@article{fdi:010096263,
  title = {{D}ynamics of the inland penetrating {I}ndian monsoon depressions},
  author = {{S}andhyavijayan, {K}. and {S}ooraj, {K}. {P}. and {S}uhas, {E}. and {T}erray, {P}ascal},
  editor = {},
  language = {{ENG}},
  abstract = {{D}espite the decisive role of {B}ay of {B}engal {M}onsoon {D}epressions ({MD}s) in contributing to the {I}ndian summer monsoon mean rainfall, the exact mechanisms and processes contributing to their prolonged residence over the {I}ndian landmass remain still elusive. {S}o, a comprehensive analysis on the factors affecting the inland penetration length of {MD}s after landfall over the {I}ndian landmass, is presented here using {MD}s identified from {I}ndian {M}eteorology {D}epartment weather reports over 3 decades (1991-2020). {E}xploration of large-scale atmospheric circulation features using {ERA}-5 reanalysis data shed new insights on the processes contributing to the maintenance and sustenance of land penetrating {MD}s. {N}otably, all {H}igher {I}nland {P}ropagating ({HIP}) {MD}s were preceded by {M}id-{T}ropospheric {C}yclones ({MTC}s, with cyclonic circulation in the lower and mid-troposphere) over {N}orth-{W}est ({NW}) {I}ndia, with this entire region experiencing increased moisture flux convergence, thus facilitating the deep intrusion of {MD}s into the {I}ndian landmass. {I}n contrast, the {L}ower {I}nland {P}ropagating ({LIP}) {MD}s experience dry air intrusion from the adjacent desert region, creating unfavorable moisture conditions and leading to their rapid dissipation. {I}ntriguingly, the {HIP} {MD}s were further found to cluster with the westward propagating large-scale intraseasonal mode (i.e.,10-20 days). {U}sing the updated {GLDAS} soil moisture reanalysis, it is further revealed that the precipitation caused by both the {MTC}, and the 10-20 days intraseasonal oscillation mode saturates the land surfaces before the arrival of {MD}s in the northwestern central {I}ndian region during {HIP} events. {I}n short, our results show that the presence of cyclonic vorticity over {NW} {I}ndia, in association with the large-scale westward propagating (10-20 days) mode of variability, creates favorable conditions for the inland penetration of {HIP} events. {F}urther, the results highlighting the importance of 10-20 days mode and its propensity to cluster with the land penetrating {MD}s, assume significance in a changing climate, as the subseasonal {I}ndian monsoon rainfall variability is projected to increase in the future.},
  keywords = {{M}onsoon depressions ({MD}s) ; {H}igher inland propagating ({HIP}) {MD}s ; {L}ower inland propagating ({LIP}) {MD}s ; {M}id-tropospheric cyclones ; {S}oil moisture ; {I}ntraseasonal oscillation},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {64},
  numero = {2},
  pages = {57 [17 p.]},
  ISSN = {0930-7575},
  year = {2026},
  DOI = {10.1007/s00382-025-08014-x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010096263},
}