Page 7 - CII Artha Magazine

Focus Story

Indian El Niño, the warm phase of variation of monsoon consists
ENSO, is associated with the
of wet spells (Active phase)
with continuous rains for a
warming of SSTs over central
few days are interspersed
and east-central Equatorial
Monsoon Pacific adversely impacts the with relatively dry spells
(Break phase) of varying
Indian monsoons and hence,
agriculture in India. The La
duration. Long breaks in
critical growth periods of
Niña, cooler phase of ENSO
Variability: It’s generally favours stronger agricultural crops lead to
substantially reduced yield.
than normal Indian monsoon.
Even in normal monsoon
years, an uneven spatial and
A NEGATIVE IOD
temporal distribution of rains
Impact on the PHASE RESULTS IN has an adverse effect on
agriculture. The intra-seasonal
A WEAKER THAN
rainfall distribution over India
NORMAL INDIAN
is influenced by different
MONSOON
quasi-periodic oscillations, viz.
Indian Economy Another climatic oscillation, 3-7 days, 10-20 days and Meteorological Department, New Delhi
30-60 days. While 3-7 days
Dr D. S. Pai, Scientist -G, India
periodicity is associated with
referred to as the Indian
oscillations of the monsoon
Ocean Dipole (IOD), involves
periodicity or quasi-biweekly
fluctuations in Sea Surface trough, the 10-20 days
Temperatures (SST) across oscillations are associated
the Western Indian Ocean with the westward moving
near the Arabian Sea and the waves or synoptic scale
eastern counterpart near convective systems generated
Indonesia in the Indian Ocean. over the warm Bay of Bengal
I ndia's distinctive seasonal rainfall during JJAS, The IOD is essentially the and propagating inland
geographical features,
particularly for an economy
including its proximity to the heavily reliant on agriculture, contrast in SSTs between towards the main land of
these two regions. When the
India. The 30-60 days
Himalayas and the expansive such as India's. western part of the Indian oscillations, popularly known
Asian landmass in the north, Ocean, near the Somalia as Madden-Julian Oscillations
along with its southern The irregular behaviour of the rainfall and can have a direct (2002, 2004, 2009, 2014 and coast, experiences higher (MJOs) are the dominant
border touching the Indian Monsoon that disrupt the impact on the nation's 2015) compared to the 2 SSTs compared to that over component of the
Ocean, create distinct climatic usual rainfall patterns are economy. Consequently, excess years (2007 & 2019). the eastern Indian Ocean, it intra-seasonal variability (ISV)
patterns marked by a referred together as the comprehending and The deficient and excess signifies a positive IOD, which in the tropical atmosphere. It
pronounced contrast unpredictability of the forecasting monsoon years are identified based on tends to be conducive for the consists of large-scale
between land and sea. The monsoon. These variations in fluctuations stands as one of the departure of AISMR stronger than normal Indian coupled patterns in
period spanning from June to the monsoon stem from the the most formidable beyond ± 1 SD, which is ≈ 10 monsoon. Conversely, a atmospheric circulation and
September, known as the intricate interactions among challenges in the field of per cent of its seasonal negative IOD phase is results deep convection, propagating
Southwest Monsoon season the land, atmosphere, and atmospheric science today. average AISMR of 87 cm weaker than normal Indian eastward slowly (~5 m/s)
(JJAS), brings with it a mix of ocean components of the (Average of 1971 to 2020). monsoon. through the Indian and Pacific Dr M. Mohapatra, Director General of Meteorology,
droughts and floods, an climate system. They The interannual The atmospheric-ocean oceans where the sea surface India Meteorological Department, New Delhi
alternating pattern of active result from factors variability of coupled phenomenon like El THE VARIATION IN is warm.
and break phases in the like the premature All India Niño–Southern Oscillation RAINFALL WITHIN THE
monsoon, and heavy rainfall onset or delayed Summer (ENSO) is one of the major Considering the importance
across different regions of the withdrawal of rain, Monsoon drivers of the interannual SUMMER MONSOON of prediction of monsoon on
country. The monsoon, an which can devastate Rainfall variability of AISMR. ENSO SEASON IS KNOWN AS different time scales, IMD has Contributed by:
annual visitor, arrives crops and (AISMR) refers to the large-scale THE INTRA-SEASONAL implemented various Dr D. R. Pattanaik, Scientist - F, India
consistently but not always subsequently slow during the ocean-atmosphere climate VARIATION OF numerical models to forecast Meteorological Department, New Delhi
with the same intensity. down economic last 22 interaction linked to periodic MONSOON the monsoon rainfall in short
Hence, each summer, not only growth. Beyond years variation in the winds and sea range (up to 3 days), medium Dr D. S. Pai, Scientist -G, India
meteorologists and farmers agriculture, a consists of 5 surface temperatures (SSTs) In addition to the interannual range (up to 10 days), Meteorological Department, New Delhi
but also economists are multitude of sectors in deficient years across the central and variability of AISMR, there is extended range (up to 4
preoccupied with the India are closely linked east-central Equatorial Pacific. also variation in rainfall within weeks), and seasonal time Dr M. Mohapatra, Director General of
question of how the to monsoon the summer monsoon season scales to provide services to Meteorology, India Meteorological
monsoon will behave that from Jun to Sep and it is agriculture, water resource, Department, New Delhi
year. This concern is rooted in Dr D. R. Pattanaik, Scientist - F commonly known as the disaster management and
the profound significance of India Meteorological Department, New Delhi intra-seasonal variation of many other sectors.
monsoon. The intra-seasonal
06 ANALYSIS, RESEARCH, THOUGHT LEADERSHIP & ADVOCACY ANALYSIS, RESEARCH, THOUGHT LEADERSHIP & ADVOCACY 07
QUARTERLY JOURNAL OF ECONOMICS
QUARTERLY JOURNAL OF ECONOMICS
SEPTEMBER 2023 SEPTEMBER 2023