TITLE:
Development of a High-Resolution Multiscale Modeling and Prediction System for Bay of Bengal, Part I: Climatology-Based Simulations
AUTHORS:
Arun Chakraborty, Avijit Gangopadhyay
KEYWORDS:
Simulation, Bay of Bengal, WBC, EICC
JOURNAL NAME:
Open Journal of Marine Science,
Vol.6 No.1,
January
29,
2016
ABSTRACT: A high-resolution (10 km × 10
km) multiscale ocean modeling system was developed for short-term (1 - 2 weeks)
ocean state hindcasting/forecasting in the Bay of Bengal (BOB) region. This
paper is Part I of a two-part series of studies. The Regional Ocean Modeling
System (ROMS) was implemented and initialized with Levitus 1/4° climatological
fields for short-term forecasting. The results from these climatology-based
model simulations for three representative months (February, June and October)
in three different seasons (winter, summer and autumn) are discussed herein.
This high-resolution model implementation simulates most of the observed
dominant circulation features. The multiscale features during February include
an anticyclonic basin-scalegyre with
a strong western boundary current (WBC) in the western basin, the formation of
several shallow mesoscale eddies
in the head of the Bay and a cyclonic sub-basin-scale Myanmar Gyre in the
northeast. During June, no well-defined boundary current is simulated along the
Indian coast; instead, alternating cyclonic and anticyclonic eddies appear
along the east coast with cross-basin eastward
flow to support a deep cyclonic Andaman Gyre. In October, a basin-scale
cyclonic gyre with a continuous well-defined East India Coastal Current (EICC),
weak inflow from the Malacca Strait to the Andaman Sea and advection of BOB
water into the Arabian Sea via the Palk Strait are simulated well by the model.
A number of mesoscale eddies appear on the eastern half of the basin during
October. Physical pattern of simulated eddies and transports across selected
sections are validated against available drifter climatology, ARGO data and
previous observations. Application of this system to synoptic short-term
predictions for October 2008 will be presented in Part II.