Understanding Recycled Precipitation at Different Spatio‐Temporal Scales Over India: An Eulerian Water Tagging Approach

Abstract

Land evapotranspiration has a notable impact on the continental precipitation of India during monsoons. Given the heterogeneous land use and climate, India hosts many transition zones, which are hotspots for land-atmosphere interactions. This work aims to study the soil moisture-precipitation feedbacks over India by quantifying recycled precipitation using the Eulerian water vapor-tagging technique incorporated in the Weather Research and Forecasting model. Eulerian vapor tagging techniques provide the most accurate information on recycled precipitation. We tracked the vapor originating at two spatial scales-entire India and six homogeneous monsoon regions. The latter analysis is conducted to assess inter-regional vapor exchanges. In this process, we determined the seasonal, monthly, and diurnal variations of recycling ratio and assessed its behavior during active and monsoon break periods. We considered three contrasting monsoon seasons (surplus, normal, and deficit rainfall years) for analysis. Results show a high recycling ratio in Central India, Gangetic plain, and Northeast India. Recycling ratio increases with monsoon progression and peaks in September (∼0.30). The Himalaya and transient low-pressure systems originating from the Bay of Bengal are vital for precipitation recycling in India. The contrasting monsoons exhibit changes in recycling ratio only at monthly scale. Regional analysis indicates West Central India is the most significant vapor contributor, while Northeast India is the highest recipient of recycled precipitation. High recycling (∼20%) shifts from central India during the active period to the foothills of Himalaya during the break period. Diurnal scale analysis reveals high afternoon recycling due to enhanced convective activity.

Soil moisture–precipitation feedbacks in pre‐ and post‐monsoon landfalling tropical cyclones in Bay of Bengal

“…The precipitation associated with the tagged water vapor is termed tagged precipitation, which is equivalent to recycled precipitation ($$$ {P}_{\mathrm{Recycled}} $$$). Navale and Karthikeyan (2023) employed the same model with similar setup to study the monsoon season over the Indian subcontinent. Using $$$ {P}_{\mathrm{Recycled}} $$$, the recycling ratio $$$ \left(\vartheta \right) $$$ is defined as follows (Equation 1).…”

“…Recycled precipitation is generally quantified using analytical (Van Der Ent and Savenije, 2011; Singh et al ., 2016), Lagrangian (Dominguez et al ., 2006; Dirmeyer et al ., 2014; Holgate et al ., 2020; Tuinenburg and Staal, 2020), Eulerian (Arnault et al ., 2016, 2019, 2021; Insua‐Costa and Miguez‐Macho, 2018) and stable‐isotope approaches (Dansgaard, 1964; Zhu et al ., 2019). Recycled precipitation has been used routinely to assess the effects of land feedback on precipitation processes (Tuinenburg et al ., 2012; Pathak et al ., 2014; Sujitha et al ., 2017; Chakraborty et al ., 2022; Navale and Karthikeyan, 2023). In the context of monsoon depressions and TCs, the recycling ratio was used to determine the land–atmosphere feedback (Baisya et al ., 2017; Liu et al ., 2019).…”

“…However, the study was carried out for a single depression over the BoB, which has low intensity compared to a TC. A recent study by Navale and Karthikeyan (2023) quantified the recycled precipitation over India during the monsoon season using an online Eulerian water‐tagging approach, which is considered most accurate in the context of regional studies (Gimeno et al ., 2020). The study revealed that the low‐pressure systems originating over the BoB (monsoon depressions) affect the recycled precipitation over India.…”

Parametric and Non-parametric Analysis of Annual Precipitation for Amaravati: A Spatial and Temporal Analysis

“…Trends in precipitation have been extensively studied around the world [10] [11] [12][13] [14][15] [16] [17]. The studies reveal both rising and declining trends with the behavioral changes in seasonal precipitations at various spatial scales across India IOP Publishing doi:10.1088/1742-6596/2779/1/012026 2 [18][19] [20][21] [22][23] [24] [25]. Regular examination and understanding of rainfall patterns are essential for the efficient advancement, strategic organisation, and effective administration of water resources.…”