Modulation of ISOs by land‐atmosphere feedback and contribution to the interannual variability of Indian summer monsoon

Saha, Subodh Kumar; Halder, Subhadeep; Rao, Amit; Goswami, B. N.

doi:10.1029/2011jd017291

Cited by 52 publications

(63 citation statements)

References 41 publications

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“…The development of low pressure over subcontinental land during premonsoon months (i.e., April and May), owing to the land-sea thermal contrast between Indian land regions and the Indian Ocean, results in advection of evaporated oceanic moisture toward the Indian region (Krishnamurthy and Kinter 2003). Although the land-sea thermal contrast is one of the major mechanisms influencing summer monsoon precipitation characteristics, several land surface processes, such as soil moisture, evapotranspiration, and topography and land use, are also associated with seasonal monsoon precipitation dynamics (Meehl 1994;Yasunari 2007;Bellon 2010;Saha et al 2012). The spatial and temporal variability of rainfall is often regulated by the strength of land surface feedbacks (Shukla and Mintz 1982;Yasunari 2007).…”

Section: Introductionmentioning

confidence: 99%

Precipitation Recycling in the Indian Subcontinent during Summer Monsoon

Pathak

Ghosh

Kumar

2014

Journal of Hydrometeorology

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The Indian summer monsoon rainfall is dominated by oceanic sources of moisture. However, land surface processes also have a significant role in the generation of precipitation within the Indian subcontinent. Evapotranspiration over a region supplies moisture to the atmosphere, which may lead to precipitation in the same region. This is known as recycled precipitation. The role of evapotranspiration as an additional source of moisture to precipitation has been investigated in earlier studies at continental scales; however, the amount of monsoon precipitation generated from evapotranspiration has not been quantified at the daily scale for the Indian subcontinent. To examine the role of land surface hydrology in regional precipitation and to quantify recycled precipitation, the dynamic recycling model at a daily scale with NCEP Climate Forecast System Reanalysis (CFSR) data for the period of 1980-2010 is used. A high precipitation recycling ratio, that is, the ratio of recycled precipitation to total precipitation, is found at the end of the monsoon (September). As the monsoon progresses in India, enhanced soil moisture and vegetation cover lead to increased evapotranspiration and recycled precipitation. The recycling ratio is highest (around 25%) in northeastern India, which has high vegetation cover leading to high evapotranspiration. Recycled precipitation over central and northeastern India in September is responsible for delaying the withdrawal of the summer monsoon over these regions. A trend analysis of recycled precipitation shows a statistically significant decreasing trend in northeastern India.

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Section: Introductionmentioning

confidence: 99%

Precipitation Recycling in the Indian Subcontinent during Summer Monsoon

Pathak

Ghosh

Kumar

2014

Journal of Hydrometeorology

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“…An agricultural water allocation model at a fortnight scale or at a seasonal scale considering the improved seasonal (Saha et al, 2012) and extended range forecast (Sahai et al, 2013;Shah et al, 2017) may be useful, and this needs to be further explored in the near future.…”

Section: Discussionmentioning

confidence: 99%

“…There is a need to develop a proper irrigation scheduling considering the weather forecasts (Shah et al, 2017) and extended range forecasts (Sahai et al, 2013) of precipitation.…”

Section: North-western India (Nwi)mentioning

confidence: 99%

Water–food–energy nexus with changing agricultural scenarios in India during recent decades

Barik

Ghosh

Sahana

et al. 2017

Hydrol. Earth Syst. Sci.

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Abstract. Meeting the growing water and food demands in a densely populated country like India is a major challenge. It requires an extensive investigation into the changing patterns of the checks and balances behind the maintenance of food security at the expense of depleting groundwater, along with high energy consumption. Here we present a comprehensive set of analyses which assess the present status of the waterfood-energy nexus in India, along with its changing pattern, in the last few decades. We find that with the growth of population and consequent increase in the food demands, the food production has also increased, and this has been made possible with the intensification of irrigation. However, during the recent decade (after 1996), the increase in food production has not been sufficient to meet its growing demands, precipitating a decline in the per-capita food availability. We also find a statistically significant declining trend of groundwater storage in India during the last decade, as derived from the Gravity Recovery and Climate Experiment (GRACE) satellite datasets. Regional studies reveal contrasting trends between northern and western-central India. North-western India and the middle Ganga basin show a decrease in the groundwater storage as opposed to an increasing storage over western-central India. Comparison with well data reveals that the highest consistency of GRACE-derived storage data with available well measurements is in the middle Ganga basin. After analysing the data for the last 2 decades, we further showcase that, after a drought, the groundwater storage drops but is unable to recover to its original condition even after good monsoon years. The groundwater storage reveals a very strong negative correlation with the electricity consumption for agricultural usage, which may also be considered as a proxy for groundwater pumped for irrigation in a region. The electricity usage for agricultural purposes has an increasing trend and, interestingly, it does not have any correlation with the monsoon rainfall as computed with the original or de-trended variables. This reveals an important finding that the irrigation has been intensified irrespective of rainfall. This also resulted in a decreasing correlation between the food production and monsoon rainfall, revealing the increasing dependency of agricultural activities on irrigation. We conclude that irrigation has now become essential for agriculture to meet the food demand; however, it should be judiciously regulated and controlled, based on the water availability from monsoon rainfall, specifically after the drought years, as it is essential to recover from the deficits suffered previously.

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“…intraseasonal variability (ISV)] the onset tends to be led by a northeastward propagation of an intraseaonal convective anomaly from the western equatorial Indian Ocean. In boreal summer, these northward-propagating ISVs carry a large amount of moisture and momentum from the tropics to the subtropics (Saha et al, 2012), which delivers a strong pulse of perturbation to the background state over the Bay of Bengal and the Indian subcontinent. Therefore, northwardpropagating ISVs are a key precursor of monsoon onset, as pointed out by Wang et al (2009a).…”

Section: Onset Of the Asian Summer Monsoonmentioning

confidence: 99%

From MONEX to the global monsoon: A review of monsoon system research

et al. 2014

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Substantial progress has been made over the past three decades since the Monsoon Experiments (MONEX) of 1978-79. Here, we review these achievements by highlighting four breakthroughs in monsoon research: (1) The identification of the coupled ocean-land-atmosphere nature of the monsoon in the process of the annual cycle of solar heating; (2) new understanding of the changes in the driving forces of monsoon systems, with anthropogenic factors (climate effects of increased greenhouse gas and aerosol emissions) playing an important role in the regulation of monsoons; (3) detection of the interdecadal-and centennial-scale variability of monsoon systems, and its attribution to the combined impact of global warming and natural (especially oceanic) effects; and (4) the emerging concept of the global monsoon and its long-term variation under the impact of global climate change. All the observational and model-derived evidence demonstrates that the monsoon system, as an important component of the global climate system, has already changed and will continue to change in the future. This picture of an evolving monsoon system poses great challenges for near-term prediction and long-term projection.

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Modulation of ISOs by land‐atmosphere feedback and contribution to the interannual variability of Indian summer monsoon

Cited by 52 publications

References 41 publications

Precipitation Recycling in the Indian Subcontinent during Summer Monsoon

Precipitation Recycling in the Indian Subcontinent during Summer Monsoon

Water–food–energy nexus with changing agricultural scenarios in India during recent decades

From MONEX to the global monsoon: A review of monsoon system research

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