Scale-dependent measurement and analysis of ground surface temperature variability in alpine terrain

نویسندگان

  • S. Gubler
  • J. Fiddes
  • M. Keller
چکیده

Measurements of environmental variables are often used to validate and calibrate physically-based models. Depending on their application, the models are used at different scales, ranging from few meters to tens of kilometers. Environmental variables can vary strongly within the grid cells of these models. Validating a model with a single measurement is therefore delicate and susceptible to induce bias in further model applications. To address the question of uncertainty associated with scale in permafrost models, we present data of 390 spatially-distributed ground surface temperature measurements recorded in terrain of high topographic variability in the Swiss Alps. We illustrate a way to program, deploy and refind a large number of measurement devices efficiently, and present a strategy to reduce data loss reported in earlier studies. Data after the first year of deployment is presented. The measurements represent the variability of ground surface temperatures at two different scales ranging from few meters to some kilometers. On the coarser scale, the dependence of mean annual ground surface temperature on elevation, slope, aspect and ground cover type is modelled with a multiple linear regression model. Sampled mean annual ground surface temperatures vary from −4 C to 5 C within an area of approximately 16 km2 subject to elevational differences of approximately 1000 m. The measurements also indicate that mean annual ground surface temperatures vary up to 6 C (i.e., from −2 C to 4 C) even within an elevational band of 300 m. Furthermore, fine-scale variations can be high (up to 2.5 C) at distances of less than 14 m in homogeneous terrain. The effect of this high variability of an environmental variable on model validation and applications in alpine regions is discussed. Correspondence to: S. Gubler [email protected]

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Vertical Height Errors in Digital Terrain Models Derived from Airborne Laser Scanner Data in a Boreal-Alpine Ecotone in Norway

It has been suggested that airborne laser scanning (ALS) could be used for operational monitoring of vegetation changes in the alpine tree line caused by climate change. Because the vegetation is low in such tree-less areas close to the alpine zone, the accuracy of the digital terrain model (DTM) becomes crucial for early detection of, e.g., pioneer trees representing an ongoing tree migration ...

متن کامل

Characterisation of the surface morphology of an alpine alluvial fan using airborne LiDAR

Alluvial fans of alpine torrents are both natural deposition areas for sediment discharged by floods and debris flows, and preferred sites for agriculture and settlements. Hazard assessment on alluvial fans depends on proper identification of flow processes and their potential intensity. This study used LiDAR data to examine the morphology of the alluvial fan of a small alpine stream (Moscardo ...

متن کامل

Helicopter-based Microwave Radar Measurements in Alpine Terrain

Due to the time-consuming nature of traditional snowpit measurements, and the large spatial variability that often exists in alpine snowpacks, tools which can rapidly characterize snowpack properties are in great need. Microwave radar has an additional advantage in that it is non-destructive and measurements can be made remotely, providing the opportunity to make measurements over large areas r...

متن کامل

Landsat and Local Land Surface Temperatures in a Heterogeneous Terrain Compared to MODIS Values

Land Surface Temperature (LST) as provided by remote sensing onboard satellites is a key parameter for a number of applications in Earth System studies, such as numerical modelling or regional estimation of surface energy and water fluxes. In the case of Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Terra or Aqua, pixels have resolutions near 1 km2, LST values being an average o...

متن کامل

Presenting a Morphological Based Approach for Filtering The Point Cloud to Extract the Digital Terrain Model

The Digital terrain model is an important geospatial product used as the basis of many practical projects related to geospatial information. Nowadays, a dense point cloud can be generated using the LiDAR data. Actually, the acquired point cloud of the LiDAR, presents a digital surface model that contains ground and non-ground objects. The purpose of this paper is to present a new approach of ex...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2011