect and forecast tsunamis has improved in the last five years, such as the Deep-Ocean Assessment and Reporting of Tsunamis (DART) sensor network, current efforts are still not sufficient to meet the challenges presented by tsunamis that are generated near land that would leave little time for adequate warning to tsunami-susceptible coastal areas. The report also calls for a comprehensive national assessment of tsunami risk, together with improved communication and coordination among the NOAA's Tsunami Warning Centers, emergency managers, media, and the public. [EurekAlert!]
• Research finds promise and peril associated with global fisheries --
The results of four investigations conducted by the University of British Columbia's Fisheries Centre, with support from the Pew Environment Group, were recently published that the global fisheries, which is estimated at between $225-$240 billion per year, represents a major source of food and revenue around the world, yet could help reduce malnourishment in close to 20 million people in underdeveloped nations. The researchers also noted that while fishing generates incomes, overfishing reduces revenue and financial incentives offered to national fishing industries may encourage overfishing, which contributes to depleted fish stocks. [EurekAlert!]
• 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, 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: Sea Water Salinity and Carbon Dioxide

In view of the contemporary concern regarding global climate change, scientists are studying the various factors that govern the ocean's ability to absorb atmospheric carbon dioxide. Concentrations of atmospheric carbon dioxide are on the rise primarily because of the burning of fossil fuels (i.e., coal, oil, natural gas). Carbon dioxide is a greenhouse gas (an atmospheric gas that absorbs and radiates infrared radiation) so that higher levels of atmospheric carbon dioxide may be contributing to global warming. The ocean's role in regulating the concentration of atmospheric carbon dioxide depends on the temperature, salinity, and biological components of surface waters.

As noted in Chapter 3 of your textbook, gases are more soluble in cold seawater than warm seawater. Hence, changes in sea surface temperature affect the ability of the ocean to absorb carbon dioxide. As noted in Chapter 1 of your textbook, photosynthetic organisms take up carbon dioxide and release oxygen. And through cellular respiration, all organisms release carbon dioxide. What about the effects of changes in salinity on the ocean's uptake of atmospheric carbon dioxide? Research from the Pacific Ocean near Hawaii provides some insight on this question.

Since the late 1980s, scientists have been recording ocean conditions at a site (dubbed ALOHA) about 100 km (62 mi) north of Oahu. In 2003, David M. Karl, a biogeochemist at the University of Hawaii in Honolulu, reported a decline in the rate at which surface ocean waters were absorbing carbon dioxide from the atmosphere. In fact, in 2001, the rate of CO₂ uptake was only about 15% of what it was in 1989. Why the change in CO₂ uptake? In this region of the Pacific north of Hawaii, sea surface temperatures showed no significant change during the period of observation but precipitation decreased and evaporation increased. Less precipitation coupled with higher rates of evaporation caused the surface water salinity at ALOHA to increase by about 1%. Increasing salinity inhibits water's ability to absorb gases including carbon dioxide. Karl and his colleagues attribute 40% of the decline in the ocean's CO₂ uptake to the saltier waters. The balance of the decline may be due to changes in biological productivity or ocean mixing

Concept of the Week: Questions

1. With rising sea surface temperatures, the rate of evaporation of sea water [(increases)(decreases)].
2. With increasing salinity and constant temperature, the amount of atmospheric carbon dioxide that is taken up by ocean water [(increases)(decreases)].

Historical Events

• 21 September 1938...The "Great New England Hurricane" smashed into Long Island and bisected New England from New Haven, CT across Massachusetts and Vermont, causing a massive forest blowdown and widespread flooding. Winds gusted to 186 mph at Blue Hill Observatory in Milton, MA, and a storm surge of nearly 30 ft caused extensive flooding along the coast of Rhode Island. The hurricane killed over 600 persons and caused $500 million damage. The hurricane, which lasted twelve days, destroyed 275 million trees. Hardest hit were Massachusetts, Connecticut, Rhode Island, and Long Island NY. The "Long Island Express" produced gargantuan waves with its 150 mph winds. Waves smashed against the New England shore with such force that earthquake-recording machines on the Pacific coast clearly showed the shock of each wave. (David Ludlum) (The Weather Channel)
• 22-23 September 1998...Hurricane Georges raked Hispaniola leaving over 580 dead in Haiti and the Dominican Republic, due mainly to flash flooding and subsequent mud slides in high terrain regions. Damage estimates from the storm exceeded $1 billion (US). (The Weather Doctor)
• 23 September 1551...The Grand Harbour at Valetta, Malta was hit by a waterspout that then moved inland and caused extensive damage. A shipping armada in the harbor about to go into battle was destroyed by the waterspout killing at least 600 people. (The Weather Doctor)
• 23 September 1815...One of the most powerful hurricanes to strike New England made landfall initially on Long Island, NY and then again at Old Saybrook, CT before crossing into Massachusetts and New Hampshire. Extensive structural damage resulted. Providence, RI was flooded and six people were killed. This "Great September Gale" was the worst tempest in nearly 200 years, equal in strength to the Great 1938 Hurricane, and one of a series of severe summer and autumn storms to affect shipping lanes that year. (David Ludlum)
• 24 September 1493...Christopher Columbus set sail with 17 ships on his second expedition to the New World, reaching the Lesser Antilles, the Virgin Islands, Puerto Rico and Hispaniola before returning to Europe in March 1496. (Wikipedia)
• 25 September 1513...Vasco Núñez de Balboa, a Spanish conquistador-explorer, crossed the isthmus of Panama and reached the Pacific Ocean, which he christened Mar del Sur (South Sea), claiming the ocean and all adjacent lands for Spain. (Wikipedia)
• 25 September 1939...A West Coast hurricane moved onshore south of Los Angeles bringing unprecedented rains along the southern coast of California. Nearly 5.5 in. of rain drenched Los Angeles during a 24-hr period. The hurricane caused $2 million in damage, mostly to structures along the coast and to crops, and claimed 45 lives at sea. "El Cordonazo" produced 5.66 in. of rain at Los Angeles and 11.6 in. of rain at Mount Wilson, both records for the month of September. (David Ludlum) (The Weather Channel)
• 25 September 1956...The world's first transatlantic telephone cable system began operating (Clarenville, Newfoundland to Oban, Scotland). Previous cables had been limited to telegraph transmissions. (Today in Science History)
• 26 September 1580...English seaman Francis Drake returned to Plymouth, England, in the Golden Hind, becoming the first British navigator to circumnavigate the globe. He had commenced his voyage around the world on 13 December 1577 with five ships, but returned with only one ship. During his voyage in the Pacific Ocean, he paused near San Francisco Bay and then traveled as far north as present-day Washington State. He brought back valuable information about the world's ocean to Queen Elizabeth I. (The History Channel)
• 26-27 September 1959...Typhoon Vera ravaged Honshu, Japan, the nation's largest island, leaving over 5000 dead, more than 40,000 injured, 1.5 million homeless and 40,000 homes destroyed. It was Japan's greatest storm disaster. (The Weather Doctor)

Return to DataStreme Ocean website

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