Silvia Trini Castelli - CNR ISAC Torino

1. Modellistica Lagrangiana in
ISAC – Torino
Risultati e nuovi sviluppi
Silvia TRINI CASTELLI
VI giornata sulla Modellistica in ARIA(NET)
31 gennaio 2019

2. SHORT RANGE

3. Validating (Micro)SPRAY model
S. Trini Castelli, P. Armand, G. Tinarelli, C. Duchenne, M. Nibart
MSS version and PMSS version

4. The MicroSwift-Spray modelling system has been validated on a
panel of experimental test cases from the COST Action ES1006 in
both idealized and realistic urban mock-ups, wind tunnel and field
trials, continuous and puff releases.
Michelstadt CUTE field and
wind tunnel experiment wind tunnel experiment
Validating (Micro)SPRAY model

5. Validating (Micro)SPRAY model
Michelstadt Wind-Tunnel case

6. MODEL
CONFIGURATION
MSS_A PMSS_B PMSS_C
Horizontal
resolution
2 m 1.5 m 3 m
Horizontal grid
(nx × ny points)
676 × 451 451 × 301 533 × 309
Vertical grid
1 m below 12 m
top = 200 m
21 points
1 m below 27 m
top = 200 m
40 points
2 m from 1st level to
top
top = 200 m
21 points
Emission time step 3 s 1 s 1 s
Number of particles
(per time step dt)
1000 1275 100
Averaging period 3600 s 3600 s 3600 s
Validating (Micro)SPRAY model
Michelstadt Wind-Tunnel case

7. Validating (Micro)SPRAY model
Michelstadt Wind-Tunnel case
Michelstadt case study, continuous releases. Contours of stationary concentrations (in ppmv) 7.5 m
above the ground in the simulation domain for configuration MSS_A (top), PMSS_B (middle) and
PMSS_C (bottom). The coloured squares represent observations in the same colour scale as for the
simulations. Sources S2 (left), S4 (middle) and S5 (right).

8. Validating (Micro)SPRAY model
Michelstadt Wind-Tunnel case
Puff releases for the non-blind test cases (S2, S4 and
S5 sources, blue colour) and the blind test cases (S5,
S6, S7 and S8 sources, red colour). Scatter plot of the
mean duration for two configurations, MSS_A
(asterisks) and PMSS_B (circles).
Continuous releases. Scatter plot of the predicted
and simulated mean concentrations, for the non-
blind test (blue for S2, red for S4 and green for S5)
for the (P)MSS configurations (asterisks for MSS_A,
dots for PMSS_B and triangles for PMSS_C).

9. Validating (Micro)SPRAY model
The Complex Urban Terrain Experiment – CUTE; field and wind tunnel!
FIELD (Case 1) WIND TUNNEL (Case 3)

10. MODEL CONFIGURATION MSS PMSS
Horizontal resolution 5 m 4 m
Horizontal grid
(nx × ny points)
Case 1: 510 × 521
Case 3: 261 × 301
625 × 525
Vertical grid
1 m below 10 m
top = 500 m
20 points
2 m up to 20 m
top = 200 m
26 points
Emission time step 2 s 1 s
Number of particles (per
time step dt)
Case 1: 400
Case 3: 200
Case 1: 2000
Case 3: 1000
Averaging period
Case 1: 600 s
Case 3: 3600 s
Case 1: 600 s
Case 3: 3600 s
Validating (Micro)SPRAY model
The Complex Urban Terrain Experiment – CUTE; field and wind tunnel!

