HR: 15:45h
AN: OS52F-06    [PDF]
TI: The summer coastal upwelling and its implication to the biochemical processes in Massachusetts Bay
AU: * Jiang, M
EM: mingshun.jiang@umb.edu
AF: ECOS, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125 United States
AU: Zhou, M
EM: meng.zhou@umb.edu
AF: ECOS, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125 United States
AB: Massachusetts Bay (MB) is a semi-enclosed embayment with a deep basin, Stellwagen Basin(SB), linked to the Gulf of Maine by a deep channel between Cape Ann and Stellwagen Bank. Observations indicate that the basin water in SB has the characteristics of the Gulf of Maine water modified by local heating and freshwater input. Another channel to the Gulf of Maine is located south of Stellwagen Bank, through which water leaves the MB. A hydrodynamic model is developed to understand the physical processes and their effects on the biochemical processes. The model results are compared with observations from a long-term monitoring project. The results from 4-year observations and model simulations in 1998-2001 reveal that the surface circulation in the MB freqently shows an anti-cyclonic pattern with coastal upwelling and northward coastal jets in response to strong south winds during the summer season. The Ekman pumping in response to the surface wind transports the bottom water from the SB to the western coast of the MB, with compensation waters eventually come from the Gulf of Maine through the northern deep channel. These enhance the bottom inflow of water, nutrients and dissolved oxygen from the Gulf of Maine. In summer periods, water column in the deep area has little vertical exchange of water due to strong stratification but ubiquitous subsurface chlorophll maximum at around 20m. Therefore these upwelling events will significantly enhance the phytoplankton production and are important to the cycling of nutrients and dissolved oxygen in the MB during summer.
DE: 4243 Marginal and semienclosed seas
DE: 4255 Numerical modeling
DE: 4279 Upwelling and convergences
DE: 4546 Nearshore processes
DE: 4805 Biogeochemical cycles (1615)
SC: Ocean Sciences [OS]
MN: 2004 Ocean Sciences Meeting