The NASA Lightning Nitrogen Oxides Model (LNOM): Application to air quality modeling

Recent improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) and its application to the Community Multiscale Air Quality (CMAQ) modeling system are discussed. The LNOM analyzes Lightning Mapping Array (LMA) and National Lightning Detection Network™ (NLDN) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx (= NO + NO2) production. The latest LNOM estimates of mean lightning channel length, the lightning 10-m segment altitude distribution, and the vertical profile of lightning NOx production are obtained. The primary improvement to the LNOM is the inclusion of non-return stroke lightning NOx production due to: hot core stepped and dart leaders, stepped leader corona sheath, K-changes, continuing currents, and M-components. The impact of including LNOM-estimates of lightning NOx for an August 2006 run of CMAQ is discussed. An estimate of global annual lightning NOx production is also provided using the NASA satellite global lightning climatology.