stratiRed (vertical gradients of potential temperature, salinity and potential density, averaged horizontally or in time, are zero). The terminology is most precise in the case of a convectively forced boundary layer. Elsewhere, oceanographers use the term loosely to describe the region of the ocean that responds most directly to surface processes. Late in the day, following periods of strong h...

Ocean upwelling rates are difficult to measure because of the relatively small velocities involved, and therefore are typically inferred from indirect methods such as heat budget estimates or tracer observations. Here we present the first results using a novel technique, based on the isotope Be, to infer rates of upwelling along the equator. Beryllium-7 (half-life1⁄453.3 d) is a cosmic-ray prod...

Observations near a large tabular iceberg in theWeddell Sea inMarch and April 2009 show evidence that water from ice melting below the surface is dispersed in two distinct ways. Warm, salty anomalies in T–S diagrams suggest that water from the permanent thermocline is transported vertically as a result of turbulent entrainment of meltwater at the iceberg’s base. Stepped profiles of temperature,...

Ocean sunfish Mola mola are a seasonally common inhabitant of southern Californian waters, and comprise the largest bycatch component (29% of total catch) of the California drift gillnet fishery for swordfish. We used temperature and depth-sensing acoustic transmitters to quantify the fine-scale movement patterns of ocean sunfish near Santa Catalina Island, California. Eight ocean sunfish were ...

In the tropical Atlantic, planktonic fomminfera species are vertically distributed with highest abundances occunfng in the photic zone (approximately 0-100 m). The tropical Atlantic thermocline dips from east to west and varies seasonally due to changes in the southeast and northeast trade winds. In the east, the thermocline is in the photic zone, and in the west, the well-mixed surface layer e...

The dissolved methane (CH4) plume rising from the crater of the blowout well 22/4b in the Central North Sea was mapped during stratified water column conditions. Geochemical surveys were conducted close to the seafloor at 80.3 m water depth, below the thermocline (61.1 m), and in the mixed surface layer (13.2 m) using membrane inlet mass spectrometry (MIMS) in combination with a towed CTD. Seaw...

We used acoustic telemetry to examine the small-scale movement patterns of yellow®n tuna (Thunnus albacares) in the California Bight at the northern extent of their range. Oceanographic pro®les of temperature, oxygen, currents and ̄uorometry were used to determine the relationship between movements and environmental features. Three yellow®n tuna (8 to 16 kg) were tracked for 2 to 3 d. All three...

Mixed layer (ML) gross (GOP) and net (NOP) oxygen production rates based on in situ mass balances of triple oxygen isotopes (TOI) and O2/Ar are influenced by vertical transport from below, a term traditionally difficult to constrain. Here we present a new approach to estimate vertical eddy diffusivity (Kz) based on density gradients in the upper thermocline and wind speed-based rates of turbule...

Abstract Decadal variability of the North Pacific subtropical mode water (STMW) and its influence on upper thermocline mixed layer are examined in a four-dimensional variational ocean re-analysis for Western over 30 years (FORA–WNP30). The STMW that forms south Kuroshio Extension becomes thick/cold thin/warm decadal timescales. These variations subducted advected to south, where thick (thin) ca...

marine environment of the caspian sea, due to extensive human exploitation and discharge of large magnitudes of urban, industrial and agricultural waste, is under extensive pressure and human wastes threaten marine life and ecosystem of the sea. therefore, there is a substantial need for a good understanding of physical and chemical characteristics of the caspian waters. however, the data avail...