Glaciological and meteorological monitoring at Long Term Ecological Research (LTER) sites Mullwitzkees and Venedigerkees, Austria, 2006-2022

Glaciers in the Alps are losing mass at unprecedented and accelerating rates. Monitoring of glacier mass change as well as relevant atmospheric parameters plays an important role in improving understanding of local and downstream impacts. We present sub-seasonal, seasonal, and annual glaciological mass balance data and meteorological observations from Mullwitzkees and Venedigerkees, two glacier monitoring sites in the Hohe Tauern range of the Austrian Alps. Ablation stake networks were established on Mullwitzkees in 2006/07 and on Venedigerkees in 2011/12. Monitoring is ongoing. In addition to stake readings at sub-seasonal intervals, accumulation measurements (snow pits and probing) are carried out seasonally. The glaciological dataset consists of sub-seasonal floating-date measurements as well as fixed-date seasonal and annual values. The fixed-date glacier-wide mass balance was derived from annual point mass balance values. Automatic weather stations measuring standard meteorological parameters were installed near Mullwitzkees and Venedigerkees in 2020 and 2019, respectively. Meteorological data are provided in 10 min intervals. Uncertainties in individual point mass balance measurements were computed following the approach of the Swiss Glacier Monitoring (GLAMOS) programme, taking into account estimated density and reading errors. The sub-seasonal mass balance records highlight shorter-term variability in mass loss and the linkage with meteorological conditions. The most negative annual point mass balance recorded in the period of record was -5.8 +/- 0.66 m w.e. at an elevation of 2536 m on Venedigerkees, and 2022 stands out as the most negative mass balance year to date in both time series, particularly at higher elevations. The cumulative specific mass balances (glacier-wide) over the period of record were -14.68 m w.e. at Mullwitzkees and -8.79 m w.e. at Venedigerkees. Data are available in the PANGAEA publication series and the associated datasets. The main publication series are updated annually. The Mullwitzkees mass balance datasets can be found in Stocker-Waldhuber et al. (2016) (https://doi.org/10.1594/PANGAEA.965660) and Stocker-Waldhuber et al. (2024d) (https://doi.org/10.1594/PANGAEA.965719). The Venedigerkees data can be found in Seiser and Fischer (2016) (https://doi.org/10.1594/PANGAEA.965648) and Seiser et al. (2024d) (https://doi.org/10.1594/PANGAEA.965729).