Conductive properties of muscle fibres from green sunfish (Lepomis cyanellus) acclimated to different temperatures were examined. The relative membrane permeability to chloride and potassium ions, PCl/PK, measured at acclimation temperature, was approximately 7.0 after acclimation at 25 degrees C and 1.3 after acclimation at 7 degrees C. This difference was due to a six-fold reduction in the me...

Ž . An earlier study with a repeating no-feedrrefeed schedule D2 schedule elicited compensatory Ž . Ž growth CG in age-0 hybrid sunfish F1: female green sunfish, Lepomis cyanellus=male bluegill . L. macrochirus held individually and fed ad libitum on feeding days. Weight gain under these conditions exceeded that of daily-fed controls. The present study sought to determine whether similar growth...

We have recorded ocular potentials in response to brief flashes of light from two teleosts, the white perch (Roccus americana) and the green sunfish (Lepomis cyanellus). The animals were respired and maintained in an alert state for up to 2 d. Responses were recorded with corneal and transcleral electrodes. The responses of green sunfish were composed of electroretinogram (ERG) and eye movement...

The authors exploit three years of data from the CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellites to document for the first time the seasonally varying vertical structure of cloudiness throughout Antarctica and the high-latitude Southern Ocean. The results provide a baseline reference of Southern Hemisphere high-latitude cloudiness for future o...

The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Cli...

Productivity in the Southern Oceans is iron-limited, and the supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine reservoir. Glacial sediment sources of iron have rarely been considered, as the iron has been assumed to be inert and non-bioavailable. This study demonstrates the presence of potentially bioavailable Fe as ferrihydrite and goethite in...

Large biases in climate model simulations of cloud radiative properties over the Southern Ocean cause large errors in modeled sea surface temperatures, atmospheric circulation, and climate sensitivity. Here, we combine cloud-resolving model simulations with estimates of the concentration of ice-nucleating particles in this region to show that our simulated Southern Ocean clouds reflect far more...

[1] We reexamine the relationship between circulation, bathymetry, and surface chlorophyll in the Southern Ocean, using new high-resolution maps of the frontal structure of the Antarctic Circumpolar Current (ACC) derived from satellite altimetry. The maps reveal that the ACC consists of multiple filaments or jets. By averaging surface chlorophyll measurements along streamlines, we show that the...

Experiments with the coupled climate model CLIMBER-3a, which contains an oceanic general circulation model, show deep upwelling in the Southern Ocean to be proportional to the surface wind stress in the latitudinal band of Drake Passage. At the same time, the distribution of the Southern Ocean upwelling onto the oceanic basins is controlled by buoyancy distribution; the inflow into each basin b...

[1] A physical mechanism is proposed for the glacial-interglacial variations in the rate of vertical mixing and in sea ice cover in the Southern Ocean. Such variations were postulated without an explanation by Toggweiler [1999] and Stephens and Keeling [2000], who used them to explain the glacial-interglacial CO2 variations. In the physical mechanism explored here, initially given by Gildor and...