Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 20-24 April 2015

Item of Interest:

National Park Week -- The US Department of the Interior's National Park Service has designated the week commencing this week (18-26 April 2015) as National Park Week.
5th Grade Hurricane Webinar offered for Gulf Coast Region -- The Hurricanes: Science and Society (HSS) team at the University of Rhode Island in partnership with the NOAA National Hurricane Center (NHC) and the NOAA Aircraft Operations Center (AOC) is offering a Hurricane Webinar for 5th grade classes in the Gulf Coast Region this upcoming Tuesday morning, 21 April 2015. Additional Hurricane Webinars are planned in May for those in Southeast and Northeast regions of the nation. The purpose of these Hurricane Webinars is to raise awareness about hurricanes in advance of the 2015 North Atlantic hurricane season. Registration for this first webinar ends late Monday afternoon. [Hurricanes: Science and Society]
Celebrate Earth Day --This Wednesday (22 April 2015) marks the 45th Earth Day, first proposed by the late Senator Gaylord Nelson of Wisconsin in 1970 as a teach-in to heighten awareness of the environment. The Nelson Institute for Environmental Studies at the University of Wisconsin-Madison has posted a website called "Gaylord Nelson and Earth Day: The Making of the Modern Environmental Movement" that highlights Senator Nelson and his idea became Earth Day. Several governmental websites provides links to various activities and resources planned for this week, including a website maintained by the US Environmental Protection Agency (EPA). NASA also provides a list of live public events and online activities between 21 and 27 April designed to celebrate Earth Day.
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 --- During the last week several tropical cyclones were detected across the tropical waters of the Indian and Pacific Oceans in the Southern Hemisphere.

In the South Indian basin Cyclone Joalane, a category 2 tropical cyclone on the Saffir-Simpson Scale, continued its travel to the south before it weakened to a tropical storm and then became an extratropical cyclone (midlatitude storm) before dissipating early last week approximately 750 miles to the east-southeast of Port Louis, Mauritius. Satellite images and additional information on Cyclone Joalane are found on the NASA Hurricane Page.
In the western South Pacific basin Tropical Storm Solo passed over New Caledonia before dissipating at the start of last week. The NASA Hurricane Page has satellite images and additional information on Tropical Storm Solo.

