2011-2012 winter RADIATION FOGS at

CIBA (Spain): Observations compared to WRF

simulations using different PBL parameterizations

Carlos Román-Cascón (carlosromancascon@fis.ucm.es)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

2/19

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

8/19

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