DATASTREME OCEAN WEEK TWELVE: 29 November-3 December 2010

• Eye on the tropics --- As the official hurricane seasons in both the North Atlantic and eastern North Pacific basins draw to a close during this upcoming week, neither basin experienced tropical cyclone activity during the last week. However: in the western South Pacific basin, the first tropical depression of the season formed over the waters near Fiji. For more information about this depression, identified as Tropical Depression 1F and a satellite image, see the NASA Hurricane Page.
• The 2010 hurricane seasons reviewed -- With the end of the official 2010 hurricane season in both the North Atlantic and North Pacific on Tuesday, 30 November 2010, a quick review of this year's tropical cyclone statistics for official 2010 hurricane season has been made for both basins. [AMS DataStreme Atmosphere]
• Comparing rainfall in 2010 Atlantic hurricane season with 2005 record season - Scientists at NASA's Goddard Space Flight Center produced corresponding maps of the tropical cyclone rainfall distribution across the North Atlantic basin (including the Caribbean, the Gulf of Mexico and surrounding land masses in North and South America) during the 2005 and 2010 hurricane season. These precipitation maps were produced from data collected by NASA's TRMM (Tropical Rainfall Measuring Mission) satellite; cyclone tracks were also plotted on these maps for reference. Due to differences in the tracks of the tropical cyclones during these two active seasons, the area of largest precipitation during this nearly concluded 2010 season was displaced to the south and east across sections of the central Caribbean and the central tropical Atlantic as compared with the 2005 season, when most of the largest area of precipitation was over the Gulf of Mexico, the western Caribbean and the western North Atlantic. [NASA GSFC]
• Tropical cyclone climatologies of North Atlantic and the eastern North Pacific -- The National Hurricane Center (NHC) has an updated and revised edition of its "Tropical Cyclones of the North Atlantic Ocean, 1851-2006." While a paper copy of this book is available for a cost from NHC, a 243-pg pdf file of this edition can be downloaded for free. NHC also released the first edition of "Tropical Cyclones of the Eastern North Pacific Ocean, 1949-2006." In addition to a paper copy is available for sale, a free 164-page pdf file is available. Both of these climatologies have numerous graphics that show long-term changes in tropical cyclone frequency in the two basins.
  A climatology of tropical cyclones in the central North Pacific from the 1950s to 2008 is available from the CPHC climatology website maintained by the Central Pacific Hurricane Center (CPHC) in Honolulu, HI.
• Escalation of Icelandic whaling criticized by US Commerce Secretary -- Last week, Gary Locke, the US Department of Commerce Secretary, issued a formal statement that was critical of Iceland’s decision to resume international trade in fin whale meat and its escalation of commercial whaling outside of the control of the International Whaling Commission (IWC). [US Commerce Dept.]
• Enforcement actions designed to ensure safe seafood from Gulf -- In effort to ensure the safety of seafood reaching America’s dinner tables, NOAA's Fisheries Service has charged eight shrimp trawlers with allegedly fishing in an area of the Gulf of Mexico off the Louisiana coast that was closed this last summer because of the Deepwater Horizon/BP oil spill. [NOAA News]
• "Oil Budget Calculator" undergoes further review -- During the last week, the Federal Interagency Solutions Group released a peer-reviewed report detailing the scientific calculations used in the Deepwater Horizon BP Oil Spill "Oil Budget Calculator" response tool developed this past summer. The Federal Interagency Solutions Group was established at the request of the US Coast Guard and authorized under a directive from the National Incident Commander. This report, which was developed in collaboration with federal and independent scientists, revised the estimated short-term fate of the oil discharged from the well prior the capping of the wellhead. [NOAA News]
• Sea salt sensor for new satellite undergoes preflight testing -- A team of scientists from NASA's Jet Propulsion Laboratory and the Goddard Space Flight Center have gone to Brazil's National Institute for Space Research to participate in a series of environmental tests on NASA's Aquarius instrument that will be placed onboard a joint US and Argentine Aquarius/SAC-D spacecraft to be launched late next spring. NASA's Aquarius instrument is designed to designed to provide monthly global maps of salinity on the ocean surface, which should ultimately help in the studies of the Earth's climate through the monitoring of the planetary hydrologic cycle and ocean circulation. [NASA JPL]
• Hybrid tugboat found to have reduced emissions -- Researchers at the University of California, Riverside have found that the tugboat Carolyn Dorothy, believed to be the world’s only hybrid electric tugboat, is effective in reducing emissions at the Ports of Los Angeles and Long Beach in southern California. This hybrid electric tugboat reduced emissions of soot by approximately 73 percent, oxides of nitrogen by 51 percent and carbon dioxide by 27 percent. [University of California, Riverside]
• Results of annual bonefish census send a warning -- The annual bonefish census conducted in October by a fisheries scientist with the University of Miami’s Rosenstiel School of Marine & Atmospheric Science in which he poled more than 60 guides and anglers in the Florida Keys has produced some potentially troubling results. Although this year's count was held in unsettled weather with lowered visibility, approximately 240,000 bonefish were counted, a new low for the last eight years during which the census has been held. Future counts will be needed to determine if this downward population trend will continue. [Rosenstiel School of Marine & Atmospheric Science News Releases]

