pp coloboc 9.2008-9.2011 : different aspects of snow parameterization

PP COLOBOC 9.2008-9.2011: Different aspects of snow parameterization

2010-2011: task 5 “Revision of snow analysis and snow model”

General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop

Inna Rozinkina, Inna Rozinkina, [email protected]@mail.ru, Ekaterina Kazakova, Ekaterina Kazakova, [email protected], ,

Developments at Roshydromet, with an Developments at Roshydromet, with an emphasis on snow density, partial snow cover emphasis on snow density, partial snow cover

and T2m forecasting errorsand T2m forecasting errors

mailto:[email protected]

mailto:[email protected]

Why Roshydromet?Why Roshydromet?

Near 95% of territory of Russia (incl 85 % of modeling Near 95% of territory of Russia (incl 85 % of modeling domain of COSMO-RU07 and 100% of COSMO-RU02c) is domain of COSMO-RU07 and 100% of COSMO-RU02c) is covered by snow during winter periodcovered by snow during winter period

During 3-5 cold months the quality of During 3-5 cold months the quality of COSMO-Ru weather forecasts depends COSMO-Ru weather forecasts depends on success of snow-cover on success of snow-cover parameterizationparameterization

The data of hydrological The data of hydrological monitoring (from monitoring (from RoshydrometRoshydromet network) permits to realize the network) permits to realize the verification of snow modeling verification of snow modeling results (from polar to results (from polar to subtropical zones)subtropical zones)

Review of results 2008-2009:

The new multi-layer snow parameterization scheme was developed (Lykosov, Machulkaya) with description of metamorphism and snow compression, cooling/melting of snow layers, penetration of solar radiation, water dynamic with phase perturbation (melting & freezing) and heat release.

Ekaterina Machulskaya (Roshydromet) realized this scheme, made the validation (based on the data of Valday observatory, 1-d stand-alone experiments), adapted the codes of new multi-layer snow scheme to TERRA soft.

In development of this activities the new multi-layer scheme was included into MeteoSwiss forecast system (data assimilation system) and also into operational COSMO versions since 4.11 . Tests for some points in Swiss mountains were carried out.

Review of results 2009-2010: Analysis of effects of new

multi-layer snow parameterization scheme coupled to TERRA into COSMO-model is made for European part of Russia:

The measurements more than 30

hydrological stations with special snow measurements in northern, central, south parts of European Russia were used during 2-6 months

The different criteria of scores were analyzed.

NorthNorth

CentreCentre

SouthSouth


It was establishedIt was established::

- TERRA with multi-layer snowTERRA with multi-layer snow scheme simulates more accurately the scheme simulates more accurately the process of snow melting;process of snow melting;

- TERRA with multi-layer now schemeTERRA with multi-layer now scheme produces more accurately T2m for produces more accurately T2m for the night – timethe night – time during the period of snow melting;during the period of snow melting;

- There is some underestimation ofThere is some underestimation of fresh snow density fresh snow density (immediately after (immediately after snow-fall events) by multi-layer snow schemesnow-fall events) by multi-layer snow scheme


-14,0-12,0-10,0-8,0-6,0-4,0-2,00,02,04,0

11 m

arch

13 m

arch

15 m

arch

17 m

arch

19 m

arch

21 m

arch

23 m

arch

25 m

arch

27 m

arch

29 m

arch

date

0С

station

forec 24h

forec 24h - new

Snow layer Snow layer appeared appeared warmer warmer Freezing after Freezing after meltingmelting

05

101520253035404550556065707580859095

100105110115

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 26 27 28 29 30 31 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 26 27 28 29 30 31 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 26 27 28

декабрь январь февраль

см

осадки снег, мм

осадки дождь, мм

станция

72ч-нов

72ч-стар

(Т+100С), 12UTC

Review or results 2009-2010Review or results 2009-2010

It was establishedIt was established, that in independemce of use snow , that in independemce of use snow parameterisation:parameterisation:

- There areThere are large errors large errors (150-300%)(150-300%) of COSMO-model simulations of snow of COSMO-model simulations of snow water equivalent (SWE). water equivalent (SWE). They are due to largeThey are due to large errors in the prescribed SWE errors in the prescribed SWE as initial data. as initial data. On the other hand, the initial data of values of snow height On the other hand, the initial data of values of snow height (SH) are convenient. Also SH is well simulated by the COSMO-model(SH) are convenient. Also SH is well simulated by the COSMO-model

