Weekly Ocean News

15-19 October 2018

For Your Information

Hurricane Michael was a historic hurricane on several counts -- This past Wednesday, Hurricane Michael made landfall as an unprecedented high-end Category 4 hurricane (on the Saffir-Simpson Scale) along the Florida Panhandle region with a preliminary estimated maximum sustained wind speed of 155 mph at landfall and a minimum air pressure of 919 mb (27.14 inches of mercury).
In terms of central barometric pressure, Michael was the third most powerful hurricane to strike the U.S. mainland, ranked behind the unnamed Labor Day Hurricane of September 1935 (892 mb) and Hurricane Camille (900 mb) in August 1969. However, Michael's central pressure was the lowest on record for any October hurricane to strike the United States.
In terms of maximum sustained wind speed at landfall, Michael was the fourth strongest, behind the Labor Day 1935 hurricane (184 mph), Hurricane Camille (172 mph) and Hurricane Andrew in 1992 (167 mph). Michael is the first Category 4 hurricane on record to make landfall on the Florida Panhandle. [National Weather Service Tallahassee (FL) Office] [Washington Post]
NASA's Terra satellite reaches a milestone -- On Saturday, 6 October 2018, NASA's Terra satellite had completed 100,000 orbits around planet Earth after being launched on 18 December 1999. The Terra satellite, which is an orbit approximately 400 miles above the Earth's surface, has five onboard scientific instruments that provide observations of the planet: The Advanced Spaceborne Thermal Emission and Reflection (ASTER) instrument; the Moderate Imaging Spectroradiometer (MODIS); Multi-angle Imaging Spectroradiometer (MISR); Measurements of Pollution in the Troposphere (MOPITT); and the Clouds and Earth's Radiant Energy System (CERES). [NASA Goddard Space Flight Center Feature]
Celebrate Earth Science Week 2018 -- The National Oceanic and Atmospheric Administration, including the National Weather Service, along with NASA, the US Geological Survey and several professional scientific organizations such as the American Geological Institute have recognized this week (14-20 October 2018) as Earth Science Week 2018 to help the public gain a better understanding and appreciation for the earth sciences and to encourage stewardship of the Earth. This year's theme for the 21th annual Earth Science Week is “Earth as Inspiration” that is designed to "emphasize artistic expression as a unique, powerful opportunity for geoscience education and understanding in the 21st century." [American Geological Institute]
Observe Earth Observation Day -- On Tuesday 16 October 2018, Earth Observation Day (EOD) will be observed as a celebration of the NASA/USGS (US Geological Survey) Landsat mission. EOD is a Science, Technology, Engineering, and Mathematics (STEM) educational outreach event sponsored by AmericaView, a nationwide, university-based, and state-implemented consortium, and its partners. The goal of EOD is to engage students and teachers in remote sensing as an exciting and powerful educational tool. Lesson plans and educational resources for educators and students are available from the EOD website. [AmericaView]
International ShakeOut Day -- This Thursday, 18 October 2018, has been designated International ShakeOut Day, in which people and organizations around the world are encouraged to practice "Drop, Cover, and Hold On" to reduce injury and death during earthquakes. Some coastal states including California and Washington are providing information on how to evacuate, survive and recover from tsunamis that could be generated along the coast by the earthquakes.
Oceanographic expeditions that made an impact -- This week's Supplemental Information ... In Greater Depth provides a historical perspective of some of the oceanographic expeditions that made an impact upon science, especially in terms of oceanography.

