Observational and Numerical Modeling Studies of Downdrafts Within Precipitating Convection

来自成熟对流风暴的下降气流已被证明对许多气象现象都很重要。例如，在较小的空间尺度上，强烈的下降气流已被证明对航空是一种危害（“微暴”），并且在确定新的对流活动的性质和时间方面非常重要。在更大的区域内，数值模式对风暴尺度下降气流的参数化不正确常常导致定量降水预测出现重大误差。首席研究员将研究对流风暴中局部下沉气流的特征和形成机制。研究的一个领域将是检验这样一种假设，即下沉气流主要是由地球表面附近的融化和蒸发过程引发和控制的。他提出，为了应对低空下降气流，高空夹带可以被诱导。这种解释与早期的研究不同，早期的研究认为，中层对流风暴的夹带可能是下行气流形成的原因。首席研究员将使用数值模拟和先前收集的观测数据来完成他的研究目标。

Downdrafts from mature convective storms have been shown to be important to a wide range of meteorological phenomena. For example, at smaller spatial scales, intense downdrafts have been shown to be a hazard to aviation ("microbursts") and to be very important in determining the nature and timing of new convective activity. Over larger areas, it has been shown that incorrect parameterization of stormscale downdrafts in numerical models often leads to substantial errors in quantitative precipitation predictions. The Principal Investigator will study the characteristics and formation mechanism of local downdrafts in convective storms. One area of investigation will be to test the hypothesis that downdrafts are initiated and controlled mainly thought melting and evaporation processes near the earth's surface. He proposes that in response to low altitude downdrafts, entrainment aloft can be induced. This explanation differs from earlier studies which suggest that entrainment into convective storms at mid levels might be responsible for downdraft formation. The Principal Investigator will use numerical modelling and previously collected observational data to accomplish his research goals.