- There areThere are large errors (2-15°C) of COSMO-model simulations of T2m during large errors (2-15°C) of COSMO-model simulations of T2m during the melting period. the melting period. They are originated from the fact that TS within the cell, They are originated from the fact that TS within the cell, covered by snow, can not be more thancovered by snow, can not be more than melting-pointmelting-point


0

30

60

90

120

150

180

210

1 2 3 4 5 6 7 8 91

01

11

21

31

41

51

61

71

81

92

02

12

22

32

42

52

62

72

82

93

03

1 1 2 3 4 5 6 7 8 91

01

11

21

31

41

51

61

71

81

92

02

12

22

32

42

52

62

72

82

93

03

1 1 2 3 4 5 6 7 8 91

01

11

21

31

41

51

61

71

81

92

02

12

22

32

42

52

62

72

8

december january february

mm

SWE forec 24h - new

SWE forec 24h

station (forest)

-6,0-4,0-2,00,02,04,06,08,0

10,0

11 m

arch

13 m

arch

15 m

arch

17 m

arch

19 m

arch

21 m

arch

23 m

arch

25 m

arch

27 m

arch

29 m

arch

date

0С

station

forec 36h

forec 36h - new


- To refresh TERRA code using SH instead of SWESH instead of SWE;

- To change the algorithms of TERRA to improve the calculations of Ts of Ts and TGand TG of fractional snow covered cells with possible values above above the melting pointthe melting point;

- To propose and to validate the new algorithms for determination the the initial values of snow densityinitial values of snow density (to include into codes preparation of the start information);

- To include the multi-layer snow scheme into operational codes of include the multi-layer snow scheme into operational codes of COSMO-ModelCOSMO-Model. The more important effects should appear in systems of long-term integrations (f.ex, DAS, CLM)

Next recommendations were obtained: Next recommendations were obtained:



Karachev

-6

-4

-2

0

2

4

6

8

25 26 27 28 29 30 31 1

march april

0C

station

model 24h experiment

model 24h

Poniry

-6

-4

-2

0

2

4

6

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

Rilsk

-4

-2

0

2

4

6

8

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

Gotnya

-4

-2

0

2

4

6

8

10

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

Anna

-10-8-6-4-20246

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

-12-10

-8-6-4-2024

25 26 27 28 29 30 31 1

march april

0C

Vetluga

station


model 24h

Moscow

-10-8-6-4-20246

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

Kaluga

-10-8-6-4-20246

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

Kursk

-6-4-202468

10

25 26 27 28 29 30 31 1

march april

0C

station


model 24h

Review of results 2010-2011: 1. T2m forecasting: Some changes in TERRA were made to improve T2m forecasts during snow-melt period. T2m forecast errors were significantly reduced for test forecasts for winters of 2009-2010

and 2010-1011 in COSMO-Ru07 and COSMO-Ru14 Since 4th Apr 2011 the modifications were included in operational codes for COSMO-

Ru07 and COSMO-RUSib. The results of mechanisms of such changes were analyzed.

Date of changing operational codes Date of changing operational codes COSMO-RUCOSMO-RU


T2m(experiment)-T2m(ctrl)36h forecast36h forecast 48h forecast48h forecast

T2m temperature raised up to 10T2m temperature raised up to 10ºC on the territory where according ºC on the territory where according to model data to model data snow cover snow cover was below 40 cmwas below 40 cm



2.Snow-density

Some parameterizations for the start values of snow-density are proposed and tested. The more realistic variant was selected. The data of the tests for 33 stations in different climatic zones were used.

motivation: large errors in initial SWE. No regular observation data



Example of start field of snow density Example of start field of snow density in COSMO- model. 25 March 2010in COSMO- model. 25 March 2010

- The values ofThe values of snow density snow density are in dependenceare in dependence of weather of weather during the full winterduring the full winter period, using of constant values of period, using of constant values of snow density led to large errors in most part of snow-covered snow density led to large errors in most part of snow-covered regionsregions

- Connection between typical (climatic) snow density values Connection between typical (climatic) snow density values andand types of vegetation cover may be showed types of vegetation cover may be showed

- - The algorithm of calculations of snow density as function of The algorithm of calculations of snow density as function of sum of positives values of T2m duringsum of positives values of T2m during full snow period full snow period andand climatic values of snow density climatic values of snow density (Vg, LAI and Zo) was (Vg, LAI and Zo) was proposed and tested for stations in different zones. The proposed and tested for stations in different zones. The algorithm can be recommended to be included into COSMO- algorithm can be recommended to be included into COSMO- forecasting technologiesforecasting technologies

