In the summers of 2008–2010, Dr. Ned Cokelet added rugged instruments to NOAA bottom trawl survey nets on the eastern Bering Sea continental shelf – site of the nation’s most productive fisheries – to measure ocean temperature and salinity at over 350 locations. The results, released in Deep Sea Research II, provide the most comprehensive view to date of the three-dimensional thermohaline structure. Horizontal variations of the ocean’s mass density, computed from the temperature and salinity measurements, give the ocean currents shown by arrows in the accompanying figure for summer 2010. The flow was strongest west of the Pribilof and St. Matthew Islands, and there was clockwise circulation around St. Matthew Island. The upper layer of the ocean was mixed down to less than 30 m over much of the region, but reached depths greater than 70 m along the Alaska Peninsula. Upper-to-lower layer salinity differences contributed more than temperature to density differences over most of the region. These observations enhance our understanding of plankton and fish-larval transport and can serve to calibrate predictive computer models of the ecosystem.
PMEL in the News
The devastation of earthquake-generated tsunami waves is well known. Take the Magnitude 9 tsunami that wiped out portions of the northeast Japanese coastline in 2011. Seismologists and other scientists have long warned that a tsunami and Magnitude 9-plus earthquake will hit the Northwest coast....
New design standards created by a group of engineers would require that hospitals, police stations and schools be strong and tall enough to survive a tsunami and provide shelter.
Quarterly time-series estimates of aragonite saturation state from 15 to 500 meters water depth at CalCOFI Station 80.0 80, in the California Current. Dashed vertical white lines denote the extreme 1997–1999 ENSO period. Solid horizontal white lines represent the decadal average depths of the aragonite saturation horizon before and after the ENSO event.
Changes in large-scale ocean circulation due to climate change appear to be underway throughout the world ocean and stand to significantly affect marine ecosystems and resources. This new study by McClatchie et al. investigated whether changes in the character of coastal waters over the last 30 years have affected the composition of fish communities in the southern California Current ecosystem. The... more