01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-03-0016 |
| Title of Abstract | Atmospheric conditions on the west coast of India during the dry and wet spells event in July 2024 |
| Authors | Anupama Sahoo*, Dr. Girishkumar M.S |
| Organisation | INCOIS, Hyderabad |
| Address | INCOIS, Pragathi nagar, hyderabad Hyderabad, Telangana, India Pincode: 500090 E-mail: a.sahoo-rf@incois.gov.in |
| Country | India |
| Presentation | Oral |
| Abstract | The western coast of the Indian peninsula experiences intense rainfall during the summer monsoon months (June⿿September), and some regions record seasonal totals exceeding 250cm. Variations in atmospheric conditions during the monsoon⿿s active and break spells significantly influence water availability, agriculture, and related sectors. However, the physical mechanisms governing atmospheric structure and variability during these transitional phases are still not fully understood. To address this gap, we examine the thermodynamic evolution of the atmosphere using high-resolution radiosonde observations collected in July 2024 during a dedicated field campaign over the southeastern Arabian Sea. These observations were conducted at a fixed time-series location (11.25°N, 72.53°E), where both active and break phases of the monsoon were captured. To complement as well as extend our analysis, we also utilize simulations from the IITM model and ERA5 reanalysis data to explore the broader-scale thermodynamic and dynamical context. Our findings indicate a clear rise in SST and a drop in precipitation during break spells, while the opposite feature occurs during active phases. Vertically integrated moist static energy exhibits a declining trend during the onset of break conditions and begins to increase again as the monsoon transitions into an active phase. This variation is closely linked with prominent intensification of zonal wind speeds along with decreases in mid-tropospheric relative humidity, which decrease sharply during breaks. Analyzing further reveals that rainfall strongly relates to vertically integrated moisture content across different monsoon phases. The modulation of MSE is predominantly driven by moisture processes, with horizontal moisture advection playing a critical role in shaping its divergence. Elevated MSE values during active periods correspond with enhanced convective activity and rainfall, whereas suppressed MSE during breaks contributes to reduced precipitation. This study provides a detailed assessment of the atmospheric moisture and energy budgets and highlights the contrasting mechanisms during transitional phases. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Moist static energy (MSE), Active and break spells, ISM |
| For Awards | yes |
| Date Of Birth | 08-08-1999 |
| ECSN Registration Number | IIOE2-ECSN-0109 |