Ocean in the News

Eye on the tropics -- Tropical cyclone activity was reported last week in the Atlantic, eastern Pacific and Indian Ocean basins of the Northern Hemisphere:

In the North Atlantic Basin (that also includes the Caribbean Sea and Gulf of Mexico):
- Tropical Storm Michael continued to strengthen rapidly at the start of last week as it traveled northward from the western Caribbean and through the Yucatan Channel. By sunrise last Monday morning, Michael was a high-end tropical storm that was headed to the north and was approximately 70 miles to south of the western tip of Cuba. By late Monday morning, Michael had become the seventh Atlantic hurricane of 2018 as maximum sustained surface winds reached 75 mph. Continuing toward the north and then north-northwest across the Gulf of Mexico on Monday and Tuesday, Michael became a major category 3 hurricane (on the Saffir-Simpson Scale) late Tuesday afternoon as its central eye was 470 miles to the south of Panama City, FL. At this time, maximum sustained surface winds were determined to be 120 mph, making Michael the second major hurricane of the 2018 Atlantic hurricane season. By early Wednesday morning, Air Force Reserve and NOAA Hurricane Hunter aircraft had collected data indicating that maximum sustained winds have increased to 130 mph with higher gusts, meaning that Michael had become an extremely dangerous category 4 hurricane as it continued to head to the north toward the Florida Panhandle. Michael continued to strengthen as it took a track toward the north-northeast, making landfall early Wednesday afternoon near Mexico Beach, FL with maximum sustained winds determined to be 155 mph, just shy of the 157-mph threshold for category 5 hurricanes. At that time, the minimum central pressure was 919 mb. The hurricane-force winds, the life-threatening storm surge and the torrential rains that accompanied Hurricane Michael caused widespread and extensive damage to the Florida Panhandle, especially from Panama City Beach eastward to past Apalachicola. After making landfall, Michael traveled toward the northeast across the Florida Panhandle and southern Georgia as a hurricane before weakening to a tropical storm early Thursday morning as its center was approximately 30 miles to the south-southwest of Macon, GA. Continuing to the northeast, this tropical storm traveled across eastern Georgia, and the Carolinas on Thursday. By early Friday morning, Michael was losing its tropical characteristics as it crossed southeastern Virginia and moved out over the waters of the North Atlantic offshore of Norfolk, VA. Michael began re-strengthening as it became an extratropical cyclone during the morning. Consult the NASA Hurricane Blog Page for more information and satellite images on Hurricane Michael. As of last Friday, damage estimates in the United States were believed to have exceeded $8 billion. At least 18 were killed in Florida, Georgia, North Carolina and Virginia because of Hurricane Michael.
- Tropical Storm Leslie, which had reached hurricane status during the week before last, was traveling to the east-southeast across the central North Atlantic at the start of this past week. As of last Monday morning, Leslie was located nearly 1000 miles to the east-southeast of Bermuda. Leslie continued to strengthen as it traveled toward the southeast on Tuesday, becoming a hurricane for a second time by early Wednesday morning as it was located approximately 1070 miles to the east-southeast of the Azores. After traveling toward the south-southeast on Wednesday, Leslie turned toward the east-northeast by early Thursday. On Friday, Hurricane Leslie passed to the south of the Azores and near the Madeira Archipelago. Continuing to head toward the east-northeast, Leslie began weakening on Saturday, as it approached the Iberian Peninsula as a minimal hurricane. However, before making landfall on Saturday evening, Leslie had lost its tropical characteristics, transitioning into a strong extratropical cyclone approximately 120 miles to the west-northwest of Lisbon, Portugal. Strong winds, high surf and torrential rain accompanying Leslie spread across the Iberian Peninsula over this past weekend. The NASA Hurricane Blog Page has satellite images and additional information on Hurricane Leslie.
