2011-2012 winter RADIATION FOGS at
CIBA (Spain): Observations compared to WRF
simulations using different PBL parameterizations
Carlos Román-Cascón ([email protected])Carlos YagüeMariano SastreGregorio Maqueda
Universidad Complutense de Madrid
EMS & ECAC 2012. Łódź, Poland11th September 2012
1. Introduction2. Overview3. Observations4. WRF Model results5. Conclusions6. Future study
CONTENTS
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RADIATION FOGS- Effects on daily life – Transport.- Physical processes not well understood. - not well parameterized in NWP models. - no good forecasts of fogs.
ROLE OF TURBULENCE OVER FOGS- It acts favoring the development (Welch et al.,1986).- It acts favoring the dissipation (Roach et al.,1976).- Turbulence threshold between development and dissipation (Zhou et al., 2008).
MAIN GOALS- To improve the fog prediction and to improve the knowledge about the
physical processes affecting the formation/dissipation of fogs.
1. INTRODUCTION
3/19
2. OVERVIEWIberian Peninsula
25 km
Northern Spanish Plateau Montes Torozos
800 km2 840m asl
CIBA site
CIBA SITE
4/19
2. OVERVIEW 3-14 January 2012 (12 days) Synoptic Situation
500 hPa Geopotential
(gpdm)&
Sea level pressure
(hPa)
5/19
Fog Thickness
(m)
Time (day at 00 UTC)
2. OVERVIEW Fog Thickness (approximation)
6/19
3 4 5 6 7 8 9 10 11 12 13 14 -8
-6
-4
-2
0
2
4
6
8
10Temperature at different heigths
(ºC
)
Day
2m 10m 35m 97m
Fog thickness
(m)
ObservedTemperatureat different
heights (ºC)
3. OBSERVATIONS Fog Thickness & Temperature
Time (day at 00 UTC)
2m 10m 35m 97m 20m
7/19
2m 10m 35m 97m 20m
2m 10m 35m 97m 20m
2m 10m 35m 97m 20m
Fog thickness
(m)
Frictionvelocity (m/s)
3. OBSERVATIONS Fog Thickness & Friction velocity
Time (day at 00 UTC)3 4 5 6 7 8 9 10 11 12 13 14
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35Friction velocity
(m/s
)
0,163 0,263 0,094 0,082 0,056 0,067 0,079 0,100 0,046 0,054 0,057 0,094
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0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.2210
20
30
40
50
60
70
80
90
Fog thickness
(m)
Fog thickness
(m)
3. OBSERVATIONS Fog Thickness & Friction velocityrelations
Friction velocity (m/s)9/19
- Horizontal domains - 4 nested domains- Grid - 27, 9, 3, 1 km - Boundary conditions - NCEP, 1º, 6 hours- Vertical resolution 50 levels “eta” (8 levels< 100 m) (28 levels< 1 km)- Time step - 90 s- Spin up -36 h (restart run)- SW radiation- Dudhia (1998)- LW radiation - RRTM
4. WRF SIMULATIONS- PBL parameterizations
- MYJ- QNSE- MYNN 2.5- MYNN 2.5 + Gravity settling
- Microphysics parameterizations (QNSE fixed)
- WSM3 (default)- Lin et al.- Goddard scheme
- Land-surface parameterizations (QNSE & Goddard fixed)
- Noah LSM (default)- RUC LSM
Average of 17 points
centered at CIBA
CIBA
4 km
4 km
1 km
10/19
4. WRF SIMULATIONS LWC (g/kg) PBL schemes
MYJ
QNSE
MYNN2.5
MYNN2.5GS
LWCsimulated
byWRF
(g/kg)
Time (day at 00 UTC)
3 4 5 6 7 8 9 10 11 12 13 14 0
0.5
300m 100m 35m 10m
3 4 5 6 7 8 9 10 11 12 13 14 0
0.5
3 4 5 6 7 8 9 10 11 12 13 14 0
0.5
3 4 5 6 7 8 9 10 11 12 13 14 0
0.5
4. WRF SIMULATIONS Temperature PBL schemes
2mTemp.
