Publications

In Review or Submitted

• Collier, E., Sauter, T., Mölg, T., & Hardy, D.. Anomalous snowfall and regional circulation around Kilimanjaro in 2006-2007 influenced by tropical cyclone activity. Geophsysical research letters, (submitted).
[Bibtex]
@article{collier2018,
author = {Collier, Emily and Sauter, Tobias and M\"{o}lg, Thomas and Hardy, Doug},
journal = {Geophsysical Research Letters},
pages = {(submitted)},
title = {{Anomalous snowfall and regional circulation around Kilimanjaro in 2006-2007 influenced by tropical cyclone activity}}
}
• Sauter, T.. Revisiting extreme precipitation amounts over southern South America and implications for the Patagonian Icefields. Science advances, (submitted).
[Bibtex]
@article{sauter2018,
author = {Sauter, Tobias},
pages = {(submitted)},
title = {{Revisiting extreme precipitation amounts over southern South America and implications for the Patagonian Icefields}}
}
• Braun, M. H., Malz, P., Sommer, C., {Farias Barahona}, D., Sauter, T., Casassa, G., Soruco, A., Skavarca, P., & Seehaus, T. C.. (2018). Glacier elevation and mass changes over entire South America between 2000 and 2011–15. Nature climate change, (accepted).
[Bibtex]
@article{braun2018,
author = {Braun, Matthias H and Malz, Philipp and Sommer, Christian and {Farias Barahona}, David and Sauter, Tobias and Casassa, Gina and Soruco, Alaro and Skavarca, Pedro and Seehaus, Thorsten C},
journal = {Nature Climate Change},
pages = {(accepted)},
title = {{Glacier elevation and mass changes over entire South America between 2000 and 2011–15}},
year = {2018}
}

