Abstract. Model simulations of tropospheric O3 require an accurate specification of the NOx source from lightning that is consistent in time and space with convective transport of O3 precursors. Lightning NOx production in global models is often parameterized in terms of convective cloud top heights (CLDHT). However, a closer relationship may exist between flash rate and other measures of convective intensity. In this study, flash rates are parameterized in terms of convective fields (upward mass flux (MFLUX), precipitation (PRECON), and CLDHT) from the Goddard Earth Observing System Data Assimilation System (GEOS DAS). GEOS-based flash rates are compared to flash rates from the National Lightning Detection and Long Range Flash Networks (NLDN/LRF) and the Optical Transient Detector (OTD). The shape and magnitude of the flash rate distribution over the United States is best captured by the MFLUX-based method. Large-scale latitudinal and seasonal variations in the flash rate are reasonably well captured by each of the methods; although, the percent of total flashes occurring in the tropics is overestimated by the PRECON- and CLDHT-based methods. The MFLUX- and PRECON-based flash rates are a factor of three too high (low) over the equatorial western Pacific (central and southern Africa), while CLDHT-based flash rates are much too low at nearly all marine locations. In general, biases in the flash rate distributions can be traced to biases in the GEOS DAS convective fields. Improvements in flash rate parameterizations will be tied closely to improvements in model physics as well as to increases in the amount of tropical data that are available for assimilation. Flash rates from the CLDHT-based method are much less variable than observed. O3 production rates calculated using the NOx produced from these flash rates are likely to be larger than observed.