the investigation future evolution of glacier and ... · an underestimate of the rates of glacier...

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:luli@norceresearch.no

Catchments

Catchments

Reservoirs

• 10catchments• DEM10mtopography• Dischargedatamostmissedafter

1980th.

• Investigateconvective-scaleevents,relatedprocessesandtheirchanges

• Provideacollectivemulti-modelensembleassessmentandintercomparison

• Shapeacoherentandrobustassessmentoftheconsequencesofclimatechangeonconvectivephenomenaimpactsatlocaltoregionalscales

WCRP-CORDEXFlagshipPilotStudyonConvection

ByStefanSobolowski,ErikaCoppolaandTheFPSConvectionteam

(Courtesy:StefanSobolowski)

TheFPSConvectionlaunchedFall2016(31participatinginstitutes),Fall2019firstfuturechangeensemblescompleted