2018

• Mayr, C., Langhamer, L., Wissel, H., Meier, W., Sauter, T., Laprida, C., Massaferro, J., Försterra, G., & Lücke, A.. (2018). Atmospheric controls on hydrogen and oxygen isotope composition of meteoric and surface waters in Patagonia. Hydrology and earth system sciences discussions, 1–22.
[Bibtex]
@article{Mayr2018,
abstract = {{\textless}p{\textgreater}{\textless}p{\textgreater}{\textless}strong{\textgreater}Abstract.{\textless}/strong{\textgreater} The southern tip of South America, commonly referred to as Patagonia, is a key area to understand Southern Hemisphere Westerlies (SHW) dynamics and orographic isotope effects in precipitation. However, only few studies have addressed these topics. We evaluated the stable isotope ($\delta${\textless}sup{\textgreater}2{\textless}/sup{\textgreater}H, $\delta${\textless}sup{\textgreater}18{\textless}/sup{\textgreater}O) compositions of precipitation, lentic waters, and lotic waters in that area to characterize and understand isotope fractionation processes associated with orographic rainout, moisture recycling and moisture sources. Observational data were interpreted with the help of backward trajectory modelling of moisture sources using reanalysis climate data. While the Pacific serves as the exclusive moisture source for sites upwind of the Andes and on the immediate downwind area of the Andes, recycled moisture from the continent seems to be the main humidity source at the Patagonian Atlantic coast. In contrast, the Pampean Atlantic coast north of Patagonia obtains moisture from the Atlantic Ocean. In the core zone of the SHW at a latitude of 50°{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}S, a depletion in the heavy isotopes of 10{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}‰ and 85{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}‰, for $\delta${\textless}sup{\textgreater}18{\textless}/sup{\textgreater}O and $\delta${\textless}sup{\textgreater}2{\textless}/sup{\textgreater}H, respectively, occurs due to orographic rainout corresponding to a drying ratio of 0.45.{\textless}/p{\textgreater}{\textless}/p{\textgreater}},
author = {Mayr, Christoph and Langhamer, Lukas and Wissel, Holger and Meier, Wolfgang and Sauter, Tobias and Laprida, Cecilia and Massaferro, Julieta and F{\"{o}}rsterra, G{\"{u}}nter and L{\"{u}}cke, Andreas},
doi = {10.5194/hess-2018-431},
issn = {1812-2116},
journal = {Hydrology and Earth System Sciences Discussions},
month = {aug},
pages = {1--22},
title = {{Atmospheric controls on hydrogen and oxygen isotope composition of meteoric and surface waters in Patagonia}},
url = {https://www.hydrol-earth-syst-sci-discuss.net/hess-2018-431/},
year = {2018}
}
• Langhamer, L., Sauter, T., & Mayr, G. J.. (2018). Lagrangian Detection of Moisture Sources for the Southern Patagonia Icefield (1979-2017). Frontiers in earth science, 6, 219.
[Bibtex]
@article{Langhamer2018,
abstract = {The origin of moisture for the Southern Patagonia Icefield and the transport of moisture towards it are not yet fully understood. These quantities have a large impact on the stable isotope composition of the icefield, adjacent lakes and nearby vegetation, and is hard to quantify from observations. Clearly identified moisture sources help to interpret anomalies in the stable isotope compositions and contribute to paleoclimatological records from the icefield and the close surrounding. This study detects the moisture sources of the icefield with a Lagrangian moisture source method. The kinematic 18-day backward trajectory calculations use reanalysis data from the European Centre for Medium-Range Weather Forecasts (ERA-Interim) from January 1979 to January 2017. The dominant moisture sources are found in the South Pacific Ocean from 80◦ W to 160◦ W and 30◦S to 60◦ S. A persistent anticyclone in the subtropics and advection of moist air by the prevailing westerlies are the principal flow patterns. Most of the moisture travels less than 10 days to reach the icefield. The majority of the trajectories originate from above the planetary boundary layer but enter the Pacific boundary layer to reach the maximum moisture uptake 2 days before arrival. During the last day trajectories rise as they encounter topography. The location of the moisture sources are influenced by seasons, Antarctic Oscillation, El-Niño Southern Oscillation, and the amount of monthly precipitation, which can be explained by variations in the location and strength of the westerly wind belt.”},
author = {Langhamer, Lukas and Sauter, Tobias and Mayr, Georg Johann},
doi = {10.3389/FEART.2018.00219},
issn = {2296-6463},
journal = {Frontiers in Earth Science},
keywords = {Antarctic Oscillation,ERA-Interim,El-Ni{\~{n}}o Southern Oscillation,Lagrangian perspective,Moisture origin,Southern Patagonia Icefield,moisture sources,moisture transport,specific humidity,trajectories},
pages = {219},
publisher = {Frontiers},
