1. A-Train Symposium, April 19-21, 2017 Pasadena, California
Assessing a high-resolution NWP model’s ability to predict high ice water content conditions using data from A-Train satellites and in situ aircraft
Zhipeng Qu (1), Alexei Korolev(1), Howard Barker(1), Jason Milbrandt(2), Mengistu Wolde(3), Alfons Schwarzenboeck(4), Delphine Leroy(4), J. Walter Strapp(5), Stephane Belair(2), and Jason Cole(1)
Environment and Climate Change Canada, Toronto, ON, Canada
Environment and Climate Change Canada, Dorval, QC, Canada
(3) National Research Council Canada, Ottawa, ON, Canada
(4) Laboratoire de Meteorologie Physique, CNRS/Université Blaise Pascal, Clermont-Ferrand, France
(5) Met Analytics Inc., Aurora, Canada,
A-Train Symposium, April 19-21, 2017 Pasadena, California

2. A-Train Symposium, April 19-21, 2017 Pasadena, California
Objectives:
Assessment of the performance of Environment and Climate Change Canada’s hi-res Global Environmental Multiscale (GEM) model;
Potentiality of predicting high ice water content conditions in high altitude for aviation safety;
Understanding of the secondary ice process.
Microphysics scheme:
Predicted Particle Properties (P3) scheme (Morrison and Milbrandt, 2015);
Bulk scheme, single ice categories with 4 degrees of freedom.
Simulation:
0.25 km horizontal grid-spacing;
57 vertical levels;
300 km x 300 km domain.
Case:
Cayenne, French Guiana (May 16, 2015);
Tropical deep convective cloud;
Aircraft in situ measure;
A-train overpasses.
A-Train Symposium, April 19-21, 2017 Pasadena, California

3. A-Train Symposium, April 19-21, 2017 Pasadena, California
1. High Resolution NWP model simulation
Domains of the simulation:
LAM-2.5 (km) domain
Cayenne
2 Aircraft
A-Train Symposium, April 19-21, 2017 Pasadena, California

4. A-Train Symposium, April 19-21, 2017 Pasadena, California
2. Aircraft in situ measure
CloudSat
Canadian Convair-580 aircraft:
Altitude: ~7 km;
T: -5 °C to -15 °C
French Falcon-20 aircraft:
Altitude: ~7 to 12 km;
T: -10 ° to - 40 ° C
Measured variables:
Temperature;
Pressure;
Ice water content;
Extinction Coefficient;
Mean cube/mass diameters;
Size distribution;
Particle 2D imagery;
X-band radar reflectivity;
W-band radar reflectivity.
A-Train Symposium, April 19-21, 2017 Pasadena, California

5. A-Train Symposium, April 19-21, 2017 Pasadena, California
3. Results and Comparisons
GEM - 3D RT(0.25 km -> 1 km GOES)
GOES images (Visible)
CloudSat
Aircraft
Storm motion: E to W
A-Train Symposium, April 19-21, 2017 Pasadena, California

6. A-Train Symposium, April 19-21, 2017 Pasadena, California
3. Results and Comparisons
Convair-580 at altitude: 6.6 km. CloudSat: Cloud Water Content Product (2B-CWC-RO).
Overpass location
A-Train Symposium, April 19-21, 2017 Pasadena, California

7. A-Train Symposium, April 19-21, 2017 Pasadena, California
3. Results and Comparisons
Falcon-20 at altitude of 10.7 km. CloudSat: Cloud Water Content Product (2B-CWC-RO).
Overpass location
A-Train Symposium, April 19-21, 2017 Pasadena, California

8. A-Train Symposium, April 19-21, 2017 Pasadena, California
4. Discussions
(1). Dynamics ?
Underestimation of the IWC at ~11 km: the simulated heading cells didn't rise to the altitude as high as those shown by the GOES image?
GEM simulation
GOES L2 product
CloudSat
Aircraft
Storm motion: E to W
A-Train Symposium, April 19-21, 2017 Pasadena, California

9. A-Train Symposium, April 19-21, 2017 Pasadena, California
4. Discussions
(2). Ice multiplication?
Current approach: Hallett and Mossop, 1974
N of splintering depends on rime mass & T;
-3°C<T<-8°C.
New approach: Lawson et al., 2015
N depends on droplet size, N of frizzing droplet & T;
-5°C < T < -15°C.
Lawson et al., 2015
A-Train Symposium, April 19-21, 2017 Pasadena, California

10. A-Train Symposium, April 19-21, 2017 Pasadena, California
4. Discussions
(2). Ice multiplication?
Implementation of the new IM parameterization in P3 microphysics scheme.
Test of the scheme in a 1D model.
g/m #/m g/m cm g/m #/m3
Higher IWC & N
Quicker depletion of rain
A-Train Symposium, April 19-21, 2017 Pasadena, California

11. A-Train Symposium, April 19-21, 2017 Pasadena, California
4. Discussions
(2). Ice multiplication?
g/m #/m g/m cm g/m #/m3
More ice at ~11 km
Less ice at ~7 km
A-Train Symposium, April 19-21, 2017 Pasadena, California

12. A-Train Symposium, April 19-21, 2017 Pasadena, California
4. Discussions
(2). Ice multiplication?
Next step: 3D full simulation with new IM parametrization.
More complicated and need more efforts to look into the results.
A-Train Symposium, April 19-21, 2017 Pasadena, California

13. A-Train Symposium, April 19-21, 2017 Pasadena, California
5. Conclusion
In the studied case, the CloudSat IWC retrievals (2B-CWC-RO) are close to the in situ observation, some differences are observed with high IWC (>1g/m3);
The hi-res GEM model shows the potentiality to predict the tropical deep convective clouds;
At ~ 7 km, the IWC is slightly overestimated by the model with P3 scheme;
At ~ 11 km, the IWC is underestimated;
Two directions are currently under study for explaining the underestimation of IWC at high altitude with the P3 microphysics scheme: dynamics & secondary ice process.
A-Train Symposium, April 19-21, 2017 Pasadena, California