- A tropical depression formed on Tuesday morning approximately 475 miles to the southwest of the southernmost of the Cabo Verde Islands. Traveling toward the west-northwest, this tropical depression became Tropical Storm Nadine on Tuesday afternoon, the fourteenth named tropical cyclone of 2018 in the Atlantic basin. Nadine strengthened as it traveled generally toward the northwest over the next day, reaching maximum strength by Wednesday afternoon and evening as this small tropical storm was at least 600 miles to the west of the Cabo Verde Islands. Continuing toward the northwest and then west-northwest, Nadine began weakening and becoming disorganized on Thursday. During the predawn hours of Friday morning, became a remnant low as it was approximately 1000 miles to the west of the southernmost Cabo Verde Islands. Additional information and satellite images for Tropical Storm Nadine are available on the NASA Hurricane Blog Page.
In the eastern North Pacific basin (east of the 140-degree West meridian of longitude):
- Hurricane Sergio was drifting across the waters of the eastern Pacific last Monday morning, approximately 1300 miles to the west-southwest of Cabo San Lucas at the southern tip of Mexico's Baja California Peninsula. After accelerating toward the northeast, Sergio weakened to a tropical storm on Tuesday afternoon. Over the next two days, Sergio continued on a track toward the northeast. Early Friday morning, Tropical Storm Sergio made landfall along the coast of Mexico's Baja California Sur, approximately 125 miles to the southwest of Santa Rosalia, Mexico. Traveling to the northeast across the Baja California Peninsula, Sergio weakened rapidly. Tropical Storm Sergio moved out over the Sea of Cortez on Friday morning, before weakening into a tropical depression during the midday hours. As of Friday afternoon, Tropical Depression Sergio had degenerated into a remnant low over northwestern Mexico, approximately 100 miles to the northeast of Guaymas, in the Mexican state of Sonora. Locally heavy rains accompanying Sergio spread across northwestern Mexico, as well as into Arizona and New Mexico. The NASA Hurricane Blog Page has additional information and satellite images on Hurricane Sergio.
- Tropical depression 22-E (TD-22E) formed on Sunday morning off the coast of southwestern Mexico, approximately 170 miles to the southeast of Manzanillo, Mexico. Although this tropical depression initially was moving toward the west-southwest, it curved toward the west-northwest. Rains associated with this system had tropical depression began spreading across southwestern Mexico. As of late Sunday evening, TD-22E was located approximately to 105 miles to the south of Manzanillo, with essentially no change in strength. TD-22E was expected to continue traveling toward the west-northwest and strengthen on Monday to become Tropical Storm Tara.
In North Indian Ocean:
- Tropical Cyclone 5A, which was also identified as Cyclone Luban, was traveling toward the west-northwest across the Arabian Sea at the start of last week, approximately 600 miles to the east-southeast of the coast of Oman. Luban intensified as it curved toward the northwest. As of Sunday afternoon (local time), Cyclone Luban had made landfall to the north of Nishtun, Yemen. Additional information on Cyclone Luban can be found on the NASA Hurricane Blog Page
- A tropical depression formed over the east central Bay of Bengal last Monday. By early Tuesday, this tropical depression had strengthened to become Tropical Cyclone 06B, or Cyclone Titli. Over the next two days, Cyclone Titli traveled to the northwest, headed toward the coast of India. By Thursday evening, Titli had made landfall along the eastern coast of India approximately 360 miles to the southwest of Calcutta, India. Titli weakened quickly as it traveled toward the northwest and then to the north and northeast. See the NASA Hurricane Blog Page for satellite images and additional information on Cyclone Titli.

