TITLE:
Development of a High-Resolution Multiscale Modeling and Prediction System for Bay of Bengal, Part II: An Application to October 2008
AUTHORS:
Arun Chakraborty, Avijit Gangopadhyay
KEYWORDS:
ARGO, TMI, ROMS, Simulation
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 the Bay of Bengal
(BOB) region for short-term ocean hindcasts/forecasts. A physical validation of
this system that was based on climatological initialization and short-term
simulations was presented in Part I of this series of studies. Realistic structures
for prevalent eddies, fronts and gyres were reasonably reproduced and validated
for three individual months (February, June and October). In this study, we
present an application and synoptic validation of the system for October 2008
in a hindcast mode. The system is based on the Regional Ocean Modeling System
(ROMS), which assimilates satellite andin-situmeasurements within the background
climatology using an objective analysis to produce the synoptic initial
condition for the model and/or to produce an estimation of the current ocean
state. A meteorological forecast is then input into this synoptic
three-dimensional ocean model to produce the ocean hindcast/forecast. The
high-density Array for Real-time Geotropic Oceanography (ARGO) observations,
and the Tropical Rain Measuring Mission (TRMM) satellite’s microwave imager
(TMI) passes during the beginning of the month of October 2008, provided a
unique opportunity for the system to assimilate thesein-situobservations at initialization. Then,
the ARGO and TMI observations during the later part of October 2008 were used
for the statistical validation of the system’s fidelity. The validation shows
that the hindcast/forecast system can reasonably predict the ocean currents,
temperature and salinity. The forecast error increases as the forecast time
window increases, although the system has a reasonable predictability for up to
seven to ten days. The assimilation of bothin-situARGO and satellite data at
initialization produced better hindcasts/forecasts.