title = {{Lagrangian Detection of Moisture Sources for the Southern Patagonia Icefield (1979-2017)}},
url = {https://www.frontiersin.org/articles/10.3389/feart.2018.00219/abstract},
volume = {6},
year = {2018}
}
• Weidemann, S. S., Sauter, T., Kilian, R., Steger, D., Butorovic, N., & Schneider, C.. (2018). A 17-year Record of Meteorological Observations Across the Gran Campo Nevado Ice Cap in Southern Patagonia, Chile, Related to Synoptic Weather Types and Climate Modes. Frontiers in earth science, 6, 53.
[Bibtex]
@article{weidemann201817,
abstract = {The network of long-term meteorological observations in Southernmost Patagonia is still sparse but crucial to improve our understanding of climatic variability, in particular in the more elevated and partially glaciated Southernmost Andes. Here we present a unique 17-year meteorological record (2000-2016) of four automatic weather stations across the Gran Campo Nevado Ice Cap (53{\$}{\^{}}{\{}\backslashcirc{\}}{\$}S) in the Southernmost Andes (Chile) and the conventional weather station Jorge Schythe of the Instituto de la Patagonia in Punta Arenas for comparison. We revisit the relationship between in-situ observations and large-scale climate models as well as mesoscale weather patterns. For this purpose, a 37-year record of ERA Interim Reanalysis data has been used to compute a weather type classification based on a hierarchical correlation-based leader algorithm. The orographic perturbation on the predominantly westerly airflow determines the hydroclimatic response across the mountain range, leading to significant west-east gradients of precipitation, air temperature and humidity. Annual precipitation sums heavily drop within only tens of kilometers from $\backslash$textasciitilde 7500 mm$\backslash$,a{\$}{\^{}}{\{}-1{\}}{\$} to less than 800 mm$\backslash$,a{\$}{\^{}}{\{}-1{\}}{\$}. The occurrence of high precipitation events of up to 620 mm in 5 days and wet spells of up to 61 consecutive days underscore the year-around wet conditions in the Southernmost Andes. Given the strong link between large-scale circulation and orographically controlled precipitation, the synoptic-scale weather conditions largely determine the precipitation and temperature variability on all time scales. Major synoptic weather types with distinct low-pressure cells in the Weddell Sea or Bellingshausen Sea, causing a prevailing southwesterly, northwesterly or westerly airflow, determine the weather conditions in Southernmost Patagonia during 68{\$}\backslash{\%}{\$} of the year. At Gran Campo Nevado, more than 80{\$}\backslash{\%}{\$} of extreme precipitation events occur during the persistence of these weather types. The evolution of the El Ni$\backslash${\~{}}{\{}n{\}}o Southern Oscillation and Antarctic Oscillation impose intra- and inter-annual precipitation and temperature variations. Positive Antarctic Oscillation phases on average are linked to an intensified westerly airflow and warmer conditions in Southernmost Patagonia. Circulation patterns with high-pressure influence leading to colder and dryer conditions in Southernmost Patagonia are more frequent during negative Antarctic Oscillation phases.},
author = {Weidemann, Stephanie S. and Sauter, Tobias and Kilian, Rolf and Steger, David and Butorovic, Nicolas and Schneider, Christoph},
doi = {10.3389/feart.2018.00053},
issn = {2296-6463},
journal = {Frontiers in Earth Science},
pages = {53},
publisher = {Frontiers},
title = {{A 17-year Record of Meteorological Observations Across the Gran Campo Nevado Ice Cap in Southern Patagonia, Chile, Related to Synoptic Weather Types and Climate Modes}},
url = {http://journal.frontiersin.org/article/10.3389/feart.2018.00053/full},
volume = {6},
year = {2018}
}
• Aguirre, F., Carrasco, J., Sauter, T., Schneider, C., Gaete, K. R., Garin, E., Adaros, R., Jaña, R. A., & Casassa, G.. (2018). Snow cover change as a climate indicator in Brunswick Peninsula, Patagonia. Frontiers in earth science, 6, 130.
[Bibtex]
@article{aguirre2018snow,
author = {Aguirre, Francisco and Carrasco, Jorge and Sauter, Tobias and Schneider, Christoph and Gaete, Katherine R and Garin, Enrique and Adaros, Rodrigo and Ja{\~{n}}a, Ricardo A and Casassa, Gino},
doi = {https://www.frontiersin.org/articles/10.3389/feart.2018.00130/abstract},
journal = {Frontiers in Earth Science},
pages = {130},
publisher = {Frontiers},
title = {{Snow cover change as a climate indicator in Brunswick Peninsula, Patagonia}},
url = {https://www.frontiersin.org/articles/10.3389/feart.2018.00130/abstract},
volume = {6},
year = {2018}
}
• Collier, E., Mölg, T., & Sauter, T.. (2018). Recent atmospheric variability at Kibo Summit, Kilimanjaro, and its relation to climate mode activity. Journal of climate, 31(10), JCLI–D–17–0551.1.
[Bibtex]
@article{collier2018recent,
