Publication Detail

Mechanism Studies of Seasonal Variability of Dissolved Oxygen in Massachusetts Bay: A Multi-Scale FVCOM/UG-RCA Application

Pengfei Xue, Changsheng Chen, Jianhua Qi, Robert C Beardsley, Rucheng Tian, Liuzhi Zhao
1 pp.
MITSG 12-23
$5.50 DOM / $7.50 INT

Long-term (1992-present) water quality monitoring records reveal that the
dissolved oxygen (DO) concentration in Massachusetts Bay (MB) exhibits a
seasonal cycle with insignificant interannual variability. A multi-domain nested
coupled physical-biogeochemical model was developed with an aim at identifying
the key mechanisms controlling the temporal/spatial variability of DO in MB. Built
on good agreement between model results and observations, an EOF analysis
indicates that DO variation in MB is dominated by seasonal and spatial varying
modes, with the highest value occurring in March-April and lowest in October, and
varying more significantly in the southern bay earlier in phase than in the northern
bay. Although biogeochemical, advection and mixing processes vary year to year,
their net contribution to DO variation remains relatively small (~ 10%) on an
interannual basis. However, the dominant processes that control DO variation in
the northern and the southern bay are significantly different. In the northern MB,
horizontal advection, which is connected to the upstream Western Maine Coastal
Current (WMCC), plays an important role in the DO variation. In the southern MB,
particularly within Cape Cod Bay (CCB), a well-defined local retention mechanism
results in a longer residence time, and the DO variation is more controlled by local
biogeochemical processes.

type: Presentations

Parent Project

Project No.: 2010-R/RC-116
Title: Development and Validation of the Water Quality Model System for Massachusetts Coastal Waters

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