Full WRF-Chem output in support of the NASA Atmospheric Carbon and Transport (ACT)-America project (7/1/2016 – 7/31/2019)

The NASA Atmospheric Carbon and Transport (ACT) – America project conducted five airborne campaigns across three regions in the eastern United States to study the transport and fluxes of atmospheric carbon dioxide (CO2) and methane (CH4). Each six-week campaign measured how weather systems transport these greenhouse gases. The objective of the study is to enable more accurate and precise estimates of the sources and sinks of these gases. Better estimates of greenhouse gas sources and sinks are needed for climate management and for prediction of future climate. ACT America addresses three primary sources of uncertainty in our ability to infer carbon dioxide and methane sources and sinks – transport error, prior flux uncertainty and limited data density. This WRF-Chem simulation is the baseline simulation in support of the ACT-America team and broader community to achieve above project goals. It serves as the complementary information to the ACT-America measurements and help scientists to interpret the data with a broader picture in space and time. The simulation domain contains most of North America at 27 km horizontal resolution. The model has 50 levels up to 50 hPa with 20 levels in the lowest 1 km. The model meteorology is initialized every five days and driven with ERA5 reanalysis every six hours at 25-km horizontal resolution. The WRF-Chem dynamic is relaxed to ERA5 meteorology every six hours using grid nudging. We also update sea surface temperature every six hours at 12-km resolution. Choices of the model physics parameterizations used in this experiment are documented as the baseline setup in Feng et al (2019a; 2019b). This simulation is run with WRF-Chem version 3.6.1 with the tracer modification described in Lauvaux (2012). Specifically, the CarbonTracker (Peters et al., 2007) CO2 components, CASA biogenic fluxes (Zhou et al, 2019), SiB4 biogenic fluxes (Haynes et al., 2019a; Haynes et al., 2019b), CH4 EPA emissions (Maasakkers et al., 2016), CH4 wetland (from WETCharts), CarbonTracker CH4, EDGAR (nssens-Maenhout et al., 2019), and Ethane inventory (Tzompa-Sosa et al., 2017) are included in this simulation.