abstract = {AbstractAccurate knowledge of the impact of internal atmospheric variability is required for the detection and attribution of climate change and for interpreting glacier records. However, current knowledge of such impacts in high-mountain regions is largely based on statistical methods, as the observational data required for process-based assessments are often spatially or temporally deficient. Using a case study of Kilimanjaro, we combined twelve years of convection-permitting atmospheric modelling with an eight-year observational record to evaluate the impact of climate oscillations on recent high-altitude atmospheric variability during the short rains (the secondary rain season in the region). We focus on two modes that have a well-established relationship with precipitation during this season, the El Ni{\~{n}}o Southern Oscillation and the Indian Ocean Zonal Mode, and demonstrate their strong association with local and mesoscale conditions at Kilimanjaro. Both oscillations correlate positively with humidity...},
author = {Collier, Emily and M{\"{o}}lg, Thomas and Sauter, Tobias},
doi = {10.1175/JCLI-D-17-0551.1},
issn = {0894-8755},
journal = {Journal of Climate},
number = {10},
pages = {JCLI--D--17--0551.1},
title = {{Recent atmospheric variability at Kibo Summit, Kilimanjaro, and its relation to climate mode activity}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0551.1},
volume = {31},
year = {2018}
}
• Weidemann, S. S., Sauter, T., Malz, P., Jaña, R., Arigony-Neto, J., Casassa, G., & Schneider, C.. (2018). Glacier Mass Changes of Lake-Terminating Grey and Tyndall Glaciers at the Southern Patagonia Icefield Derived From Geodetic Observations and Energy and Mass Balance Modeling. Frontiers in earth science, 6, 81.
[Bibtex]
@article{weidemann2018glacier,
abstract = {In this study we demonstrate how energy and mass fluxes vary in space and time for Grey and Tyndall glaciers at the Southern Patagonia Icefield (SPI). Despite the overall glacier retreat of most Patagonian glaciers, a recent increase in mass loss has been observed, but individual glaciers respond differently in terms of spatial and temporal changes. In this context, the detailed investigation of the effect of mass balance processes on recent glacier response to climate forcing still needs refinement. We therefore quantify surface energy-fluxes and climatic mass balance of the two neighboring glaciers, Grey and Tyndall. The COupled Snow and Ice energy and MAss balance model COSIMA is applied to assess recent surface energy and climatic mass balance variability with a high temporal and spatial resolution for a 16-year period between April 2000 to March 2016. The model is driven by downscaled 6-hourly atmospheric data derived from ERA-Interim reanalysis and MODIS/Terra Snow Cover and validated against ablation measurements made in single years. High resolution precipitation fields are determined by using an analytical orographic precipitation model. Frontal ablation is estimated as residual of climatic mass balance and geodetic mass balance derived from TanDEM-X/SRTM between 2000 and 2014. We simulate a positive glacier-wide mean annual climatic mass balance of +1.02{\$}\backslashpm{\$}0.52$\backslash$,m$\backslash$,w.e. a{\$}{\^{}}{\{}-1{\}}{\$} for Grey Glacier and of +0.68{\$}\backslashpm{\$}0.54$\backslash$,m$\backslash$,w.e. a{\$}{\^{}}{\{}-1{\}}{\$} for Tyndall Glacier between 2000 and 2014. Climatic mass balance results show a high year to year variability. Comparing climatic mass balance results with previous studies underlines the high uncertainty in climatic mass balance modeling with respect to accumulation on the SPI. Due to the lack of observations accumulation estimates differ from previous studies based on the methodological approaches. Mean annual ice loss by frontal ablation is estimated to be 2.07{\$}\backslashpm{\$}0.70$\backslash$,m$\backslash$,w.e.$\backslash$,a{\$}{\^{}}{\{}-1{\}}{\$} for Grey Glacier and 3.26{\$}\backslashpm{\$}0.82$\backslash$,m$\backslash$,w.e.$\backslash$,a{\$}{\^{}}{\{}-1{\}}{\$} for Tyndall Glacier between 2000 and 2014. Ice loss by surface ablation exceeds ice loss by frontal ablation for both glaciers. The overall mass balance of Grey and Tyndall glaciers are clearly negative with -1.05{\$}\backslashpm{\$}0.18$\backslash$,m$\backslash$,w.e.$\backslash$,a{\$}{\^{}}{\{}-1{\}}{\$} and -2.58{\$}\backslashpm{\$}0.28$\backslash$,m$\backslash$,w.e.$\backslash$,a{\$}{\^{}}{\{}-1{\}}{\$} respectively.},
author = {Weidemann, Stephanie S. and Sauter, Tobias and Malz, Philipp and Ja{\~{n}}a, Ricardo and Arigony-Neto, Jorge and Casassa, Gino and Schneider, Christoph},
doi = {10.3389/feart.2018.00081},
issn = {2296-6463},
journal = {Frontiers in Earth Science},
pages = {81},
publisher = {Frontiers},
title = {{Glacier Mass Changes of Lake-Terminating Grey and Tyndall Glaciers at the Southern Patagonia Icefield Derived From Geodetic Observations and Energy and Mass Balance Modeling}},
url = {https://www.frontiersin.org/article/10.3389/feart.2018.00081/full},
volume = {6},
year = {2018}
}

