Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 1-5 December 2014

Items of Interest:

Beginning of meteorological winter season -- The winter meteorological season in the Northern Hemisphere starts on Monday (1 December). Recall that climatologists and meteorologists have elected to use a standard three-month grouping to identify each meteorological season. Hence, the months of December, January and February are considered the winter meteorological season. You will note that the winter solstice, marking the day where the length of daylight is least in the Northern Hemisphere is still three weeks away, falling on Sunday, 21 December 2014. Since the lowest temperatures typically fall in mid to late January, the meteorological winter tends to be centered on the coldest time of the year in the Northern Hemisphere.
In addition, this past Sunday marked the end of the official 2014 hurricane seasons in the North Atlantic, which includes the Gulf of Mexico and the Caribbean, along with the eastern and central North Pacific basins.
The 2014 hurricane seasons reviewed -- With the end of the official 2014 hurricane season in both the North Atlantic and North Pacific on Sunday (30 November 2014), a quick review of this year's tropical cyclone statistics for the official 2014 hurricane season has been made for both basins. [AMS DataStreme Atmosphere] Additional information is available from NOAA News.
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 2013. 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.
It's Sure Dark! -- Have you noticed that the sun is setting early these days? During the first ten days of December, many locations throughout the country will experience their earliest sunset times of the year. The exact day for the earliest sunset depends upon the latitude, so you may want to check the date in your locale from the sunrise tables appearing in an on-line, interactive service available for the entire year at most cities in the United States. The reason for the earliest sunsets occurring in early December rather than on the winter solstice (during the morning hours of Sunday, 21 December 2014) is that the sun is not as precise a timekeeper as our watches. Because of a combination of factors involved with Earth's elliptical orbit about the sun and the tilt of Earth's spin axis with respect to the plane of the ecliptic, the sun appears to "run fast" by as much as 15 minutes as compared with clock time in November. However, with the approach of the winter solstice and perihelion (the smallest earth-sun distance during the early morning of 4 January 2015), the apparent sun slows during December and finally lags the clock by 12 minutes in February. Consequently, a noticeable and welcome trend toward later sunsets can be detected by the end of December, especially by those residents in the northern part of the country. However, the latest sunrises occur at most locales in early January, meaning that early risers will continue seeing dark and dreary mornings for another month.
SKYWARN™ recognition -- Next Saturday 6 December 2014 (starting at 00Z or 7:00 EST PM on Friday night) has been declared SKYWARN™ Recognition Day, a day in which the National Weather Service and the American Radio Relay League celebrate the contributions made by volunteer SKYWARN™ radio operators during the past year's Severe Weather Operations.
Accessing and interpreting climate data -- If you would like to obtain a variety of climate data for your home town or state that are available from the National Weather Service, please read this week's Supplemental Information...In Greater Depth. This Supplemental not only identifies some of the sites to find the data, but also provides you with a brief explanation of the terminology used to identify the climate data.

Ocean in the News:

Eye on the tropics --- No tropical cyclone activity was reported across either the North Atlantic and eastern North Pacific basins during the last week as the official hurricane seasons in both basins drew to a close. Elsewhere, tropical cyclone activity was relatively light last week across the other world's tropical ocean basins:

In the western North Pacific Ocean basin, the twentieth tropical depression of 2014 formed early last week over the Philippine Sea off the eastern coast of the island of Mindanao in the southern Philippines. Moving toward the west-northwest across the southern Philippine islands, this tropical depression strengthened to become Tropical Storm Sinlaku over the warm waters of the South China Sea. Sinlaku made landfall along the central coast of Vietnam north of Quang Ngai over the past weekend, followed by a rapid weakening. The NASA Hurricane Page has more information and satellite images for Tropical Storm Sinlaku.
In the South Indian Ocean basin, Tropical Storm 2S formed late last week to the northeast of Mauritius and Reunion Islands. This tropical storm traveled to the southwest toward these islands over this past weekend. Satellite imagery and additional information are available on the NASA Hurricane Page for Tropical Storm 2S.

