'The Deadly Delhi Air Pollution Episode of November 2017; As Seen by NASA GMAO Models'

The onset of the India subcontinent dry Northeast Monsoon 2017 was marked by a particularly deadly air pollution event during the first and second week of November. Air quality standards at reporting stations in northern India and Pakistan were exceeded by as much as a factor of ten. The NASA Global Modeling and Assimilation Office (GMAO) MERRA-2 system has a record that extends back to 1980 so that this event can be placed in an historical sense both in terms of its meteorology and aerology, as MERRA-2 employs a fully coupled atmosphere-aerosol model. Such a retrospective analysis can also give insight into whether or not such extreme events are occurring at an accelerated pace. Additionally, we can review forecasts from the GMAO flagship forward processing system (FP) leading up to this event to determine the type of potential lead times possible for such forecasted episodes which can then be used by various weather forecasting agencies and health organizations to make critical calls to action. Each day the GMAO FP system produces a ten-day forecast at high spatial (12km) and temporal (hourly) resolution of the global meteorology and chemistry, surface and aloft. The FP system is capable of distinguishing various pollutant species both near the ground as well as throughout the column. With such high density populations centers at risk of adverse health effects from these noxious combinations of meteorology and air pollution, it is vital we exploit these coupled atmosphere-aerosol chemistry models for inevitable future extreme events such as this mid-November 2017 case.