The 2014 hurricane season reviewed -- The 2014 hurricane season in both the North Atlantic and North Pacific is reviewed and compared to the more than 150 years of record keeping in the North Atlantic and the 40 years in the eastern North Pacific. [AMS DataStreme Atmosphere]
Nation's fisheries continue rebuilding as overfishing declines -- In the 2014 Status of US Fisheries report that NOAA Fisheries made to the US Congress, the number of domestic fish stocks listed as overfished or subject to overfishing has dropped to an all-time low since 1997, the year when the tracking of stock status commenced by NOAA. The continued progress made toward sustainable maintenance of fish stocks is the result of the combined efforts of NOAA Fisheries, the regional fishery management councils, the fishing industry and other partners. [NOAA Fisheries News]
An example of one of the fish species that has been rebuilt since 2000 according to the NOAA Fisheries' 2014 Status of Stocks is the Gulf of Mexico gag grouper.[NOAA Fisheries Stories]
Seafloor mapping expedition concludes -- Scientists with NOAA's National Ocean Service recently completed an 11-day mission to the Caribbean onboard the NOAA Ship Nancy Foster in order to map undersea habitats around the Island of St. Croix. in the Caribbean, Using a remotely operated vehicle (ROV) to investigate the type of seafloor cover, the mission will produce the first high-resolution bathymetric and habitat maps of the area that include coral habitats used by valuable species of reef fish. [NOAA Fisheries Features]
Sunken WWII-era aircraft carrier remains "amazingly intact" off the California coast -- In a collaborative effort, NOAA, private industry partners and the US Navy have located and inspected the sunken remains of the USS Independence, a light aircraft carrier used during World War II that is located in 2600 feet of the waters of the eastern North Pacific off California's Farallon Islands. A 3-D sonar instrument on the Boeing Autonomous Underwater Vehicle (AUV) Echo Ranger made the archaeological survey of the ship, reporting that the hull and flight deck of the Independence is clearly visible and what appears to be a plane in the carrier's hangar bay. The ship had been scuttled in 1951. [NOAA National Marine Sanctuaries News]
A dozen years of satellite data help assess changes in climate -- The Atmospheric Infrared Sounder (AIRS) instrument onboard NASA's Aqua satellite has amassed 12 years of global temperature, greenhouse gas and cloud data that scientists have been using to assess how the atmosphere responds to changes from the short term such as El Niño Southern Oscillation (ENSO) events to long term climate trends. [NASA Global Climate Change News]
Large iceberg remains afloat off Antarctica for 15 years -- A natural-color image was made in mid January 2015 of the largest fragments of iceberg B-15 by the Operational Land Imager (OLI) onboard NASA's Landsat 8 satellite. This fragment, identified as B-15T, is floating off Antarctica's Princess Astrid Coast and has a size nearly equivalent to that of Connecticut. The original iceberg B-15 broke from Ross Ice Shelf in late March 2000. [NASA Earth Observatory]
Wind bursts can affect severity of El Niño events -- Scientists from the University of Maryland and their colleagues from Columbia University and China report that large-scale bursts in the westerly winds across the Tropical Pacific Ocean have a strong influence on El Niño events, which help produce three distinct varieties or "flavors" of El Niño. These westerly wind bursts that form over the western Pacific tend to be "intraseasonal," or at scales between weather and climate. Analyzing 50 years of tropical Pacific sea surface temperature and westerly wind burst data, differences in El Niño events. The researchers hope that new knowledge about detecting and measuring these wind bursts may help in the forecasting of El Niño events. [University of Maryland News]
Review of global weather and climate for March 2015 -- Using preliminary data collected from the global network of surface weather stations, scientists at NOAA's National Climatic Data Center have determined that the combined global land and ocean surface temperature for March 2015 was the highest for any March since sufficiently detailed global climate records began in 1880. The global temperature for March 2015 was 1.53 Fahrenheit degrees above the 20th century (1901-2000) average. When considered separately, the average land temperature tied 1990 as second highest for any March since 1880, while the temperature over the oceans was the third highest for March. El Niño conditions had developed in March with above average sea surface temperatures across the equatorial Pacific. In addition, the global temperature for the first three months of 2015 were also the highest on record.
The researchers at the National Snow and Ice Data Center noted the areal extent of the Arctic sea ice reached its annual maximum extent near the end of the third week of March. The areal extent of this sea ice for March 2015 was the smallest since satellite surveillance began in 1979. Conversely, the extent of the Antarctic sea ice was the second largest in the 37-season record. According to data from the Rutgers Global Snow Lab, the Northern Hemisphere snow cover extent for March was the seventh smallest in the 49-year period of record. [NOAA/NCDC State of the Climate] A global map of Selected Significant Climate Anomalies and Events for March 2015 is available from NCDC.
One day of rain causes flooding in "world's driest climate" -- A low pressure system moving onto the coast of central and northern Chile produced in late March produced one to two inches of rain in a 24-hour span on 25 March 2015 at several locations on the Atacama Desert, arguably the "world's driest climate." This high-altitude South American desert typically receives less than 0.2 inches of rain per year, while some locations claim no measurable rainfall in recorded human history. The recent rain caused flooding of Chile's Copiapó River that had been essentially dry for the last 17 years. Several cities sustained flood damage that claimed at least 24 lives. The combination of strong subtropical high pressure located over the eastern South Pacific Ocean and the cold Humboldt Current near the coast typically create a sufficiently stable atmosphere that limits precipitation across the region. This pattern was disrupted most likely by the current El Niño event, which resulted in the historic rains. [NOAA Climate.gov 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 -- 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

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:

20 April 1534...Jacques Cartier, a French explorer, set sail from St. Malo, France with two ships to explore the North American coastline in an attempt to find a passage to China. In this first voyage, he explored the Gulf of St. Lawrence.
20 April 1952...The tankers Esso Suez and Esso Greensboro collided in thick fog off the coast of Morgan City, LA. Only five of the Greensboro's crew survived after the ship burst into flame. (David Ludlum)
21 April 1910...The U.S. Government took over sealing operation of Alaska's Pribilof Islands in the Bering Sea from private lessees. (USCG Historian's Office)
21 April 1906...Commander Robert Peary, USN, discovered that the supposed Arctic Continent did not exist. (Naval Historical Center)
22 April 1500...Portuguese navigator Pedro Álvares Cabral became the first known European to sight Brazil, claiming it for Portugal. (Wikipedia)
23 April 1924...A tube transmitter for radio fog-signal stations, developed to take the place of the spark transmitters in use, was placed in service on the Ambrose Channel Lightship and proved successful. (USCG Historian's Office)
24 April 1884...USS Thetis, Bear, and Alert sailed from New York to search for Greeley expedition lost in the Arctic. (Naval Historical Center)
24 April 1928...The fathometer was patented by Herbert Grove Dorsey (No. 1,667,540). The invention measured underwater depths by using a series of electrical sounds and light signals. (Today in Science History)