WEEKLY OCEAN NEWS

DATASTREME OCEAN WEEK THREE: 19-23 September 2005

Ocean in the News

(Thurs.) Hurricane Rita is now number 3 -- Hurricane Rita rapidly intensified to a category 5 hurricane on the Saffir Simpson Scale Wednesday afternoon as it moved out over the warm waters of the Gulf of Mexico. The minimum central pressure fell to 897 millibars (26.49 inches of mercury), meaning that Rita became the third most intense Atlantic hurricane in terms of central pressure since records began in the mid-nineteenth century. Maximum sustained winds reached 175 mph. This monumental hurricane should reach the Texas coast later this week. [CNN]
NASA posts images of Rita in Gulf including views of water temperatures and winds. Also earlier images of Rita's Florida encounter are available. [NASA Life on Earth]
(Tues.) Rita takes on the Keys -- Rita, expected to become a minimal hurricane, will pass across the Florida Keys on Tuesday. Rita's storm surge could be from 4 to 7 feet while 6 to 8 inches of rain deluge the islands. [USA Today]
(Tues.) A workshop to focus on Envisat sensors -- A five-day workshop is to be held next week near Rome, Italy, where more than 200 scientists from at least 30 countries will show how they use two types of sensors onboard the European Space Agency's polar-orbiting Envisat satellite to monitor the ocean, land, atmosphere and ice. The Medium Resolution Imaging Spectrometer (MERIS) takes images of the precise color of the ocean and coastal zones, enabling determination of the biological and sediment loading of the water, while the Advanced Along Track Scanning Radiometer (AATSR) measures global sea surface temperature (SST) to an accuracy of 0.3 Celsius degrees. [ESA]
(Tues.) Toxic algae bloom blamed on Florida fish kills -- A spokesperson with the Florida Marine Research Institute reported that toxic algae was found in dead fish recently killed in the Gulf of Mexico off the southwest coast of Florida and appears to be associated with the "red tide" bloom that has lingered across the region for much of this year. [ENN]
(Tues.) Shortages in potable water continue following the Indian Ocean tsunami -- A report issued by the UN Millennium Development Goals update indicates that nearly 90,000 residents of the Maldives archipelago in the Indian Ocean are still experiencing shortages in potable water following the disastrous tsunami that hit their islands in December 2004. [ENN]
News from Ophelia -- The fourteenth named tropical cyclone and the sixth hurricane of the 2005 Atlantic hurricane season, Ophelia, brushed along the North Carolina coast late last week after moving northward on an erratic path off the Florida and Georgia coasts:
- Scientists from the NOAA Atlantic Oceanographic and Meteorological Laboratory used a remotely controlled unmanned aircraft, called Aerosonde, for the first time to probe a tropical cyclone when they sent the specially equipped instrument platform into Tropical Storm Ophelia for 10 hours, where it relayed back observations of the near-surface atmospheric environment considered too hazardous for the traditional hurricane hunter aircraft. [NOAA News]
- The National Hurricane Center employed techniques developed at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison to monitor Hurricane Ophelia with satellite imagery, to make analyses and then to prepare forecasts of the anticipated track of the system as it moved along the North Carolina coast late last week. [EurekAlert!]
- The visit by Ophelia to the Outer Banks of North Carolina has created more beach erosion and made the situation worse along the coast. [USA Today]
Additional updates on Katrina -- While this former Category 5 hurricane hit the Gulf coast and dissipated three weeks ago, the nation's attention continues to focus on its aftermath:
- While other governmental agencies on the federal and state levels have been criticized for slow response to the disaster wrought by Hurricane Katrina along the Gulf Coast, the National Hurricane Center and the National Weather Service appear to be two agencies that had made remarkably accurate forecasts well in advance of the impending landfall. The Director of the National Hurricane Center also made a nearly unprecedented warning call to the governors of Louisiana and Mississippi and to the New Orleans mayor two days in advance. [USA Today]
- In their report of the recently concluded meteorological summer (June through August), scientists at the National Climatic Data Center (NCDC) reported that the four named tropical cyclones that formed during the summer represented a record number, and Hurricane Katrina appears to be the most destructive hurricane to have struck the nation in terms of economic losses. Due to low barometric pressure and wind considerations, Katrina also ranks as the fourth strongest hurricane in the Atlantic and one of the most powerful to hit the continental US. [NOAA News]
- Fisheries scientists from the NOAA Fisheries Service and from several of the Gulf coast states used a NOAA research vessel during the last week to continue studying the effects that Hurricane Katrina has had on the marine resources and ecosystem along the lower Mississippi River and the Gulf coast of Louisiana, Mississippi and Alabama. This study is in conjunction with the announcement by the US Commerce Secretary of a formal determination of a fishery failure along much of the country's Gulf Coast. [NOAA News] Researchers and crew onboard this research vessel have found debris carried out into the Gulf. They did note that the oyster beds appear not to have sustained the major damage from silt as previously suspected. However, oil spills could be a problem, with the US Coast Guard estimating that 7 million gallons of oil have been spilled from facilities in southeast Louisiana. [ENN]
- NOAA Navigational Response Teams, along with the US Coast Guard and FEMA, are attempting to respond to the hazardous materials in New Orleans floodwaters in addition to continuing search and rescue missions. These teams have employed airborne LIDAR instruments and satellite imagery to create detailed aerial maps of the devastated regions and assist in the tracking of the progress of removing floodwaters from the Crescent City. [NOAA News] By late last week, ports on the Gulf Coast and river channels along the Mississippi River were again navigable and safe for ship traffic, in part due to the efforts of the Navigational Response Teams. [NOAA News]
- The US Environmental Protection Agency has announced that new tests of water samples taken daily from the floodwaters in New Orleans following Katrina have found dangerous amounts of sewage-related bacteria and lead, along with high levels of chromium compounds. [ENN]
- A Dutch flood expert is offering advice to his American counterparts concerning preparations in anticipation of another devastating hurricane similar to Katrina, based upon his experiences with how Holland made changes to its flood control systems following the storm surge that caused flooding and the deaths of over 1800 people in 1953. [CNN]
- Researchers at the Dartmouth Flood Observatory at Dartmouth University have been collaborating with state and federal officials in developing maps intended to aid in the analysis of river and coastal flood associated with Katrina. [Dartmouth News]
- An ecologist at the University of North Carolina at Chapel Hill suggests that more rain across New Orleans and adjacent sections of southern Louisiana and Mississippi would be beneficial since the added rainwater would help dilute some of the floodwaters that contain a variety of sewage and other harmful pollutants. [University of North Carolina at Chapel Hill]
Modeling the effects of storm surge -- An engineering professor and his graduate students have been using storm surge models to study how the storm surge and coastal flooding caused by a Category 4 hurricane on the Saffir-Simpson Scale could affect the Tampa Bay area along the west coast of Florida. They plan to run similar models for Miami and Jacksonville on Florida's east coast. [University of Central Florida]
Hurricanes appear to be stronger -- Researchers at the Georgia Institute of Technology and the National Center for Atmospheric Research report that the worldwide number of major hurricanes, rated Category 4 and 5 on the Saffir-Simpson Scale, appears to have nearly doubled since 1970, while the total number of hurricanes has dropped . [NCAR/UCAR] See [EurekAlert!] for graphic of time series of hurricanes.
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