2016

• Sauter, T., & {Peter Galos}, S.. (2016). Effects of local advection on the spatial sensible heat flux variation on a mountain glacier. Cryosphere, 10(6), 2887–2905.
[Bibtex]
@article{Sauter2016,
abstract = {... Monin–Obukhov scaling law neither applies to complex terrain nor is it. formulated to apply the laws locally . However, there is as yet no better solution to solve this. problem. ... Non- local . topographic effects , such as gap flows or bluff bodies, can favor the. probability of periodic occurrence of burst events at a given point on the. ... area. Spatial variations of the surface sensible heat flux . According to the principle of energy conservation the local change in the. ...},
author = {Sauter, Tobias and {Peter Galos}, Stephan},
doi = {10.5194/tc-10-2887-2016},
file = {:Users/tsauter/Documents/Publications/Literature/Papers/Sauter and Galos - Effects of local advection on the sensible heat flux.pdf:pdf},
issn = {19940424},
journal = {Cryosphere},
number = {6},
pages = {2887--2905},
title = {{Effects of local advection on the spatial sensible heat flux variation on a mountain glacier}},
volume = {10},
year = {2016}
}

2015

• Huintjes, E., Sauter, T., Schröter, B., Maussion, F., Yang, W., Kropáček, J., Buchroithner, M., Scherer, D., Kang, S., & Schneider, C.. (2015). Evaluation of a Coupled Snow and Energy Balance Model for Zhadang Glacier, Tibetan Plateau, Using Glaciological Measurements and Time-Lapse Photography. Arctic, antarctic, and alpine research, 47(3), 573–590.
[Bibtex]
@article{huintjes2015evaluation,
abstract = {We present a new open-source, collaborative “COupled Snowpack and Ice surface energy and MAss balance model” (COSIMA) that is evaluated for Zhadang glacier, Tibetan Plateau. The model is calibrated, run, and validated based on in situ measurements and atmospheric model data from the High Asia Refined analysis (HAR) over the period April 2009 to June 2012. Results for the model runs forced by both in situ measurements and HAR agree well with observations of various atmospheric, glaciological, surface, and subsurface parameters on the glacier. A time-lapse camera system next to the glacier provides a 3-year image time series of the mean transient snow line altitude and the snow cover pattern, which is used for the spatial and temporal validation of the model. The model output corresponds very well to the observed temporal and spatial snow cover variability. The model is then run for a 10-year period of October 2001 to September 2011 forced with HAR data. In general, the radiation components dominate the overall energy turnover (65{\%}), followed by the turbulent fluxes (31{\%}). The generally dry atmosphere on the Tibetan Plateau causes sublimation to be responsible for 26{\%} of the total mass loss. A proportion of 11{\%} of the surface and subsurface melt refreezes within the snowpack.},
author = {Huintjes, Eva and Sauter, Tobias and Schr{\"{o}}ter, Benjamin and Maussion, Fabien and Yang, Wei and Krop{\'{a}}{\v{c}}ek, Jan and Buchroithner, Manfred and Scherer, Dieter and Kang, Shichang and Schneider, Christoph},
doi = {10.1657/AAAR0014-073},
issn = {1523-0430},
journal = {Arctic, Antarctic, and Alpine Research},
number = {3},
pages = {573--590},
publisher = {Taylor {\&} Francis},
title = {{Evaluation of a Coupled Snow and Energy Balance Model for Zhadang Glacier, Tibetan Plateau, Using Glaciological Measurements and Time-Lapse Photography}},
url = {http://www.bioone.org/doi/10.1657/AAAR0014-073},
volume = {47},
year = {2015}
}

2013

• Weidemann, S., Sauter, T., Schneider, L., & Schneider, C.. (2013). Impact of two conceptual precipitation downscaling schemes on mass-balance modeling of Gran Campo Nevado ice cap, Patagonia. Journal of glaciology, 59(218), 1106–1116.
[Bibtex]
@article{weidemann2013impact,
abstract = {Semi-permanent snow is part of the continuum between seasonal snow and glacier ice. Although ubiquitous in the High Arctic, most late-lying snow banks and snow beds have lost their perennial status over the past decade as the summers have become progressively warmer. The loss over the past decade is the most unprecedented since aerial photography of the Canadian Arctic islands was first undertaken over half a century ago, and it has produced observable thermal, hydrological and ecological impacts. Where the ground has become exposed beneath the perennial snow cover, seasonal ground thaw has deepened. Tundra ponds and patchy wetlands fed principally by meltwater in the summer have suffered water-level decline or desiccation. The water balance of headwater basins is also affected, losing a buffering vehicle that accumulates storage surplus from the wet cool years to support streamflow and evaporation in the dry warm years. The tundra vegetation, already sparse, undergoes changes in the long term. As an essential source of water in the polar desert environment, the widespread distribution of semi-permanent snow magnifies its Arctic-wide importance.},
author = {Weidemann, Stephanie and Sauter, Tobias and Schneider, Lars and Schneider, Christoph},
doi = {10.3189/2013JoG13J046},
issn = {00221430},
journal = {Journal of Glaciology},
number = {218},
pages = {1106--1116},
publisher = {Cambridge University Press},
title = {{Impact of two conceptual precipitation downscaling schemes on mass-balance modeling of Gran Campo Nevado ice cap, Patagonia}},
volume = {59},
year = {2013}
}
• Sauter, T., & Schneider, C.. (2013). Climate Change and Consequences for the Glaciation in Southern South America. Geographische rundschau, 65(12), 38–43.
[Bibtex]
@article{sauter2013climate,
author = {Sauter, Tobias and Schneider, Christoph},
journal = {Geographische Rundschau},
number = {12},
pages = {38--43},
publisher = {Westermann Schulbuchverlag GmbH},
title = {{Climate Change and Consequences for the Glaciation in Southern South America}},
volume = {65},
year = {2013}
}
• Sauter, T., Möller, M., Finkelnburg, R., Grabiec, M., Scherer, D., & Schneider, C.. (2013). Snowdrift modelling for the vestfonna ice cap, north-eastern Svalbard. Cryosphere, 7(4), 1287–1301.
[Bibtex]
@article{Sauter2013,
abstract = {The redistribution of snow by drifting and blowing snow frequently leads to an inhomogeneous snow mass distribution on larger ice caps. Together with the thermodynamic impact of drifting snow sublimation on the lower atmospheric boundary layer, these processes affect the glacier surface mass balance. This study provides a first quantification of snowdrift and sublimation of blowing and drifting snow on the Vestfonna ice cap (Svalbard) by using the specifically designed snow2blow snowdrift model. The model is forced by atmospheric fields from the Polar Weather Research and Forecasting model and resolves processes on a spatial resolution of 250 m. The model is applied to the Vestfonna ice cap for the accumulation period 2008/2009. Comparison with radio-echo soundings and snow-pit measurements show that important local-scale processes are resolved by the model and the overall snow accumulation pattern is reproduced. The findings indicate that there is a significant redistribution of snow mass from the interior of the ice cap to the surrounding areas and ice slopes. Drifting snow sublimation of suspended snow is found to be stronger during spring. It is concluded that the redistribution process is strong enough to have a significant impact on glacier mass balance.},
author = {Sauter, T. and M{\"{o}}ller, M. and Finkelnburg, R. and Grabiec, M. and Scherer, D. and Schneider, C.},
doi = {10.5194/tc-7-1287-2013},
file = {:Users/tsauter/Documents/Publications/Literature/Papers/Sauter et al - Snowdrift.pdf:pdf},
issn = {19940416},
journal = {Cryosphere},
number = {4},
pages = {1287--1301},
title = {{Snowdrift modelling for the vestfonna ice cap, north-eastern Svalbard}},
volume = {7},
year = {2013}
}

