This site uses cookies, as explained in our terms of use. If you consent, please close this message and continue to use this site.
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
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
Share
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.
RELATED CONTENTS
Agroforestry is practiced in both tropical and temperate regions where it produces food, fiber and biomass energy, contributes to food ...
Water-induced hazards are common in the Koshi basin, and disasters can cross boundaries, as we saw with the late July ...
ICIMOD Koshi Basin Programme (KBP) can now rapidly produce ‘flood inundation map’ to speed up response to flooding in the ...
Twenty eight highly motivated journalists from eight countries of the Hindu Kush Himalayan (HKH) region —Afghanistan, Bangladesh, Bhutan, China, India, ...
In Nepal, many community forests are involved in the production of charcoal from forest materials generated from the annual cutting ...
Women are primary users of natural resources; yet their voices are rarely sought when plans are prepared to manage natural ...
The reports launched also available for downloading at http://napnepal.gov.np/publication are: Synthesis of the Stocktaking Report for the NAP Process Vulnerability ...
Twenty-one participants attended a four-day training “Introduction to Data Analysis with R” organised by the Cryosphere initiative of the International ...
