Studies of Midlatitude Mesoscale Convective Systems

中纬度中尺度对流系统研究

• 批准号: 0500061
• 负责人: Richard Johnson
• 金额: $ 96.02万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0500061&HistoricalAwards=false
• 关键词: Studies; Midlatitude; Mesoscale; Convective; Systems

The objective of this research is to enhance understanding of processes associated with midlatitude mesoscale convective systems (MCSs) and their accompanying severe weather, and ultimately to improve the prediction of such systems. Of particular interest are MCSs having varying patterns of organization of their attendant stratiform precipitation regions and those producing high winds and extreme rainfall. At present, the surface meteorological features associated such systems are not well documented.To address this problem, the Principal Investigator will utilize surface observations from the Oklahoma Mesonet (administered by the Oklahoma Climatological Survey), a dataset now with a record length of ten years, radar data from the WSR-88D network, and Rapid Update Cycle (RUC) analyses to investigate the surface and environmental conditions (wind, pressure, thermodynamic, and precipitation features) accompanying MCSs with trailing, leading, and parallel stratiform precipitation; bow echoes; mesoscale convective vortices (MCVs); and MCSs that produce extreme rainfall. The Oklahoma Mesonet data, consisting of 5-min surface observations at about 30-km resolution, will enable detailed analyses of the mesoscale surface pressure fields. Particular attention will be focused on mesohigh/wake low couplets within MCSs.The intellectual merit of the research derives from the new understanding it will provide of the structure and physical processes associated with a broad range of mesoscale convective systems. The surface signatures of MCSs having different orientations of their stratiform precipitation regions (trailing, leading, and parallel), bow echoes, MCVs, and extreme-rain-producing MCSs have heretofore only been documented from a limited number of case studies. The ten-year record of Oklahoma Mesonet observations now affords the opportunity to more comprehensively determine the surface signatures of a large sample of such precipitation systems, from which inferences can be made about their dynamics. The broader impacts of the research relate to how it will improve understanding and ultimately prediction of MCSs and accompanying severe weather. The surface features associated with a large class of MCSs are measures, sometimes direct and sometimes indirect, of their severity and processes within the storms. For example, bow echoes are characterized by extreme surface winds, MCSs with trailing stratiform precipitation by mesohigh/wake low couplets, and certain extreme rain-producing storms by regeneration of new cells in the same location along storm-generated outflow boundaries. The recognition of such features in relation to the storms they produce is important to weather services for reliable nowcasting and short-term forecasting. These storms are responsible annually for significant life and property damage, and currently the forecast skill for them is low. This research is ultimately directed toward improving the skill in such forecasts.

这项研究的目的是增强对中纬度中尺度对流系统（MCS）及其随附的恶劣天气相关的过程的理解，并最终改善了此类系统的预测。 特别令人感兴趣的是MCS具有不同的组织层状降水区以及产生大风和极端降雨的MCS。 At present, the surface meteorological features associated such systems are not well documented.To address this problem, the Principal Investigator will utilize surface observations from the Oklahoma Mesonet (administered by the Oklahoma Climatological Survey), a dataset now with a record length of ten years, radar data from the WSR-88D network, and Rapid Update Cycle (RUC) analyses to investigate the surface and environmental conditions (wind, pressure,热力学和降水特征）伴随MCS，带有落后，领先和平行地层降水；弓回声；中尺度对流漩涡（MCVS）；和产生极端降雨的MCS。 俄克拉荷马州的介质数据由约30公里分辨率的5分钟表面观测组成，将对中尺度表面压力场​​进行详细分析。 特别关注MCS中的Mesohigh/Wake低对联。该研究的智力优点源自它将提供与广泛的中尺度对流系统相关的结构和物理过程的新理解。 MCS的表面特征在其层状降水区（拖尾，领先和平行），弓回声，MCV和极端产生的MCSS的表面签名仅在有限的案例研究中得到记录。 现在，俄克拉荷马州介质观测的十年记录使得有机会更全面地确定大量降水系统样本的表面特征，从中可以从中对其动态进行推论。该研究的更广泛影响与它将如何改善对MCS的理解和预测以及随之而来的恶劣天气有关。 与大量MCS相关的表面特征是措施，有时是直接的，有时甚至是间接的，其严重性和过程中的过程。 例如，弓回声的特征是极端的表面风，中等/尾流的MCS，具有落后的层状降水量/尾流较低的对联，以及通过在风暴生成的流出边界沿着同一位置的新细胞再生的某些极端雨水暴风雨。 与它们产生的风暴有关的此类功能的认可对于可靠的现象和短期预测至关重要。 这些风暴每年对重大的生命和财产损失负责，目前对他们的预测技能很低。 这项研究最终是针对提高此类预测技能的。