Rôle des courants de densité dans l émission des poussières et le flux de mousson

Transcription

1 Rôle des courants de densité dans l émission des poussières et le flux de mousson Irene Reinares Martínez, Jean-Pierre Chaboureau Laboratoire d Aérologie, Université de oulouse, CNRS Atelier DEPHY2 2 novembre 2015 Météopole, oulouse

2 AMMA Case Study from 9 to 14 June 2006 (Flamant et al., 2009) 1 Dust lifting Bodélé Sudan 2 ransport by AEJ 3 Interaction with MSC MSG product

3 AMMA Case Study from 9 to 14 June 2006 (Flamant et al., 2009) 1 Dust lifting Bodélé Sudan 2 ransport by AEJ 3 Interaction with MSC MSG product

4 AMMA Case Study from 9 to 14 June 2006 (Flamant et al., 2009) 1 Dust lifting Bodélé Sudan 2 ransport by AEJ 3 Interaction with MCS MSG product

5 AMMA Case Study from 9 to 14 June 2006 (Flamant et al., 2009) 1 Dust lifting Bodélé Sudan 2 ransport by AEJ 3 Interaction with MCS MSG product 0ºN 20ºN 37ºN

6 AMMA Case Study from 9 to 14 June 2006 (Flamant et al., 2009) 1 Dust lifting Bodélé Sudan 2 ransport by AEJ 3 Interaction with MCS MSG product 0ºN 20ºN 37ºN Precipitation: What controls the distribution of precipitation and deep convective clouds? Diurnal variability of precipitation? Cloud-dynamics interaction: What is the role of MCSs on AEWs? Do cold pools associated to MCSs have an impact on the ID? What is the dust radiative effect on cloud & rain distribution and dynamics?

7 Cloud-Resolving Modeling Δx=2.5 km, Δz= m, 3072 x 1536 x 72, 1/3 billion grid points, 7 B km : range between 5000 and 20 km 3840 km Initialization: 9 June at 00 UC, ECMWF (Δx ~25 km, no dust). Vertical wind speed 6 days, outputs every 3 hours. Standard Méso-NH parameterizations: ICE3 bulk microphysics, 1D turbulence, RRM radiation, dust by DEAD + ORILAM only radiative effects. Sensitivity experiments: LowRes: between 5000 and 200 km - LowRes Δx=20 km with KFB convective parameterization. - without dust radiative effect.

8 Precipitation: accumulated during the 6-day period RMM3B42 + ECMWF 8 g/kg Precipitation stays south of the ID. 12 g/kg

9 Precipitation: accumulated during the 6-day period RMM3B42 + ECMWF 8 g/kg Precipitation stays south of the ID. 12 g/kg LowRes

10 Precipitation: accumulated during the 6-day period RMM3B42 + ECMWF 8 g/kg Precipitation stays south of the ID. 12 g/kg Scattered LowRes

11 Precipitation: accumulated during the 6-day period RMM3B42 + ECMWF 8 g/kg Precipitation stays south of the ID. 12 g/kg Scattered Further north LowRes

12 Precipitation: accumulated during the 6-day period RMM3B42 + ECMWF 8 g/kg Precipitation stays south of the ID. 12 g/kg Scattered Further north LowRes Precipitation distribution is well reproduced by

13 Precipitation (mm/3h) Precipitation: diurnal cycle > 2 mm day -1 > 5 mm day -1 > 10 mm day -1 RMM LowRes ime (UC) Maximum of precipitation ~21UC.

14 Precipitation (mm/3h) Precipitation: diurnal cycle > 2 mm day -1 > 5 mm day -1 > 10 mm day -1 RMM LowRes ime (UC) Maximum of precipitation ~21UC. reproduces well diurnal cycle. Some precipitation is missing in the night and early morning.

15 Precipitation (mm/3h) Precipitation: diurnal cycle > 2 mm day -1 > 5 mm day -1 > 10 mm day -1 RMM LowRes ime (UC) Maximum of precipitation ~21UC. reproduces well diurnal cycle. Some precipitation is missing in the night and early morning. Relationship with MCSs life duration?

