关键词: 降解地膜, 降解地膜, 控释肥, 中稻, 再生稻

Abstract: We studied the atmospheric stratification features and the formation reasons of snow only and ice particles days, aiming to enhance the distinguishing ability of different precipitation phases, provide more accurate meteorological services for agricultural production and meet the needs of agricultural disaster prevention and mitigation and government decision making. Taking two different types of solid precipitation weather processes in winter of Jiangsu as an example, based on the surface eteorological observation data, sounding data and NCEP/NCAR reanalysis data, we emphatically analyzed the difference of temperature and humidity profiles as well as the evolution of vertical movement and temperature advection in the two weather processes. The results showed that: in the process of snow only days, the temperature vertical profile was below 0℃ from near the ground to the sky, which approached but not passed through 0℃ isotherms; while in the weather process of ice particles, the temperature vertical profile passed through 0℃ isotherms many times and the near ground temperature was above 0℃. The up and down configuration in melting layer and freezing layer helped the solid precipitation refreeze after melting. The formation of melting layer and freezing layer was related to warm and cold advection, respectively. The dry layer with low relative humidity existed under 850 hPa when the ice particles weather happened. The dry layer formation was associated with sinkin movement of dry and cold air and invasion of the dry advection, moreover, the location heights of both dry layer and freezing layer were consistent. The liquid precipitation content led to further decreasing of temperature in freezing layer by evaporation and heat absorption when passing through dry layer, which indicated that the positive feedback mechanism was the key factor to the formation of ice particles.