Eidgenssisches Departement des Innern EDI Bundesamt fr Meteorologie

Eidgenössisches Departement des Innern EDI Bundesamt für Meteorologie und Klimatologie Meteo. Schweiz The COSMO-LEPS cloud problem over the Alpine region André Walser Meteo. Swiss COSMO General Meeting, Moscow, 6 -10 September 2010

Typical summer case… COSMO-LEPS median COSMO-7 Observations many members with a too small diurnal cycle in 2 m temperature COSMO-LEPS predicts clearly more clouds than COSMO-7 large spread in deterministic case COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 2

SYNOP verif T_2 M Europe JJA 2010 lead-time +(25 -48)h ~1 K Observations COSMO-LEPS ensemble mean COSMO-7 00 UTC COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 00 UTC 3

SYNOP verif T_2 M CH JJA 2010 lead-time +(25 -48)h ~2 K Observations COSMO-LEPS ensemble mean COSMO-7 00 UTC COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 00 UTC 4

SYNOP verif CLCT CH JJA 2010 Mean Error 20 lead-time +(25 -48)h 0 COSMO-LEPS ensemble mean COSMO-7 -20 00 UTC COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 00 UTC 5

SYNOP verif CLCT Europe JJA 2010 COSMO-LEPS ensemble mean of CLCT: Mean error COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 6

June 24 case COSMO-LEPS median COSMO-7 Observations COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 7

June 24 15 UTC: A sunny day. . . COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 8

June 24 15 UTC: COSMO-LEPS Total cloud cover (CLCT) Low-level cloud cover (CLCL) member 7 COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 9

Low level clouds (CLCL) COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 10

Low level clouds (CLCL) COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 11

Member configuration itype_conv=1 turlen=150 pat_len=500 crsmin=50 rat_sea=40 rlam_heat=0. 1 itype_conv=1 turlen=500 pat_len=2000 crsmin=50 rat_sea=20 rlam_heat=1 itype_conv=1 turlen=1000 pat_len=5000 crsmin=50 rat_sea=1 rlam_heat=0. 1 itype_conv=1 turlen=150 pat_len=2000 crsmin=50 rat_sea=1 rlam_heat=5 itype_conv=1 turlen=150 pat_len=5000 crsmin=50 rat_sea=1 rlam_heat=1 itype_conv=0 turlen=150 pat_len=5000 crsmin=50 rat_sea=1 rlam_heat=1 itype_conv=1 turlen=1000 pat_len=500 crsmin=50 rat_sea=1 rlam_heat=1 itype_conv=0 turlen=150 pat_len=500 crsmin=50 rat_sea=1 rlam_heat=0. 1 itype_conv=1 turlen=500 pat_len=500 crsmin=150 rat_sea=20 rlam_heat=5 itype_conv=1 turlen=1000 pat_len=5000 crsmin=200 rat_sea=1 rlam_heat=5 itype_conv=0 turlen=150 pat_len=5000 crsmin=150 rat_sea=40 rlam_heat=5 itype_conv=0 turlen=500 pat_len=2000 crsmin=150 rat_sea=40 rlam_heat=0. 1 itype_conv=0 turlen=150 pat_len=2000 crsmin=200 rat_sea=20 rlam_heat=1 itype_conv=0 turlen=150 pat_len=5000 crsmin=200 rat_sea=20 rlam_heat=0. 1 itype_conv=0 turlen=1000 pat_len=5000 crsmin=150 rat_sea=20 rlam_heat=1 itype_conv=1 turlen=1000 pat_len=5000 crsmin=50 rat_sea=40 rlam_heat=1 COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 12