11. Validating (Micro)SPRAY model
The Complex Urban Terrain Experiment – CUTE; field and wind tunnel!
Scatter plot of concentrations at the sensor locations by different MSS and PMSS configurations
CUTE : Field experiment continuous release Wind tunnel continuous release
MSS_W1 green asterisks, MSS_W2 orange asterisks,
PMSS_D blue circles, PMSS_M red circles
MSS green asterisks,
PMSS_D blue circles, PMSS_M red circles

12. The MicroSwift-Spray modelling system has been validated on a panel of experimental test cases
from the COST Action ES1006 in both idealized and realistic urban mock-ups, wind tunnel and
field trials, continuous and puff releases.
The sensitivity of the model to the meteorological input data is
assessed and the results are discussed comparing predicted
concentrations to measurements.
The performances of the modelling system are evaluated through a
statistical analysis.
They are found to depend on the type of test case, type of release
and location of the source in the built-up domain.
Results show that the model is compliant with the validation criteria,
established in literature for the reference metrics, in the large majority
of the test cases.
The modelling system proved to be robust enough to be used in the
context of emergency response, when fast but still reliable results are
needed.
Validating (Micro)SPRAY model

13. LONG RANGE

14. Reviving MILORD model
Model for the Investigation of LOng Range Dispersion

15. Reviving MILORD model
Background
A renewed interest in long-range dispersion started since 2010 after the
emissions of the volcano Eyjafjallajokull in Iceland in May 2010, and even
more after the radioactive release from the Fukushima Daichi nuclear power
plant in Japan in March 2011, consequent to the earthquake that devastated
that area.
Motivation
Our research group was thus motivated to brush up the MILORD model and to
proceed with further developments of the code. In particular, the emission
module was made more flexible and adaptable to any time and space
modulation and, the deterministic displacement algorithm of the trajectories, was
adapted to properly deal also with extreme meteorological conditions, the
backward-trajectory mode was tested and applied.

16. The Lagrangian particle dispersion model MILORD was
created in 1992/93 as a tool for the long-range simulation of
tracers:
•• release
•• transport
•• diffusion
•• removal
•• deposition
In the PAST MILORD was applied and validated in two case
studies: the Chernobyl accident (ATMES project) and the
ETEX I field experiment.
Reviving MILORD model

17. In the PRESENT:
I. simulating the dispersion of the release during Fukushima nuclear
plant accident
On 11 March 2011 an earthquake occurred o the eastern coast of Honshu,
subsequently a tsunami struck the eastern coastal area of Japan
Reviving MILORD model – FUKUSHIMA case study

18. Model configuration
Geographical domain:
Longitude → 100 – 280 °E; Latitude → 0 – 80 °N;
Time period:
beginning → 10/03/2011 at 15:00 UTC; ending 31/03/2011 at 12:00 UTC;
time step → 2160-1080 s.
Reviving MILORD model – FUKUSHIMA case study

19. Several runs were performed in order to investigate the sensitivity of the model
to different quantities. The input parameters modified are the PBL height HPBL,
the horizontal diffusion coefficients KH, the number of the standard pressure
levels NL from the ECMWF input files and the integration time step Δt.
RUNS HPBL [m] KH [m^2/s] NL Δt [s]
Run 1 variable 50 4 2160
Run 2 variable 45000 4 2160
Run 3 Fixed, 1500 45000 4 2160
Run 4 variable 45000 5 2160
Run 5 Fixed, 1500 45000 5 2160
Run 6 variable 45000 4 1080
MILORD configuration for the different runs
Reviving MILORD model – FUKUSHIMA case study

20. Cumulated deposition for the Run 1- 6 different setups.
137Cs cumulated deposition 10-31/3/2011. Top line from left to right: Run
1-2-3; bottom line from left to right :Run 4-5-6
Reviving MILORD model – FUKUSHIMA case study

21. 137Cs cumulated deposition 10-31/3/2011. Top line, from left to right: Run
1-2-3; bottom line, from left to right: Run 4-5-6
Reviving MILORD model – FUKUSHIMA case study
Cumulated deposition for the Run 1- 6 different setups: ZOOM around the source