2011

• Sauter, T., Venema, V., Climate, J. O. F., Geography, P., Sauter, T., & Venema, V.. (2011). Natural three-dimensional predictor domains for statistical precipitation downscaling. Journal of climate, 24(23), 6132–6145.
[Bibtex]
@article{Climate2011,
abstract = {The paper presents an approach for conditional airmass classification based on local precipitation rate distributions. The method seeks, within the potential region, three-dimensional atmospheric predictor domains with high impact on the local-scale phenomena. These predictor domains are derived by an algorithm consisting of a clustering method, namely, self-organizing maps, and a nonlinear optimization method, simulated annealing. The findings show that the resulting spatial structures can be attributed to well-known atmospheric processes. Since the optimized predictor domains probably contain relevant information for precipitation generation, these grid points may also be potential inputs for nonlinear downscaling methods. Based on this assumption. the potential of these optimized large-scale predictors for downscaling has been investigated by applying an artificial neural network as a nonparametric statistical downscaling model. Compared to preset local predictors, using the optimized predictors improves the accuracy of the downscaled time series, particularly in summer and autumn. However, optimizing predictors by a conditional classification does not guarantee that a predictor increases the explained variance of the downscaling model. To study the contribution of each predictor to the output variance, either individually or by interactions with other parameters, the sources of uncertainty have been estimated by global sensitivity analysis, which provides model-free sensitivity measures. It is shown that predictor interactions play an important part in the modeling process and should be taken into account in the predictor screening.},
author = {Sauter, Tobias and Venema, Victor and Climate, Journal O F and Geography, Physical and Sauter, Tobias and Venema, Victor},
doi = {10.1175/2011JCLI4155.1},
isbn = {1520-0442},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Algorithms,Climate classification/regimes,Local effects,Precipitation,Statistical techniques},
number = {23},
pages = {6132--6145},
title = {{Natural three-dimensional predictor domains for statistical precipitation downscaling}},
volume = {24},
year = {2011}
}
• Brands, S., Taboada, J. J., Cofiño, A. S., Sauter, T., & Schneider, C.. (2011). Statistical downscaling of daily temperatures in the NW Iberian Peninsula from global climate models: Validation and future scenarios. Climate research, 48(2-3), 163–176.
[Bibtex]
@article{brands2011statistical,
abstract = {We used the analogue method to generate ensemble projections of local daily mean, maximum and minimum air temperatures in the NW Iberian Peninsula until the middle of this century. A 3-step method was followed. (1) The error of the analogue method under optimal conditions was estimated, using air temperatures at 850 hPa and mean sea level pressure from reanalysis data as predictor variables. (2) The method's error under suboptimal conditions was assessed by taking these predictors from control runs of a multi-model, multi-initial- conditions ensemble of global climate models. Neither the predictor data nor the downscaled series were corrected. Under these sub-optimal conditions, none of the individual downscaled series could robustly reproduce the cumulative distribution function (CDF) of the observations in any season of the year. However, when the single downscaled series were combined into a multi-model series, CDFs were reliably reconstructed for summer and autumn. (3) Temperature series were downscaled from the ensemble's scenario runs and compared to observations in the reference period to detect local climate change. In addition to the mean relative warming, it can be shown that the less frequent the event in the reference period, the higher its frequency increase and the broader its uncertainty interval in the scenario period. This tendency is more pronounced for daytime than for night-time heat/warm events, leading to a tripling to quadrupling of the former in summer. The local projections' uncertainty intervals are dominated by model errors rather than by forcing or initial-conditions uncertainties. {\textcopyright} Inter-Research 2011.},
author = {Brands, S. and Taboada, J. J. and Cofi{\~{n}}o, A. S. and Sauter, T. and Schneider, C.},
doi = {10.3354/cr00906},
isbn = {0936-577X},
issn = {0936577X},
journal = {Climate Research},
keywords = {Air temperature,Climate projections,Extreme events,GCM,Global climate models,Iberian Peninsula,Multi-model,Statistical downscaling,Uncertainty},
number = {2-3},
pages = {163--176},
title = {{Statistical downscaling of daily temperatures in the NW Iberian Peninsula from global climate models: Validation and future scenarios}},
volume = {48},
year = {2011}
}

