Grantee Research Project Results

Hydrodynamics and Phytoplankton Distributions in the Upper Ocean

EPA Grant Number: F6E21102
Title: Hydrodynamics and Phytoplankton Distributions in the Upper Ocean
Investigators: Steinbuck, Jonah Vittorio
Institution: Stanford University
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2006 through September 1, 2009
Project Amount: $111,344
RFA: STAR Graduate Fellowships (2006) RFA Text | Recipients Lists
Research Category: Fellowship - Aquatic Ecology and Ecosystems , Academic Fellowships , Fellowship - Physical Oceanography

Objective:

The abundance and distribution of phytoplankton in the upper ocean are of fundamental importance to the functioning of marine ecosystems and to the exchange of gases between the atmosphere and ocean. Physical processes in the upper ocean -- internal waves, convection, and shear-generated turbulence -- regulate the distribution of phytoplankton and influence conditions for growth and grazing. In this project, we seek to clarify the linkages between hydrodynamics and phytoplankton distributions via field observations in the Gulf of Aqaba, Red Sea, and off the coast of California.

The central goal of this research is to improve our characterization of upper ocean physical processes and to develop our understanding of the role of hydrodynamics in controlling phytoplankton distributions and population dynamics.

Approach:

We are currently undertaking three interdisciplinary field studies -- spanning physics, biology, and marine technology. These studies utilize new instrumentation and novel sampling strategies that permit simultaneous measurement of biological and physical variables on the same spatial and temporal scales. Our observations in the Gulf of Aqaba and off the coast of California are made from instrumented moorings (with Acoustic Doppler Current Profilers and Velocimeters to characterize flow conditions) and shipboard profilers (including an in-situ Particle Image Velocimetry system, a Self-Contained Autonomous Microstructure Profiler, and fluorometers used to infer vertical turbulent transport of phytoplankton).

Expected Results:

This work will improve our description of upper ocean physical processes, including convection and wind-driven motions, and help us better parameterize turbulent mixing from properties of the flow field and water column. Improved parameterizations for turbulent mixing will be crucial to the development of accurate models of ocean circulation, global climate change, and marine ecosystems. Our work will improve our understanding of the role of hydrodynamics in redistributing phytoplankton and altering planktonic population dynamics in the upper ocean.

Supplemental Keywords:

upper ocean, hydrodynamics, turbulence, phytoplankton, marine ecosystems,, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Air, Water, algal blooms, Atmosphere, Air Pollution Effects, Biochemistry, climate change, Environmental Monitoring, nutrient enrichment, phytoplankton, phytoplankton population dynamics, biogeochemical, HAB ecology, vitamins, carbon-specific growth rates, nitrogen, hydrography, algal bloom detection

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.