22. MILORD outputs have been compared to measurements from the network
established by the Japan Atomic Energy Agency (JAEA). The cumulative
frequency distributions for the deposition predicted and observed for Run 1 and
Run 6 are shown:
137
Cs observed (black) and predicted (red) cumulated deposition, 10-31/3/2011;
Run 1 (left), Run 6 (rigth)
Reviving MILORD model – FUKUSHIMA case study

23. Comparison with measured data
R NMSE FB FA2 FA5
Run 1 0.49 8.05 -0.43 0.42 0.79
Run 2 0.56 14.90 0.29 0.57 0.96
Run 3 0.56 17.02 0.38 0.58 0.97
Run 4 0.56 13.56 0.16 0.56 0.96
Run 5 0.53 14.57 0.22 0.59 0.95
Run 6 0.59 16.74 0.43 0.58 0.96
R NMSE |FB|_min |FB|_max
MILORD 0.49 – 0.59 8.05 – 17.02 0.16 0.43
NAME 0.69 – 0.88 n.a. 0.19 0.46
HYSPLIT 0.55 – 0.83 4.20 – 14.09 0.30 0.74
FLEXPART 0.78 – 0.83 2.55 – 3.84 0.08 0.13
Comparison with other models
Reviving MILORD model – FUKUSHIMA case study

24. In the PRESENT:
II. simulating the backward dispersion to identify CO2 peaks at Plateau
Rosa high-mountain site
Reviving MILORD model – PLATEAU ROSA case study
In Italy, at the station of Plateau Rosa (PRS, longitude: 7.71°E, latitude:
45.93°N), on the Italian Alps near the Mt. Cervino, at the altitude of 3480 m
a.s.l., the CO2 concentration has been measured since 1989 (and continuously
since 1993).
The geographical position of the station at high altitude and far from urbanized and
industrialized zones, allows to obtain frequently representative measurements of the
atmospheric background (carbon dioxide, methane, and ozone).
In February 2004 extreme CO2
concentration events were identified
in the measured data and analyzed
with the use of meteorological and
dispersion models

25. Reviving MILORD model – PLATEAU ROSA case study
The case study has been examined applying two Lagrangian particle models at
two scales, in order to trace the provenience of the CO2 mass using backwards
trajectories. At the regional scale FLEXPART-WRF model was used, for the
long-range MILORD model was applied.
MILORD FLEXPART

26. Reviving MILORD model – PLATEAU ROSA case study
The case study has been examined applying two Lagrangian particle
models at two scales, in order to trace the provenience of the CO2 mass
using backwards trajectories. At the regional scale FLEXPART-WRF
model was used, for the long-range MILORD model was applied.
MILORD FLEXPART

27. Reviving MILORD model
MILORD was proven to be able to correctly simulate the dispersion from
the Fukushima nuclear plant not only at the long range but even at the
regional scale, as the comparison with the observations and other models
demonstrates.
MILORD was run for the first time in the backward mode!
It provided similar dispersion patterns as FLEXPART, despite different
scales and different physical parameterisations. MILORD has the
advantage of less computational effort….
…a long range to success!!!

28. References
Trini Castelli S., Armand P., Tinarelli G., Duchenne C., Nibart M., 2018. Validation of a
Lagrangian particle dispersion model with wind tunnel and field experiments in urban
environment. Atmospheric Environment, 273-289
Boetti M., Trini Castelli S., Ferrero E., 2017. Reviving MILORD long-range model for
simulating the dispersion of the release during Fukushima nuclear power plant accident.
Chapter 62 in Air Pollution Modeling and its Application XXV, C. Mensink and G. Kallos
(eds.) Springer Proceedings in Complexity, Springer International Publishing Switzerland,
387-391
Ferrarese S., Apadula F., Andreoli V., Cassardo C., Greco S., Heltai D., Lanza A., Trini
Castelli S., 2018.The atmospheric carbon dioxide series at the Alpine site of Plateau
Rosa, Italy. Proceedings of the 6th Annual Conference of the Italian Society for Climate
Sciences, Venice, Italy, 17-19 October 2018, 4 pages