Modelling surface mass balance and water discharge of tropical glaciers The case study of three glaciers in La Cordillera Blanca of Perú Presented by:

Modelling surface mass balance and water

discharge of tropical glaciers

The case study of three glaciers in La Cordillera Blanca of Perú

Presented by: MSc. Maria Fernanda LozanoSupervised by: Prof. Dr. rer. nat. Manfred Koch

Content

Problem statement Objectives Study area Available data (temperature,

precipitation, mass balance measurements, radiation data)

Filling data gaps Methods

Energy balance Model Temperature Index ModelModelling mass balance under climate change simulation by REMO

Problem statementChanges in

climate

Alteration of mass balance

Front advance or

Retreatment

Changes in discharge

Identification of causes what will happen

Energy balance models

Temperature Indexmodels

Not large records

Data gaps

Estimation of Future

discharge

Objectives Contribute to the understanding of glacier

climate interaction in tropical areas. Foresee the possible variation on surface water

discharge due to climate change.

Evaluate historical trends of hidroclimatic time series. Fill the gaps in time series Simulate the dynamic of the mass balance and runoff

with a Energy Balance Model (4 years) Simulate runoff of the glaciers with a Temperature Index

model. Examine the sensitivity of stream-flow of surface water

resources under future climate scenarios of global warming

Study Area

Study Area

Available data

Total Number of Station (Santa)

Stations over 4000 m.a.s.l

Stations in Glaciers

Temperature 52 10 5Precipitation 90 11 4Relative humidity 6 5 4Wind Speed 18 4 1Discharge 12 6 5

Available data

Variables 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010Radiation, wind and relative humidityMass balanceTemperaturePrecipitationDischargeRelative HumidityWind Speed

Variables 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010RadiationMass balanceTemperaturePrecipitationDischargeRelative HumidityWind Speed




Glacier Huarapasca

Glacier Artesonraju

Glacier Yanamarey

Glacier Uruashraju

Glacier Shallap

Variable 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4 5 6 7 8TemperaturePrecipitationDischarge

Variable 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4 5 6 7 8TemperaturePrecipitationDischargeWind Speed

Variable 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4 5 6 7 8TemperaturePrecipitationDischargeRelative HumidityWind Speed

Variable 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4 5 6 7 8Temperature PrecipitationDischarge



Basin Llanganuco

Basin Querococha

Basin Artesoncocha

Basin Paron

Basin Olleros

Basin Quilcay

Time series available in glaciers

Time series available in related basins

Temperature and precipitation

3500 4000 4500 5000 5500

-50

51

0

Mean Daily Temperature vs Elevation

m.a.s.l

oC

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

050

100

150

200

250

300

Monthly Precipitation Querococha

mm


010

020

030

040

0

Monthly Precipitation Artesonraju

mm

3800 4000 4200 4400 4600 4800 5000 5200

2.5

3.0

3.5

4.0

4.5

5.0

Mean Daily Precipitation vs Elevation

Elevation (m.a.s.l)

mm


45

67

89

10

Monthly Temperature Querococha

°C


1.0

1.5

2.0

2.5

Monthly Temperature Artesonraju

°C

Temperature and precipitation

1970 1980 1990 2000

-5.5

-5.0

-4.5

Reanalysis North

Year

oC

1970 1980 1990 2000

60

08

00

10

00

12

00

14

00

Querococha

Year

mm

Mass balance measurementsMass Balance

Time

m.w

.e

2003 2004 2005 2006 2007

-5-4

-3-2

-10

ArtesonrajuUruashrajuYanamarey

ELA

Time

m.a

.s.l

2003 2004 2005 2006 2007

4850

4900

4950

5000

5050

5100

ArtesonrajuUruashrajuYanamarey

Y-9

Y-16

08-09-05

06-10-04

06-05-76

02-09-0317-07-02

22-06-0115-11-00

23-10-99

29-12-98

09-10-9702-10-96

28-09-95

23-09-94

14-10-93

30-09-9203-10-9124-10-8909-08-8824-09-87

20-05-8629-05-85

28-06-8405-05-83

20-05-82

21-05-81

10-05-80

1948

Y-18

31-08-06 23/01/09

GLACIAR YANAMAREY

27-09-07

junio 2007Derrumbe ocurrido en el mes de

27-09-07

Y-16

Morrena cubiertode hielo, producto

de pequeñas avalanchas

Retreatment of the Yanamarey glacier since 1948.

