Observational and Numerical Modeling Studies of Downdrafts Within Precipitating Convection

降水对流内下降气流的观测和数值模拟研究

• 批准号: 8800606
• 负责人: Kevin Knupp
• 金额: $ 17.48万
• 依托单位: University of Alabama in Huntsville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-05-01 至 1991-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8800606&HistoricalAwards=false
• 关键词: Observational; Numerical; Modeling; Studies; Downdrafts

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.

成熟的对流风暴的下沉气流已经被证明 对很多气象现象都很重要 例如，在较小的空间尺度上， 已被证明对航空有危害（“微暴流”） 在确定自然界的性质和 新的对流活动的时间。 在更大的范围内，它 已经表明，不正确的参数化 数值模式中的风暴尺度下沉气流通常会导致 定量降水的实质性误差 预测。 主要研究者将研究 局地下沉气流特征及形成机制 在对流风暴中。 调查的一个领域将是 测试下降气流开始的假设， 主要通过融化和蒸发过程控制 在地球表面附近。 他建议，为了应对 低高度的下降气流，可以引起高空的卷吸。 这一解释与早期的研究不同， 在中层对流风暴中的夹带可能 形成下沉气流。 主要研究者将使用数值模型 以及之前收集的观测数据 他的研究目标。