16 Precipitation (mm/3h) Precipitation: diurnal cycle > 2 mm day -1 > 5 mm day -1 > 10 mm day -1 RMM LowRes ime (UC) Maximum of precipitation ~21UC. reproduces well diurnal cycle. Some precipitation is missing in the night and early morning. For LowRes maximum at 15UC for 2 and 5 mm/day. Cycle not well marked for 10mm/day. Relationship with MCSs life duration?

17 Precipitation: how does it propagate?, with AEWs? RMM+ECMWF Convection: 12UC over Ethiopian Highs. Day of June W#1 W#2 2 AEWs propagate at 10-11m/s. MCSs propagate with the AEJ at 16m/s (red) and 14m/s (orange) Averaged between 5ºN 15ºN lat MCS - t t-δt + lon Longitude

18 Longitude Precipitation: how does it propagate?, with AEWs? RMM+ECMWF Convection: 12UC over Ethiopian Highs. Day of June W#1 W#2 2 AEWs propagate at 10-11m/s. MCSs propagate with the AEJ at 16m/s (red) and 14m/s (orange) Averaged between 5ºN 15ºN lat MCS - t t-δt + lon LowRes W#2 W#2 Convection: 12UC for, 3 hours earlier for LowRes. W#1 W#1 W#2 is slower for LowRes (9m/s) than for ECMWF or (11m/s)

19 Latitude RMM+ECMWF MCSs and AEWs: how do they interact? ID 10g/kg Day of June Averaged between 5ºW 5ºE

20 Latitude MCSs and AEWs: how do they interact? RMM+ECMWF AEWs and associated troughs ( ) Day of June Averaged between 5ºW 5ºE

21 Latitude MCSs and AEWs: how do they interact? RMM+ECMWF 3 days AEWs and associated troughs ( ) Precipitation 10ºN-15ºN coincident with troughs (3 days time spacing). Day of June Averaged between 5ºW 5ºE

22 Latitude MCSs and AEWs: how do they interact? RMM+ECMWF 3 days AEWs and associated troughs ( ) Precipitation 10ºN-15ºN coincident with troughs (3 days time spacing). Day of June Dynamics: & LowRes Averaged between 5ºW 5ºE LowRes

23 Latitude MCSs and AEWs: how do they interact? RMM+ECMWF 3 days AEWs and associated troughs ( ) Precipitation 10ºN-15ºN coincident with troughs (3 days time spacing). Day of June Averaged between 5ºW 5ºE Dynamics: & LowRes Precipitation: : same spacing but not with troughs LowRes: no interaction with waves LowRes 3 days

24 Latitude Day of June A MCS and the ID: are they linked? Averaged between 5ºW 5ºE ID

25 Latitude Day of June A MCS and the ID: are they linked? Averaged between 5ºW 5ºE 03 UC 13 June ID

26 A MCS and the ID: impact of the cold pool emperature Water vapor mixing ratio 03 UC 13 June All the fields at the surface

27 A MCS and the ID: impact of the cold pool emperature Water vapor mixing ratio 03 UC 13 June Q1-Qrad 3-hly heating rate All the fields at the surface Q2 3-hly drying rate ID ID 06 UC 13 June

28 A MCS and the ID: impact of the cold pool emperature Water vapor mixing ratio 03 UC 13 June Q1-Qrad 3-hly heating rate All the fields at the surface Q2 3-hly drying rate ID ID 06 UC 13 June Density current pushes humidity to the north perturbing the ID.

29 A MCS and dust: impact of the cold pool Wind speed 03 UC 13 June 3-hly dust flux 06 UC 13 June

30 A MCS and dust: impact of the cold pool Wind speed 03 UC 13 June 3-hly dust flux 06 UC 13 June Density current favors dust emission

31 Conclusions & perspectives Precipitation (and Deep Convective Clouds) found south of the ID. Precipitation marked diurnal cycle with maximum ~21UC. Relationship between the diurnal cycle and the MCSs life duration? For each type of precipitating system? AEWs modulate the propagation of MCSs to the west. Role of MCSs on AEWs? A cold pool associated to a MCS in pushes humidity to the north and favors dust emission. Effect of the ensemble of cold pools? Sensitivity of dynamics to dust radiative effect, preliminary results (not shown)