The dataset contains borehole-GPR (ground penetrating radar) data from a shallow quaternary glacial aquifer at the test site "TestUM" in Wittstock/Dosse (Germany). At the test site a geological latent heat storage concept was tested while freezing and thawing a subsurface volume in a controlled manner. Therefore, 16 heat exchanger probes, 18 m deep each, are installed in a 1 m x 1 m-grid. 22 2-inch wells and eight multilevel wells are installed to provide direct access to the aquifer for groundwater sampling and borehole measurements. The borehole deviation of the 2-inch monitoring wells was measured using a deviation probe (DevProbe1, Geotomographie, Neuwied, Germany). Readings of tilt and direction were taken for every borehole, allowing calculation of the well path in the subsurface.
Reflection and crosshole borehole GPR measurements were performed before and during two freezing cycles. The data were collected from November 2022 to December 2023. The borehole GPR measurements were performed in the 2-inch monitoring wells. To record the data, we used a GSSI SIR 4000 (GSSI Geophysical Survey Systems, Inc., Nashua, USA) and one (reflection measurements) or two (crosshole measurements) Tubewave-100 antennas (Radarteam Sweden AB, Boden, Sweden). For reflection measurements, an antenna was used that served as both transmitter and receiver. It was lowered into a borehole, and measurements were taken every 0.25 meters starting at a maximum of 16.75 m up to 0.25 m depth. The crosshole measurements were realized as zero offset profiles with two antennas. One served as a transmitter and one as a receiver. They were placed in two boreholes and lowered simultaneously, with measurements taken every 0.25 m at the same depth starting at a maximum of 16.75 m up to 0.25 m depth.
The naming of the 2-inch wells was adjusted according to the groundwater flow direction from northeast to southwest. Wells located upstream of the freezing area start with the letter U, central wells with the letter C, and downstream wells with the letter D. For the reflection measurements, four boreholes were measured upstream (U03, U04, U05, U06), two in the center (C04, C05), and five downstream (D02, D04, D05, D06, D08). For crosshole, various measurements were chosen to characterize the subsurface before freezing, including combinations of upstream-downstream, upstream-center, center-center, and center-downstream. During the freezing phase, the crosshole measurements were conducted using combinations of upstream-upstream, upstream-downstream, center-center, and downstream-downstream.
Forested headwaters that are snowmelt dominated produce 60Prozent of the freshwater runoff of the world. Forested areas also act as vast storage units and within the northern hemisphere and can house 17Prozent of total terrestrial water storage in the form of snow and ice during the winter season. However, the state of forest structures within these zones are continually changing due to effects from climate change, land use management as well as a variety of natural disturbances which creates uncertainty regarding the fate of this major water cycle component. The necessity to fully understand the interplay between forest structures and snow is augmented by alarmingly high global water withdrawal predictions ranging from an 18-50Prozent increase for just 13 years from now in 2025. Arriving at accurate estimations of snowmelt and runoff rate variations from forested areas is of great importance to hydrologic forecasters throughout the world, but in spite of this and the recognized impacts of these areas, many forest snow processes are still poorly understood. With the emerging need to understand and quantify snow-vegetation interactions, a significant number of land surface models have included forest canopy representations and their effect on seasonal snow. The model inter-comparison initiative SnowMIP2 constituted the first comprehensive assessment of the capabilities of these models to reproduce snow cover dynamics under canopy and revealed important shortcomings. Enhancing the consistency of model simulations between locations, years and differing forested and open areas needs to be addressed as this deficiency limits the applicability of current models used for water resources monitoring as well as impact studies in forested areas. Specifically, traditional forest snow melt models typically utilize site-based representations of the canopy. But unless the field area has homogenous canopy coverage, a simplified representation of canopy structure can hamper the ability of current land surface models to accurately quantify the effect of forest canopy on snow accumulation and melt. Recent advances in high resolution availability of LiDAR data will allow us to investigate and create new parameters of canopy characteristics over varying scales in order to more accurately represent the natural heterogeneity of forest systems. These characteristics will be integrated with field based ground penetrating radar (GPR) measurements of snow distribution to arrive at improved predictions of snow cover dynamics under heterogeneous canopy. The development of improved canopy structure descriptors will also reduce the reliance on site specific calibration and allow for more accurate data transference and upscaling to larger scale model applications. (...)
This dataset comprises data of an interdisciplinary pedon-scale irrigation experiment at a grassland site near Karlsruhe, Germany, including pedo-hydrological, geophysical, and remote sensing data. The objective of this experiment is to monitor soil moisture dynamics during a well-defined infiltration process with a combination of direct and non-invasive techniques.Overall, the quantification of soil water dynamics and, in particular, its spatial distributions is essential for the understanding of land-atmosphere interactions. However, the precise measurement of soil water dynamics and its spatial distribution in a continuous manner is a challenging task. Pedo-hydrological monitoring techniques rely on direct, point-based measurement with buried probes for soil water content and matric potential. Non-invasive remote sensing (RS) and geophysical measurement techniques allow for spatially continuous measurements on different spatial scales and extents. This experiment provides a basis for the analyses of signal coherence between the measurement techniques and disciplines. It contributes to forthcoming developments of monitoring setups and modeling approaches to landscape-water dynamics.For direct monitoring, an array of time-domain reflectometry (TDR) probes and tensiometers was used. As non-invasive techniques, we applied a ground-penetrating radar (GPR), a hyperspectral snapshot sensor, a long-wave infrared (LWIR) sensor, and a hyperspectral field spectroradiometer. We provide the data in nearly raw format, including information about the site properties and calibration references. The data are organized along with the different sensors and disciplines. Thus, the distinct sensor data can also be used independently of each other. In addition, exemplary scripts for reading and processing the data are included.
In order to place recent climate change in a longer term context the reconstruction of climatic variations on annual, interannual, and decadal time scales of the last 1000 years is a priority target in current climate research. In its recent report the IPCC recommends that in order to reduce uncertainty associated with present palaeoclimate estimates of Northern Hemispheric temperatures, further work is necessary to produce many more, especially early, palaeoclimate series with much wider geographical coverage. This project aims to reconstruct different climate parameters from a very continental site with low data coverage, the Altai mountain range in Central Asia. For this purpose, an ice core will be recovered from a high-mountain glacier in the Mongolian Altai, suitable for palaeo climate reconstruction. To achieve this goal as a first step, a reconnaissance study will be conducted in order to find the best glacier site. Ideally, a survey helicopter flight to two or three potential glacier sites will be performed. Ground Penetrating Radar will be applied to determine the ice thickness. Based on the results of the radar survey at the most promising sites, shallow firn cores will be collected. The firn cores will be analysed for chemical composition and stable isotope ratios. All parameters together will allow evaluating the quality of the preservation of the climate and atmospheric signals. A first estimation of the annual accumulation and the approximate age will be made. Based on these data the site for deep drilling will be selected and in a second step the deep ice core will be recovered. This project will be conducted in collaboration between the Analytical Chemistry Group of the Laboratory of Radiochemistry and Environmental Chemistry, Paul Scherrer Institut, the Glaciology Group of the Department of Geography at the University of Zurich, Switzerland, the Institut for Water and Environmental Problems SB RAS, Barnaul, Russia, and the Institute of Meteorology and Hydrology, Ulaanbaatar, Mongolia. Methods used are field measurements and ice core chemical analysis in the laboratory. Existing instrumental climate data and other available palaeo data are collected, especially meteorological data from four climate stations operated in the Mongolian Altai for the last 60 years.