"The role of the bottom boundary layer in biogeochemical cycles of the coastal ocean", Siedlecki (U of Chicago)

Start Date/Time: Thursday, June 10, 2010, 10:30 AM
Location: 120 Wallace Hall (Former Academic Computing Center)

Speaker: Samantha Siedlecki (University of Chicago. Samantha is interviewing for a joint JISAO and PCC post-doctoral fellow position.

Topic: "The role of the bottom boundary layer in biogeochemical cycles of the coastal ocean"

Abstract: Despite contributing 8% of the global ocean area, the coastal ocean is more productive on average than the open ocean and a source of iron to the open ocean. Currently, global biogeochemical models do not resolve the coastal ocean. A nonhydrostatic, three-dimensional model is implemented for an idealized shelf-slope geometry to simulate an eastern and western boundary coastal ocean. Tracers are designed to investigate mechanisms for nutrient supply, export, and ventilation. The interaction between the winds and bottom boundary layer determines the fate of the nutrients on both eastern and western boundaries. On eastern boundary margins, wind-driven upwelling supplies nutrients to the coastal ocean from the open ocean, and dissolved nutrients are exported offshore in the bottom boundary layer during downwelling-favorable winds. On western boundary margins, where exchange between the open and coastal ocean is regulated by dynamics of a shelf break front, nutrient-rich water from the bottom boundary layer is pumped up to the surface in response to the oscillation between the wind directions. The dynamics of the bottom boundary layer controls these mechanisms and are not resolved in global circulation models.