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Spatio-temporal reconstruction of winter glacier mass balance is important for assessing long-term impacts of climate change. However, high-altitude regions significantly lack reliable observations, which is limiting the calibration of glaciological and hydrological models. Reanalysis products provide estimates of snow precipitation also for remote high-mountain regions, but this data come with inherent uncertainty, and assessing their biases is difficult given the low quantity and quality of available (long-term) in situ observations. In this study, we aim at improving knowledge on the spatio-temporal variations in winter glacier mass balance by exploring the combination of data from reanalyses and direct snow accumulation observations on glaciers using machine learning. We use the winter mass balance data of 95 glaciers distributed over the European Alps, western Canada, Central Asia and Scandinavia and compare them with the total precipitation from the ERA5 and the MERRA-2 reanalysis products during the snow accumulation seasons from 1981 until 2019. We develop and apply a machine learning model to adjust the precipitation from the reanalysis products along the elevation profile of the glaciers and consequently to reconstruct the winter mass balance in both space (for glaciers without observational data) and time (filling observational data gaps). The employed machine learning model is a gradient boosting regressor (GBR), which combines several meteorological variables from the reanalyses (e.g. air temperature, relative humidity) with topographical parameters. These GBR-derived estimates are evaluated against the winter mass balance data using (i) independent glaciers (site-independent GBR) and (ii) independent accumulation seasons (season-independent GBR). Both approaches resulted in reduced biases and increased correlation between the precipitation of the original reanalyses and the winter mass balance data of the glaciers. Generally, the GBR models have also shown a good representation of the spatial (vertical elevation intervals) and temporal (years) variability of the winter mass balance on individual glaciers.

Accurate and reliable solid precipitation estimates for high mountain regions are crucial for many research applications. Yet, measuring snowfall at high elevation remains a major challenge. In consequence, observational coverage is typically sparse, and the validation of spatially distributed precipitation products is complicated. This study presents a novel approach using reliable daily snow water equivalent (SWE) estimates by a cosmic ray sensor on two Swiss glacier sites to assess the performance of various gridded precipitation products. The ground observations are available during two and four winter seasons. The performance of three readily-available precipitation data products based on different data sources (gauge-based, remotely-sensed, and re-analysed) is assessed in terms of their accuracy compared to the ground reference. Furthermore, we include a data set, which corresponds to the remotely-sensed product with a local adjustment to independent SWE measurements. We find a large bias of all precipitation products at a monthly and seasonal resolution, which also shows a seasonal trend. Moreover, the performance of the precipitation products largely depends on in situ wind direction during snowfall events. The varying performance of the three precipitation products can be partly explained with their compilation background and underlying data basis.

Radiotherapy and surgery for early laryngeal cancer achieve comparably good results in patient survival, and the choice of treatment between them is being influenced increasingly by the expected voice quality and quality of life (QoL). The superiority of vocal function after radiotherapy has been shown in previous objective voice assessment studies. This study compared the QoL of long-term survivors after endoscopic laser surgery or radiotherapy for early laryngeal carcinoma. QoL was evaluated with two validated questionnaires: the global EORTC QLQ-C30 and the head- and neck-specific EORTC QLQ-H&N35. A total of 62 patients were included. Among 56 patients completing the questionnaires (90% completion rate) 40 were treated by endoscopic CO2 laser surgery and 16 with radiation therapy. All 56 patients showed a good global QoL with no significant difference between the two treatment modalities. The head- and neck-specific evaluation revealed significantly better scores for surgically treated patients in questions about swallowing of solid food, xerostomia, and tooth problems, but no difference in questions about voice quality. Both treatment modalities achieve good QoL after treatment of early laryngeal tumors. Irradiated patients mainly complain about xerostomia related problems. In contrast to objective measurements long-term survivors after surgery do not rate their voice poorer than irradiated patients. The EORTC questionnaires are validated and useful tools in assessing QoL and should further be used in prospective trials.

Radiotherapy and surgery for laryngeal cancer achieve comparable results in patient survival. Therefore, the expected quality of life is increasingly influencing the choice of treatment. The aim of this study was to compare the quality of life of patients after surgery or radiotherapy for laryngeal carcinoma. To evaluate quality of life, we used the validated European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and the EORTC Head and Neck module (EORTC QLQ-H&N35). 65 patients who were treated with either radiotherapy or surgery for laryngeal cancer between January 1990 and December 1995, and who were alive and free of tumour in January 1999, were included in this study. In the first group with small tumours (T1/T2), 40 patients were treated by CO2-laser surgery and 16 by primary radiotherapy. In the second group with more advanced tumours (T3/T4), 5 patients underwent total laryngectomy and 4 primary radiotherapy. In the first group there was good global quality of life with no significant difference between the two treatment modalities. Surgically treated patients scored significantly better than the irradiated patients in questions about swallowing of solid food, xerostomia and dental problems. No other significant differences were found: hoarseness in particular was rated equally after both treatments. In the second group there was also good global quality of life with no significant difference between the two treatment modalities. The laryngectomized patients scored equally on questions about voice function, talking on the phone and social behaviour. As far as quality of life is concerned we can recommend both treatment modalities for patients with laryngeal cancer of all stages.