1948 1986 1993 2001 2009

VARIACIONES DEL FRENTE DE LOS GLACIARES MONITOREADOS EN LA CORDILLERA BLANCA

-1000

-900

-800

-700

-600

-500

-400

-300

-200

-100

0

19

48

68

70

71

72

74

19

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

20

00

01

02

03

20

04

20

05

20

06

20

07

20

08

Años

Retr

oce

so (

m)

ALPAMAYO BROGGI URUASHRAJU YANAMAREY GAJAP PASTORURI

Glacier front variation in glaciers of the Cordillera Blanca

Energy data in ArtesonrajuShortwave incoming radiation

ArtesamaTime

Wm

-2

2004 2005 2006 2007 2008 2009

100

200

300

400

Shortwave reflected radiation

ArtesamaTime

Wm

-2

2004 2005 2006 2007 2008 2009

050

150

250

Longwave incoming radiation

Time

Wm

-2

2004 2005 2006 2007 2008 2009

20

02

50

30

03

50

Longwave emitted radiation

TimeW

m-2

2004 2005 2006 2007 2008 2009

29

03

00

31

03

20

Station Min 1st Q Median Mean 3rd Q Max SD VARSwin (Wm-2) 110.00 182.40 227.50 234.60 282.60 408.80 65.76 4325.37

Swref (Wm-2) 6.97 60.56 91.01 95.64 126.50 248.14 48.23 2326.76

Lwatm (Wm-2) 194.30 254.20 290.70 280.60 311.10 369.40 36.36 1322.31

Lwsurf (Wm-2) 287.70 303.90 309.70 308.50 313.50 320.00 6.80 46.27

Rnette (Wm-2) -38.79 44.26 80.68 87.87 123.02 266.38 56.51 3193.47

Filling gaps in time series Multilinear regression STL

Original Temperature Artesonraju

years

T o

C

1970 1980 1990 2000 2010

-10

12

34

5

Filled Temperature Artesonraju

Multilinear regression methodyears

T o

C

1970 1980 1990 2000 2010

-10

12

34

5

Nash Coefficient-Filled Temperature Artesonraju

years

Nas

h C

oeffi

cien

t

1970 1980 1990 2000 2010

0.4

0.6

0.8

1.0

Data with interpolated gaps

Time

AT

RS

win

c

2004 2005 2006 2007 2008 2009

010

020

030

040

0

2004 2005 2006 2007 20080 5 10 15 20 25 30

0.0

0.1

0.2

0.3

0.4

Lag

AT

RS

win

c

ACF

Initially interpolated data

100

200

300

400

da

ta

-50

050

100

sea

son

al

230

235

240

245

tre

nd

-150

-50

050

150

2004 2005 2006 2007 2008 2009

rem

ain

de

r

time

Harmonic analysis

Time

AT

RS

win

c

2004 2005 2006 2007 2008 2009

100

150

200

250

300

350

400

Energy balance model (Hock) Distributed model. Works in a subdiurnal or

diurnal temporal resolution. Solves the energy balance

equation on the glacierized area (calculation per each grid of DTM).

Calculates water discharge from the melting of three areas (firn, snow and ice) and the liquid precipitation.

Accounts for the spatial distribution of topographic shading.

Calculates individual energy balance components

RLHGSM QQQQLLGGQ )(/

wf

M

L

QM

ACCUMULATION:

Precipitation (temperature)

ABLATION

Melting and Sublimation

Energy balance model (Hock)

Global radiation

Main station Extrapolation

1.Interpolation of G directly

2. Separating G into direct and diffuse

radiation considering terrain effects

Amounts of diffuse radiation

Cloud Cover

Gs/Ics

Gg=Icg*(Gs/Ics)

the radio of global radiation to top of the atmosphere G/IToA

Is=Gs-Ds

Ig=Icg*(Is/Ics)

Direct radiation

Diffuse radiation


Albedo

Extrapolation

Snow Albedo Variable:

Number of days since last snowfall

Air temperature

Assumed constant according to the surface

Ice Albedo Variable:

Assumed increase of 3%(100m-1)

Account for the tendency of debris to accumulate towards the glacier.

