Glaciers of the Himalayas

Page 71

Data and Methodology  l  51

TABLE 4.3  Process Representations Used in the Conceptual Cryosphere Hydrologic Framework (CCHF) Process

Representation

Short explanation

Heat transfer

Enhanced temperature index (ETI) with empirical glacier debris

Main ETI formulation follows Pellicciotti et al. (2005). Impact of debris cover on ice heat transfer is an empirical representation derived from Kraaijenbrink et al. (2017).

Snow mass flux

Step based on temperature

Melt is allowed to occur when temperature is above an empirically derived value.

Ice flux

Ratio

Heat first melts any snowpack present. If there is additional heat, the portion of the heat that melts ice is based on how much has been used to melt snow. This scales the modeled ice heat flux.

Snow albedo

Amount of incoming shortwave radiation that is absorbed at the snow or ice surface

Exerts a strong influence on the spatial and temporal evolution of melt rates. Based on Pellicciotti et al. (2005).

Ice albedo

Constant

Debris-free and debris-covered albedos are based on broadly accepted values (DeWalle and Rango 2008).

Black carbon impact on albedo

Concentrations in snow and ice

Empirically derived formula that modifies snow and ice albedo based on field experiments by Ming et al. (2009).

Snowpack moisture-holding capacity

Percentage

The snowpack is modeled to hold an amount of water as an empirically derived portion of its total water-equivalent snow content.

Snow sublimation

Elevation dependent

Follows formulation by Lutz et al. (2016).

Snow to ice

Depth

Snow is assumed to become part of the ice when its depth is greater than a threshold.

Snow avalanche

Angle

Snow avalanches for all spatial grid cells when the steepest angle is greater than a threshold.

Runoff

Leaky bucket

The top layer of ground acts as a “leaky bucket” with a maximum reservoir size and a set percentage that drains every time step. Based on Moore, Trubilowicz, and Buttle (2012).

Top of atmosphere radiation

DeWalle and Rango method

Solar radiation is modeled as a function of day of the year and grid attributes (latitude, aspect, slope). Based on DeWalle and Rango (2008).

Atmospheric transmittance

Linear function of elevation

More top of atmosphere radiation reaches the ground the higher the elevation. Based on Coops, Wulder, and Iwanicka (2009).

Source: The explanations contain the sources for each process.


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C.3 CCHF Performance during Validation for Each Climate Product

10min
pages 129-135

C.2 CCHF Performance during Calibration for Each Climate Product

2min
page 128

References

27min
pages 109-126

The Way Forward

2min
page 108

References

1min
pages 101-102

Black Carbon Deposition in the Region

2min
page 95

Implications of the Findings

11min
pages 103-107

Current HKHK Water Production

2min
page 92

Results

4min
pages 81-82

Hindu Kush Region, by Month, 2013

2min
pages 84-85

Black Carbon and Glacier Modeling to Date

2min
page 80

Black Carbon and Air Pollution

2min
page 78

Creating the Black Carbon Scenarios

5min
pages 66-67

CCHF Model: Linking Climate, Snow and Glaciers, and Water Resources

2min
page 69

Downscaling Climate in the Himalayas

2min
page 68

Framework (CCHF

1min
page 71

Climate Data

2min
page 64

4.2 Aspects of Climate Modeling

1min
page 65

4.1 Previous Analyses Related to the Current Research

2min
page 62

Overview

1min
page 61

References

4min
pages 58-60

Indus River Basin

2min
page 53

Notes

2min
page 57

Knowledge Gaps

2min
page 56

References

13min
pages 44-51

2.3 Impact of Aerosols on Regional Weather Patterns and Climate

2min
page 43

2.4 Average Annual Monsoon Precipitation in South Asia, 1981–2010

1min
page 41

1 Average Percentage of Annual Precipitation in South Asia, by Season 1981–2000 32

2min
page 23

Drivers of Glacial Change in South Asia

2min
page 35

Glacial Change

2min
page 31

References

1min
page 28

Implications of Glacial Change

2min
page 34

Economic Importance

1min
page 29

1.1 The Indus (Left), Ganges (Center), and Brahmaputra (Right) Basins in South Asia

1min
page 27
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