• Old ship logs help in reconstruction of weather history during last two centuries -- Various groups of professional and citizen scientists are examining long-buried ships logs and other notes made by weather observers in Europe and the United States that may date back over the last 250 years. Several of these groups include NOAA's Climate Database Modernization Program, the International Environmental Data Rescue Organization, the United Kingdom's "Old Weather" and the International Atmospheric Circulation Reconstructions over the Earth. Their efforts, which include digitizing these old records, are motivated by the desire to fill in the weather history since the mid 18th century, to place modern-day weather extremes into better context and to improve computer models that predict climate conditions. [USA Today]

• Animated global maps show seasonal and variations in climate elements over last decade -- NASA's Earth Observatory Mission at the agency's Goddard Space Flight Center have recently assembled animations generated from monthly data for a variety of climate elements collected by the sensors on board the NASA satellite fleet, primarily the Aqua and Terra satellites. These animations that may run up to eight years in length provide a means for visualizing the seasonal and interannual variability of surface temperature, aerosols and water vapor:
• An eight-year animation of Earth's monthly surface temperatures for the land surface running from February 2000 through September 2010 was obtained from the MODIS sensor on the Terra satellite. [NASA Earth Observatory]
  A corresponding animation of the sea surface temperature anomalies (arithmetic difference between actual monthly and the 1985-1997 average monthly temperatures) was produced from data collected by the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) on the NOAA satellite series running from June 2002 through October 2010. [NASA Earth Observatory]
• An animation of the monthly average aerosol optical depth, which is a measure of the amount of liquid and solid particulate matter in the atmosphere, was produced for the interval running from January 2005 through September 2010 from data collected by the MODIS instrument on the Terra satellite. [NASA Earth Observatory]
• An animation of the atmospheric water vapor, as described by the monthly average precipitable water, was produced from data collected by the MODIS sensor on the Aqua satellite from July 2002 through October 2010. The precipitable water represents the depth of an equivalent amount of water that could be produced if all the water vapor in the atmospheric column were condensed. [NASA Earth Observatory]
• 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, including drought, floods and storms during the current month. [NCDC]
• Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Climate Feedback Processes

Earth's climate system includes many interacting variables. Some variables are external to the Earth-atmosphere system and some are internal. External variables include solar energy output and Earth-sun geometry (i.e., the Milankovitch cycles). Internal variables include properties of the Earth's surface (e.g., albedo, moisture), the concentration of key atmospheric components (e.g., greenhouse gases, sulfurous aerosols), and cloud cover and thickness.

An important consideration in understanding how Earth's climate system responds to some perturbation is feedback. Feedback is defined as a sequence of interactions among variables in a system that determines how the system responds to some initial perturbation in one or more of the variables. Variables in Earth's climate system may interact in such a way as to either amplify (positive feedback) or lessen (negative feedback) a change in climate. An example of positive feedback is the ice-albedo effect described in Chapter 12 of the DataStreme Ocean textbook. Less ice cover in the Arctic greatly reduces the albedo of the Arctic Ocean causing higher sea surface temperatures and accelerated melting of the multiyear pack ice.

