Grid-resolution dependence of meridional decomposition of CO2 transport during cold front passages
Abstract
This study aims to quantify the variability in CO2 transport between global scale and regional scale models during summer frontal passage events over continental US (CONUS). Atmospheric inversions typically use global chemical transport models (CTMs) to simulate the transport of CO2. These models use reanalyzed meteorology to run at coarse resolutions (3° by 2° globally) in contrast to regional scale meteorology models often running at resolutions of 10s of kilometers. Simulations of atmospheric transport of CO2 may be a function of the resolution of the numerical models employed. Studies of the synoptic scale transport of CO2 have shown that during frontal passages there is a sharp change in the atmospheric concentrations of CO2. In order to improve our knowledge of atmospheric inversion products, it is important to characterize the impact of these events on the transport of CO2 over CONUS. The NASA ACT-America 2016 Summer campaign took place between 18th July and 28th August 2016. Measurements of CO2and other Greenhouse Gas (GHG) concentrations were collected from flights over three regions - centered at Wallops Island, Virginia (Mid-Atlantic region), Lincoln, Nebraska (Mid-West region) and Shreveport, Louisiana (Gulf-Coast region). The Weather Research and Forecasting Model with Chemistry (WRF-Chem) run over the CONUS at a horizontal resolution of 27km, and Carbon Tracker (CT2017) have been used to simulate the atmosphere and CO2 transport during this period. The meridional transport of CO2 across the continent will be quantified using an eddy decomposition into mean transport and the eddy transport components for WRF-Chem as well as global models for the first time. Differences in the terms highlight the differences in the mechanistic representation of CO2 transport between global and mesoscale numerical models. The realism of both modeling systems will be evaluated using aircraft measurements. The results from this study lend insight into the transport processes responsible for producing CO2 gradients by investigating the impact of model resolution, and by comparing free-running models (WRF) vs reanalysis driven CTMs. The study will also explore how flexible regional/mesoscale models such as WRF can inform global atmospheric inversion systems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A43N3320S
- Keywords:
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- 0315 Biosphere/atmosphere interactions;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0322 Constituent sources and sinks;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0428 Carbon cycling;
- BIOGEOSCIENCES