Feature Publication Archive
Scatter plot of site spacing (left axis) and site spatial frequency (right axis) vs. ridge spreading rate for 27 ridge sections using data from the InterRidge database (red dots). Green symbols show new survey results from four of these sections; purple symbols show corroborating results from prior intensive camera surveys. Heavy black line is a linear regression between site spacing and spreading rate for the existing database (red dots).
Baker, E.T., J.A. Resing, R.M. Haymon, V. Tunnicliffe, J.W. Lavelle, F. Martinez, V. Ferrini, S.L. Walker, and K. Nakamura (2016): How many vent fields? New estimates of vent field populations on ocean ridges from precise mapping of hydrothermal discharge locations. Earth Planet. Sci. Lett., 449, 186–196, doi:10.1016/j.epsl.2016.05.031.
The heat from submarine volcanoes produces hundreds of hydrothermal hot springs along the mid-ocean ridge crest. These springs promote the exchange of heat and chemicals between the Earth’s crust and the ocean, providing energy to support ecosystems fueled by chemical reactions and creating exploitable deposits of mineral and bio-active resources. A new study by Baker et al. indicates that hot springs are far more common than previously thought, a discovery with crucial implications for diverse hypotheses by chemists, biologists, geologists, and others interested in ocean-seafloor... more »
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.
McClatchie, S., A. R. Thompson, S. R. Alin, S. Siedlecki, W. Watson, and S. J. Bograd (2016), The influence of Pacific Equatorial Water on fish diversity in the southern California Current System,J. Geophys. Res. Oceans, 121, doi:10.1002/2016JC011672.
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 California Undercurrent transports Pacific Equatorial Water into the Southern California Bight from... more »
Figure 3.6(a): Time series of annual average global integrals of in situ estimates of upper (0–700 m) OHCA (1 ZJ = 10²¹ J) for 1993–2015 with standard errors of the mean.
Every year NOAA leads a team of international scientists in issuing a report on the state of the climate in the year just passed, published as a supplement to Bulletin of the American Meteorological Society. Nine Federal, JISAO, and JIMAR scientists resident at PMEL co-authored four of twelve sections in the Global Oceans chapter and one section in the Arctic chapter for the State of the Climate in 2015 report, published in July 2016. In addition, Dr. Gregory Johnson served as lead editor of the Global Oceans chapter and participated in the media roll-out event.
Dr. Johnson’s... more »
Global map of the ratio of the mean surface geostrophic shear stress magnitude (|τp|) to the mean wind stress magnitude(|τ0|): R = |τp|/|τ0|. Where R is greater than 1, frontal effects dominate the classic "Ekman" response to wind forcing. From Cronin and Tozuka (2016).
Cronin, M.F., and T. Tozuka (2016): Steady state ocean response to wind forcing in extratropical frontal regions. Scientific Reports, 6, 28842, doi:10.1038/srep28842.
Wind forcing is fundamental to the ocean circulation. According to the classic “Ekman” theory developed in the early twentieth century, wind-induced steady flow spirals to the right of the wind stress in the Northern Hemisphere and to the left in the Southern Hemisphere, resulting in a net wind-forced “Ekman” transport that is 90 degrees to the right of the wind stress in the Northern Hemisphere and to the left in the Southern Hemisphere. This theory, however, assumes that the near-surface ocean is uniform in density (i.e., has no fronts). In frontal regions the surface “geostrophic”... more »
Composite evolution of extreme El Niño events in WWBs (contours) and anomalous temperature (colors). One WWB early in the year warms the central Pacific making additional WWBs more likely. Many WWBs are necessary to trigger an extreme El Niño event.
Levine, A.F.Z., F.-F. Jin, and M.J. McPhaden (2016): Extreme noise–extreme El Niño: How state-dependent noise forcing creates El Niño-La Niña asymmetry. J. Climate, doi:10.1175/JCLI-D-16-0091.1
Published online. http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0091.1
A major unanswered question about El Niño-Southern Oscillation (ENSO) is why the largest El Niño events are stronger in magnitude than the largest La Niña events. This paper examines one of the leading hypotheses to explain this asymmetric behavior; namely, that westerly wind bursts (WWBs) create conditions to promote additional WWBs, and the sum total of all the WWBs that occur during the initiation and growth of an El Niño event impacts the eventual magnitude of the event. WWBs are short episodic bursts of westerly winds that occur in the opposite direction of the normal trade winds.... more »