Abstract:
The data set produced is composed of relationships between total integrated radiation doses to ice floes and metrics of sea ice biotic community succession. The late winter and early spring timing coupled with the seasonally strong meridional gradient in radiant energy provided a setting whereby these relationships could be better examined. Integrated radiation doses were estimated through the ... combined analysis of sea ice concentrations, cloud cover and snow cover (derived from satellite-derived products), ship-based radiation monitoring, and in situ sea ice radiation balance measures. Succession stages of sea ice biota were evaluated through measures of sea ice geochemistry (nutrients, DOC, DON, PON and salinity), and microbial biomass (microalgal pigments, POC/N, bacterial biomass) and community composition (determined through microscopy and molecular surveys). The measures in the dataset were conducted through a hierarchical analysis of mesoscale and small scale sea ice physical attributes. When coupled with the SIMBA analysis of sea ice structure, mass balance and energy fluxes these studies substantially advanced the abilities of ecologists to determine the seasonal role of SIMCOs in the Antarctic marine ecosystems dynamics as well as southern ocean ecosystem modelers to parameterize southern ocean's geochemical fluxes.
Purpose:
To assess sea ice microalgal biomass, community composition and pack ice biogeochemistry in context of the seasonal progression and succession of the sea ice cover. The autotrophic biomass in the various sea ice habitats spanned several orders of magnitude with chla ranging from 0.05 to ~60 ug chla l-1. The preliminary analysis of the biogeochemistry of the ice indicates these communities were ... affecting the nutrient status of the ice and the austral spring development of pack ice biomass was occurring during the program. Anecdotal observations of krill aggregates in association with the ice and findings of copepods in several slush samples collected on the surface of the ice suggests the energy derived by production within these habitats was being utilized by the local food web. Preliminary estimates of the biomass in the varied sea ice habitats showed autotrophic biomass on the order of 10-20 mg chla m-2 . This value is close to that which was reached in the upper 100 meters of the water column at its highest point during the study. Thus, it appears as if the local austral spring processes produced biomass and energy within the snow, ice and water column. The coupling of these production processes to the sea ice geophysical dynamics will be ascertained through further analysis of the program’s combined efforts.
Fritsen, C.H., E.D. Wirthlin, D.K. Momberg, M.J Lewis, S.F. Ackley (2011), Bio-optical properties of Antarctic pack ice in the early austral spring, Deep-Sea Research II, 58, 9-10, 1052-1061, doi:10.1016/j.dsr2.2010.10.028, http://www.sciencedirect.com/science/article/pii/S0967064510003139