It was etablished:



The distribution snow density before melting like the allocation of plants cover

0,28-0,30 0,28-0,30 tundra, tundra, forest-tundraforest-tundra; south - ; south - steppesteppe

Types of vegetationTypes of vegetationAverage snow density (g/cmAverage snow density (g/cm33))at maximum ten-day snow heightat maximum ten-day snow height

0,26-0,28 0,26-0,28 north north - - forest-tundraforest-tundra;; steppesteppe and and

broadleaf forestbroadleaf forests (with s (with predominance predominance of of birchbirch)) 0,22-0,26 0,22-0,26 taigataiga ( (sprucespruce; spruce with a touch ; spruce with a touch

of oak); south - steppeof oak); south - steppe

0,20-0,22 0,20-0,22 swamp vegetationswamp vegetation, taiga (spruce); west - , taiga (spruce); west - broadleaf forestbroadleaf forests (with s (with predominance predominance of oak and of oak and

hornbeam)hornbeam) <0.20 <0.20 taiga (with taiga (with predominance predominance of larch)of larch)



The errors of initial The errors of initial values of SWE values of SWE were decreased were decreased

from 200-300% to from 200-300% to 25-50% on the 25-50% on the

must part of must part of stationsstations


Taiga (spruce predominance):Taiga (spruce predominance): Tacsnow limStation Pinega

100

150

200

250

300

350

400

450

20 20 31 10 20 28 5 10 15 20 25 31 5 10 15 20 25

dec jan feb march april

sno

w d

ensi

ty, k

g/m

3

station forest

formula

COSMO 00h

Station Verhnaya Toyma

100

150

200

250

300

350

400

450

20 20 31 10 20 28 5 10 15 20 25 31 5 10 15

dec january february march april

sno

w d

ensi

ty, k

g/m

3

station forest

formula

COSMO 00h

station field

11,200lim ac

BBroad-leaved forestroad-leaved forest (oak predominance): (oak predominance):

Station Spas-Demensk

100

150

200

250

300

350

400

450

20 31 10 20 31 10 20 28 5 10 15 20 25

dec january february march

sno

w d

ensi

ty, k

g/m

3

station forest

station field

formula

COSMO 00h

With With spruce/pinespruce/pine

10,230lim acT - Sum of positive

average daily temperatures With birchWith birch 10,250lim ac

Station Radishevo

100

150

200

250

300

350

400

450

10 20 31 5 10 15 20 25 28 5 10 15 20 25 31 5 10 15

january february march april

sno

w d

ensi

ty, k

g/m

3

station field

formula

COSMO 00h

FForest-steppeorest-steppe 8,280lim acStation Anna

100

150

200

250

300

350

400

450

20 31 10 31 10 20 28 5 10 15 20 25

dec jan february march

sno

w d

ensi

ty, k

g/m

3

station forest

station field

formula

COSMO 00h

SteppeSteppe 9,300lim ac

Station Urupinsk

100

150

200

250

300

350

400

450

20 31 5 10 15 20 28 5 10 15 20 25 31

jan february march

sno

w d

ensi

ty, k

g/m

3

station field

formula

COSMO 00h


Snow density for station Verhnaya Toyma: measurements, calculated values due to formula and initial values in COSMO-

model. 10 Feb - 25 March 2010

100150200250300350400450

6 26 45 52

the sum of positive T2m (0C)

sno

w d

ensi

ty, k

g/m

3

station forest

formula

COSMO 00h

Snow density for station Lalsk: measurements, calculated values due to formula and initial values in COSMO-model.

10 Feb - 25 March 2010

100150200250300350400450

10 33 61 68


sno

w d

ensi

ty, k

g/m

3

station forest

station field

formula

COSMO 00h

100150200250300350400450

27 44 45 45 48

sno

w d

ensi

ty,

kg/m

3


Snow density for station Pinega: measurements, calculated values due to formula and initial values in COSMO-model.

10 Feb - 25 March 2010

station forest

formula

COSMO 00h

Snow density for station Anna: measurements, calculated values due to formula and initial values in COSMO-model.