Australian tropical cyclone season outlook issued -- Forecasters at the Australian Government's Bureau of Meteorology recently released an outlook for the upcoming 2014-15 Australian tropical cyclone season that typically begins in November and runs through April. These forecasters foresee average to below average tropical cyclone activity in the five regions that surround that continent. Their outlook is based upon the appearance of El Niño-like conditions across the tropical Pacific Ocean and climate models suggest the possibility of a weak El Niño event before the end of 2014. Typically, the waters around Australia experience fewer tropical cyclones during El Niño events and few of these systems make landfall on the continent. [Australian Bureau of Meteorology]
New aquaculture projects receive NOAA Sea Grant awards -- Early last week officials with NOAA Sea Grant announced that 15 projects would be awarded new grants totaling $2.6 million to support development of environmentally and economically sustainable ocean, coastal, or Great Lakes aquaculture. [NOAA Office of Oceanic and Atmospheric Research News]
NOAA's contributions to aquaculture are highlighted -- The November 2014 issue of the American Fisheries Society's "Fisheries" magazine highlighted the contributions of NOAA Fisheries to the progress in aquaculture across the nation. [NOAA Fisheries]
Satellite tracks movement of large Antarctic iceberg -- An image made within the last two weeks by the MODIS sensor on NASA's Aqua satellite shows the massive iceberg B31 as it drifts toward the west across the Amundsen Sea. This iceberg had separated from Antarctica's Pine Island Glacier one year ago and began drifting across Pine Island Bay. This B31 iceberg is 33 kilometers long and 20 kilometers wide. [NASA Earth Observatory]
First 3-D images of underside of Antarctic sea ice made by robotic underwater vehicle -- Researchers from the United States, Australia and the United Kingdom recently have produced high-resolution, three-dimensional maps of the underside of Antarctic sea ice using data collected by the autonomous underwater vehicle (AUV) called "SeaBED." This vehicle measured and mapped the underside of sea-ice floes in three previously inaccessible areas off the Antarctic Peninsula at depths ranging between 20 and 30 meters. AUVs like the SeaBED are expected to serve as powerful tools for studying future changes in sea-ice extent.[National Science Foundation News]
Five new NASA field campaigns to tackle climate issues in 2015 -- NASA is planning on conducting five new airborne field campaigns during 2015 that are designed to investigate several issues that could affect the Earth's climate. These five selected campaigns are part of NASA's Earth Venture-class projects are:

Melting Greenland glaciers – intended to investigate the role of warmer, saltier Atlantic subsurface waters in Greenland glacier melting, which should help improve estimates of future sea level rise by observing changes in glacier melting where ice contacts seawater.
Atmospheric chemistry and air pollution – designed to study the impact of human-produced air pollution on certain greenhouse gases.
Ecosystem changes in a warming ocean – aimed at improving predictions of how ocean ecosystems would change with ocean warming by studying the annual life cycle of phytoplankton and the impact small airborne particles derived from marine organisms have on climate in the North Atlantic.
Greenhouse gas sources – designed to quantify the sources of regional carbon dioxide, methane and other gases, as well as to document how weather systems transport these gases in the atmosphere.
African fires and Atlantic clouds – intended to probe how smoke particles from massive biomass burning in Africa influences cloud cover over the Atlantic.

NASA Jet Propulsion Laboratory

Strengthening El Niño events during the Holocene-- A team of researchers from the United States and China running climate models on computers at the National Center for Atmospheric Research has found that El Niño events have intensified during the late Holocene or over the last 6000 years. These climate models examined the large-scale influences such as changes in atmospheric carbon dioxide, ice sheet melting and Earth's orbital changes that could affect the strength of El Niño events over the last 21,000 years. The intensification of the El Niño events appears to be related to increased global temperatures, with the feedbacks between ocean and atmosphere involving surface winds having grown stronger. The computer simulations appear to corroborate observational data obtained from historical sediments off the Central American coast and from change in fossil coral. [University of Wisconsin-Madison News]
An All-Hazards Monitor -- This Web portal provides the user information from NOAA's National Weather Service, FAA and FEMA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [NOAA/NWS Daily Briefing]
Earthweek --

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

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

Historical Events:

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)
6 December 1830...The US Naval Observatory, the first U.S. national observatory, established as the Depot of Charts and Instruments in Washington, DC, under commander of Lieutenant Louis Malesherbes Goldsborough. Its primary mission was to care for the U.S. Navy's chronometers, charts and other navigational equipment. (Naval Historical Center)
7-8 December 1703...A monstrous storm raked southern England and adjacent waters with winds in excess of 100 mph. Approximately 8000 deaths were the result of this storm, mostly at sea. Many naval and supply ships were anchored in harbors or in the English Channel. The Eddystone Lighthouse disappeared. (Accord Weather Guide Calendar)
7 December 1872...An expedition put to sea from Sheerness aboard the corvette H.M.S. Challenger under the command of Captain George Nares on a 3 1/2-year world oceanographic cruise. During the 68,890 nautical mile cruise that ended on 24 May 1876, the ship traversed the North and South Atlantic and Pacific Oceans, traveled north of the limits of drift ice in the North Atlantic polar seas and south of the Antarctic Circle. The scientists onboard the Challenger sounded the ocean bottom to a depth of 26,850-ft, found many new species, and provided collections for scores of biologists. (Today in Science History)
7 December 1932...The first gyro-stabilized vessel to cross the Atlantic, the Conte di Savoia of the Italian Line, arrived in New York City. The ship had 48,502 gross tons, an overall length 814.6 ft by beam 96.1 ft, two funnels, two masts, four screws and a speed of 27 knots. As one of the first ships to be fitted with gyrostabilizers, it was claimed that rolling was limited to a maximum of three degrees. The maiden voyage began from Genoa to Villefranche and New York on 30 November 1932. (Today in Science History)