1. Environmental & Climate Sciences Department Seminar

    "Intercontinental smog: how and why global models fail to resolve intercontinental chemical plumes"

    Presented by Sebastian Eastham, Harvard University Center for the Environment

    Thursday, October 27, 2016, 11 am
    Conference Room Bldg 815E

    Hosted by: Laura Fierce

    Air quality exceedances in California are frequently attributed to Asian pollution, but global Eulerian models consistently fail to reproduce the intercontinental chemical plumes which are responsible. This has been attributed to excessive numerical diffusion. We apply a global model over a wide range of horizontal resolutions in both 2-D and 3-D to isolate the specific causes and effects of this diffusion on the representation of intercontinental pollution. Our results show that the vast increases in computation power required to increase model horizontal grid resolutions are wasted if the aim is to better represent intercontinental transport of pollution. We instead provide motivation for modelers and researchers to experiment with higher vertical grid resolution if they wish to reproduce the ubiquitous quasi-horizontal plumes observed in atmospheric measurements.