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Lightning NOx Production in CMAQ Part I – Using Hourly NLDN Lightning Strike Data
Kang, D., N. Heath, David-C Wong, Jon Pleim, S. Roselle, K. Foley, AND R. Mathur. Lightning NOx Production in CMAQ Part I – Using Hourly NLDN Lightning Strike Data. 15th Annual CMAS Conference, Chapel Hill, NC, October 24 - 26, 2016.
The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.
Lightning-produced nitrogen oxides (NOX=NO+NO2) in the middle and upper troposphere play an essential role in the production of ozone (O3) and influence the oxidizing capacity of the troposphere. Despite much effort in both observing and modeling lightning NOX during the past decade, considerable uncertainties still exist with the quantification of lightning NOX production and distribution in the troposphere. It is even more challenging for regional chemistry and transport models to accurately parameterize lightning NOX production and distribution in time and space. With the availability of observed lightning strikes from the National Lightning Detection Network (NLDN), the raw NLDN lightning strike data are aggregated as hourly mean values and gridded into modeling domain for retrospective model applications. The lightning produced NOX column values using this implementation are compared with those generated by the previous parameterization in CMAQ which the lightning NO emissions are calculated using local scaling factors adjusted by the convective precipitation rate. Different scenarios (previous lightning NOX parameterization, NLDN hourly gridded data, and no lightning NOX) are modeled in annual WRF-CMAQ simulations. The preliminary evaluation results will be presented.
Record Details:Record Type: DOCUMENT (PRESENTATION/SLIDE)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL EXPOSURE RESEARCH LABORATORY
COMPUTATIONAL EXPOSURE DIVISION