# Mutual effects of ablation and ice temperature in a firn-free glacier: Observations from Aug 1st glacier on northeast Tibetan plateau

## TL;DR

The study examines how ice temperature and melting interact on a glacier without a protective firn layer, showing that air temperature mainly drives melting while meltwater processes reduce internal warming.

## Contribution

The study reveals how firn-free glaciers respond to air temperature and meltwater processes, offering new insights into glacier thermal dynamics.

## Key findings

- Surface ice temperature is positively correlated with air temperature but is buffered by meltwater processes.
- Ablation is primarily controlled by air temperature, not short-term ice temperature changes.
- Firn-free glaciers show reduced heat penetration and active-layer thinning due to increased ablation.

## Abstract

Glacier stability depends on the interaction between ice temperature and ablation, processes mediated by firn cover. Although firn-covered glaciers have been extensively investigated, firn-free glacier dynamics remain less clear. This study analyzes the coupled response of ice temperature and ablation to air temperature on the firn-free Aug 1st glacier in the northeastern Tibetan plateau. Results indicate that surface ice temperature is positively correlated with air temperature; however, without firn to store meltwater, latent heat uptake and runoff-related heat loss reduce the rate of surface warming. Increased ablation also limits heat penetration, encouraging active-layer thinning under stable internal ice temperatures. By contrast, ice temperature has little effect on ablation, which is governed mainly by air temperature. These results advance knowledge of glacier thermal behavior and underscore the importance of glacier type in modeling ice temperature evolution.

•Study focuses on a firn-free glacier and its thermal-ablation dynamics•Absence of firn layer alters glacier ablation-ice temperature interactions•Meltwater processes buffer englacial temperature rise•Air temperature controls ablation; short-term ice temperature fluctuations do not

Study focuses on a firn-free glacier and its thermal-ablation dynamics

Absence of firn layer alters glacier ablation-ice temperature interactions

Meltwater processes buffer englacial temperature rise

Air temperature controls ablation; short-term ice temperature fluctuations do not

Earth sciences; Earth-surface processes; Glacial processes