2010

• Maraun, D., Wetterhall, F., Chandler, R. E., Kendon, E. J., Widmann, M., Brienen, S., Rust, H. W., Sauter, T., Themeßl, M., Venema, V. K. C., Chun, K. P., Goodess, C. M., Jones, R. G., Onof, C., Vrac, M., & Thiele-Eich, I.. (2010). Precipitation downscaling under climate change: Recent developements to bridge the gap between dynamical models and the end user. Reviews of geophysics, 48(2009RG000314), 1–38.
[Bibtex]
@article{maraun2010precipitation,
abstract = {Precipitation downscaling improves the coarse resolution and poor representation of precipitation in global climate models, and helps end users to assess the likely hydrological impacts of climate change. This paper integrates perspectives from meteorologists, climatologists, statisticians and hydrologists, to identify generic end user (in particular impact modeler) needs, and to discuss downscaling capabilities and gaps. End users need a reliable representation of precipitation intensities, temporal and spatial variability, as well as physical consistency, independent of region and season. In addition to presenting dynamical downscaling, we review perfect prog statistical downscaling, model output statistics and weather generators, focussing on recent developments to improve the representation of space time variability. Furthermore, evaluation techniques to assess downscaling skill are presented. Downscaling adds considerable value to projections from global climate models. Remaining gaps are uncertainties arising from sparse data; representation of extreme summer precipitation, sub-daily precipitation, and full precipitation fields on fine scales; capturing changes in smallscale processes and their feedback on large scales; and errors inherited from the driving global climate model.},
author = {Maraun, D and Wetterhall, F and Chandler, R E and Kendon, E J and Widmann, M and Brienen, S and Rust, H W and Sauter, T and Theme{\ss}l, M and Venema, V K C and Chun, K P and Goodess, C M and Jones, R G and Onof, C and Vrac, M and Thiele-Eich, I},
doi = {10.1029/2009RG000314.1.INTRODUCTION},
isbn = {8755-1209},
issn = {87551209},
journal = {Reviews of Geophysics},
number = {2009RG000314},
pages = {1--38},
title = {{Precipitation downscaling under climate change: Recent developements to bridge the gap between dynamical models and the end user}},
volume = {48},
year = {2010}
}
• Huintjes, E., Li, H., Sauter, T., Li, Z., & Schneider, C.. (2010). The Cryosphere Discussions Degree-day modelling of the surface mass balance of Urumqi Glacier No. 1, Tian Shan, China. , 4, 207–232.
[Bibtex]
@article{Huintjes2010,
abstract = {Published by Copernicus Publications on behalf of the European Geosciences Union. 207 Abstract A distributed temperature-index melt model including potential shortwave radiation is used to calculate annual mean surface mass balance and the spatial distribution of melt rates on the east branch of Urumqi Glacier No. 1, north-western China. The lack of continuous datasets at higher temporal resolution for various climate variables 5 suggests the application of a degree-day model with only few required input variables. The model is calibrated for a six day period in July 2007, for which daily mass balance measurements and meteorological data are available. Based on point measurements of mass balance, parameter values are optimised running a constrained multivariable function using the simplex search method. To evaluate the model performance, annual 10 mass balances for the period 1987/88–2004/05 are calculated using NCEP/NCAR-Reanalysis data. The modelled values fit the observed mass balance with a correlation of 0.98 and an RMSE of 332 mm w.e. Furthermore, the calculated spatial distribution of melt rates shows an improvement in small-scale variations compared to the simple degree-day approach.},
author = {Huintjes, E and Li, H and Sauter, T and Li, Z and Schneider, C},
doi = {10.5194/tcd-4-207-2010},
file = {:Users/tsauter/Documents/Publications/Literature/Papers/Huintjes et al - Degree-day modelling of the surface mass balance of Urumqi Glacier.pdf:pdf},
issn = {1994-0440},
pages = {207--232},
title = {{The Cryosphere Discussions Degree-day modelling of the surface mass balance of Urumqi Glacier No. 1, Tian Shan, China}},
url = {www.the-cryosphere-discuss.net/4/207/2010/},
volume = {4},
year = {2010}
}

