Parcs

ID	TITEL	DATENTYP	AUTOR	JAHR
27622	Bibliographie NPHT	Project	Nationalparkrat Hohe Tauern	2013

Bemerkungen/Beschreibung

Journal of Glaciology <Cambridge>, 44(146): p 9-20
In calculations of the variation in the 2 m temperature along glaciers the lapse rate is generally assumed to be constant. This implies that the ratio of changes in the 2 m temperature above a glacier to changes in the temperature outside the thermal regime of that glacier ("climate sensitivity") is equal to 1. However, data collected during the ablation season on several mid-latitude glaciers show that this sensitivity is smaller than 1. The lowest measured value (0.3) was obtained on the tongue of the Pasterze, a glacier in Austria. The measured temperature distribution along the Pasterze cannot be described by a constant lapse rate either. However, there is almost a linear relationship between potential temperature and the distance along the glacier. This paper introduces a simple, analytical, thermodynamic glacier-wind model which can be applied to melting mid-latitude glaciers and which explains the observed "climate sensitivities" and temperature distributions much better than calculations based on a constant lapse rate. This way of modelling the 2 m temperatures has implications for the sensitivity of the surface mass balance to atmospheric warming outside the thermal regime of the glacier. The magnitude of this sensitivity is computed with a surface energy-balance model applied to the Pasterze. When a constant lapse rate is used instead of the proposed glacier-wind model to compute changes in the 2 m temperature along the glacier, the negative change in mass balance due to 1 °C warming is overestimated by 22 %.

Eintrag Nr. 13277

2m temperatures along melting mid-latitude glaciers, and implications for the sensitivity of the mass balance to variations in temperature