The Columbia Basin once supported a diversity of native fishes and large runs of anadromous salmonids that sustained substantial fisheries and cultural values. Extensive land conversion, watershed disruptions, and subsequent fishery declines have led to one of the most ambitious restoration programs in the world. Progress has been made, but...
The effects of wind-forced upwelling and downwelling on the continental shelf off Duck, North Carolina, are studied through experiments with a two-dimensional numerical primitive equation model. Moored and shipboard measurements obtained during August–November 1994 as part of the Coastal Ocean Processes (CoOP) Inner Shelf Study (ISS) are used for model–data...
The Garrett–Munk (GM) spectrum continues to be a useful description of the oceanic internal wave field. However, there are several inconsistencies and ambiguities that make it difficult to use in comparing internal wave fields at different latitudes, stratifications, and water depths. A modified spectral formulation is presented that treats three...
An unstable, nonlinear baroclinic wave-mean oscillation is found in a strongly supercritical quasigeostrophic f-plane numerical channel model with 3840 Fourier components. The growth of linear disturbances to this time-periodic oscillation is analyzed by computing time-dependent normal modes (Floquet vectors). Two different Newton–Picard methods are used to compute the unstable solution,...
Regional ocean circulation along the Oregon coast is studied numerically for forcing fields derived from year 2005 and climatological-mean conditions. The primary object is to study directly the Lagrangian pathways by which fluid arrives in the Oregon upwelling zone. Roughly half of the upwelling fluid is found to arrive in...
The oceanic circulation near the eastern margin of the African continent is dominated by the poleward flow of the Agulhas Current. The Agulhas Current separates from the African coast near the southern tip of the continent, makes an abrupt turn to the east (known as the Agulhas Retroflection), and flows...
A reduced-gravity model is presented of the warm-water branch of the middepth meridional overturning circulation in a rectangular basin with a circumpolar connection. The model describes the balance between production of warm water by Ekman advection across the circumpolar current, dissipation of warm water by eddy fluxes southward across the...
Corrections
18 Mar 2010: Shaman J, Pitzer VE, Viboud C, Grenfell BT, Lipsitch M (2010) Correction: Absolute Humidity and the Seasonal Onset of Influenza in the Continental United States. PLOS Biology 8(3): 10.1371/annotation/35686514-b7a9-4f65-9663-7baefc0d63c0.
15 Mar 2010: Shaman J, Pitzer VE, Viboud C, Grenfell BT, Lipsitch M (2010) Correction: Absolute Humidity...
A scheme is presented for retrieving aerosol properties for ocean regions from reflected sunlight at both the visible and near infrared wavelengths measured by the NOAA advanced very high resolution radiometer (AVHRR). For the Indian Ocean Experiment (INDOEX), aerosols were presumed to be a mixture of a continental haze that...
An improved bound is obtained for the radius of the semicircle in the complex plane containing the complex phase speed of baroclinically unstable plane wave disturbances. In the limit of long waves, this bound contains a term increasing with β and decreasing with the mean stratification (i.e., decreasing with the...
Three-component (NPZ), four-component (NPZD), and five-component (NNPZD) nitrogen-based ecosystem models are compared. The fixed points of the zerodimensional systems, with no spatial variation except light attenuation by water, are determined. A linear-stability analysis shows that unstable steady solutions exist for all three models. Time-periodic solutions are found in these regions....
Using stable isotope analyses of N and C we present preliminary evidence of marine-derived nutrients from introduced Chinook salmon (Oncorhynchus tshawytscha Walbaum) in stream food webs of Laguna Los Patos, NW Patagonia. Similar to values reported within Chinook salmon's native distributional range periphyton and aquatic insects are the trophic levels...
Anthropogenic carbon dioxide (CO₂) emissions are acidifying the ocean, affecting calcification rates in pelagic organisms, and thereby modifying the oceanic carbon and alkalinity cycles. However, the responses of pelagic calcifying organisms to acidification vary widely between species, contributing uncertainty to predictions of atmospheric CO₂ and the resulting climate change. At...
The early Pliocene warm phase was characterized by high sea surface temperatures and a deep thermocline in the eastern equatorial Pacific. A new hypothesis suggests that the progressive closure of the Panamanian seaway contributed substantially to the termination of this zonally symmetric state in the equatorial Pacific. According to this...
We integrate micropaleontological and geochemical records (benthic stable isotopes, neodymium isotopes, benthic foraminiferal abundances and XRF-scanner derived elemental data) from well-dated Pacific Ocean successions (15-12.7 Ma) to monitor circulation changes during the middle Miocene transition into a colder climate mode with permanent Antarctic ice cover. Together with previously published records,...
Oceanic iron (Fe) fertilization experiments have advanced the understanding of how Fe regulates biological productivity and air–sea carbon dioxide (CO₂) exchange. However, little is known about the production and consumption of halocarbons and other gases as a result of Fe addition. Besides metabolizing inorganic carbon, marine microorganisms produce and consume...
The first three years of SeaWiFS data (1997-2000) provide the most complete quantification to date of chlorophyll seasonal variability along the full latitudinal extent of the four major eastern boundary currents (EBCs). Comparisons to previously published chlorophyll seasonal climatologies deduced from the relatively sparse coverage provided by the Coastal Zone...
Climate regime shifts force fish communities through rapid transitions between alternate species assemblages, but little is known about the role that biochemical ecology plays in these transitions. We document a biochemical effect of climate-induced community transitions in boreal oceans: opposite population trajectories of lipid-rich and lipid-poor fish species. We compared...
Equilibrium climate sensitivity of the Community Climate System Model, version 4 (CCSM4) is 3.20 degrees C for 1 degrees horizontal resolution in each component. This is about a half degree Celsius higher than in the previous version (CCSM3). The transient climate sensitivity of CCSM4 at 1 degrees resolution is 1.72...
This study examines how coastal banks influence wind-driven circulation along stratified continental shelves. Numerical experiments are conducted for idealized symmetric banks; the standard bank (200 km long and 50 km wide) has dimensions similar to the Heceta Bank complex along the Oregon shelf. Model runs are forced with 10 days...