Back to news
17 Apr 2019 | Cryosphere

HKH Science News: Conventional models for glacier melt calculation may not work in High Mountain Asia environments

A recent research undertaken by ICIMOD and partners in central Nepal between 2013 and 2017 provides a guideline for ablation modelling in High Mountain Asia (HMA) environments. Maxime Litt, lead author of the study, said, “We show that the conventional models do not consider a number of important drivers of glacier mass loss at high altitudes and such approaches have to be handled with care.”

1 min Read

70% Complete
An automatic weather station on Mera Glacier, one of two ICIMOD research sites in Nepal. Researchers used data from six automatic weather stations installed on the two glaciers. (Photo: Emmy Stigter/Utrecht University).

The conventional approach of using temperature index models for modelling glacier ablation requires few input variables and relies on simple empirical relations. The approach is assumed to be reliable at lower elevations below 3,500 metres above sea level (masl), where the air temperature relates well to the energy inputs driving glacier melt.

At the high-elevation glaciers in the HMA, the scientists involved in the research observed that incoming shortwave radiation is the dominant energy input and a full surface energy balance model relates only partly to daily mean air temperature.

During monsoon in HMA environments, surface melt dominates ablation processes at lower elevations between 4,950 and 5,380 masl. As net shortwave radiation is the main energy input at the glacier surface, albedo and cloudiness play key roles while being highly variable in space and time. For these cases only, ablation can be calculated with a temperature index model or an enhanced temperature index model that includes a shortwave radiation scheme and site-specific ablation factors. In the ablation zone during other seasons, and during all seasons in the accumulation zone, sublimation and other wind-driven ablation processes are important for mass loss and remain unresolved through the use of temperature index or enhanced temperature index methods.

The research article concludes that empirical models using only one set of parameters for modelling the observed ablation at different sites and periods demonstrate limited performance. The lack of consistency in temperature index or enhanced temperature index parameters between sites and periods is similarly problematic. Furthermore, ablation modeled with a surface energy balance model can diverge from the observations, but since sublimation is important, a suitable value for surface roughness can solve the issue, acting as a tuning parameter.

For details, please see: https://www.nature.com/articles/s41598-019-41657-5

Stay current

Stay up to date on what’s happening around the HKH with our most recent publications and find out how you can help by subscribing to our mailing list.

Sign Up

RELATED CONTENTS

Continue exploring this topic

30 Aug 2017 News
Bangladesh Agricultural Research Council and Partners to Collaborate on Strengthening Climate Services for Drought Monitoring

The workshop brought together key partners to discuss anticipated methods, work plans, and the user engagement process for the effective ...

1 May 2019 DFAT Brahmaputra
Refresher training for spring management partners in Bhutan

Experts from ICIMOD and the Advanced Centre for Water Resources Development and Management (ACWADAM) facilitated the refresher training which included ...

11 Oct 2024 Press releases
PAKISTAN SECURES $10M IN CLIMATE FINANCE FOR NATURE-BASED SOLUTIONS FOR WOMEN AND YOUTH IN THE INDUS

Women in the Hunza Valley planting sea buckthorn (Photo: Kanwal Waqar) Kathmandu, ...

2 Aug 2019 Cryosphere
Keeping track of our melting glaciers

I have been part of expeditions to the Khumbu Glacier in the Everest region since 2016. It is quite a ...

30 Jan 2017 Himalica
A Regional Orientation Training on Ecosystem Services Assessment Held in Udayapur, Nepal

The Support to Rural Livelihoods and Climate Change Adaptation in the Himalayas (Himalica) programme of ICIMOD organized a regional orientation ...

24 Dec 2020 Cryosphere
Remote-sensing and field validation confirm expansion of Tsho Rolpa glacial lake

Why monitor glacial lakes? Of the 3,624 glacial lakes in the Koshi, Karnali, and Gandaki basins, our

14 Jul 2015 News
SERVIR-Himalaya project outcome promises impact in the field

Under its SERVIR-Himalaya Initiative, the International Centre for Integrated Mountain Development (ICIMOD) has supported 14 research grants and small scale application ...

30 Dec 2015 Himalica
Developing Community-led Micro-plans for Improving Livelihoods and Climate Change Adaptation

As a strategy for ensuring the sustainability of Himalica pilot interventions on livelihood improvement and climate change adaptation, Himalica supported ...