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion & El Niño watch -- NOAA's Climate Prediction Center (CPC) and the International Research Institute for Climate and Society (IRI) recently released their El Niño/Southern Oscillation (ENSO) Diagnostic Discussion showing that while ENSO-neutral conditions were observed to continue through September, the surface waters across the equatorial Pacific Ocean where beginning to warm, as indicated by an increase in the area of above-average sea surface temperatures. (ENSO-neutral conditions indicate neither El Niño or La Niña conditions.) Furthermore, subsurface waters were also warming in the waters of the equatorial Pacific to the east of the Dateline. In addition to oceanic conditions, the state of the tropical atmosphere through September also indicated ENSO conditions, but recent trends would suggest a developing El Niño. Based upon their assessment of the various computer forecast models that they use, the CPC and IRI forecasters have continued a El Niño watch that indicates a 70 to 75 percent chance that El Niño conditions will develop during the remainder of this Northern Hemisphere fall and continue through the boreal winter of 2018-19. Most of the models favor a weak to moderate episode.
An ENSO blog written by a CPC contractor describes the metrics used by CPC and IRI forecasters to identify those oceanic and atmospheric conditions across the tropical Pacific basin in their decision-making process in determining the onset of an El Niño. They believe that the current ENSO-neutral conditions should become a El Niño event during the late fall and early winter 2018-19 (in the Northern Hemisphere), which has led to their continuing a El Niño watch. The blog also has accompanying graphics. [NOAA Climate.gov News]
A detailed and more technical El Niño/Southern Oscillation Diagnostic Discussion with supporting maps and charts is available from CPC.
Forecasters with the Australian Bureau of Meteorology recently issued an updated ENSO forecast from a Southern Hemisphere perspective. They reported that a warming of the tropical Pacific had been detected due to a weakening of the trade winds, which would suggest the onset of El Niño conditions. Furthermore, they felt that with the majority of forecast models indicated a transition to an El Niño. Therefore, they have raised their Bureau's ENSO Outlook to El Niño ALERT, which means that an approximately 70% chance exists for the occurrence of an El Niño in 2018, or roughly triple the normal likelihood. [Australian Government Bureau of Meteorology]
Environmental assessment made of fjords and bays on Alaska's Kenai Peninsula -- An environmental assessment was recently published by NOAA's National Centers for Coastal Ocean Science (NCCOS), the University of Alaska Fairbanks and the Alaska Department of Environmental Conservation involving benthic habitats and contaminants of the bays and fjords along south-central Alaska's Kenai Peninsula. The report is intended primarily for state fisheries and water quality officials in need of habitat condition information to manage the region's natural resources, an important hub for commercial, recreational, and subsistence fisheries. [NOAA NCCOS News]
Benthic cyanobacteria may be a potential source of toxic blooms and a human health threat -- Approximately 50 experts from various scientific disciplines gathered at the U.S. EPA National Risk Management Research Laboratory in Cincinnati, OH this past August to assess the state of knowledge on benthic cyanobacteria, which are bottom-dwelling, blue-green algae. [NOAA National Centers for Coastal Ocean Science News]
Arctic Sea Ice Changes More Slowly with the loss of thick ice -- A scientist at NASA's Jet Propulsion Laboratory recently published an article showing the results based upon a 60-year record of changes in Arctic sea ice thickness from declassified U.S. Navy submarine measurements along with more recent data from four satellites. He found that the sea ice covering the Arctic Ocean has changed since 1958 from predominantly older, thicker ice to mostly younger, thinner ice. He concludes that with so little thick, old ice remaining, the rate of decrease in ice thickness has slowed. New ice grows faster but is more vulnerable to weather and wind, so ice thickness is now more variable, rather than dominated by the effect of warming associated with global climate change. [NASA Jet Propulsion Laboratory Feature]
Key indicators of global climate change are updated by National Climate Assessment team -- A team of science experts associated with the United States Global Change Research Program (USGCRP) have recently updated a collection of 15 "climate indicators" to show how global climate has been changing. The scientists were using the latest data to produce graphics as part of the process needed to make updates prior to the scheduled release of the new Fourth National Climate Assessment in late 2018. This National Climate Assessment release is in fulfillment of a Congressional mandate to provide updated reports that will serve as an important resource for understanding and communicating climate change science and impacts in the United States. The fifteen indicators show trends that include increases in atmospheric greenhouse gas concentrations, increases in air temperatures, rising sea levels, and decreases in both ice extent and glacier mass. [NOAA Climate.gov News]
An international report is meant to be a "wake-up" on a 1.5 Celsius degree warming of Earth -- At the start of last week, the World Meteorological Organization (WMO) released a special report entitled "The Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C." This landmark report is intended to serve as a "wake-up" call about both the huge challenges and the benefits of limiting global warming to 1.5 Celsius degrees above pre-industrial levels in the context of strengthening the global response to the threat of climate change, sustainable development and efforts to eradicate poverty. [WMO Press Release]
Nobel Prize for Economics involves Integrating innovation and climate with economic growth -- The Royal Swedish Academy of Sciences announced last week that it has awarded the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel 2018 to William D. Nordhaus of Yale University "for integrating climate change into long-run macroeconomic analysis" and Paul M. Romer of New York University's Stern School of Business "for integrating technological innovations into long-run macroeconomic analysis." [Nobel Prize Organization Press Release]
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: Seiche Model

