Publication Date:
2021-05-19
Description:
We explore the path between Indian Ocean observations and monsoon dynamics, the societal impacts
of interannual climate variations and applications of resource predictions in southeastern Africa, the
Mascarene Islands, India, southeast Asia and Australia. Recent progress in understanding ocean
dynamics associated with SST variation is reviewed. The global El Niño-Southern Oscillation (ENSO)
affects monsoon winds and ocean temperatures in a manner consistent with, but lagging, the Pacific.
The ENSO influence often propagates across the tropical Indian Ocean from Africa to Indonesia,
modulating the tropospheric moisture flux over the Indian Ocean and rainfall in surrounding
continents. An east-west dipole in SST anomalies and monsoon rainfall is identified and related to
the atmospheric Walker Cell. It appears partially in response to global ENSO conditions during
build-up phase (July-Nov.). The eastern ‘node’ is confined near Sumatra, whilst the western centre of
action extends from the Maldives to the Seychelles Islands. Correlations indicate that the strength of
ENSO in the Indian Ocean region has decreased in recent decades, while large scale, spatial and
temporal patterns suggest independent variations of the Indian Ocean. Apart from annual variations
of the monsoon and year-to-year fluctuations of climate, short-term weather events have a dramatic
impact on countries around the Indian Ocean. Recent floods in southern (2000) and eastern (1997-
98) Africa and southeast Asia (1998) are related to SST patterns and localised atmospheric
responses. Predictions of the future availability of food and water resources, and short-term forecasts
of storm events are some of the decision tools that can be offered through information from ocean
data. The close relationship between regional SST anomalies and impacts on the food and water
resources of surrounding countries provides a strong motivation for sustained observations in the
Indian Ocean. A specific design plan for the observational network is proposed, linking eastern and
western efforts in an efficient manner.
Keywords:
Indian Ocean
;
Climate impacts
;
SST patterns
;
ENSO responses
Repository Name:
AquaDocs
Format:
286391 bytes
Format:
application/pdf
