2. PAL Original Hypotheses
The central null hypothesis and several alternate hypotheses, that together comprise our integrated, transdisciplinary research prospectus, are presented below.
H0: Neither the presence nor the extent of annual sea ice in the PAL study area influences ecosystem structure and dynamics.
HA1: Interannual variations in ice dynamics are a quasi-predictable manifestation of ocean and atmospheric circulation processes which influence the extent of CDW upwelling onto the continental shelf. The presence of this warm, salt water mass affects the heat and salt budgets of the region and hence controls ice dynamics.
HA2: Primary and secondary production are enhanced during high ice years, causing a general intensification of biogeochemical cycling rates and particle export processes.
HA3: Increased food production and under-ice refuge during sequential above normal sea ice years promotes optimal recruitment and growth of krill and, in subsequent years (1-2 yr lag), a greater breeding success and survival of apex predators (e.g., Adelie penguins).
HA4: The exchange of carbon dioxide between the atmosphere and the surface ocean is influenced by ice dynamics, CDW upwelling, primary and secondary production rates and organic particle sedimentation. The WAP region may be an important, albeit temporally-variable, source/sink term in global carbon budgets.