Antarctic polar front

Van Oijen T, Van Leeuwe MA, Gieskes WWC (2003) Variation of particulate carbohydrate pools over time and depth in a diatom-dominated plankton community at the Antarctic Polar Front. Polar Biol 26 195-201... 

Landry MR, Hassett RP (1982) Estimating the grazing impact of marine micro-zooplankton. Mar Biol 67 283-288 Landry MR, Selph KE, Brown SL, et al (2002) Seasonal dynamics of phytoplankton in the Antarctic Polar Front region at 170 W Deep Sea Res Part II Top Stud Oceanogr 49 1843-1865... 

Antarctic Polar Front" Summer-Dec avg Euphotic zone ww 2.5-9 18.3-29.1 0-6.9 Sambrotto and Mace, 2000... 

Sambrotto, R. N., and Mace, B. J. (2000). Coupling of biological and physical regimes across the Antarctic Polar Front as reflected by nitrogen production and recycling. Deep Sea Res. II 47, 3339-3367. 

Figure 12.2 SOFeX depth profiles of biomass (PN)-specific NO/ uptake rates, determined during 24-h incubations in Plexiglas acrylic incubators under simulated in-situ light and temperature conditions. Ultra-clean trace-metal techniques were used for sample collection within and outside (control waters) of the Fe-enriched patch north and south of the Antarctic Polar Front zone. The/-values [f = Fn03/(1 n03 + 1 nH4 + F n02 + F Urea)] were determined at the isolume depths of 47 and 16% surface irradiance, using tracer-level isotopic enrichments, and are not corrected for the effects of isotopic dilution. Error bars represent the range of duplicate samples (n = 2). Corrected from Coale et al. (2004).

Paleoproductivity studies in the Southern Ocean, where the deep-reaching Antarctic circumpolar current causes substantial sediment redistribution, have been especially dependent on the °Th-profiling method to obtain accumulation rates of opal, excess barium, organic carbon, and other paleoproductivity proxies (Anderson et al., 2002, 1998 Chase et al., 2003a Francois et al., 1997, 1993 Frank, 1996 Frank et al., 2000 Kumar et al., 1995). Studies of the Atlantic and Indian sectors of the Southern Ocean concluded that productivity in regions south of the Antarctic polar front was lower... 

Rutgers van der Loeff M. M., Friedrich M., and Bathmann U. V. (1997) Carbon export during the Spring Bloom at the Antarctic Polar Front, determined with the natural tracer " Th. Deep-Sea Res. II Top. Stud. Oceanogr. 44(1-2), 457-478. 

Figure 4 X-ray diffraction patterns contrasting various crystallinities of silica (a) radiolarian silica, Porcelanite (opal-CT) and a-Cristobalite (made by heating silica gel at 1,350 °C for 4 h) from Calvert (1983) (b) diatom assemblage from Antarctic plankton tow, deep-sea siliceous ooze (Holocene in age) from beneath the Antarctic Polar Front, and two chert deposits from state of New York. The sharpness of the silica peak(s) between 20° and 26° two theta increases as silica undergoes diagenetic transformation from a fresh-diatom assemblage to buried sediment for...

Figure 6 Contour plot of (A) DIG and (B) DOC along a transect line in the South Pacific between the equator (0° 170° W) and the Antarctic Polar Front (66° S 170° W)- Note that in the low-latitude stratified waters DIC concentrations are depleted in surface water relative to deep water, as a result of net primary production and air-sea exchange. DOC concentrations are elevated relative to deep water. In high-latitude regions, DIC concentration are elevated in the surface water as a result of increased solubility of cooler surface...

However, Cd P ratios of phytoplankton in surface waters or derived from phytoplankton cultures are not directly comparable to those estimated from dissolved Cd and PO4 concentrations in the nutricline, as only phytoplankton species that are exported out of the euphotic zone will leave an imprint of their Cd P ratios in the nutricline. The relative recycling efficiency of P versus Cd in the nutricline may also affect these estimates. Yet, according to a study in the Antarctic Polar Front region [119], preferential Cd uptake by phytoplankton overrides the more efficient recycling of Cd (50-95%) compared to PO4 (35%) in the upper ocean. Hence, phytoplankton Cd uptake at the surface and export out of the surface waters will greatly affect the dissolved Cd and PO " concentrations in nutriclines, and ultimately the estimated particulate Cd P ratios. 

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