(Table 2) Production parameters of phytoplankton and some associated parameters in the area of the Titanic Polygon

Studies were carried out mostly in the area of RMS Titanic wreck site (41°44'N, 49°57'W) located above the continental slope and the south of the Grand Banks of Newfoundland. In a period from 18.06 to 24.09.2001 five surveys of production characteristics of surface phytoplankton were conducted over 5-9 days. Mean values of these characteristics obtained during the surveys were 9.2-11.7 mg C/m**3 per day for primary production (C_phs), 0.102-0.188 mg/m**3 for chlorophyll a (C_chls), and 4.44-7.42 mg C/mg chl. a per hour for assimilation number (AN). The main reason for low C_phs variability was a significant inverse relationship (R=-0.66) between AN and C_chls found over the research area. When cold shelf waters dominated in the area (27.07 to 19.08.2001), C_chls values for the slope region (0.125+/-0.031 µg/l) and for the outer shelf (0.130+/-0.040 µg/l) were similar. During strengthening of influence of warmer slope waters within area (from 29.08 to 13.09.2001), C_chls concentration within surface waters of the outer shelf was 0.152+/-0.039 µg/l and exceeded one for the slope region (0.094+/-0.004 µg/l) by factor 1.6. Against the background of low Cchls values, the High values of integral primary production in the water column (510-1010 mg C/m**2 per day) at low C_chls values measured within the area were determined both by high assimilation activity of phytoplankton and by the deep (30-40 m) maximum of primary production. Main reasons for formation of such a maximum were high chlorophyll concentration within the layer of the deep chlorophyll maximum (up to 0.5-2.5 µg/l) and in the relatively high solar irradiance within this layer varying from 1.4 to 8.6% of subsurface PAR.

Night biomass of dominant mesozooplankton groups within the Bismark Polygon (Northeast Atlantic) in June 2001 and June-August 2002

Vertical zooplankton distribution at the northeastern periphery of the North Atlantic subtropical gyre was studied with the use of 113/140 BR nets and Mir manned submersibles. Vertical distribution of selected dominant taxonomic, ecological, and trophic groups was considered. Results were compared with data obtained at the same location in 2001 that allowed to estimate interannual variability of the planktonic community.

Wet tundra polygon centers and distance between polygon centroids on Samoylov Island, Lena Delta, Siberia, Russia, with links to shape files

Subgrid processes occur in various ecosystems and landscapes but, because of their small scale, they are not represented or poorly parameterized in climate models. These local heterogeneities are often important or even fundamental for energy and carbon balances. This is especially true for northern peatlands and in particular for the polygonal tundra, where methane emissions are strongly influenced by spatial soil heterogeneities. We present a stochastic model for the surface topography of polygonal tundra using Poisson-Voronoi diagrams and we compare the results with available recent field studies. We analyze seasonal dynamics of water table variations and the landscape response under different scenarios of precipitation income. We upscale methane fluxes by using a simple idealized model for methane emission. Hydraulic interconnectivities and large-scale drainage may also be investigated through percolation properties and thresholds in the Voronoi graph. The model captures the main statistical characteristics of the landscape topography, such as polygon area and surface properties as well as the water balance. This approach enables us to statistically relate large-scale properties of the system to the main small-scale processes within the single polygons.