Post on 23-Jan-2016
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Eidgenössisches Departement des Innern EDIBundesamt für Meteorologie und Klimatologie MeteoSchweiz
The COSMO-LEPS cloud problem over the Alpine region
André Walser
MeteoSwiss
COSMO General Meeting, Moscow, 6-10 September 2010
2 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Typical summer case…
COSMO-LEPS median
COSMO-7
Observations
many members with a too small diurnal cycle in 2m temperature COSMO-LEPS predicts clearly more clouds than COSMO-7 large spread in deterministic case
3 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
SYNOP verif T_2M Europe JJA2010
00 UTC 00 UTC
ObservationsCOSMO-LEPS ensemble meanCOSMO-7
~1K
lead-time +(25-48)h
4 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
SYNOP verif T_2M CH JJA2010
~2K
ObservationsCOSMO-LEPS ensemble meanCOSMO-7
lead-time +(25-48)h
00 UTC 00 UTC
5 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
SYNOP verif CLCT CH JJA2010
20
-20
00 UTC 00 UTC
lead-time +(25-48)h
COSMO-LEPS ensemble meanCOSMO-7
0
Mea
n E
rro
r
6 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
SYNOP verif CLCT Europe JJA2010COSMO-LEPS ensemble mean of CLCT: Mean error
7 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
June 24 case
COSMO-LEPS median
COSMO-7
Observations
8 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
June 24 15 UTC: A sunny day...
9 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
June 24 15 UTC:COSMO-LEPS
Total cloud cover (CLCT)
member 7
Low-level cloud cover (CLCL)
member 7
10 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Low level clouds (CLCL)
11 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Low level clouds (CLCL)
12 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Member configurationitype_conv=1turlen=150pat_len=500crsmin=50rat_sea=40rlam_heat=0.1
itype_conv=1turlen=500pat_len=2000crsmin=50rat_sea=20rlam_heat=1
itype_conv=1turlen=1000pat_len=5000crsmin=50rat_sea=1rlam_heat=0.1
itype_conv=1turlen=150pat_len=2000crsmin=50rat_sea=1rlam_heat=5
itype_conv=1turlen=150pat_len=5000crsmin=50rat_sea=1rlam_heat=1
itype_conv=0turlen=150pat_len=5000crsmin=50rat_sea=1rlam_heat=1
itype_conv=1turlen=1000pat_len=500crsmin=50rat_sea=1rlam_heat=1
itype_conv=0turlen=150pat_len=500crsmin=50rat_sea=1rlam_heat=0.1
itype_conv=1turlen=500pat_len=500crsmin=150rat_sea=20rlam_heat=5
itype_conv=1turlen=1000pat_len=5000crsmin=200rat_sea=1rlam_heat=5
itype_conv=0turlen=150pat_len=5000crsmin=150rat_sea=40rlam_heat=5
itype_conv=0turlen=500pat_len=2000crsmin=150rat_sea=40rlam_heat=0.1
itype_conv=0turlen=150pat_len=2000crsmin=200rat_sea=20rlam_heat=1
itype_conv=0turlen=150pat_len=5000crsmin=200rat_sea=20rlam_heat=0.1
itype_conv=0turlen=1000pat_len=5000crsmin=150rat_sea=20rlam_heat=1
itype_conv=1turlen=1000pat_len=5000crsmin=50rat_sea=40rlam_heat=1
13 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Member configurationitype_conv=1turlen=150pat_len=500crsmin=50rat_sea=40rlam_heat=0.1
itype_conv=1turlen=500pat_len=2000crsmin=50rat_sea=20rlam_heat=1
itype_conv=1turlen=1000pat_len=5000crsmin=50rat_sea=1rlam_heat=0.1
itype_conv=1turlen=150pat_len=2000crsmin=50rat_sea=1rlam_heat=5
itype_conv=1turlen=150pat_len=5000crsmin=50rat_sea=1rlam_heat=1
itype_conv=0turlen=150pat_len=5000crsmin=50rat_sea=1rlam_heat=1
itype_conv=1turlen=1000pat_len=500crsmin=50rat_sea=1rlam_heat=1
itype_conv=0turlen=150pat_len=500crsmin=50rat_sea=1rlam_heat=0.1
