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  • Author or Editor: R. Subramanian x
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L. M. Beal
,
J. Vialard
,
M. K. Roxy
,
J. Li
,
M. Andres
,
H. Annamalai
,
M. Feng
,
W. Han
,
R. Hood
,
T. Lee
,
M. Lengaigne
,
R. Lumpkin
,
Y. Masumoto
,
M. J. McPhaden
,
M. Ravichandran
,
T. Shinoda
,
B. M. Sloyan
,
P. G. Strutton
,
A. C. Subramanian
,
T. Tozuka
,
C. C. Ummenhofer
,
A. S. Unnikrishnan
,
J. Wiggert
,
L. Yu
,
L. Cheng
,
D. G. Desbruyères
, and
V. Parvathi

Abstract

The Indian Ocean Observing System (IndOOS), established in 2006, is a multinational network of sustained oceanic measurements that underpin understanding and forecasting of weather and climate for the Indian Ocean region and beyond. Almost one-third of humanity lives around the Indian Ocean, many in countries dependent on fisheries and rain-fed agriculture that are vulnerable to climate variability and extremes. The Indian Ocean alone has absorbed a quarter of the global oceanic heat uptake over the last two decades and the fate of this heat and its impact on future change is unknown. Climate models project accelerating sea level rise, more frequent extremes in monsoon rainfall, and decreasing oceanic productivity. In view of these new scientific challenges, a 3-yr international review of the IndOOS by more than 60 scientific experts now highlights the need for an enhanced observing network that can better meet societal challenges, and provide more reliable forecasts. Here we present core findings from this review, including the need for 1) chemical, biological, and ecosystem measurements alongside physical parameters; 2) expansion into the western tropics to improve understanding of the monsoon circulation; 3) better-resolved upper ocean processes to improve understanding of air–sea coupling and yield better subseasonal to seasonal predictions; and 4) expansion into key coastal regions and the deep ocean to better constrain the basinwide energy budget. These goals will require new agreements and partnerships with and among Indian Ocean rim countries, creating opportunities for them to enhance their monitoring and forecasting capacity as part of IndOOS-2.

Free access
L. M. Beal
,
J. Vialard
,
M. K. Roxy
,
J. Li
,
M. Andres
,
H. Annamalai
,
M. Feng
,
W. Han
,
R. Hood
,
T. Lee
,
M. Lengaigne
,
R. Lumpkin
,
Y. Masumoto
,
M. J. McPhaden
,
M. Ravichandran
,
T. Shinoda
,
B. M. Sloyan
,
P. G. Strutton
,
A. C. Subramanian
,
T. Tozuka
,
C. C. Ummenhofer
,
A. S. Unnikrishnan
,
J. Wiggert
,
L. Yu
,
L. Cheng
,
D. G. Desbruyères
, and
V. Parvathi
Full access
Yolande L. Serra
,
Jennifer S. Haase
,
David K. Adams
,
Qiang Fu
,
Thomas P. Ackerman
,
M. Joan Alexander
,
Avelino Arellano
,
Larissa Back
,
Shu-Hua Chen
,
Kerry Emanuel
,
Zeljka Fuchs
,
Zhiming Kuang
,
Benjamin R Lintner
,
Brian Mapes
,
David Neelin
,
David Raymond
,
Adam H. Sobel
,
Paul W. Staten
,
Aneesh Subramanian
,
David W. J. Thompson
,
Gabriel Vecchi
,
Robert Wood
, and
Paquita Zuidema
Full access
Emily Shroyer
,
Amit Tandon
,
Debasis Sengupta
,
Harindra J. S. Fernando
,
Andrew J. Lucas
,
J. Thomas Farrar
,
Rajib Chattopadhyay
,
Simon de Szoeke
,
Maria Flatau
,
Adam Rydbeck
,
Hemantha Wijesekera
,
Michael McPhaden
,
Hyodae Seo
,
Aneesh Subramanian
,
R Venkatesan
,
Jossia Joseph
,
S. Ramsundaram
,
Arnold L. Gordon
,
Shannon M. Bohman
,
Jaynise Pérez
,
Iury T. Simoes-Sousa
,
Steven R. Jayne
,
Robert E. Todd
,
G. S. Bhat
,
Matthias Lankhorst
,
Tamara Schlosser
,
Katherine Adams
,
S. U. P Jinadasa
,
Manikandan Mathur
,
M. Mohapatra
,
E. Pattabhi Rama Rao
,
A. K. Sahai
,
Rashmi Sharma
,
Craig Lee
,
Luc Rainville
,
Deepak Cherian
,
Kerstin Cullen
,
Luca R. Centurioni
,
Verena Hormann
,
Jennifer MacKinnon
,
Uwe Send
,
Arachaporn Anutaliya
,
Amy Waterhouse
,
Garrett S. Black
,
Jeremy A. Dehart
,
Kaitlyn M. Woods
,
Edward Creegan
,
Gad Levy
,
Lakshmi H. Kantha
, and
Bulusu Subrahmanyam

Abstract

In the Bay of Bengal, the warm, dry boreal spring concludes with the onset of the summer monsoon and accompanying southwesterly winds, heavy rains, and variable air–sea fluxes. Here, we summarize the 2018 monsoon onset using observations collected through the multinational Monsoon Intraseasonal Oscillations in the Bay of Bengal (MISO-BoB) program between the United States, India, and Sri Lanka. MISO-BoB aims to improve understanding of monsoon intraseasonal variability, and the 2018 field effort captured the coupled air–sea response during a transition from active-to-break conditions in the central BoB. The active phase of the ∼20-day research cruise was characterized by warm sea surface temperature (SST > 30°C), cold atmospheric outflows with intermittent heavy rainfall, and increasing winds (from 2 to 15 m s−1). Accumulated rainfall exceeded 200 mm with 90% of precipitation occurring during the first week. The following break period was both dry and clear, with persistent 10–12 m s−1 wind and evaporation of 0.2 mm h−1. The evolving environmental state included a deepening ocean mixed layer (from ∼20 to 50 m), cooling SST (by ∼1°C), and warming/drying of the lower to midtroposphere. Local atmospheric development was consistent with phasing of the large-scale intraseasonal oscillation. The upper ocean stores significant heat in the BoB, enough to maintain SST above 29°C despite cooling by surface fluxes and ocean mixing. Comparison with reanalysis indicates biases in air–sea fluxes, which may be related to overly cool prescribed SST. Resolution of such biases offers a path toward improved forecasting of transition periods in the monsoon.

Full access