4 research outputs found
Seasonal and interannual variations of water vapor in the upper troposphere and lower stratosphere over the Asian Summer Monsoon region- in perspective of the tropopause and ocean-atmosphere interactions
Role of Tropical easterly jet (TEJ) in stratospheric-troposphere exchange: Observations inferred from Indian MST Radar
15th MST Radar Workshop
Session M6: Middle atmosphere dynamics and structure
May 31 (Wed), NIPR Auditoriumconference objec
Diurnal variability of the global tropical tropopause: results inferred from COSMIC observations
Short and long-term variability of the tropical tropopause controls the exchange of minor constituents between the troposphere and the stratosphere. We present the diurnal variability of the global tropical tropopause altitude and temperature using 7 years of COSMIC observations. The aim of the study is to extract diurnal tropopause signals and their impact on stratosphere-troposphere exchange processes. The possible role of atmospheric tides and convection in controlling the tropopause characteristics are discussed. The most significant and new observation is that in the deep tropics the cold-point tropopause altitude is higher and temperatue is cooler over the land (ocean) during evening to late evening hours (afternoon to early evening). Lower tropopause altitude allows the stratospheric air intrusion into the troposphere during the day time. The combined effect of diurnal tropopause altitude changes and turbulent mixing increases the possibility of stratospheric intrusions. A warmer forenoon tropopause allows increased injection of water vapor from the troposphere to the lower stratosphere. Over the tropical land (ocean), the zonal mean diurnal amplitude is 130–200 m (140–180 m) for tropopause altitude and 0.6–0.9 K (0.6–0.8 K) for tropopause temperature