THE AUTUMNAL EQUINOX -- The Autumnal Equinox will occur on Thursday, 22 September (officially at 2223Z, or 6:23 PM EDT or 5:23 PM CDT, etc.). 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 on Wednesday, 21 December 2005.

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 could lead 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.

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

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

Historical Events

19 September 1957...Bathyscaph Trieste, in a dive sponsored by the Office of Naval Research in the Mediterranean, reached a record depth of 2 miles. (Naval Historical Center)
19 September 1967...Hurricane Beulah deluged Brownsville, TX with 12.19 in. of rain in 24 hrs, to establish a record for that location. Hurricane Beulah made landfall on the 20^th near the mouth of the Rio Grande River, where a wind gust of 135 mph was reported by a ship in the port. (19^th-20^th) (The Weather Channel)
20 September 1909...A strong hurricane made landfall in southeastern Louisiana. A 15-ft storm surge flooded the Timbalier Bay area. Some 350 people perished. (Intellicast)
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)
20 September 1519...Portuguese navigator Ferdinand Magellan set sail from Spain in an effort to find a western sea route to the rich Spice Islands of Indonesia. In October 1520, he passed through the straits that now bear his name separating Tierra del Fuego and the South American mainland and became the first known European explorer to enter the Pacific Ocean from the Atlantic. In September 1522 one remaining ship from the original five that set sail returned to Spain, to become the first ship to circumnavigate the globe. Magellan was killed in the Philippines in 1521. (The History 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)