10 Feb - 25 March 2010

100150200250300350400450

6 8 9 9 9 11 21


sno

w d

ensi

ty, k

g/m

3

station forest

station field

formula

COSMO 00h

Snow density for station Radishevo: measurements, calculated values due to formula and initial values in COSMO-

model. 5 Feb - 25 March 2010

100

150

200

250

300

350

400

450

10 21 31 52


sno

w d

ensi

ty, k

g/m

3

station field

formula

COSMO 00h

Snow density for station Mozhga: measurements, calculated values due to formula and initial values in COSMO-model.

10 Feb - 25 March 2010

100150200250300350400450

6 27 43


kg/m

3

station forest

station field

formula

COSMO 00h

The errors of initial values of WE were decreased The errors of initial values of WE were decreased from 200-300% to 25-50% on the must part of from 200-300% to 25-50% on the must part of stationsstations


Summary for 2010-2011

- It is not enough to change the fractional snow cover parameter in TERRA to take into account the thermal effects of thawed patches.

(It is needed to made the changes into codes of calculations of T of soil layers, radiation fluxes, effective TG)

- The success for T2m prediction can be achieved with the introduction in scheme of artificial heating surface ( looks like the effects of routes, buildings, tree branches without snow) or with modeling of more rapid melting of snow. As alternative, the mosaic approach can be developed, with mosaic calculations for some soil layers

- The values of snow density are in dependence of weather during the full winter period, the using of constants led to large errors

- It is existed the connection between typical (climatic) snow density values and types of vegetation.




2011 – start of participation of Roshydromet in the SRNWP Data Exchange Programme

EUMETNET.

The necessary preliminary jobs for organization of activities on Valday observatory were carried out


http://www.eumetnet.eu/


ValdayValday water-balance research station in Russia water-balance research station in Russia (57(57ºº58'N, 3358'N, 33ºº 14'E) 14'E) located in a boreal forest area. located in a boreal forest area.

- S- Seasonal variations with aneasonal variations with an annualannual temperaturetemperature: : range of 35range of 35ººC C - A- Annual average precipitationnnual average precipitation of 730 mm of 730 mm ((the the maximum in the summer andmaximum in the summer and a autumnutumn)).. - P- Persistent snow coverersistent snow cover period: period: from Novemberfrom November until April. until April.

Observatory Valday

Smirnova T.Smirnova T. Parameterization of cold-season processes in the MAPSParameterization of cold-season processes in the MAPS land-surface scheme // land-surface scheme // JJournalournal ofof G Geophysicaleophysical RResearchesearch, V, Volol. 105, NO. D3, . 105, NO. D3, 2000.2000.


Valday principal observations: Precipitation polygon:

Measured parameters: precipitation, Measured parameters: precipitation, precipitation intensity, evaporation, windprecipitation intensity, evaporation, wind

GGaging stationaging station::Measured parameters: daily runoff on 9 Measured parameters: daily runoff on 9 stations of river Polomet’ and its tributaries, stations of river Polomet’ and its tributaries, maximal snow survey maximal snow survey

Valday observationsValday observations


Meteorological station

Measured parameters: Measured parameters: solar radiometrysolar radiometry,, standart meteorological measurements, standart meteorological measurements, frost penetrationfrost penetration

WeirWeir

Measured parameters: runoff, Measured parameters: runoff, frost frost penetrationpenetration, precipitation, , precipitation, snow reservessnow reserves, , evaporation from soilevaporation from soil



Gradient measurements

Measurements: Measurements: Turbulent fluxesTurbulent fluxes

Meteorological radarMeteorological radar



PlansPlans

Plans for 2011-2012:Plans for 2011-2012:

1. A new parameterization of the snow pack density should be 1. A new parameterization of the snow pack density should be tested and adapted to operational snow analysis steptested and adapted to operational snow analysis step

2. The geographical maps of values of climatic density will be 2. The geographical maps of values of climatic density will be prepared (or algorithms for its calculating as function of prepared (or algorithms for its calculating as function of vegetation parameters)vegetation parameters)

3. Proposals for modification of TERRA codes for fractional 3. Proposals for modification of TERRA codes for fractional covering (heating effects of near- surface air) should be covering (heating effects of near- surface air) should be formalizedformalized


THANK YOU!THANK YOU!

pp coloboc 9.2008-9.2011 : different aspects of snow parameterization

Documents

success of snow

snow compression

partial snow cover

special snow measurements

revision of snow analysis

period of snow meltingthere

coolingmelting of snow

process of snow meltingterra