Pre-monsoon rainfall over Mawsynram region, India during 2020

The South West Monsoon rainfall data of the meteorological subdivision number 6 of India enclosing Gangetic West Bengal is shown to be decomposable into eight empirical time series, namely Intrinsic Mode Functions. This leads one to identify the first empirical mode as a nonlinear part and the remaining modes as the linear part of the data. The nonlinear part is modeled with the technique Neural Network based Generalized Regression Neural Network model technique whereas the linear part is sensibly modeled through simple regression method. The different Intrinsic modes as verified are well connected with relevant atmospheric features, namely, El Nino, Quasi-biennial Oscillation, Sunspot cycle and others. It is observed that the proposed model explains around 75% of inter annual variability (IAV) of the rainfall series of Gangetic West Bengal. The model is efficient in statistical forecasting of South West Monsoon rainfall in the region as verified from independent part of the real data. The statistical forecasts of SWM rainfall for GWB for the years 2012 and 2013 are108.71 cm and 126.21 cm respectively, where as corresponding to the actual rainfall of 93.19 cm 115.20 cm respectively which are within one standard deviation of mean rainfall.

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Time Series Analysis based Tamilnadu Monsoon Rainfall Prediction using Seasonal ARIMA

2021 6th International Conference on Inventive Computation Technologies (ICICT) ◽

10.1109/icict50816.2021.9358615 ◽

2021 ◽

Author(s):

U. Ashwini ◽

K. Kalaivani ◽

K. Ulagapriya ◽

A. Saritha

Keyword(s):

Time Series ◽

Time Series Analysis ◽

Monsoon Rainfall ◽

Rainfall Prediction ◽

Series Analysis

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Impact of the tropical Pacific SST biases on the simulation and prediction of Indian summer monsoon rainfall in CFSv2, ECMWF-System4, and NMME models

Climate Dynamics ◽

10.1007/s00382-020-05555-1 ◽

2021 ◽

Author(s):

Prasanth A. Pillai ◽

Suryachandra A. Rao ◽

Ankur Srivastava ◽

D. A. Ramu ◽

Maheswar Pradhan ◽

...

Keyword(s):

Summer Monsoon ◽

Indian Summer Monsoon ◽

Monsoon Rainfall ◽

Indian Summer Monsoon Rainfall ◽

Summer Monsoon Rainfall ◽

Tropical Pacific ◽

The Tropical Pacific

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Tectonic and climatic drivers of Asian monsoon evolution

Nature Communications ◽

10.1038/s41467-021-24244-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

James R. Thomson ◽

Philip B. Holden ◽

Pallavi Anand ◽

Neil R. Edwards ◽

Cécile A. Porchier ◽

...

Keyword(s):

Summer Monsoon ◽

Indian Summer Monsoon ◽

Asian Monsoon ◽

Monsoon Rainfall ◽

East Asian Monsoon ◽

East Asian ◽

Meridional Overturning Circulation ◽

Great Debate ◽

Climatic Drivers ◽

Meridional Overturning

AbstractAsian Monsoon rainfall supports the livelihood of billions of people, yet the relative importance of different drivers remains an issue of great debate. Here, we present 30 million-year model-based reconstructions of Indian summer monsoon and South East Asian monsoon rainfall at millennial resolution. We show that precession is the dominant direct driver of orbital variability, although variability on obliquity timescales is driven through the ice sheets. Orographic development dominated the evolution of the South East Asian monsoon, but Indian summer monsoon evolution involved a complex mix of contributions from orography (39%), precession (25%), atmospheric CO2 (21%), ice-sheet state (5%) and ocean gateways (5%). Prior to 15 Ma, the Indian summer monsoon was broadly stable, albeit with substantial orbital variability. From 15 Ma to 5 Ma, strengthening was driven by a combination of orography and glaciation, while closure of the Panama gateway provided the prerequisite for the modern Indian summer monsoon state through a strengthened Atlantic meridional overturning circulation.

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Anthropogenic warming and intraseasonal summer monsoon variability amplify the risk of future flash droughts in India

npj Climate and Atmospheric Science ◽

10.1038/s41612-020-00158-3 ◽

2021 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

Vimal Mishra ◽

Saran Aadhar ◽

Shanti Shwarup Mahto

Keyword(s):

Soil Moisture ◽

Summer Monsoon ◽

Crop Production ◽

Monsoon Rainfall ◽

Root Zone ◽

Monsoon Season ◽

Intraseasonal Variability ◽

Positive Temperature ◽

Groundwater Abstraction ◽

Increased Risk

AbstractFlash droughts cause rapid depletion in root-zone soil moisture and severely affect crop health and irrigation water demands. However, their occurrence and impacts in the current and future climate in India remain unknown. Here we use observations and model simulations from the large ensemble of Community Earth System Model to quantify the risk of flash droughts in India. Root-zone soil moisture simulations conducted using Variable Infiltration Capacity model show that flash droughts predominantly occur during the summer monsoon season (June–September) and driven by the intraseasonal variability of monsoon rainfall. Positive temperature anomalies during the monsoon break rapidly deplete soil moisture, which is further exacerbated by the land-atmospheric feedback. The worst flash drought in the observed (1951–2016) climate occurred in 1979, affecting more than 40% of the country. The frequency of concurrent hot and dry extremes is projected to rise by about five-fold, causing approximately seven-fold increase in flash droughts like 1979 by the end of the 21st century. The increased risk of flash droughts in the future is attributed to intraseasonal variability of the summer monsoon rainfall and anthropogenic warming, which can have deleterious implications for crop production, irrigation demands, and groundwater abstraction in India.

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