DATASTREME OCEAN WEEK TWELVE: 28 November-2 December 2011

• Opportunity for Teachers: The National Ocean and Atmospheric Administration's (NOAA) Teacher at Sea 2012 Field Season program is now accepting applications until 30 November 2011. Gain your "sea legs" and first-hand experience in one-week to one-month voyages. For more information, or to apply, see http://teacheratsea.noaa.gov.
• The 2011 hurricane seasons reviewed -- With the end of the official 2011 hurricane season in both the North Atlantic and North Pacific on Tuesday, 30 November 2011, a quick review of this year's tropical cyclone statistics for official 2011 hurricane season has been made for both basins. [AMS DataStreme Atmosphere]
  For those who are interested in obtaining historic hurricane information, the "Historical Hurricanes Mapping & Analysis Tool" developed by NOAA allows the search and display of detailed data for more than 6000 tropical cyclones in seven of the planet's major ocean basins based upon a data set that runs from 1842 to 2010. Coastal population trends are also available for the Atlantic and Gulf Coasts of the United States.
• 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.

• 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, only the eastern North Pacific basin experienced tropical cyclone activity during the last week. Tropical Storm Kenneth intensified to become the tenth hurricane of the 2011 eastern Pacific hurricane season early last week as it traveled westward away from the Mexican coast. By midweek, Hurricane Kenneth intensified into a major category 4 hurricane (on the Saffir-Simpson Scale) by on Tuesday. However, this hurricane weakened to a tropical storm by Wednesday and to a tropical depression on Friday. The NASA Hurricane Page has more information and satellite imagery on Hurricane Kenneth.
  In the North Indian Ocean basin, Tropical Cyclone 5 formed to the southwest of Sri Lanka and southern India at the end of last week. This minimal tropical storm traveled northward across the over the weekend. For information on this system when it was Tropical Depression 98B, see the NASA Hurricane Page.
• Report on national fisheries priorities achieved at international meeting -- Last week, Russell F. Smith III, the US deputy assistant secretary for international fisheries, reported that significant progress on key US priorities was made at the recent meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT). The national priorities included improving the science, management of fish stocks and their ecosystems, monitoring of fishing activities, and compliance. [NOAA News]
• Research into saving endangered sea turtles from toxic Gulf "red tides" funded -- NOAA recently awarded a monetary grant to a team of scientists and veterinarians from Florida Atlantic University, Harbor Branch Institute, Mote Marine Laboratory and Florida Fish and Wildlife Research Institute to determine how the "red tide" toxin, brevetoxin, affects the health of endangered sea turtles in the Gulf of Mexico. [NOAA News]
• Fisheries could be degraded by effects of climate change -- Researchers at the University of British Columbia have found that the changing climate can exert an impact upon the economic viability of current fisheries practices. Other factors that may unfavorably impact marine species include overfishing and pollution. [University of British Columbia]
• Invading shrimp could serve as food for Great Lakes fish -- Researchers at Ontario's Queens University have found that the blood red shrimp (called Hemimysis anomala), a recent invader into North America's Great Lakes, appears to have become a new food source for several native fish populations, allaying concerns about how this invading shrimp will impact the native fish populations. [Macleans Canada]
• Geosynchronous satellite is moved -- NOAA's GOES-15 satellite, which has been "parked" in a geosynchronous orbit since being launched in March 2011, is being moved westward to a position for it to become the nation's GOES West satellite, replacing the current GOES-11 satellite that will be retired soon. Visible satellite images taken by sensors onboard GOES-15 in early September and last week show the changing prospective of the North American continent during the move. [NOAA Environmental Visualization Laboratory]
• Lowering the freezing point of water -- Chemists at the University of Utah claim that they have determined that water could be cooled to a temperature as low as 55 degrees below zero Fahrenheit before it will absolutely freezes. At that temperature, the molecular structure of water changes physically liquid to "intermediate ice" to form tetrahedron shapes, with each water molecule loosely bonded to four others. The chemists claim that their research has applicability in climate models as a better estimate of atmospheric water could be obtained. [University of Utah]
• Carbon cycling in biosphere during last Ice Age appears smaller than today -- An international team of scientists recently presented their reconstruction of the plants’ productivity and the amount of carbon stored in the ocean and terrestrial biosphere during the Last Glacial Maximum (between 26,500 and 19,000 years ago), based in part by direct measurements of atmospheric carbon dioxide trapped in air bubbles obtained from ice cores taken from the Antarctic ice sheet. They have found that carbon cycling in the terrestrial biosphere appears to have been much smaller during the last Ice Age than in today’s climate. [University of Bristol]
• 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.

• 28 November 1520...Portuguese navigator Ferdinand Magellan reached the Pacific Ocean after passing through the treacherous South American strait that now bears his name in a 38-day passage. He was the first European to sail into the Pacific Ocean from the Atlantic to the east. (The History Channel)
• 28 November 1960...A severe storm produced waves 20 to 40 feet high on Lake Superior. Duluth, MN was buried under a foot of snow, and clocked wind gusts to 73 mph. The northern shore of Lake Superior was flooded, and property along the shore was battered. Thousands of cords of pulpwood were washed into Lake Superior, and up to three feet of water flooded the main street of Grand Marais. Thunder accompanied the "nor'easter". (David Ludlum) (The Weather Channel)
• 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)

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Prepared by AMS DS Ocean Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2011, The American Meteorological Society.