Interaction of MJO with Monsoon Trough over India

The 122 days period of Indian Summer Monsoon (ISM) is highly sensitive to different phases of Madden Julian Oscillation (MJO). Studies have come up with the fact that a large proportion of break spells in Indian Monsoon is aligned with 1^st, 2^nd, 7^th and 8^th phase of MJO whereas most of the active events are observed during 3^rd- 6^th phase of MJO. The active and break spells are often linked with the position of monsoon trough. It has been seen that the drowning of monsoon trough near the central and southern Bay of Bengal gives rise to the active events over India whereas during the break spells, the trough shifts its position near the foothills of Himalayas and causes extreme precipitation in the southern Himalaya and northeastern India. The present study attempts to evaluate the extent of shifting in monsoon trough during different phases of MJO. We intend to assess the changes in tropospheric temperature patterns during the active and break phases and its resulting impact on the kinetic energy budget of ISM. We see that the occurrence of MJO is responsible for changes in mean energy budget of the Indian Monsoon. The resulting changes are also reflected in the position and slope of monsoon trough. It is suggested that MJO can be a major predictor of Indian monsoon and help improve the predictability at longer time scales.