A seiche (pronounced "say-sh") is a rhythmic oscillation of water in an enclosed basin (e.g., bathtub, lake, or reservoir) or a partially enclosed coastal inlet (e.g., bay, harbor, or estuary). With this oscillation, the water level rises at one end of a basin while simultaneously dropping at the other end. A seiche episode may last from a few minutes to a few days. (Refer to your textbook for more on seiches.)

With a typical seiche in an enclosed basin, the water level near the center does not change at all but that is where the water exhibits its greatest horizontal movement; this is the location of a node. At either end of an enclosed basin, vertical motion of the water surface is greatest (with minimal horizontal movement of water); these are locations of antinodes. The motion of the water surface during a seiche is somewhat like that of a seesaw: The balance point of the seesaw does not move up or down (analogous to a node) while people seated at either end of the seesaw move up and down (analogous to an antinode).

The natural period of a seiche depends on the length and depth of the basin and generally ranges from minutes to hours. The period is directly proportional to basin length. For example, the natural period of a seiche in a small pond is considerably less than its period in a large coastal inlet. Also, for the same basin, the natural period is inversely proportional to water depth; that is, the period shortens as water deepens.

A 41-second mp4 video http://ametsoc.org/amsedu/ds-ocean/Seiche_Calculator.mp4 was produced providing a graphical simulation of a seiche by the University of Delaware's Seiche Calculator. The first demonstration on the video shows a case with the "Modal Number" set to 1 with a seiche in an enclosed basin. The second demonstration is for the "Modal Number" to 0.5, which would represent partially enclosed basins that usually have a node located at the mouth (rather than near the center) and an antinode at the landward end.

Historical Events:

