Characteristic Analysis of Relationship Between Precipitation and Turbulence in the Troposphere and Lower Stratosphere Over Tropical Western Pacific

This study aims to analyze the distribution characteristics of turbulence in the western Pacific tropical region and determine the correlation between turbulence and precipitation. The obtained results show that due to the combined action of large wind shear and thermal convection, the near-surface layer is conducive to the generation of large-scale turbulence, and the maximum Thorpe scale can reach more than 600 m. A strong mixing zone of turbulence is generated in 10-16 km, with the monthly average occurrence rate of turbulence being about 40% and the maximum value reaching 50%. There is less turbulence in lower stratosphere due to the rapidly increased atmosphere static stability. All Thorpe scales in stratosphere are less than 100 m. The response of turbulence to precipitation in the upper troposphere is strongly affected by clouds. At the altitude in the clouds, the enhancement of precipitation has a negative relationship with turbulence. The average value of LT ${L}_{T}$ and turbulence layer thickness on rainy days are both smaller than those when the precipitation weakened. At the altitude above the clouds, the enhancement of precipitation has a slight promotion effect on the turbulence, especially for the emergence of large-scale turbulence. When the precipitation intensifies, the amount of turbulence with LT ${L}_{T}$ greater than 150 m accounts for 6.7% of the total, while the proportion is only 2.6% on less rainy days.