Tuesday, December 30, 2008

Oscillation Rules as the Pacific Cools

Oscillation Rules as the Pacific Cools

PASADENA, Calif. -- The latest image of sea-surface height measurements from the U.S./French Jason-1 oceanography satellite shows the Pacific Ocean remains locked in a strong, cool phase of the Pacific Decadal Oscillation, a large, long-lived pattern of climate variability in the Pacific associated with a general cooling of Pacific waters. The image also confirms that El Niño and La Niña remain absent from the tropical Pacific.

The new image is available online at: http://www.nasa.gov/topics/earth/features/20081209.html.

The image is based on the average of 10 days of data centered on Nov. 15, 2008, compared to the long-term average of observations from 1993 through 2008. In the image, places where the Pacific sea-surface height is higher (warmer) than normal are yellow and red, and places where the sea surface is lower (cooler) than normal are blue and purple. Green shows where conditions are near normal. Sea-surface height is an indicator of the heat content of the upper ocean.

The Pacific Decadal Oscillation is a long-term fluctuation of the Pacific Ocean that waxes and wanes between cool and warm phases approximately every five to 20 years. In the present cool phase, higher-than-normal sea-surface heights caused by warm water form a horseshoe pattern that connects the north, west and southern Pacific. This is in contrast to a cool wedge of lower-than-normal sea-surface heights spreading from the Americas into the eastern equatorial Pacific. During most of the 1980s and 1990s, the Pacific was locked in the oscillation's warm phase, during which these warm and cool regions are reversed. For an explanation of the Pacific Decadal Oscillation and its present state, see: http://jisao.washington.edu/pdo/ and http://www.esr.org/pdo_index.html .

Sea-surface temperature satellite data from the National Oceanic and Atmospheric Administration mirror Jason sea-surface height measurements, clearly showing a cool Pacific Decadal Oscillation pattern, as seen at: http://www.cdc.noaa.gov/map/images/sst/sst.anom.gif.

"This multi-year Pacific Decadal Oscillation 'cool' trend can cause La Niña-like impacts around the Pacific basin," said Bill Patzert, an oceanographer and climatologist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. “The present cool phase of the Pacific Decadal Oscillation will have significant implications for shifts in marine ecosystems, and for land temperature and rainfall patterns around the Pacific basin.”

According to Nathan Mantua of the Climate Impacts Group at the University of Washington, Seattle, whose research contributed to the early understanding of the Pacific Decadal Oscillation, "Even with the strong La Niña event fading in the tropics last spring, the North Pacific's sea surface temperature anomaly pattern has remained strongly negative since last fall. This cool phase will likely persist this winter and, perhaps, beyond. Historically, this situation has been associated with favorable ocean conditions for the return of U.S. west coast Coho and Chinook salmon, but it translates to low odds for abundant winter/spring precipitation in the southwest (including Southern California)."

Jason's follow-on mission, the Ocean Surface Topography Mission/Jason-2, was successfully launched this past June and will extend to two decades the continuous data record of sea surface heights begun by Topex/Poseidon in 1992. The new mission has produced excellent data, which have recently been certified for operational use. Fully calibrated and validated data for science use will be released next spring.

JPL manages the U.S. portion of the Jason-1 mission for NASA's Science Mission Directorate, Washington. JPL is managed for NASA by the California Institute of Technology in Pasadena.

For more information on NASA's ocean surface topography missions, visit http://sealevel.jpl.nasa.gov/ . To view the latest Jason-1 data, visit http://sealevel.jpl.nasa.gov/science/jason1-quick-look/ .


Wave surge hits PNG

A huge wave has hit a Papua New Guinea island, submerging buildings and causing widespread damage but no casualties.

The giant wave hit Kavieng, on the New Ireland province, late on Tuesday and there were reports of a similar surge hitting PNG’s north-eastern coast province of East Sepik.

Details remain sketchy but one witness told AAP the water surge hit late this afternoon and disaster teams are now working through the damage.

“The wave took out the hospital and the east coast road of New Island,” local resident Nessie Amos said.

“The hospital’s equipment was washed out but patients were saved and taken to another hospital,” she said.

“There were no casualties but major damage was caused to the hospital and everything was washed out.”

Amos said one small island off Kavieng, Tents, is mostly under water and villagers have been moved to the neighbouring island of Emirau.

Government officials held a press conference in Wewak earlier this evening.


Report on Collision Death off Pt. Reyes

On Dec. 10, the U.S. Coast Guard released the results of two investigations. One report outlines the causes of the July 13, 2007 fatal collision between a cargo ship and a small fishing boat which occurred in heavy fog off Pt. Reyes, and the other is an internal review of the service's handling of the incident.

The incident involved the 291 ft motor vessel Eva Danielsen, a Bahamian-flagged cargo ship, and a 28 ft wooden fishing vessel, the Buona Madre, home ported in Santa Cruz, California. A collision between the two vessels resulted in the destruction of the fishing boat and the death of Mr. Paul Wade.

A Coast Guard Marine Casualty Investigation, which was conducted by San Francisco-based investigators and reviewed and released from Coast Guard headquarters in Washington D.C., found numerous factors contributing to the cause of the collision including: failure to ensure proper manning of the respective vessels in light of the prevailing weather conditions (heavy fog); and the freighter proceeding at an unsafe speed based upon the weather conditions, failing to follow applicable Navigational Rules of the Road (i.e., fog signals), and negligence with respect to the operation of the vessel.

An internal administrative investigation was also conducted by the 11th Coast Guard District to evaluate how Coast Guard policies and procedures were followed. The internal investigation found that some internal briefing requirements and communications processes were not followed. Several recommendations of the report have been adopted to improve management of communications among Coast Guard units including: Revision of Command Center Standard Operating Procedures to include recent CG policy changes; review and revision of all Quick Response Sheets (QRS) to ensure proper notifications are made in a timely fashion; Introduction of Search and Rescue fundamentals in the Coast Guard Vessel Traffic Service (VTS) training program; and cross training among various watch positions in the Coast Guard Sector Command Center and VTS.


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