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) 实地活动一部分的建模活动。 DC3将研究深部、中纬度大陆对流云，包括其动力、物理和闪电过程对对流层上层成分和化学的影响。 该项目的工作重点是改进闪电产生的氮氧化物 (LNOx) 的模型表示，以及对每次闪光和每单位闪光长度的产生量的估计，以及由此产生的氮氧化物混合比的垂直分布。 将使用 WRF-Chem 模型模拟案例研究。 将分析 DC3 观测结果和模型输出，以确定暴风云内和顺风云流出中臭氧变化的幅度。在 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，这可能会建议闪电预测方案的改进或改变。 然后，该团队将通过分析和解释该期间运行的 WRF-Chem 预测的输出，参加 2011 年 5 月的 DC3 试飞。 随后将评估预测，并在 DC3 任务之前进一步改进 LNOx 算法。 在 2012 年 5 月至 6 月 DC3 任务期间，学生将在现场解释 WRF-Chem 的飞行计划预测输出。 他们将检查可能发生对流的区域、对流类型、预测闪蒸率的大小、氮氧化物的产生量、对流流出羽流的高度以及下游臭氧的产生。 任务完成后，将选择单独观测到的风暴进行案例研究模拟。 各种闪电 NOx 方案将纳入 WRF-Chem 并使用 DC3 观测进行评估。 案例研究模拟的目的是通过与氮氧化物砧观测结果的比较，得出每次闪光和每单位闪光长度的闪电氮氧化物产生量的估计值。 将使用现场数据评估由于风暴内和顺风处的对流输送和化学作用而导致的臭氧变化的模型估计。 将检查垂直风切变、闪光长度和闪电氮氧化物产生之间的关系，以及大气气溶胶含量和闪光速率之间的关系。该奖项将支持两名研究生参与 DC3 准备、现场活动和任务后分析和建模。 对 LNOx 理解的改进将应用于更大规模的化学和气候模型。