Consider an example of negative feedback. Increasing concentrations of atmospheric carbon dioxide enhances the greenhouse effect causing global warming. Global warming in turn raises sea surface temperatures and increases the rate of evaporation. A more humid atmosphere means more persistent and thicker cloud cover but clouds have both a cooling and warming effect on the lower atmosphere. The relatively high albedo of cloud tops causes cooling whereas absorption and emission of infrared radiation by clouds causes warming by contributing to the greenhouse effect. Satellite measurements and numerical models indicate that cooling would dominate.

In general, negative feedback tends to dominate over positive feedback in Earth's climate system, limiting the magnitude of climate change. The great thermal inertia of the ocean is the principal reason for dampening the planetary temperature response.

Concept of the Week: Questions

1. Feedback in Earth's climate system that amplifies climate change is described as [(positive)(negative)] feedback.
2. In general, [(negative)(positive)] feedback tends to prevail in Earth's climate system.

• 1 December 1969...Ocean swells generated by a storm more than 1000 miles to the north-northwest of the French Frigate Shoals produced 50-foot high surf along the outer shoals of Tern Island, submerging the 300-foot wide island under two to three feet of water. The 19-member Coast Guard contingent was evacuated, but considerable damage was done to buildings. (Accord Weather Guide Calendar)
• 1 December 1990...Workers from the United Kingdom and France on the Channel Tunnel construction project met approximately 120 feet beneath the English Channel seabed, to establish the first ground connection between the British Isles and mainland Europe since the last Ice Age. (Wikipedia)
• 2 December 1755...The second Eddystone Lighthouse near Plymouth, England was destroyed by fire. This light had replaced an earlier light that had been destroyed in the "Great 1703 Storm." The current structure is the fourth light to be constructed at that site. (Wikipedia)
• 3 December 1952...A remarkable display of sea smoke was seen in Hong Kong harbor. The sea-smoke, induced by a strong surge of arctic air, poured from the water of Kowloon Bay from 8 AM to 9:30 AM. The air temperature near the sea wall was 44 degrees F. (Accord Weather Guide Calendar)
• 3 December 1992...The Greek oil tanker Aegean Sea carrying 80,000 tons of crude oil ran aground in a storm while approaching La Coruña, Spain, spilling much of its cargo. (Wikipedia)
• 3 December 1999...After rowing for 81 days and 2962 miles, Tori Murden became the first woman to cross the Atlantic Ocean by rowboat alone when she reached Guadeloupe after departing from the Canary Islands. (Wikipedia)
• 4 December 1786...The first of two great early December storms began. The storm produced high seas at Nantucket that did great damage. (David Ludlum)
• 4-13 December 1991...Tropical Cyclone Val with gusts to 150 mph caused $700 million damage. Seventeen deaths were reported in American and Western Samoa, with 95 percent of the houses in Savaii either destroyed or badly damaged. Savaii was essentially hit twice by Val as the system completed a loop on the 8^th. (Accord Weather Guide Calendar)
• 4 December 2003...A tropical depression became Tropical Storm Odette in the Caribbean well south of Kingston, Jamaica, becoming the first December tropical storm of record to form in the Caribbean Sea. Odette made landfall on near Cabo Falso, Dominican Republic on 6 December, causing eight deaths and destroying 35 percent of the banana crop. (Accord Weather Guide Calendar)
• 5 December 1872...A British brigantine, the DeGratia, discovered the American ship Mary Celeste derelict and boarded her. The Mary Celeste, a brigantine had set sail from New York harbor for Genoa, Italy, on 5 November 1872. Everyone aboard the Mary Celeste had vanished-her captain, his family, and its 14-man crew. The ship, which appeared to have been abandoned for approximately nine days, was in perfect order with ample supplies and there was no sign of violence or trouble. The fate of the crew remains unknown. (Infoplease.com) (Wikipedia)
• 5 December 1492...The explorer Christopher Columbus became the first European to set foot on the island of Hispaniola, which now contains the countries of Haiti and the Dominican Republic. (Wikipedia)
• 5 December 1949...A typhoon struck fishing fleet off Korea; several thousand men reported dead. (Infoplease.com)

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