El Niño Watch, Advisory 2008-06
Coastal Ocean Mean SST (°F) and Deviation from Normal, June, 2008
Several complementary images are now available:
Satellite Chlorophyll a (view image) QuikSCAT Wind Stress Curl a (view image)
Regional Oceanic Conditions
Regional monthly average sea surface temperature (SST) fields for June 2008, derived from NOAA satellites, showed below-average monthly SST over much of the north Pacific east of 145°W. However, the broad coastal band of negative SST noted in May weakened and began to breakdown in June. Positive anomalies developed along the coast south of 35°N and offshore east of 135°W. Areas of negative SST anomaly extend offshore north of 40°N and into the subarctic Pacific and Gulf of Alaska. SST anomaly trends were toward higher anomalies.
The North Pacific high atmospheric pressure system (NPH) dominated atmospheric forcing between Cape Flattery (48°N) and Cerros Island (28°N). In the monthly mean wind stress field the STH was centered near 36°N, 144°W. Strong southeastward, upwelling favorable, wind stress occurred along the coast between Cape Blanco (43°N) and Point Baja (30°N) in patterns also seen in March, April and May 2008. Upwelling indices, computed from monthly mean fields, showed weak and variable wind forced upwelling north of 45°N, anomalously strong upwelling at 39°N and 42°N, and weaker than average upwelling from 36°N to 27°N (NMFS/SWFSC/ERD monthly coastal upwelling index).
May 2008 chlorophyll-a concentration patterns from MODIS satellite imagery showed continued high coastal concentrations. However, the high coastal chlorophyll-a anomaly noted in April decreased in May and became negative in many near-shore areas during June, particularly south of 42°N.
Equatorial Pacific Conditions
La Niña conditions weakened in the equatorial Pacific during June 2008. The NOAA Climate Prediction Center is monitoring transition to ENSO-neutral conditions in the tropical Pacific during June-August 2008. For details, see the
official NOAA ENSO Advisory bulletin.
Biological and Fisheries Observations
The coast-wide sardine fishery was officially reopened July first. Catches were reported from Southern California, Monterey, Oregon and Washington ports. These were the first sardine catches of 2008 for Oregon and Washington fishers. The SWFSC pelagic juvenile rockfish midwater trawl survey was completed on June eighteenth. Large numbers of jellyfish often prevented trawling. Juvenile rockfish (Sebastes spp.), lingcod (Ophiodon elongatu), and Pacific hake (Merluccius productus) catches were higher than their respective 2005 Ð 2007 catches. Widow rockfish were the dominant rockfish north of Point Conception (35°N). Catches of northern anchovy (Engraulis mordax) were five times higher south of Point Conception than north of the Point, while the opposite was true for Pacific sardine (Sardinops sagax), with six times more fish collected north of Point Conception than south. Catches of market squid (Loligo opalescens), dominated by individuals less than 30 cm, were also greater than in the previous three years. Humboldt squid (Dosidicus gigas) were caught in several trawls outside Monterey Bay and off Piedras Blancas (35°N - 37°N). Spring and Summer run salmonids continued their return to the lower Columbia River and Willamette drainage and other rivers north of 37°N. Thus far fish counts at the Bonneville Dam show good returns of chinook and sockeye salmon (Fish Passage Center, Portland, OR ).
Humpback and Blue Whales were commonly encountered by observation excursions operating in coastal waters south of San Francisco.