Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK TWELVE: 21-25 April 2014

Item of Interest:

National Park Week -- The US Department of the Interior's National Park Service has designated the week commencing this week (19-27 April 2014) as National Park Week. The focus for this year's observance is "Go Wild!!"
Celebrate Earth Day --This Tuesday (22 April 2014) marks the 44th 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, including the NASA #GlobalSelfie Event where people from around the world would go outside on Tuesday and post a "selfie."
Casting a vote for NOAA Climate.gov -- NOAA' climate website called NOAA Climate.gov has been nominated by the International Academy of the Digital Arts & Sciences as one of five nominees for the 18th Annual Webby Awards for online excellence. This website has been nominated in both the "Government" and "Green" categories. Therefore NOAA Climate.gov is inviting anyone who enjoys this website to vote for Climate.gov in the Government category or the "Teaching Climate" in the Green category no later than Thursday, 24 April. [NOAA Climate.gov News]
National Science Bowl set for next weekend -- The US Department of Energy (DOE) National Science Bowl®, a nationwide academic competition for middle and high school students will be held this coming weekend (24-28 April 2014) in Washington, DC. This event will test students' knowledge in all areas of science and is meant to encourage high school students to excel in science and math and to pursue careers in those fields. [DOE Office of Science]
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 tropical cyclone activity was limited to the Indian and the western Pacific basins of the Southern Hemisphere:.

In the South Indian basin a tropical storm formed to the west-northwest of the Cocos Islands near the end of last week. Initially moving toward the west, this system became Cyclone Jack as it turned southward. By Sunday (local time) Jack had intensified to a category 2 tropical cyclone on the Saffir-Simpson Scale. Forecasts indicate that Jack should weaken to a tropical storm as it would travel toward the south-southeast during the first half of this current week.
In the western South Pacific basin Cyclone Ita weakened to become a tropical storm at the beginning of last week before loosing its tropical characteristics as it traveled to the southeast over the Coral Sea off the coast of Queensland in northeastern Australia. Ita had been a major category 4 tropical cyclone on the Saffir-Simpson Scale over the previous weekend. Flooding and strong winds resulted in major damage to agriculture coastal areas of Queensland and then later to parts of New Zealand as remnants of Ita approached. Consult the NASA Hurricane Page for satellite images and additional information on the Cyclone Ita.

The 2013 hurricane season reviewed -- The 2013 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]
Proposal for expansion of national marine sanctuaries along northern California coast released -- During the last week NOAA's Office of National Marine Sanctuaries released a proposal that would expand the boundaries of the Gulf of the Farallones and the Cordell Bank National Marine Sanctuaries in the waters of the Pacific located off the north-central California coast. The agency is inviting public comments on the proposal through the end of June. [NOAA National Marine Sanctuaries News]
"Water World" theory of life's origins outlined -- Researchers at NASA's Jet Propulsion Laboratory and the Icy Worlds team at NASA's Astrobiology Institute based at NASA's Ames Research Center have recently provided a description of how electrical energy naturally produced at the sea floor might have given rise to life on ancient Earth at least four billion years ago. Their "water world" theory, which is based upon field and theoretical research, suggests that early life may have begun inside warm, gentle springs on the sea floor of an early planet that had expansive oceans. [NASA Jet Propulsion Laboratory]
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, drought, floods, marine weather, tsunamis, rip currents, Harmful Algal Blooms (HABs) and coral bleaching. [NOAAWatch]
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:

21 April 1910...The U.S. Government took over sealing operation of 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)
27 April 1521...The Portuguese navigator Ferdinand Magellan was killed by natives during a tribal skirmish on Mactan Island in the Philippines after completing nearly three-quarters of a trip around the world. One of his ships, the Victoria, under the command of the Basque navigator Juan Sebastiýn de Elcano, continued west to arrive at Seville, Spain on 9 September 1522, the first ship to circumnavigate the globe. (The History Channel)