ACROSS_LISA_WRF-CHIMERE_HYSPLIT_Backtraj_1H

HYSPLIT (Stein et al., 2015) backtrajectories simulations were performed at the Paris Rive Gauche (PRG), SIRTA and Rambouillet (RambForest) ground-based sites, using the WRF-CHIMERE (Menut et al., 2021) meteorological fields from the 6x6km and 2x2km spatial resolution nested domains as HYSPLIT backtrajectory meteorological model inputs (three nested domains centered over the Ile de France region at 30km, 6km and 2km have been deployed for the ACROSS campaign). The WRF-CHIMERE meteorological fields have 10 minutes temporal resolution. The dataset is grouped on a daily basis and contains four backtrajectories runs per day starting at 00, 06, 12 and 18 UTC and with a maximum duration of 48 hours. Two different options are available: 1) one single backtrajectory starting at 25 m, 10 m, 40 m agl respectively for the PRG, SIRTA and RambForest locations; 2) an ensemble backtrajectory simulation composed by 27 ensemble members. The 27 ensemble members include all the possible offset combinations due to perturbations in the initial meteorological data: ±1 grid point in the horizontal direction (X and Y directions), ±0.01 sigma units corresponding to ~±250m. The dataset contains the longitude, the latitude and the altitude of the simulated air parcel as backtrajectory, as well as the ambient pressure, temperature, relative humidity and specific humidity. All the dataset variables have 3D dimensions and depend on i) the number of runs per day (run_starting_time), ii) the number of backtrajectories simulated hours (ntime_backtraj) and iii) the number of trajectories (ntraj, 1 for single backtrajectory, 27 for the ensemble simulation). Missing data are possible if the air parcel leaves the simulated domain due to backtrajectories and have been identified as -999., -999 and “NA” respectively for float, integer and string variable types. Detailed information can be provided upon request to the authors.

Menut, L., Bessagnet, B., Briant, R., Cholakian, A., Couvidat, F., Mailler, S., Pennel, R., Siour, G., Tuccella, P., Turquety, S., and Valari, M.: The CHIMERE v2020r1 online chemistry-transport model, Geosci. Model Dev., 14, 6781–6811, https://doi.org/10.5194/gmd-14-6781-2021, 2021.

Stein, A.F., Draxler, R.R, Rolph, G.D., Stunder, B.J.B., Cohen, M.D., and Ngan, F., (2015). NOAA’s HYSPLIT atmospheric transport and dispersion modeling system, Bull. Amer. Meteor. Soc., 96, 2059-2077, http://dx.doi.org/10.1175/BAMS-D-14-00110.1