TY - JOUR

T1 - Revisiting forest effects on winter air temperature and wind speed-new open data and transfer functions

AU - Klein, Michael

AU - Garvelmann, Jakob

AU - Förster, Kristian

N1 - Funding Information: Acknowledgments: The presented data was collected during the following research projects: “Field Observations and Modelling of Spatial and Temporal Variability of Processes Controlling Basin Runoff during Rain on Snow Events” funded by the German Research Foundation (DFG) and carried out at the Chair of Hydrology (PI Stefan Pohl), University of Freiburg, Germany; “Alpine water resources research: Observing and modeling the spatio-temporal variability of snow dynamics and water-and energy fluxes” funded by Helmholtz Water Alliance and carried out at the Institute of Meteorology and Climate Research (IMK-IFU, PI Jakob Garvelmann, research group Harald Kunstmann), Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany. Technical infrastructure from TERENO; “Storylines of Socio-Economic and Climatic drivers for Land use and their hydrological impacts in Alpine Catchments (STELLA)” funded by the Austrian climate and energy fond and carried out at the Institute of Geography (PI Ulrich Strasser), University of Innsbruck, Austria. Many thanks to Daniel Günther, Franziska Zieger, Michael Warscher and others for assistance in field work and Emil Blattmann and the staff from KIT-Campus Alpin for technical support. At the University of Innsbruck Elisabeth Mair led the field work within the STELLA-project. Furthermore, we would like to thank Nationalpark of Berchtesgaden for supporting the micrometeorological and snow hydrological measurement campaign. Last but not least, we also thank the reviewers for their helpful comments and Larissa van der Laan for proof reading. Funding Information: Funding: The publication of this article was funded by the Open Access Fund of Leibniz Universität Hannover.

PY - 2021/5/31

Y1 - 2021/5/31

N2 - The diurnal cycle of both air temperature and wind speed is characterized by considerable differences, when comparing open site conditions to forests. In the course of this article, a new two-hourly, open-source dataset, covering a high spatial and temporal variability, is presented and analyzed. It contains air temperature measurements (128 station pairs (open/forest); six winter seasons; six study sites), wind speed measurements (64 station pairs; three winter seasons, four study sites) and related metadata in central Europe. Daily cycles of air temperature and wind speed, as well as further dependencies of the effective Leaf Area Index (effective LAI), the exposure in the context of forest effects, and the distance to the forest edge, are illustrated in this paper. The forest effects on air temperature can be seen particularly with increasing canopy density, in southern exposures, and in the late winter season, while wind speed depends on multiple factors such as effective LAI or the distance to the forest edge. New transfer functions, developed using linear and non-linear regression analysis, in a leave-one-out cross-validation, improve certain efficiency criteria (NSME; r2; RMSE; MAE) compared to existing transfer functions. The dataset enables multiple purposes and capabilities due to its diversity and sample size.

AB - The diurnal cycle of both air temperature and wind speed is characterized by considerable differences, when comparing open site conditions to forests. In the course of this article, a new two-hourly, open-source dataset, covering a high spatial and temporal variability, is presented and analyzed. It contains air temperature measurements (128 station pairs (open/forest); six winter seasons; six study sites), wind speed measurements (64 station pairs; three winter seasons, four study sites) and related metadata in central Europe. Daily cycles of air temperature and wind speed, as well as further dependencies of the effective Leaf Area Index (effective LAI), the exposure in the context of forest effects, and the distance to the forest edge, are illustrated in this paper. The forest effects on air temperature can be seen particularly with increasing canopy density, in southern exposures, and in the late winter season, while wind speed depends on multiple factors such as effective LAI or the distance to the forest edge. New transfer functions, developed using linear and non-linear regression analysis, in a leave-one-out cross-validation, improve certain efficiency criteria (NSME; r2; RMSE; MAE) compared to existing transfer functions. The dataset enables multiple purposes and capabilities due to its diversity and sample size.

KW - Air temperature

KW - Microclimate observations

KW - Modeling

KW - Open dataset

KW - Transfer functions

KW - Wind speed

KW - Winter forest meteorology

UR - http://www.scopus.com/inward/record.url?scp=85107979287&partnerID=8YFLogxK

U2 - 10.3390/atmos12060710

DO - 10.3390/atmos12060710

M3 - Article

AN - SCOPUS:85107979287

VL - 12

JO - Atmosphere

JF - Atmosphere

SN - 2073-4433

IS - 6

M1 - 710

ER -