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2.2.9. SUEWS_Snow.txt

SUEWS_Snow.txt specifies the characteristics for snow surfaces when SnowUse=1 in RunControl.nml. If the snow part of the model is not run, fill this table with ‘-999’ except for the first (Code) column and set SnowUse=0 in RunControl.nml. For a detailed description of the variables, see Järvi et al. (2014) (Järvi et al., 2014).

No.

Column Name

Use

Description

1

Code

L

Code linking to a corresponding look-up table.

2

RadMeltFactor

MU

Hourly radiation melt factor of snow [mm W-1 h-1]

3

TempMeltFactor

MU

Hourly temperature melt factor of snow [mm K-1 h-1]

4

AlbedoMin

MU

Effective surface albedo (middle of the day value) for wintertime (not including snow).

5

AlbedoMax

MU

Effective surface albedo (middle of the day value) for summertime.

6

Emissivity

MU

Effective surface emissivity.

7

tau_a

MD

Time constant for snow albedo aging in cold snow [-]

8

tau_f

MD

Time constant for snow albedo aging in melting snow [-]

9

PrecipLimAlb

MD

Limit for hourly precipitation when the ground is fully covered with snow [mm]

10

SnowDensMin

MD

Fresh snow density [kg m-3]

11

SnowDensMax

MD

Maximum snow density [kg m-3]

12

tau_r

MD

Time constant for snow density ageing [-]

13

CRWMin

MD

Minimum water holding capacity of snow [mm]

14

CRWMax

MD

Maximum water holding capacity of snow [mm]

15

PrecipLimSnow

MD

Temperature limit when precipitation falls as snow [°C]

16

OHMCode_SummerWet

L

Code for OHM coefficients to use for this surface during wet conditions in summer, linking to SUEWS_OHMCoefficients.txt.

17

OHMCode_SummerDry

L

Code for OHM coefficients to use for this surface during dry conditions in summer, linking to SUEWS_OHMCoefficients.txt.

18

OHMCode_WinterWet

L

Code for OHM coefficients to use for this surface during wet conditions in winter, linking to SUEWS_OHMCoefficients.txt.

19

OHMCode_WinterDry

L

Code for OHM coefficients to use for this surface during dry conditions in winter, linking to SUEWS_OHMCoefficients.txt.

20

OHMThresh_SW

MD

Temperature threshold determining whether summer/winter OHM coefficients are applied [°C]

21

OHMThresh_WD

MD

Soil moisture threshold determining whether wet/dry OHM coefficients are applied [-]

22

ESTMCode

L

Code for ESTM coefficients linking to SUEWS_ESTMCoefficients.txt

23

AnOHM_Cp

MU

Volumetric heat capacity for this surface to use in AnOHM [J m-3]

24

AnOHM_Kk

MU

Thermal conductivity for this surface to use in AnOHM [W m K-1]

25

AnOHM_Ch

MU

Bulk transfer coefficient for this surface to use in AnOHM [-]

An example SUEWS_Snow.txt can be found below:

1     	 2             	 3              	 4         	 5         	 6          	 7     	 8     	 9            	 10          	 11          	 12    	 13     	 14     	 15            	 16                	 17                	 18                	 19                	 20           	 21           	 22       	 23       	 24       	 25
Code  	 RadMeltFactor 	 TempMeltFactor 	 AlbedoMin 	 AlbedoMax 	 Emissivity 	 tau_a 	 tau_f 	 PrecipLimAlb 	 SnowDensMin 	 SnowDensMax 	 tau_r 	 CRWMin 	 CRWMax 	 PrecipLimSnow 	 OHMCode_SummerWet 	 OHMCode_SummerDry 	 OHMCode_WinterWet 	 OHMCode_WinterDry 	 OHMThresh_SW 	 OHMThresh_WD 	 ESTMCode 	 AnOHM_Cp 	 AnOHM_Kk 	 AnOHM_Ch
99999 	 -999          	 -999           	 -999      	 -999      	 -999       	 -999  	 -999  	 -999         	 -999        	 -999        	 -999  	 -999   	 -999   	 -999          	 61                	 61                	 61                	 61                	 10           	 0.9          	 99999    	 100000   	 1.2      	 4        	 !
1     	 0.0016        	 0.12           	 0.18      	 0.85      	 0.99       	 0.018 	 0.11  	 2            	 100         	 400         	 0.043 	 0.05   	 0.2    	 2.2           	 61                	 61                	 61                	 61                	 10           	 0.9          	 61       	 100000   	 1.2      	 4        	 ! 	 Helsinki   (HCW   added   0.99   for      emissivity) 	 Jarvi   et   al.   (2014)
550   	 0.001         	 0.14           	 0.18      	 0.8       	 0.99       	 0.01  	 0.1   	 2            	 100         	 450         	 0.02  	 0.03   	 0.1    	 2.2           	 61                	 61                	 61                	 61                	 10           	 0.9          	 61       	 100000   	 1.2      	 4        	 ! 	 Swindon  	 Ward   et      al.    (2013)
660   	 0.001         	 0.14           	 0.18      	 0.8       	 0.99       	 0.01  	 0.1   	 2            	 100         	 450         	 0.02  	 0.03   	 0.1    	 2.2           	 61                	 61                	 61                	 61                	 10           	 0.9          	 61       	 100000   	 1.2      	 4        	 ! 	 London
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