Member configuration itype_conv=1 turlen=150 pat_len=500 crsmin=50 rat_sea=40 rlam_heat=0. 1 itype_conv=1 turlen=500 pat_len=2000 crsmin=50 rat_sea=20 rlam_heat=1 itype_conv=1 turlen=1000 pat_len=5000 crsmin=50 rat_sea=1 rlam_heat=0. 1 itype_conv=1 turlen=150 pat_len=2000 crsmin=50 rat_sea=1 rlam_heat=5 itype_conv=1 turlen=150 pat_len=5000 crsmin=50 rat_sea=1 rlam_heat=1 itype_conv=0 turlen=150 pat_len=5000 crsmin=50 rat_sea=1 rlam_heat=1 itype_conv=1 turlen=1000 pat_len=500 crsmin=50 rat_sea=1 rlam_heat=1 itype_conv=0 turlen=150 pat_len=500 crsmin=50 rat_sea=1 rlam_heat=0. 1 itype_conv=1 turlen=500 pat_len=500 crsmin=150 rat_sea=20 rlam_heat=5 itype_conv=1 turlen=1000 pat_len=5000 crsmin=200 rat_sea=1 rlam_heat=5 itype_conv=0 turlen=150 pat_len=5000 crsmin=150 rat_sea=40 rlam_heat=5 itype_conv=0 turlen=500 pat_len=2000 crsmin=150 rat_sea=40 rlam_heat=0. 1 itype_conv=0 turlen=150 pat_len=2000 crsmin=200 rat_sea=20 rlam_heat=1 itype_conv=0 turlen=150 pat_len=5000 crsmin=200 rat_sea=20 rlam_heat=0. 1 itype_conv=0 turlen=1000 pat_len=5000 crsmin=150 rat_sea=20 rlam_heat=1 itype_conv=1 turlen=1000 pat_len=5000 crsmin=50 rat_sea=40 rlam_heat=1 COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 13

COSMO-7 Kain-Fritsch test-suite (1) Impact on CLCT (4 weeks in summer 2010): Tiedtke Kain-Fritsch ~10 -15 % higher, but mainly for high cloud cover cases V. Stauch COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 14

COSMO-7 Kain-Fritsch test-suite (2) SYNOP verif T_2 M Switzerland (lead-time +(01 -24)h): Observations Tiedtke Kain-Fritsch IFS 00 UTC COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 00 UTC 15

COSMO-7 Kain-Fritsch test-suite (3) • Overestimation of cloud cover for northern Europe (but not for Switzerland) • Impact on diurnal cycle of 2 m temperature for Switzerland very small For entire results see talk about comparison of Tiedtke, Kain -Fritsch and IFS convection schemes in WG 3 Results suggest that Kain-Fritsch alone cannot explain the COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 16

June case: Too moist boundary layer COSMO-LEPS TD_2 M and OBS @ Zurich SYNOP station [o. C] Kain-Fritsch members Tiedtke members COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 17

SYNOP verif TD_2 M CH JJA 2010 Mean Error 3 0 COSMO-LEPS ensemble mean COSMO-7 -3 00 UTC COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 00 UTC 18

SYNOP verif TD_2 M Europe JJA 2010 COSMO-LEPS ensemble mean of TD_2 M: Mean error COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 19

Soil moisture: typical summer case COSMO-7 initial conditions [mm] level 1 (0 -1 cm) COSMO-LEPS member initial conditions wet Alpine region in COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 20

Soil moisture: typical summer case COSMO-7 initial conditions [mm] level 2 (1 -3 cm) COSMO-LEPS member initial conditions wet Alpine region in COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 21

Soil moisture: typical summer case COSMO-7 initial conditions [mm] level 3 (3 -9 cm) COSMO-LEPS member initial conditions wet Alpine region in COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 22

Soil moisture: typical summer case COSMO-7 initial conditions [mm] level 4 (9 -27 cm) COSMO-LEPS member initial conditions wet Alpine region in COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 23

Conclusions • Cloud problem in COSMO-LEPS seems to be caused by Kain-Fritsch together with a too moist boundary layer • Has dramatic impact on 2 m 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 ( WG 3 talk) consider to use it Soil moisture should be added to COSMO-LEPS output COSMO-LEPS cloud problem | COSMO GM 2010 André Walser (andre. walser@meteoswiss. ch) 24