pp coloboc 9.2008-9.2011 : different aspects of snow parameterization
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General Meeting 2011, COLOBOC Workshop. PP COLOBOC 9.2008-9.2011 : Different aspects of snow parameterization. Developments at Roshydromet, with an emphasis on snow density, partial snow cover and T2m forecasting errors. 2010-2011: task 5 “Revision of snow analysis and snow model”. - PowerPoint PPT PresentationTRANSCRIPT
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
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
-14,0-12,0-10,0-8,0-6,0-4,0-2,00,02,04,0
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forec 24h
forec 24h - new
Snow layer Snow layer appeared appeared warmer warmer Freezing after Freezing after meltingmelting
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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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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december january february
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SWE forec 24h - new
SWE forec 24h
station (forest)
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Review or results 2009-2010Review or results 2009-2010
- 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:
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
Review or results 2009-2010Review or results 2009-2010
Karachev
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model 24h experiment
model 24h
Poniry
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Rilsk
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Gotnya
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Anna
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march april
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model 24h experiment
model 24h
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march april
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Vetluga
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model 24h experiment
model 24h
Moscow
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model 24h experiment
model 24h
Kaluga
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march april
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model 24h experiment
model 24h
Kursk
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10
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march april
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model 24h experiment
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
Review or results 2010-2011Review or results 2010-2011
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
Review or results 2010-2011Review or results 2010-2011
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:
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
Review or results 2010-2011Review or results 2010-2011
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)
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
Review or results 2010-2011Review or results 2010-2011
Taiga (spruce predominance):Taiga (spruce predominance): Tacsnow limStation Pinega
100
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350
400
450
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sno
w d
ensi
ty, k
g/m
3
station forest
formula
COSMO 00h
Station Verhnaya Toyma
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250
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350
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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
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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
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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
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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
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ty, k
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station field
formula
COSMO 00h
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
the sum of positive T2m (0C)
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
the sum of positive T2m (0C)
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
the sum of positive T2m (0C)
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
the sum of positive T2m (0C)
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
the sum of positive T2m (0C)
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
Review or results 2010-2011Review or results 2010-2011
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.
Review or results 2010-2011Review or results 2010-2011
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
Review or results 2010-2011Review or results 2010-2011
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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.
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
Valday observationsValday observations
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
Gradient measurements
Measurements: Measurements: Turbulent fluxesTurbulent fluxes
Meteorological radarMeteorological radar
Valday observationsValday observations
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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
General Meeting 2011, COLOBOC WorkshopGeneral Meeting 2011, COLOBOC Workshop
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