simulatedby
WRFandobs.(ºC)
Time (day at 00 UTC)3 4 5 6 7 8 9 10 11 12 13 14 15
-6
-4
-2
0
2
4
6
8
10
obs MYJ QNSE MYNN 2.5 MYNN 2.5 GS
OBS
4. WRF SIMULATIONS LWC (g/kg) MICROPHYSICS schemes
WSM3(default)
Jin et. al
Goddard
LWCsimulated
byWRF
(g/kg)
Time (day at 00 UTC)
3 4 5 6 7 8 9 10 11 12 13 14 0
0.2
0.4
300m 100m 35m 10m
3 4 5 6 7 8 9 10 11 12 13 14 0
0.2
0.4
3 4 5 6 7 8 9 10 11 12 13 14 0
0.2
0.4
QNSE fixed!
4. WRF SIMULATIONS Temperature & Mixing RatioMICROPHYSICS schemes
Temperature (ºC)
Mixing ratio
(g/kg)
Time (day at 00 UTC)
3 4 5 6 7 8 9 10 11 12 13 14
-5
0
5
10
obs WSM3 ( default) Lin Goddard
3 4 5 6 7 8 9 10 11 12 13 14 2
3
4
5
6
7
QNSE fixed!
4. WRF SIMULATIONS LWC (g/kg) LAND-SURFACE schemes
LWCsimulated
byWRF
(g/kg)
Time (day at 00 UTC)
3 4 5 6 7 8 9 10 11 12 13 14 0
0.1
0.2
0.3
0.4
0.5
300m 100m 35m 10m
3 4 5 6 7 8 9 10 11 12 13 14 0
0.1
0.2
0.3
0.4
0.5
Noah(default)
RUC
QNSE & Goddard microph. fixed!
4. WRF SIMULATIONS LWC (g/kg) LAND-SURFACE schemes
Time (UTC)
12 12.5 130
0.1
0.2
0.3
0.4
0.5
300m 100m 35m 10m
12 12.5 130
0.1
0.2
0.3
0.4
0.5
LWCsimulated
byWRF
(g/kg)
Noah(default)
RUC
QNSE & Goddard LSM
fixed!
5. CONCLUSIONSOBSERVATIONS- Certain degree of turbulence to extend the fog in the vertical. - Nocturnal turbulence ~ 0.05 m/s Great surface thermal inversions Shallower fogs.
SIMULATIONS- Tendency to overestimate the temperature. - Tendency to “rise up” the fog. - Tendency to dissipate the fog at midday (not able to simulate persistent fogs)- Problems to predict shallow fogs related to high inversions.
- QNSE and MYNN2.5 in general better. - Lin et al. & Goddard Microphysics Improve the fog forecasting for days with difficulties. - RUC Land Surface Improve more the fog forecasting- Combination of errors good prediction of fog?
- Many different processes working together! - Still many problems simulating fogs, and consequently affecting T2, SW, LW…
17/19
6. FUTURE STUDY (soon)- Statistic with more data (bias, RMSE)
- Detailed analysis of some concrete day
- More data (ceilometer + visibilimeter) Better comparison with simulations
- Interaction between Internal Gravity waves & Fogs
17.5 18 18.5-0.1
-0.05
0
0.05
0.1
17,5 18 18.5
10
15
20
25
0.5
1
1.5
2
x 10-4
17.5 18 18.5-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4Temperature
UTC
2m 10m 20m 35m 97m
Filtered pressure
(hPa)
Wavelet analysis
35 mTemperature
(ºC)
18/19
THANK YOU !!
(this is not a radiation fog!!!)
Thanks to EMS for the Young Scientist Travel Award (YSTA) 19/19