Production of Nitrogen Oxides (NOx) by Lightning during the Deep Convective Clouds and Chemistry (DC3) Experiment

深对流云和化学 (DC3) 实验期间闪电产生氮氧化物 (NOx)

• 批准号: 1063479
• 负责人: Kenneth Pickering
• 金额: $ 42.86万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1063479&HistoricalAwards=false
• 关键词: Production; Nitrogen; Oxides; NOx; Lightning

This award will support modeling activities as part of the Deep Convective Clouds and Chemistry (DC3) field campaign. DC3 will study the impact of deep, mid-latitude continental convective clouds, including their dynamical, physical, and lightning processes, on upper tropospheric composition and chemistry. Efforts in this project will be focused on improving model representation of the production of nitrogen oxides by lightning (LNOx) and estimates of the magnitude of the production per flash and per unit flash length, as well the vertical distribution of the resulting NOx mixing ratios. Case studies will be simulated using the WRF-Chem model. DC3 observations and the model output will be analyzed to determine the magnitude of resulting ozone changes both within the storm clouds and in the downwind cloud outflow. Prior to the DC3 mission, test cases from the DC3 regions will be simulated using the WRF model. The model output will be compared with Lightning Mapping Array data, which may suggest improvements or changes in the lightning prediction scheme. The team will then participate in the May 2011 DC3 test flights through analysis and interpretation of output from WRF-Chem forecasts run operationally for the period. This will be followed up with evaluation of the forecasts and making possible further improvements to the LNOx algorithms prior to the DC3 mission. During the May-June 2012 DC3 mission, students will be in the field interpreting the WRF-Chem forecast output for flight planning. They will examine likely areas where convection may occur, types of convection, magnitudes of predicted flash rates, amount of NOx production, altitudes of convective outflow plumes, and downstream ozone production. Following the mission, individual observed storms for case study simulations will be selected. Various lightning NOx schemes will be incorporated into WRF-Chem and evaluated using DC3 observations. The case study simulations will be designed to yield estimates of lightning NOx production per flash and per unit flash length through comparisons with the anvil observations of NOx. Model estimates of ozone changes due to convective transport and chemistry within and downwind of storms will be evaluated using field data. Relationships between vertical wind shear, flash length and lightning NOx production will be examined, as well as relationships between atmospheric aerosol content and flash rates.This award will support the participation of two graduate students in DC3 preparation, field activities, and post-mission analysis and modeling. Improvement in the understanding of LNOx will be applied to larger-scale chemistry and climate models.

该奖项将支持作为深对流云和化学（DC3）领域活动一部分的建模活动。DC3将研究深层中纬度大陆对流云的影响，包括它们的动力学、物理和闪电过程，对对流层上层成分和化学的影响。这个项目的重点是改进闪电产生氮氧化物（LNOx）的模型表示，估计每次闪电和单位闪电长度的产量，以及由此产生的氮氧化物混合比的垂直分布。案例研究将使用WRF-Chem模型进行模拟。将对DC3观测和模式输出进行分析，以确定风暴云内部和顺风云流出的臭氧变化幅度。在执行DC3任务之前，将使用WRF模型模拟来自DC3区域的测试用例。模型输出将与闪电映射阵列数据进行比较，这可能会对闪电预测方案提出改进或改变的建议。该团队随后将参与2011年5月的DC3试飞，通过分析和解释WRF-Chem在这段时间内运行的预测结果。随后将对预测进行评估，并在DC3任务之前对LNOx算法进行进一步改进。在2012年5月至6月的DC3任务期间，学生们将在现场解释WRF-Chem的预测输出，用于飞行计划。他们将检查可能发生对流的区域、对流的类型、预测闪速的大小、氮氧化物产生的数量、对流流出羽流的高度和下游臭氧产生。任务结束后，将选择个别观测到的风暴进行案例研究模拟。各种雷电NOx方案将纳入WRF-Chem，并使用DC3观测进行评估。案例研究模拟将通过与氮氧化物的铁砧观测结果进行比较，得出闪电每次闪光和每单位闪光长度产生的氮氧化物估计值。模式估计由于对流输送和风暴内部及下风的化学作用而引起的臭氧变化，将使用现场资料进行评估。将研究垂直风切变、闪电长度和闪电产生氮氧化物之间的关系，以及大气气溶胶含量和闪电速率之间的关系。该奖项将支持两名研究生参与DC3准备、实地活动以及任务后分析和建模。对LNOx认识的提高将应用于更大规模的化学和气候模式。