Easterly waves and ocean–atmospheric oscillations associated with contrasting northeast monsoon seasons over India

Regional and remote influences of ocean‐atmospheric processes on northeast monsoon rainfall during 2021 over India

“…Although the positive MSLP anomalies over the ASSP region in the case of the OND season of 2016 have been shown in Figure 9b, it significantly confirmed the dry conditions that may be one of the reasons for the deficient NEM. Reba et al (2022) also suggested La Niña and the negative IOD index caused drought in the NEM of 2016. The moisture flux transport at the 850 hPa level is represented in Figure 9d–f.…”

“…However, the climatological ASSP and moisture flux anomaly (calculated using the 30-year mean monthly data from 1982 to 2011) show an interesting aspect of these contrasting NEM years. The intensity of ASSP indicates extreme negative anomalies of MSLP as seen in 2021 over the entire AS (Figure9c) and in 2015 (Figure9a).Although the positive MSLP anomalies over the ASSP region in the case of the OND season of 2016 have been shown in Figure9b, it significantly confirmed the dry conditions that may be one of the reasons for the deficient NEM Reba et al (2022). also suggested La Niña and the negative IOD index caused drought in the NEM of 2016.…”

“…However, 2016 was recorded as deficient in NEMR due to weak La Niña, negative to neutral IOD, and MJO in the other half of the hemisphere, causing a weakening of easterlies and the penetration of continental northerlies into the PI. Reba et al (2022) have studied the characteristics of the NEM of 2015, 2016 and 2017 and reported that the combined effect of strong El Niño and positive IOD dominated by anomalous low‐level easterly wind over the equatorial IO caused excess monsoon in 2015, whereas prevailed weak easterly wind caused deficient monsoon in 2016 and 2017.…”