Variable for snow and ice.


Long inc.radiation

Long out.radiation

Main station Extrapolation

It requires the estimation of Lo at climate

station and it is assumed invariant for all grids.

Lsky:

Lterrain:

Linc in each grid is calculated as the sum of Lsky and Lterrain in each grid.

Direct measurements of longwave outgoing radiation

Linear decrease with increasing elevation when surface temperature is negative, if temperature is 0 Lout is spatially constant

44SSsL TTE


000

2

0

0

/ln/ln

6323.0eeu

zzzz

k

PLQ zz

ewL

Sensibleheat

Latentheat

Qh proportional to Temperature (Tz) andWind speed (zu)

Calculated from the aerodynamic approach

Calculated from the aerodynamic approach

000

2

/ln/lnTTu

zzzz

kcQ zz

TwpH

QL proportional to vapour pressure (ez) and Wind speed (zu)

L Latent heat of evaporation or sublimation

ρ density of air

Po mean atmospheric pressure at the sea level

Cp specific heat capacity of air

k Karman´s constant

To surface temperature

Eo vapor pressure of the surface

Zow, zoT and zoe

are the roughness lengths fro logarithmic profiles of wind speed, temperature and water vapor


Conditions Daily resolution No separation of direct

and diffuse radiation Albedo constant Snow water equivalent

interpolated with linear interpolation.

Discharge

Artesoncocha (r2=0.64)Time

m3

/s

2004.5 2005.0 2005.5

0.0

0.5

1.0

1.5 Qmeas

Qcalc

Temperature Index Model (Hock)

Melt=(DDF/24)*T(timestep) T>0Melt=0 T<=0

Melt=(MF/24+ rsnow/ice*I)*T(timestep) T>0Melt=0 T<=0

Melt=(MF+rsnow/ice*I*Globs/Is)*T(timestep) T>0Melt=0 T<=0

DDF= Degree day factor mm/oCdía MF= Melt factor mm/h K rsnow/ice= radfactorice mm

m2/WhK

Melting is related to the positive air temperatures and the amount of time that this temperature exceeds the melting point.

This relation uses a factor of proportionality (DDF) which shows the decrease of water content in the snow cover or ice by 1°C above freezing in 24 hours.

Incorporates clear sky solar radiation (I)accounts for the spatial topographic variability

Incorporates global measured radiation

Which account for deviations on clear sky

conditions

Temperature Index Model (Hock)

Discharge

ArtesoncochaTime

m3

/s

2004.4 2004.6 2004.8 2005.0 2005.2 2005.4 2005.6

0.2

0.4

0.6

0.8

1.0

1.2

1.4

r2

fm ice 4 5 6 7 8 9

8 0.5605 0.6166 0.648 0.6617 0.6622 0.6512

9 0.6044 0.6504 0.6712 0.6739 0.6631 0.648

10 0.637 0.6715 0.6812 0.6724 0.6499 0.616

11 0.6578 0.6801 0.6777 0.657 0.6226 0.5769

12 0.6665 0.6756 0.6606 0.6277 0.5811 0.5232

13 0.6633 0.6581 0.6298 0.5841 0.525 0.4548

14 0.6482 0.6274 0.5853 0.5264 0.4544 0.3717

15 0.621

fm ice 1 2 3 4

13 0.2384 0.526 0.6312 0.6633

14 0.2791 0.5489 0.6347 0.6482

15 0.3134 0.5642 0.6282 0.621

16 0.5719 0.6116 0.5816

fm snow

Simulation of glacier discharge in future scenarios of climate change

MPI Regional Climate Model Remo

Horizontal Resolution 50Km x 50 Km (0.44°x 0.44°)

Variables: Temperature, surface pressure, horizontal wind components, precipitation and humidity.

Domain. South América

Time step: 240 s

Forcing Data: ERA Interim

Simulation Period: 1989-2008

Future Simulation: until 2100 (in process)

THANK YOU

Mass Balance Year of positive mass balance Year of negative mass balance

Modelling surface mass balance and water discharge of tropical glaciers The case study of three glaciers in La Cordillera Blanca of Perú Presented by:

Documents