the investigation future evolution of glacier and ... · an underestimate of the rates of glacier...
TRANSCRIPT
TheFirstWorkshopoftheChinese-Norwegian'ThirdPole-ArcticCenter’,2019.10.7,Bergen
Theinvestigationfutureevolutionofglacierandhydrologicalimpactsbyanintegratedatmosphere-glacier-hydrologicalmodelling system:casestudyof
aNorwegianglacier
LuLi1(李李璐璐),Trude Eidhammer2,AdamBooth4,Bhuwan Bhatt3,AtleNesje1,3 andStefanSobolowski1
1. NORCENorwegianResearchCentre,Bjerknes CenterforClimateResearch,Bergen,Norway
2. NationalCenterforAtmosphericResearch(NCAR),Boulder,USA3. UniversityofBergen,Bergen,Norway4. UniversityofLeeds,UK
• Glacierscover∼10%oftheEarth’slandsurface;• Watersupplyfordomesticandindustrial
consumption,irrigationandhydropower;• Glaciersareshrinkingrapidly,leadingto
cascadingimpactsondownstreamsystem.
Background
Westilldon’tfullyunderstandthesechangesandhowtheywillpanoutinthefuture.
ü Observationsscarcity;ü topographiccomplexity;ü Toocoarseatmosphericmodels;ü Regional‘atmosphere-only’models; Globalglacierlengths(Roeetal.,2016,Naturegeosciences)
Glacier
Reservoir
Hypothesis:missingfeedbacksandresolutiondependentprocessesresultinanunderestimateoftheratesofglacierchangeandattendanthydrologicalimpacts.
Anintegratedcoupled-modellingapproachisneededinordertofullyassesstheeffectsofawarmingclimateonglaciersandtheirhydrologicalimpacts.
Glacier
LinLout Hsen Hlat
P
SinSout
Land/hydro
Albedo
Layer1(T,liquid,grain,density)
Tair
Ts
MeltRefreezing
… Hcon
Atmosphere
Layers
GSubsurface
Rm
Ex
Underground
Q
Groundsurface
IR
ET
Finse
Blåisen
Midtdals- breen
Rembesdalsskåka ’Tipping point’ ELA ~1800 m a.s.l.
1670
1670
1670
1670
1670 = Steady-state ELA
norgeskart.no
Oslo Bergen
Trondheim
Maingoal
WRF-HydroSystem
Model Chain
Meteorological forcing (Observations or model)
https://www.ral.ucar.edu/projects/wrf_hydro
One-waycoupling(canbetwo-waywithWRF(WeatherResearchandForecastingModel))
CouplingofCrocussnowmodelinWRF-Hydromodelsystem(WRF-Hydro/Glacier)
LandsurfaceofWRF-Hydromodelsystem
Crocussnowmodel
• One-dimensionalmultilayersnowscheme;• Variablesnowlayers(upto50);• Detailedphysicaldescriptionofsnowproperties.
WRF-Hydro/GlacierModelling
WRF1kmrunsasmeteorological forcinginput
WRF-Hydro/Glacierrunsat100mgrid
CrocusSnowModeloverGlacier grids
• Drivenby6hourlyERA-Interim
Temperatureisaccurate(left),details inprecipitation(right)aremissinginSeNorge2;WRFismore‘true’inaphysicalsense
WRF
Observation(SeNorge2)
mm/drainfallTemperature
Meandaily(1995)
(Courtesy:Bhuwan Bhatt)
Topography
General pattern in agreement, although some issues with absolute values.
More faith in GPR depths over the thin snow, more faith in the model over thicker snow.(Courtesy:Adam)
Snowdepth:Modelvs.Radarsurvey
MassbalanceRembesdalskåka: CROCUSvs.NoahMP
CROCUSNoahMP
ModelObservations
(Courtesy:Trude)
1995 2055
• GlacierwillberetreatinginHardangerjøkulen during2005– 2055takenfrom(Åkesson,2018)
• Hindcast:1995-2005andFuture:2055-2065• FuturesimulationbyPGWmethod.
Glacier(icethickness)initialization
The results show a change ~ -2 m/yr of glacier mass balance in the future(2055-2065) compared with the historical period (1995-2005).
FuturemassbalancechangesofRembesdalskaka
NVE-Obs Ba: -0.58Hindcast Ba: 0.04Future Ba: -1.98
2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065
(massbalanceobservationfromNVE)
Futurechangeofrunoff
• FuturerunoffareprojectedtoincreaseinSpring andAutumn;
• Summerrunoffwillincreaseintheheavilyglacierized anddecreaseinthenon- /little-glacierized basins.
heavilyglacierized(60%)
Future(2055-2065)vs.Hindcast (1995-2005)
littleglacierized
• Modelprecipitationshowedamorereasonableresultthangriddedobservationdata;
• TheintegratedmodelwithCROCUSimprovesthemassbalanceresultscomparingwithNoahMP;
• InHardangerjøkulen,futurewarmingclimate(2055-2065,RCP8.5)willconductachange~-2m/yr massbalancecomparingwithhistoricalperiod(1995-2005),whichwillresultinrunoffincreaseinbothSpringandAutumn,whilemoremixedchangesinsummer,i.e.,runoff decreaseinthelittle/noglacierized basinwhileincreaseintheheavilyglacierized (60%)basin.
Forward:• ComparetheoutputsfromWRF-Hydro/GlaciersimulationsandHBVmodel
withglacierparameterization.• ModelcanbeappliedtootherglaciersinNorwayandbeyond(i.e.,Himalaya,
TP).
Summary
Midtdalsbreentongue
Ellen
2.6m
Kickoffmeeting,Bergen, Nov.15-16, 2016
Finalworkshop,Rosendal,May27-29,2019Middalselvi streamflow
Lu andStefan
EllenAdam
GPRsurvey
GPRsurvey
Atle
AcknowledgementstothewholeEvoGlac teamandsupportsfromLATICEgroup,NVEandHiddenCost project!LuLi:[email protected]
Catchments
Catchments
Reservoirs
• 10catchments• DEM10mtopography• Dischargedatamostmissedafter
1980th.
• Investigateconvective-scaleevents,relatedprocessesandtheirchanges
• Provideacollectivemulti-modelensembleassessmentandintercomparison
• Shapeacoherentandrobustassessmentoftheconsequencesofclimatechangeonconvectivephenomenaimpactsatlocaltoregionalscales
WCRP-CORDEXFlagshipPilotStudyonConvection
ByStefanSobolowski,ErikaCoppolaandTheFPSConvectionteam
(Courtesy:StefanSobolowski)
TheFPSConvectionlaunchedFall2016(31participatinginstitutes),Fall2019firstfuturechangeensemblescompleted