 |
|
Home -- ENSO Cycle -- ENSO Effects -- Missions -- Data -- Tools -- Site Map |
|
Introduction -- Ocean -- Rainfall -- Crops -- Local Links -- Web Links |
|
||||
Northeastern Pacific Ocean and the West Coast of North America
Introduction
The Northeastern Pacific Ocean and the West Coast of the United States, Mexico, and Canada are affected by the winds (NSCAT wind data), storm waves, and ocean currents that are warmed or cooled by ENSO events.
|
Santa Cruz Wave |
TOVS HIRS2 |
Ocean
Even far from the Equator, the surface of the ocean is warmed by El Niño. Sea surface temperature (SST) measured at the north end of Vancouver Island, British Columbia, showed the intense long-lived warming that was associated with the 1982-83 El Niño (for the 2002-03 El Niño, see: Gulf of Alaska Warmer Than Usual). The warming was typically 2° C and occasionally as much as 3° C above normal. The warming due to El Niño was half the difference between summer and winter! When one computes the "degree days of warming" associated with the different El Niños, the recent 1991-92 event (which was moderate on the equator) is shown to be about 80 percent of the largest anomaly of the century. At the Farallon Islands off San Francisco, a biologist reported a 30-year-record SST of 19.2° C on August 26, 1997.
Surfers love El Niño because it brings waves and warm water (Pathfinder SST data). However, the warm water impacts fisheries and marine ecosystems. Warm surface waters result in increased stratification of the water column, decreasing the upwelling of nutrients critical for phytoplankton production (SeaWiFS chlorophyll data) from the cooler, deeper waters into surface waters. During the 1997-98 El Niño, elevated SSTs reduced landings of market squid from 110,000 metric tons in the 1996-97 season to less than 1,000 tons in the 1997-98 season. The Food and Drug Administration issued a warning against eating live oysters from Washington state, which may have higher levels of bacteria due to the heat wave in the Pacific Northwest. Changes in the distribution and abundance of major fish stocks resulted in widespread sea lion pup deaths in California. Alaska experienced an early Spring, and seabird die-offs were reported along the Alaska Peninsula and on St. Lawrence Island.
Rainfall
El Niño and La Niña provide major year-to-year variations in the climate of the western coastal regions, deserts, and mountains. Much of western North America lies in the path of storms that can be carried by the atmospheric circulation patterns spawned by El Niño. In general, El Niño events increase precipitation (TOVS rain data) (TRMM TMI rain data) and landslide activity in southern California and the Southwest, but may bring drought to the northern Rocky Mountains. In the southwestern United States during El Niño years, temperatures in the winter are cooler than normal across the Colorado Plateau. Major El Niño events have also produced exceptionally wet weather in the region. But during more moderate El Niño events, very dry conditions have been the rule.
In 1997-98, El Niño conditions affected the position and intensity of the jet stream over the northern Pacific and North America (for the 2002-03 El Niño, see: Severe Weather Hits United States West Coast). An unusually wet summer was reported on the eastern slope of the Cascade Mountains of Washington state. In September 1997, San Diego reported high temperatures, very high humidity, thunderstorms and big floods in the desert, with water closing a major freeway. In the Winter and Spring of 1998, California received 228 percent of normal rainfall, and an estimated $500 million in property damage: levees, equipment, buildings, irrigation systems, and land. In early February, storm damage closed scenic Highway 1 both north and south of Big Sur for a month or more. El Niño events affected regional precipitation, streamflow, lake-level change of Great Salt Lake, and landslide potential.
Crops
In California, the increased precipitation produced extensive wildflower blooms, and resulting high yields of wildflower honey (up to 120 pounds of honey per hive). However, the unseasonal wetness affected the timing and set success of plum trees, adversely affecting the California prune crop. Similar effects were felt by the grape crop, which also suffered from various pests that liked the wet weather. California county agricultural commissioners reported that the hardest-hit crops and estimated value of losses were strawberries, $10.7 million; wheat and barley, $8.1 million; alfalfa, $3.9 million; lettuce, $2.7 million; and broccoli, $2.5 million. Statewide loss of livestock and poultry was estimated at $688,000.
La Niña 1999-2000 featured a large area of cool water (Pathfinder SST data) from Alaska to Baja California that scientists say influenced regional weather patterns along the West Coast. La Niña conditions more predictably bring warmer and drier conditions to the region. This results in low numbers of wildflowers blooming, and resulting low yields of honey (less than 40 pounds per hive). This accounts for severe wildfire years in New Mexico, Arizona, and Colorado in both 2000 and 2002 (U.S. Fire Season Statistics).
Jump to 'Northeastern Pacific Ocean and West Coast' List of Web Sites
Disclaimer: NASA offers these suggested sites for additional information regarding effects of El Niño and La Niña teleconnection events. Web access is required to reach these sites. Link existence and contents are not under the control of the EOSDIS Science Operations Office.
Northeastern Pacific Ocean and West Coast Web Sites
