Simulating topoclimatic data to support bioclimatic research in alpine environments: application and assessment of a mesoscale atmospheric model

Abstract

Many bioclimatic modelling efforts are based on the use of gridded climatic datasets that inadequately account for topoclimatic effects. We evaluate a mesoscale atmospheric model, TAPM, as an alternative means of generating spatially explicit topoclimatic data applicable to small scale (200-m resolution) bioclimatic research. Temporal and spatial assessments of TAPM were carried out across New Zealand's mountains. First, goodness-of-fit analyses of TAPM-simulated meteorology against three weather station observations temperature extremes and wind speeds were compared against interpolated climate grid data for approximately 37 000 grid cells across New Zealand. Third, deviations of TAPM-simulated data from the gridded climate dataset baseline were modelled against GIS-derived landscape position in order to quantify the nature and extent of topoclimatic effects. Temporal assessments indicated that TAPM provided reasonably accurate simulations for hourly temperatures and wind speeds, moderately good estimates for solar radiation and poor estimates for humidity. On the whole, the greatest simulation errors occurred for daily extreme values. Relative to the climate grid baseline, TAPM-simulated temperatures and wind speeds were also relatively unbiased. However, TAPM-simulated values varied widely around climate grid values, and these deviations were significantly related to landscape position. The relative congruence of simulation biases across time and space suggests that uncertainties are systematic and inherent to the model architecture rather than due to location-related variability. While results suggest caution in using TAPM to simulate daily extremes, biases may be less problematic for studies where relative differences in topoclimate across locations are of interest. Topoclimatic effects appear pervasive across New Zealand's mountain systems and are predictable as a function of topography. On the basis of our results, further investigations into the use of mesoscale atmospheric models to generate topoclimate data in support of research in mountainous areas are merited.

Spatial variability of near-surface temperature over the coastal mountains in southern Chile (38°S)

“…More recent studies have relied on satellite data (Kloog et al 2016;Lin et al 2016;Oyler et al 2016) or outputs from numerical meteorological models (Case et al 2016;Liu et al 2016) to obtain the two-dimensional T ns field. In both cases, one obtains an estimate of the temperature derived from a calibration that does not necessarily represent local conditions.…”

Peer Review #2 of "Local-scale topoclimate effects on treeline elevations: a country-wide investigation of New Zealand’s southern beech treelines (v0.1)"

“…A number of readilyavailable meso-scale atmospheric models are suited to this task. For example, The Air Pollution Model (TAPM) produced by CSIRO Australia (Hurley, 2008a) is a mesoscale model that has been applied at sites worldwide (Hurley, Edwards & Luhar, 2008) and has been shown to be able to account for topographically-mediated meteorological processes such as cold air drainage and ponding in complex terrain (Hurley, Physick & Luhar, 2005;Mocioaca, Sivertsen & Cuculeanu, 2009;Case, Zawar-Reza & Tait, 2015). used TAPM to generate spatiallyexplicit meteorological data for a range of sites across New Zealand and showed that TAPM could relatively accurately simulate temperature and wind speed at these sites and that prediction accuracies were relatively consistent among sites and years for the different variables examined.…”

“…For example, an analysis by Case and Duncan (2014) indicated that the position of treeline varied mainly due to solar radiation and mountain mass effects at a range of scales across the country, although the coarseness of the explanatory data limited the degree to which local-scale effects could be reliably assessed. Based on field observations, Wardle (1985Wardle ( , 2008 Reviewing Manuscript set of novel topoclimatic indices derived from meteorological data generated using the TAPM meso-scale atmospheric model (Case, Zawar-Reza & Tait, 2015). With these data we address two main questions: (1) Are treelines at different locations across New Zealand characterised by distinctive topoclimatic conditions?…”

Digital long‐term topoclimate surfaces of the Pyrenees mountain range for the period 1950–2012

“…Many studies have shown the relevance of accounting for local climate variation in mountainous areas by combining mesoclimatic and topoclimatic information, from pioneer studies (Daly et al, 1994;Goovaerts, 2000) to recent approaches (Gutiérrez Illan et al, 2010;Ashcroft and Gollan, 2012;Case et al, 2016;Aalto et al, 2017;Meineri and Hylander, 2017). Many studies have shown the relevance of accounting for local climate variation in mountainous areas by combining mesoclimatic and topoclimatic information, from pioneer studies (Daly et al, 1994;Goovaerts, 2000) to recent approaches (Gutiérrez Illan et al, 2010;Ashcroft and Gollan, 2012;Case et al, 2016;Aalto et al, 2017;Meineri and Hylander, 2017).…”

“…High-resolution climate surfaces, which account for toposcale effects, have increasingly become essential tools for understanding landscapes and managing the territory. Many studies have shown the relevance of accounting for local climate variation in mountainous areas by combining mesoclimatic and topoclimatic information, from pioneer studies (Daly et al, 1994;Goovaerts, 2000) to recent approaches (Gutiérrez Illan et al, 2010;Ashcroft and Gollan, 2012;Case et al, 2016;Aalto et al, 2017;Meineri and Hylander, 2017). Several studies have developed climate surfaces for mountain regions; for instance, for The Alps, Efthymiadis et al (2006), Isotta et al (2014), Schar (1998), andTobin et al (2011) developed precipitation climate surfaces and Chimani et al (2013) developed them for temperature.…”