2009

• Sauter, T., Weitzenkamp, B., & Schneider, C.. (2009). Spatio-temporal prediction of snow cover in the Black Forest mountain range using remote sensing and a recurrent neural network. International journal of climatology, 30(15), n/a. doi: 10.1002/joc.2043.
[Bibtex]
@article{sauter2010spatio,
author = {Sauter, T and Weitzenkamp, B and Schneider, C},
journal = {International Journal of Climatology},
keywords = {Black Forest,Germany,climate change,downscaling,recurrent neural network,skiing,snow cover prediction,snow pattern},
number = {15},
pages = {n/a. doi: 10.1002/joc.2043},
publisher = {John Wiley {\&} Sons, Ltd. Chichester, UK},
title = {{Spatio-temporal prediction of snow cover in the Black Forest mountain range using remote sensing and a recurrent neural network}},
url = {http://dx.doi.org/10.1002/joc.2043},
volume = {30},
year = {2009}
}
• Sauter, T., Schneider, C., Kilian, R., & Moritz, M.. (2009). Simulation and analysis of runoff from a partly glaciated meso-scale catchment area in Patagonia using an artificial neural network. Hydrological processes, 23(7), 1019–1030.
[Bibtex]
@article{sauter2009simulation,
abstract = {In this study, a model based on an artificial neural network (ANN) was developed to forecast the runoff of a meso-scale, partly glaciated (40{\%}), Alpine catchment area in the southernmost Andes in Patagonia, Chile. The study area is located in a maritime climate with a mean annual air temperature of C + 5.7 {\&}{\#}x00B0;C and about 5500 mm of precipitation per year at sea level. The multilayer feed-forward network is designed to make use of the Levenberg-Marquardt algorithm to increase the speed of computation (convergence). Using climate data recorded at an automatic weather station nearby as well as water level records measured simultaneously, the ANN model was trained and verified using independent training and validation datasets. Parameters and the corresponding time lags were determined by statistical methods such as partial, cross- and autocorrelation. The results of the simulation confirm that the proposed model was able to identify the underlying non-linear relationships between the input parameters and the observed discharge. The correlation during validation shows a significant correlation coefficient of 0.98,and an RMSE of 0.02 m respectively. However, it is almost impossible to decipher the internal behaviour of ANN due to its black-box character. Nevertheless, valuable insights were gained in the complex input-output relationships, and the occurrence of dependencies between different input variables were detected using global sensitivity analysis (GSA). The results of the GSA were compared with those of multiple linear regression (MLR). While the performance of the ANN is much better than the MLR, both models return similar results in terms of the dependency of the discharge upon input variables. It was found that despite the large proportion of glaciated surface area within the catchment, discharge is mainly controlled by precipitation (49{\%}). Furthermore, the runoff is slightly influenced by temperature (19{\%}), global radiation (15{\%}) and wind speed (16{\%}). While the ANN proves to be a very efficient tool for simulating runoff in glacerized, Alpine catchments from meteorological data, the GSA method, as outlined and used in this paper, offers a useful approach of analysing ANN output. Copyright {\&}{\#}x00A9; 2008 John Wiley {\&} Sons, Ltd.},
archivePrefix = {arXiv},
arxivId = {arXiv:1011.1669v3},
author = {Sauter, Tobias and Schneider, Christoph and Kilian, Rolf and Moritz, Michael},
doi = {10.1002/hyp.7210},
eprint = {arXiv:1011.1669v3},
isbn = {0885-6087},
issn = {08856087},
journal = {Hydrological Processes},
keywords = {Artificial neural network,Global sensifivity analysis,Patagonia,Rainfall-runoff modelling,South America,Stream-flow forecasting},
number = {7},
pages = {1019--1030},
pmid = {264460600012},
publisher = {John Wiley {\&} Sons, Ltd. Chichester, UK},
title = {{Simulation and analysis of runoff from a partly glaciated meso-scale catchment area in Patagonia using an artificial neural network}},
volume = {23},
year = {2009}
}

Books

Sauter, T. (2012): Non-parametric modelling in Geoscience: Application, optimization and uncertainty estimation. Südwestdeutscher Verlag für Hochschulen.

Roth, R., A. Krämer, C. Schneider, B. Weitzenkamp, T. Sauter, C. Simmer & H. Wilker (2009): GIS-KliSchee – Anpassung des Wintersporttourismus in den deutschen Mittelgebirgen an Klimawandel und Witterungsvariabilität. – In: Mahammadzadeh, M., H. Biebeler & H. Bardt (Hrsg.): Klimaschutz und Anpassung an die Klimafolgen, Kap. 32, S. 263 – 270 Köln. Research Project: GIS-KliSchee

Schneider, C., T. Sauter & B. Weitzenkamp (2009): Klimawandel und Wintersport in Mittelgebirgen. – Nationalatlas aktuell 11 (26.11.2009), Leibnitz-Institut für Länderkunde (IfL) Leipzig. Research Project: GIS-KliSchee  [pdf]