Signals of northward propagating monsoon intraseasonal oscillations (MISOs) in the RegCM4.7 CORDEX-CORE simulation over South Asia domain

Northward propagating summer monsoon intraseasonal oscillations (MISOs) in the Indian Ocean region remain poorly understood and difficult to predict. Here we examine a free-running high-resolution regional atmospheric model (RegCM4.7 with 25 km resolution), forced distantly at boundaries by observations (ERA-Interim, 0.75 $$^{\circ }$$ ) locally observed sea-surface temperature (SST) over period 1979–2016, assess its ability reproduce key aspects of these MISOs. We find that MISO exhibits spatial structures northward propagation characteristics broadly similar when confining analysis 25–90 day band. The precipitation anomalies are then shown be consistent previously known relationships broad-scale sea-level pressure patterns, Inter-Tropical Convergence Zone (ITCZ) positioning, changes Hadley Cell component. total simulated seasonal (JJAS) rainfall India not significantly correlated observations, indicating intrinsic variations atmosphere dominate most variability. However, bandpass-filtered surprisingly exhibit significant correlation (0.61) observations. This suggests instabilities circulation, e.g., linked ITCZ position or strength, may partly controlled large-scale flows specified domain and/or local SST help guide some fraction developing follow result motivates further research on initiation development using this type model.