The intraseasonal fluctuation of Indian summer monsoon rainfall and its relation with monsoon intraseasonal oscillation (MISO) and Madden Julian oscillation (MJO)

Abstract

The intra-seasonal uctuations of Indian summer monsoon rainfall (ISMR) are mainly controlled by northward propagating Monsoon Intra-seasonal Oscillation (MISO) and eastward propagating Madden Julian Oscillation (MJO). In the current study, we examine the relationship between the intra-seasonal uctuations (active and break spells) of ISMR with the phase propagation and amplitude of MISO and MJO. We notice that active spells generally occur during MISO phase 2-5 (MJO phase 3-6), and break spells mainly occur during MISO phase 6-8 (MJO phase 6-8 and 1). The association of active/break spells with MISO phases is more prominent than with MJO phases. We show the phase composite of un ltered and regression based reconstructed rainfall for eight MISO and MJO phases, and the same is consistent with the earlier ndings. We notice that the reconstructed eld shows a systematic and wellorganised northward propagation compared to the un ltered eld. Phase composite also indicates that there is a lead-lag relationship between MISO and MJO phases. MISO phase composite shows more robust northward propagation than the MJO phase composite. MISO reconstructed rainfall explained more percentage variance than MJO reconstructed rainfall with reference to 20-90 days ltered rainfall.It is found that long active (> 7 days) predominantly occurs when either MISO or MJO, or both of them are active, and the associated signal is somewhere in between phase 2-5. A long break occurs when either one or both of them are feeble, or even though associated signals are strong, they are primarily located in phases 1, 6, 7 and 8.

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

“…In order to identify active and break periods in monsoon, we utilized the analysis carried out by A. Dey et al. (2022), which gave a list of active and break periods in monsoon from 1998 to 2018 (Table 1 in A. Dey et al., 2022) using the method proposed by Rajeevan et al. (2010).…”

“…Dey et al (2022), which gave a list of active and break periods in monsoon from 1998 to 2018 (Table 1 in A. Dey et al, 2022) using the method proposed by Rajeevan et al (2010). For brevity, the active and break periods are selected from 2018 since it was a normal monsoon year (91% of LPA).…”

Orographic effects on droughts in a monsoon climate with the world's highest rainfall

“…Coupled with such intraseasonal variability, active (wet) and break (dry) phases of monsoon rainfall can influence the occurrence of drought (Roman‐Stork et al, 2020). Active and break phases are largely controlled by the most prominent quasi‐bi‐weekly oscillation with a period of 7–25 days and a Madden–Julian oscillation with a period of 30–60 days (Dey et al, 2022; Goswami & Mohan, 2001). In particular, the submonthly oscillation associated with the north–south movement of the monsoon trough is significantly more robust than the Madden–Julian oscillation associated with the northward propagation of convection from the equatorial Indian Ocean (Fujinami et al, 2011).…”

Estudio De Teleconexiones: Oferta Hídrica En Santa Marta Versus Fenómenos Macroclimáticos.

“…El régimen pluviométrico define la oferta y la disponibilidad del recurso hídrico y, como consecuencia, condiciona las actividades socioeconómicas dependientes del agua. En su parte, en diferentes lugares del mundo la pluviosidad depende de los diferentes fenómenos macroclimáticos como ENSO (Veiga, 2022), Oscilación Cuasibienal (Habtegebreal, 2021), Madden -Julian (Dey, 2022), entre otros. El efecto de estos fenómenos se refleja en la alteración del régimen de precipitaciones tanto en su oferta como en su variabilidad.…”