Weekly Ocean News

WEEKLY OCEAN NEWS

WEEK SIX: 6-10 March 2017

For Your Information

Tracking the lunar shadow on Earth from space -- Instruments onboard several Earth-orbiting satellites were able to track the path of the Moon's shadow as it raced across the South America and the South Atlantic Ocean on Sunday, 26 February 2017, as part of the annular solar eclipse. The images obtained from the EPIC (Earth Polychromatic Imaging Camera) instrument onboard NOAA's Deep Space Climate Observatory (DSCOVR) satellite were pieced together to form an animation. The DSCOR satellite is located approximately one million miles from Earth at the L1 point, a neutral gravity point between Earth and the Sun. A similar animation, but with more detail, was made from the assembling of images from the MODIS instruments on NASA's Terra and Aqua satellites and the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the NASA/NOAA Suomi NPP satellite. These three satellites are in a low-altitude polar orbit with an altitude above Earth of approximately 440-500 miles. The Earth-Sun geometry of the annular solar eclipse created a red-orange ring (or "Ring of Fire") on the satellite images because the Earth was not able to obscure all of the Sun, even at the height of the eclipse. [NASA Earth Observatory]
Time change -- Daylight Saving Time will go into effect next Sunday morning (12 March 2017) for essentially the entire nation -- the exceptions include Arizona, Hawaii, Puerto Rico and about 18 counties in Indiana. These changes have been mandated by the U.S. Congress in the Energy Policy Act of 2005, which extended Daylight Saving Time across the nation, with the start on the second Sunday in March and end on the first Sunday in November (5 November 2017). In other words, following the old adage of "spring ahead, fall behind", you will need to turn your clocks ahead by one hour to conform with the local time observance. Most of Canada also observes Daylight Saving Time changes at the same time [National Research Council Canada].
What does this time change mean to you (other than later sunsets)? Contrary to a popular belief that has surfaced at times, the change from Standard to Daylight Saving Time does not add an extra hour of daylight to the day nor does it affect weather patterns. While the weather will not change because of the time change, the times when you will be able to obtain weather charts will now be one hour later. The reason is that the National Weather Service operates on "Z time" (variously called Greenwich Mean Time or Universal Coordinated Time) which does not observe Daylight Saving Time, and the charts are still produced and transmitted at the same Z time.
A Reminder -- Next week (beginning Monday, 13 March 2017) is Spring vacation week for DataStreme Ocean. All the familiar DataStreme Ocean products will be available throughout the week. The Investigation and Supplemental Information files from this week will remain on the RealTime Ocean Portal and the Concept of the Week will be repeated for those who are on spring break. If you have questions, check with your mentor.
Biomixing in ocean motion -- If you would like information on recent findings that indicate marine organisms contribute to motion in the ocean, please read this week's Supplemental Information…In Greater Depth.

