Moist Synoptic Transport of CO2 Along Midlatitude Storm Tracks, Transport Uncertainty, and Implications for Flux Estimation

OF DISSERTATION Moist Synoptic Transport of CO2 Along Midlatitude Storm Tracks, Transport Uncertainty, and Implications for Flux Estimation Mass transport along moist isentropic surfaces on baroclinic waves represents an important component of the atmospheric heat engine that operates between the equator and poles. This is also an important vehicle for tracer transport, and is correlated with ecosystem metabolism because large-scale baroclinicity and photosynthesis are both driven seasonally by variations in solar radiation. In this research, I pursue a dynamical framework for explaining atmospheric transport of CO2 by synoptic weather systems at middle and high latitudes. A global model of atmospheric tracer transport, driven by meteorological analysis in combination with a detailed description of surface fluxes, is used to create time varying CO2 distributions in the atmosphere. Simulated mass fluxes of CO2 are then decomposed into a zonal monthly mean component and deviations from the monthly mean in space and time. Mass fluxes of CO2 are described on moist isentropic surfaces in order to include transport along frontal systems in the eddy-terms rather than in the mean. Synoptic weather systems transport large amounts of CO2 north and south in northern mid-latitudes, up to 1 PgC month−1 during winter when baroclinic waves ramp up. During boreal winter when northern plants respire, warm moist air, high in CO2, is swept upward and poleward along the east side of baroclinic waves and dumped into the polar vortex, while cold dry air, low in CO2, that had been transported into the polar vortex earlier in the year is swept equatorward. Synoptic eddies strongly reduce seasonality in the