15 October 1947...A hurricane made a hairpin turn off the Georgia coast after being seeded with dry ice. The storm passed over Savannah and tracked inland through Georgia. (Intellicast)
15 October 1954...Hurricane Hazel struck the Carolina coastline near Cape Fear, NC. The hurricane (category 4 on the Saffir-Simpson Scale) demolished every pier along a 170-mile stretch from Myrtle Beach, SC to Cedar Island, NC, and obliterated rows of beach homes. At Long Beach, 300 homes vanished; no debris remained. Hurricane Hazel also destroyed 1500 homes as it made landfall with 17-ft tides. Winds between Myrtle Beach, SC and Cape Fear, NC gusted to 150 mph. Later, the remnants of Hazel moved northward into Ontario and became the most remembered storm in Canadian history. Winds gusted to 75 mph and as much as 7.2 inches of rain fell. Eighty people died, mostly from flooding in the Toronto area (David Ludlum) (The Weather Channel) (The Weather Doctor)
15 October 1999...A waterspout (a tornado over water) moved onshore at Fort Lauderdale Beach, FL and blew out a plate glass window in a bar, injuring 8 patrons. The waterspout also overturned a vehicle and caused other significant damage on Los Olas Blvd. (Accord Weather Calendar)
16 October 1780...The most deadly Western Hemisphere hurricane on record raged across the Caribbean. It killed 22,000 people on the islands of Martinique, St. Eustatius, and Barbados. Thousands more died at sea. (National Weather Service files)
16 October 1877...Bjørn Helland-Hansen, the Norwegian pioneer of modern oceanography, was born on this date. His studies of the physical structure and dynamics of the ocean were instrumental in transforming oceanography from a descriptive science to one based on the principles of physics and chemistry. (Today in Science History)
16 October 1944...The 1944 Cuba - Florida hurricane, also known as the Pinar del Rio Hurricane, stuck western Cuba on this day as a Category 4 hurricane. This hurricane killed an estimated 300 people in Cuba and nine in Florida. This is currently the 7th costliest U.S. Atlantic hurricane with an estimated $40.6 billion in damage (adjusted to 2010 dollars). (National Weather Service files)
17 October 1997...Late on October 17, Super Typhoon Ivan attained its peak intensity with winds of 185 mph and an official barometric pressure of 905 millibars (26.72 inches of mercury) as it was traveling to the west-northwest toward Luzon in the Philippines. On the same day, while near peak intensity, Typhoon Joan was located about 1300 miles east of Typhoon Ivan. (National Weather Service files)
18 October 1910...Northeasterly winds as high as 70 mph (from a hurricane moving northward up the Florida peninsula) carried water out of Tampa Bay and the Hillsboro River. The water level lowered to nine feet below mean low water. Forty ships were grounded. (The Weather Channel)
18-19 October 2005...Hurricane Wilma developed a tiny, well-defined eye and began intensifying rapidly, reaching Category 5 strength with a record-setting pressure of 882 millibars (26.04 inches of mercury) by 19 October. The rapid intensification from tropical storm to Category 5 hurricane in 24 hours was the fastest ever recorded in the Atlantic Ocean, and the second-fastest worldwide, after Super Typhoon Forrest. (National Weather Service files)
19 October 1843...Captain Robert Stockton of the Princeton, the first screw propelled naval steamer, challenged the British merchant ship Great Western to a race off New York, which Princeton won easily. (Naval Historical Center)
20 October 1892...After ten years of difficult and costly construction, the St. George Reef Lighthouse, built on a rock lying six miles off the northern coast of California, midway between Capes Mendocino and Blanco, was first lighted. (USCG Historian's Office)
20 October 1956...A German physician, Dr. Hannes Lindemann, began a voyage on which he would become the first person to cross the Atlantic in the smallest craft. Using a double-seat folding kayak that was 17 feet in length and outfitted with an outrigger and sail, he made the trip from Las Palmas in the Canary Islands to St. Thomas in the US Virgin Islands in 72 days. He had made a prior crossing in a 23-foot African dugout canoe. He later wrote a book, Alone at Sea, describing his experiences. (Today in Science History)
20 October 1984...The Monterey Bay Aquarium opened on Cannery Row in Monterey, CA as the largest artificial environment for marine life, housing 500 marine animals from at least 525 species. The aquarium also supports active research and conservation programs. (Today in Science History)
20 October 2004...Typhoon Tokage became the tenth typhoon to strike Japan that year. Rain accompanying this typhoon triggered flash floods that washed away entire hillsides, killing 55 people and leaving at least 24 people missing. (National Weather Service files)
21 October 1797...The USS Constitution was launched at the Charlestown Navy Yard in Boston, MA. The ship, nicknamed "Old Ironsides," is now the oldest commissioned ship in the U.S. Navy. (Naval Historical Center)
21 October 1580...Portuguese navigator Ferdinand Magellan on his famous circumnavigation voyage of the globe reached Cape Virgenes and the strait at the tip of South America that now bears his name. Only three ships entered the 373-mile long passage separating Tierra del Fuego (land of fire) and the continental mainland. Navigating the treacherous strait in 38 days, the expedition entered the South Pacific Ocean, which Magellan named "Mar Pacifico" for the relatively tranquil seas that he found. However, one ship had been wrecked and another deserted. (The History Channel)
21-26 October 1998...Hurricane Mitch, a category 5 hurricane (on the Saffir-Simpson Scale), developed as a tropical depression over the southwestern Caribbean Sea about 360 mi south of Kingston, Jamaica on the 21^st. It would intensify over the next few days to become the second deadliest Atlantic hurricane on record, on the 24^th. By the 26^th, Mitch finally dissipated after remaining a category 5 hurricane for 33 hours. Estimated rainfall totals of up to 75 in. caused devastating flooding and mudslides in Honduras and Nicaragua for days. Estimated death toll from this hurricane was more than 11,000, the worst since 1780. (The Weather Doctor) (Accord Weather Calendar)