Ocean in the News

Eye on the tropics --- Although meteorological summer in the Southern Hemisphere (December, January and February) has drawn to a close, tropical cyclone activity was limited to the western South Indian Ocean basin during the last week. The ninth named tropical cyclone of the 2016-17 season in the South Indian Ocean formed at the end of last week approximately 500 miles north of Port Louis, Mauritius. This system, which initially had tropical-storm force winds (maximum sustained surface winds of 39 to 74 mph), was named Tropical Cyclone 9S and then it intensified to become a category 1 tropical cyclone on the Saffir-Simpson Scale (winds in excess of 74 mph) that was called Cyclone Enawo. Travel was toward the west-southwest. As of Sunday afternoon (local time), Cyclone Enawo was located 460 miles north of Port Louis. Enawo was forecast to strengthen as it would continue traveling toward the west-southwest and then to the southwest, making an anticipated landfall on the eastern coast of Madagascar early Wednesday. Landfall should result in dissipation as this cyclone would interact with the high terrain of this island. The NASA Hurricane Page has additional information and a satellite image on Cyclone Enawo.
Over the past weekend, Tropical Storm Blanche formed over the waters of the Joseph Bonaparte Gulf in the eastern section of the South Indian Ocean basin off the coast of the Northern Territory of Australia and Western Australia. As of late Sunday (local time), Blanche was located approximately 145 miles to the west-southwest of Darwin, Northern Territory of Australia, taking a track that was toward the southwest. With a projected track that would remain toward the southwest, Blanche was expected to make landfall north of Wyndham along the northeast coast of the Kimberley region of Western Australia on Monday, followed by rapid dissipation.
Public input solicited for proposed marine sanctuary in Maryland -- NOAA's Office of National Marine Sanctuaries is inviting the public to two public meetings in suburban Maryland during this upcoming week that will provide information and gather public input on the proposed Mallows Bay National Marine Sanctuary. This new sanctuary would be along the tidal Potomac River in Maryland where more than 100 known remains of vessels built during World War I reside. [NOAA News]
Impact of Olympic Coast National Marine Sanctuary upon Washington state's economy is assessed -- A recent analysis conducted by NOAA's Office of National Marine Sanctuaries and partners reveals that visitors to NOAA's Olympic Coast National Marine Sanctuary along the Pacific coastal waters of Washington's Olympic Peninsula has generated "significant economic revenues to coastal economies." Using data for 2014, visitors coming to the region for various recreational activities boosted the region's economy with $102 million in spending and generated $46 million in local income for businesses. In addition the money helped support nearly 1200 jobs. Furthermore, 41 percent of Washington state households visited the Outer Coast region. [NOAA News]
List of lessons learned in restoring coastal habitat is provided -- With 25 years of experience in habitat restoration, the NOAA's Restoration Center has made available a list of six of the most interesting lessons that the center learned over the years as it restored more than 130,000 acres of habitat, including marshes, wetlands, rivers and barrier islands. [NOAA Stories]
Funding is available for research into finding bycatch solutions -- The National Marine Fisheries Service has announced that it is currently accepting applications for its Bycatch Reduction Engineering Program in support of its goal to find creative approaches and strategies for preventing and reducing bycatch, which occurs occurs when fishing operations discard fish or interact with marine mammals, seabirds, or sea turtles. Full applications are due at the end of this month of March 2017. [NOAA Fisheries]
Importance of the "MJO" to large-scale precipitation patterns is assessed -- A tropical climate expert at the North Carolina Institute for Climate Studies wrote a feature for the Beyond the Data blog that describes how a large eastward moving pattern called the "Madden-Julian Oscillation" or MJO affects the precipitation patterns not only in the tropics, but also in midlatitudes. Unlike ENSO patterns that are generally fixed in the tropics for months, the MJO with its enhanced convective phase and suppressed convective phase traverses the Earth from west to east in the tropics, returning to its initial starting point in 30 to 60 days, on average. Emphasis is placed upon recent cloud and wind patterns and their relationship to the MJO. [Editor's note: The reference to butterflies in the beginning of this blog is to the "butterfly effect" that was proposed by the famous theoretical meteorologist, Dr. Edward Lorenz, approximately 55 years ago when he suggested that the flap of a butterfly's wings might ultimately cause a tornado in reference to the slight changes in some of the data being entered as initial conditions in a numerical weather prediction model resulted in drastically different output results. EJH] [NOAA Climate.gov News]
New forecast model using satellite data is intended to improve forecasts of summer Arctic sea ice -- Researchers at NASA's Goddard Space Flight Center have developed a new forecast model that utilizes satellite measurements of Arctic sea ice extent and melt onset, or the time at which sea ice starts melting and open water appears. This new model, which will be run this spring, is intended to help forecasters make better estimates of the summer ice across various sections of the Arctic Ocean, such as in the Beaufort and Chukchi Seas to the north of Alaska. In addition, the scientists should be able to use their predictions of sea ice minimum extent to assess changing climate conditions in the arctic. [NASA Goddard Space Flight Center Feature]
Nuisance flooding from smaller storms and climate change could be more costly over time than extreme, infrequent events -- Researchers at the University of California Irvine claim that rising sea levels associated with changing climate will cause relatively small storms to cause increasingly more frequent nuisance flooding in the future. They argue that a cumulative effect of these smaller events could exceed the catastrophic and more infrequent extreme events such as Hurricane Katrina or Superstorm Sandy. The researchers based their conclusions on their analysis of the likelihood of exceedances above mean higher high water and the corresponding property value exposure for minor, major, and extreme coastal floods in 11 coastal cities in the US. They proposed a Cumulative Hazard Index (CHI) that would serve as a tool for framing the future cumulative impact of low cost incidents relative to infrequent extreme events. [University of California Irvine News]
Record high temperature in Antarctica is finally recognized -- During the last week the World Meteorological Organization (WMO) announced that after evaluation by an international committee of polar scientists, a new record high temperature for the entire continent of Antarctica and its surrounding islands is recognized. This new record high temperature of 63.5 degrees Fahrenheit was observed at an Argentine Esperanza Research Station on 24 March 2015, eclipsing the previous record high of 59 degrees. The official WMO recognition of this record high temperature appears on their World Weather & Climate Extremes Archive website maintained by Arizona State University. [Science Daily]
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]

Concept of the Week: Abyssal Storms

Until recently, ocean scientists thought of the deep ocean abyss as a dark and cold, but serene place where small particles rained gently onto the ocean floor. However, instruments lowered to the sea floor to measure ocean motion or currents and resulting mobilization of bottom sediments detected a much more active environment. Scientists found that bottom currents and abyssal storms occasionally scour the ocean bottom, generating moving clouds of suspended sediment. A surface current of 5 knots (250 cm/sec) is considered relatively strong. A bottom current of 1 knot (50 cm/sec) is ripping. Although this may be called an abyssal storm, the water motion pales by comparison to wind speeds in atmospheric storms.

