Campaign has ended - forecast production ceased on 14th June 2016.

Please contact Christoph (christoph.knote@lmu.de) for additional simulations.

KORUS-AQ trajectory forecasting

Experiment: Ground stations (back) FINN fires (fwd) Flight plans (back) Chinese cities (fwd) Power plants (fwd) Seoul & Busan (fwd) Y12-Hebei (fwd)

Release location:


Plot interpretation

All plots show, color-coded, the density of 'particles' started from a given release point and followed back-/forwards in time. Particle density is shown using opacity, the more opaque a grid cell is, the more particle did reside in it. Hence, opacity is a measure of probability. Color-coding varies by plot, and can be airmass-age (for backtrajectories) or source (e.g. for Hebei cities or power plants). Additional information is given by a deterministic trajectory shown as dots connected by a line. This trajectory is the mass-weighted center of all individual particles used in the simulation, which can or cannot be a good approximation of the real plume distribution. Stohl et al., 2002 has the details of this clustering method. The ICARTT file (link below plot) contains the machine-readable data of these trajectories.

Ground stations: 72 hours backward simulations, where 10.000 particles are released from the station location during the first hour of the simulation.
Fires: 11 day forward simulation with continuous emissions from the 50 largest FINN fire emission locations. Particles are continuously emitted during the simulation run. Each day, fire locations are updated using FINN output. For missing FINN files and forecasts in the future, persistence is assumed (i.e., the latest available FINN file is considered).
Flight plans: 48 hour backward simulation from planned flight track. Particles are released in 15 minute intervals from the then-current aircraft position.
Flight tracks: 48 hour backward simulation from actual flight track. Particles are released in 10 minute intervals from the then-current aircraft position.
Hebei cities: 72 hour forward simulation from biggest cities (Bejing, Baoding, Shijiazhuan) in Hebei province (China). Particles are emitted continuously during the simulation period.
Power plants: 24 hour forward simulation from large power plants in South Korea. Particles are emitted continuously during the simulation.
Seoul: 24 hour forward simulation from Seoul and Busan urban areas. Particles are emitted continuously during the simulation.
Y12: 72 hour forward simulation from Y12 plane (Hebei) flight area (3 different altitudes), with particles started at 04 UTC.

All times shown are UTC.

Methods

All simulations done using FLEXPART 9.1, driven by 3 hourly NCEP GFS wind fields (analyses and +03 hrs forecast interlaced for past periods) on a 0.25 deg lat-lon grid.
FLEXPART is developed at NILU, and released under the GNU General Public License 3.0. Some postprocessing tools used are courtesy of Stephan Henne at Empa.

Data availability

Please contact Christoph Knote (christoph.knote@lmu.de) when you use these data in presentations or publications. For quantitative analysis, NetCDF files with the full 4-D trajectory output are available, as well as the possibility for further simulations for specific science questions. Consider offering co-authorship if trajectory results constitute a relevant contribution to your analysis.

Christoph Knote (LMU Munich, Germany) christoph.knote@lmu.de - last updated 2016-06-14 08:50:48 UTC