itype_conv=1turlen=500pat_len=500crsmin=150rat_sea=20rlam_heat=5
itype_conv=1turlen=1000pat_len=5000crsmin=200rat_sea=1rlam_heat=5
itype_conv=0turlen=150pat_len=5000crsmin=150rat_sea=40rlam_heat=5
itype_conv=0turlen=500pat_len=2000crsmin=150rat_sea=40rlam_heat=0.1
itype_conv=0turlen=150pat_len=2000crsmin=200rat_sea=20rlam_heat=1
itype_conv=0turlen=150pat_len=5000crsmin=200rat_sea=20rlam_heat=0.1
itype_conv=0turlen=1000pat_len=5000crsmin=150rat_sea=20rlam_heat=1
itype_conv=1turlen=1000pat_len=5000crsmin=50rat_sea=40rlam_heat=1
14 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Tiedtke Kain-Fritsch
~10-15 % higher, but mainly for high cloud cover cases
V.Stauch
Impact on CLCT (4 weeks in summer 2010):
COSMO-7 Kain-Fritsch test-suite (1)
15 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
00 UTC 00 UTC
ObservationsTiedtkeKain-FritschIFS
COSMO-7 Kain-Fritsch test-suite (2)
SYNOP verif T_2M Switzerland (lead-time +(01-24)h):
16 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
COSMO-7 Kain-Fritsch test-suite (3)
• Overestimation of cloud cover for northern Europe (but not for Switzerland)
• Impact on diurnal cycle of 2m temperature for Switzerland very small
For entire results see talk about comparison of Tiedtke, Kain-Fritsch and IFS convection schemes in WG3
Results suggest that Kain-Fritsch alone cannot explain the COSMO-LEPS cloud problem
17 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
June case: Too moist boundary layer
COSMO-LEPS TD_2M and OBS @ Zurich SYNOP station[oC]
4
8
12
16
12:00 23.06. 00:00 24.06. 12:00 24.06. 00:00 25.06.
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2
3
4
5
6
7
8
9
10
11
12
13
14
15
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obsKain-Fritsch membersTiedtke members
18 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
SYNOP verif TD_2M CH JJA2010
00 UTC 00 UTC
Mea
n E
rro
r
0
3
-3
COSMO-LEPS ensemble meanCOSMO-7
19 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
SYNOP verif TD_2M Europe JJA2010
COSMO-LEPS ensemble mean of TD_2M: Mean error
20 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Soil moisture: typical summer case
COSMO-LEPS memberinitial conditions
COSMO-7initial conditions
leve
l 1
(0-1
cm)
[mm]
wet Alpine region in COSMO-LEPS
21 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Soil moisture: typical summer case
COSMO-LEPS memberinitial conditions
COSMO-7initial conditions
leve
l 2
(1-3
cm)
[mm]
wet Alpine region in COSMO-LEPS
22 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Soil moisture: typical summer case
COSMO-LEPS memberinitial conditions
COSMO-7initial conditions
leve
l 3
(3-9
cm)
[mm]
wet Alpine region in COSMO-LEPS
23 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Soil moisture: typical summer case
COSMO-LEPS memberinitial conditions
COSMO-7initial conditions
leve
l 4
(9-2
7cm
)
[mm]
wet Alpine region in COSMO-LEPS
24 COSMO-LEPS cloud problem | COSMO GM 2010André Walser (andre.walser@meteoswiss.ch)
Conclusions
• Cloud problem in COSMO-LEPS seems to be caused by Kain-Fritsch together with a too moist boundary layer
• Has dramatic impact on 2m temperature
• Too moist boundary layer is caused by a too moist soil
Soil merge (COSMO-EU or assimilation cycle) should be introduced as soon as possible
If not possible before spring 2011, skip Kain-Fritsch
When problems with IFS convection scheme are solved ( WG3 talk) consider to use it
Soil moisture should be added to COSMO-LEPS output