Abyssal currents and storms apparently derive their energy from surface ocean currents. Wind-driven surface ocean currents flow about the margins of the ocean basins as gyres centered near 30 degrees latitude. (Refer to Figure 6.6 in your textbook.) Viewed from above, these subtropical gyres rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. For reasons given in Chapter 6 of your textbook and this week's Supplemental Information, surface currents flow faster, are narrower, and extend to greater depths on the western arm of the gyres. These are known as western boundary currents and include, for example, the Gulf Stream of the North Atlantic basin. Abyssal currents are also most vigorous on the western side of the ocean basins, moving along the base of the continental rise, which is on the order of several kilometers deep.

Abyssal storms may be linked to or may actually be eddies (rings) that occasionally break off from the main current of the Gulf Stream (and other western boundary currents). During an abyssal storm, the eddy or ring may actually reach to the bottom of the ocean where the velocity of a bottom current increases ten-fold to about 1.5 km (1 mi) per hr. While that is an unimpressive wind speed, water is much denser than air so that its erosive and sediment-transport capacity is significant even at 1.5 km per hr. At this higher speed, the suspended sediment load in the bottom current increases by a factor of ten. Abyssal storms scour the sea floor leaving behind long furrows in the sediment. After a few days to a few weeks, the current weakens or the eddy (ring) is reabsorbed into the main surface circulation and the suspended load settles to the ocean floor. In this way, abyssal storms can transport tons of sediment long distances, disrupting the orderly sequence of layers of deep-sea sediments. Scientists must take this disruption into account when interpreting the environmental significance of deep-sea sediment cores.

Concept of the Week: Questions

(Place your responses on the Chapter Progress Response Form provided in the Study Guide.)

In the subtropical ocean gyres, boundary currents flow faster on the [(western)(eastern)] side of an ocean basin.
Currents in an abyssal storm erode, transport, and redeposit sediments that have accumulated on the [(continental shelf)(deep ocean bottom)].

Historical Events

6 March 1521...The Portuguese explorer Ferdinand Magellan reached Guam in his around the world voyage. (Wikipedia)
6 March 1987...The British ferry Herald of Free Enterprise capsized in the English Channel off the coast of Belgium with the loss of 189 people.
6 March 1962...The strongest nor'easter of the 20th century struck the Mid-Atlantic Region between the 5th and 9th. It is known as the "Ash Wednesday Storm" and caused over $200 million (1962 dollars) in property damage and major coastal erosion from North Carolina to Long Island, New York. In New Jersey alone, it was estimated to have destroyed or greatly damaged 45,000 homes. The Red Cross recorded that the storm killed 40 people. It hit during "Spring Tide." When the sun and moon are in phase, they produce a higher than normal astronomical tide. Water reached nine feet at Norfolk (flooding begins around five feet). Houses were toppled into the ocean and boardwalks were broken and twisted. The islands of Chincoteague and Assateague, Maryland were completely underwater. Ocean City, Maryland sustained major damage especially to the south end of the island. Winds up to 70 mph built 40-foot waves at sea. Heavy snow fell in the Appalachian Mountains. (National Weather Service files)
6 March 2014... The Great Lakes saw some of their worst ice cover in nearly four decades because of a frigid winter with months of below-freezing temperatures in large sections of the northern United States, the National Ocean and Atmospheric Administration said. As of 6 March 2014, 92.2 percent of the five lakes were under ice, breaking a record set in 1973 but still short of the 94.7 percent set in 1979, the federal agency said. (National Weather Service files)
7 March 1778...Captain James Cook first sighted the Oregon coast, at Yaquina Bay near present-day Newport.
7 March 1932...A severe coastal storm set barometric pressure records from Virginia to New England. Block Island, RI reported a barometric pressure reading of 955.0 millibars (28.20 inches of mercury). (David Ludlum)
7 March 1962... A powerful nor'easter lingered just off the mid-Atlantic coast for three days, resulting in severe damage along the ocean shore of the Delmarva Peninsula. Forty people were killed, and the few homesteads that were on the outer islands were destroyed. (National Weather Service files)
9 March 1454...Amerigo Vespucci, the Italian navigator, was born in Florence, Italy. The North and South American continents were named in his honor by Matthias Ringmann, a German mapmaker.
9 March 1995...The Canadian Navy arrested a Spanish trawler for illegally fishing off Newfoundland.
10 March 1496...Christopher Columbus concluded his second visit to the Western Hemisphere when he left Hispaniola for Spain. (Wikipedia)
9 March 1957...An earthquake measuring a magnitude 8.6 struck the Aleutian Islands of Alaska. A Pacific-wide tsunami was generated that caused $5 million dollars of damage in Hawaii, but fortunately, no lives were lost. Hardest hit was the island of Kauai, where houses were damaged and roads washed away. Waves reached 52.5 feet high at Haena, HI. (National Weather Service files)
10 March 1849...Abraham Lincoln applied for a patent for a device to lift vessels over shoals by means of inflated cylinders.
11 March 2002...The National Ice Center reported that satellite images indicated that an iceberg with an area larger than the state of Delaware had calved from the Thwaites Ice Tongue, a region of snow and glacial ice extending from the Antarctic mainland into the South Amundsen Sea. (Accord's Weather Guide Calendar)