Wolfgang Meier

Dr. Wolfgang Meier

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 January 2018 in Remote Sensing
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PMPhilipp Malz
Philipp Malz
WMWolfgang Meier
Wolfgang Meier
GCGino Casassa
Gino Casassa
RJRicardo Jaña
Ricardo Jaña
PSPedro Skvarca
Pedro Skvarca
MBMatthias Braun
Matthias Braun
The contribution to sea level rise from Patagonian icefields is one of the largest mass losses outside the large ice sheets of Antarctica and Greenland. However, only a few studies have provided large-scale assessments in a spatially detailed way to address the reaction of individual glaciers in Patagonia and hence to better understand and explain the underlying processes. In this work, we use repeat radar interferometric measurements of the German TerraSAR-X-Add-on for Digital Elevation Measurements (TanDEM-X) satellite constellation between 2011/12 and 2016 together with the digital elevation model from the Shuttle Radar Topography Mission (SRTM) in 2000 in order to derive surface elevation and mass changes of the Southern Patagonia Icefield (SPI). Our results reveal a mass loss rate of −11.84 ± 3.3 Gt·a−1 (corresponding to 0.033 ± 0.009 mm·a−1 sea level rise) for an area of 12573 km2 in the period 2000–2015/16. This equals a specific glacier mass balance of −0.941 ± 0.19 m w.e.·a−1 for the whole SPI. These values are comparable with previous estimates since the 1970s, but a magnitude larger than mass change rates reported since the Little Ice Age. The spatial pattern reveals that not all glaciers respond similarly to changes and that various factors need to be considered in order to explain the observed changes. Our multi-temporal coverage of the southern part of the SPI (south of 50.3° S) shows that the mean elevation change rates do not vary significantly over time below the equilibrium line. However, we see indications for more positive mass balances due to possible precipitation increase in 2014 and 2015. We conclude that bi-static radar interferometry is a suitable tool to accurately measure glacier volume and mass changes in frequently cloudy regions. We recommend regular repeat TanDEM-X acquisitions to be scheduled for the maximum summer melt extent in order to minimize the effects of radar signal penetration and to increase product quality.

29 May 2018 in Frontiers in Earth Science
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WMWolfgang Meier
Wolfgang Meier
Jussi GrießingerJussi Grießinger
Jussi Grießinger
PHPhilipp Hochreuther
Philipp Hochreuther
MBMatthias Braun
Matthias Braun
We present a satellite-derived glacier inventory for the whole Patagonian Andes south of 45. 5°S and Tierra del Fuego including recent changes. Landsat TM/ETM+ and OLI satellite scenes were used to detect changes in the glacierized area between 1986, 2005 and 2016 for all of the 11,209 inventoried glaciers using a semi-automated procedure. Additionally we used geomorphological evidence, such as moraines and trimlines to determine the glacierized area during the Little Ice Age for almost 90% of the total glacierized area. Within the last ~150 years the glacierized area was reduced from 28,091 ± 890 km2 to 22,636 ± 905 km2, marking an absolute area loss of 5,455 ± 1,269 km2 (19.4 ± 4.5%). For the whole study region, the annual area decrease was moderate until 1986 with 0.10 ± 0.04% a−1. Afterwards the area reduction increased, reaching annual values of 0.33 ± 0.28% a−1 and 0.25 ± 0.50% a−1 for the periods of 1986–2005 and 2005–2016, respectively. There is a high variability of change rates throughout the Patagonian Andes. Small glaciers, especially in the north of the Northern Patagonian Icefield (NPI) and between the latter and the Southern Patagonian Icefield (SPI) had over all periods the highest rates of shrinkage, exceeding 0.92 ± 1.22% a−1 during 2005–2016. In the mountain range of the Cordillera Darwin (CD), and also accounting for small ice fields south of 52°S, highest rates of shrinkage occurred during 1986–2005, reaching values up to 0.45 ± 0.23% a−1, but decreased during the 2005–2016 period. Across the Andean main crest, the eastern parts of the NPI, SPI and adjoined glaciers had in absolute values the highest area reduction exceeding 2,145 ± 486 km2 since the LIA. Large calving glaciers show a smaller relative decrease rate compared to land-terminating glaciers but account for the most absolute area loss. In general, glacier shrinkage is dependent on latitude, the initial glacier area, the environment of the glacial tongue (calving or non-calving glaciers) and in parts by glacial aspect.

21 October 2021 in Forests
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ADAnnette Debel
Annette Debel
WMWolfgang Meier
Wolfgang Meier
Achim BräuningAchim Bräuning
Achim Bräuning
Since recent drought events have already caused severe damage to trees and droughts in the near future are expected to occur even more frequently, this study investigated the response of forest ecosystems to changing climate conditions in the topographically complex region of Bavaria, southeast Germany. For this purpose, climate–growth relationships of important European deciduous and coniferous tree species were investigated over the past 50 years at three middle mountain ranges and corresponding basins. A response analysis between tree-ring width and climate variables was applied to detect modifications in tree responses comparing two 25-year periods at individual forest sites. Furthermore, tree responses to climatic extreme years and seasons were analyzed using a superposed epoch analysis. The results showed that Scots pine (Pinus sylvestris) proved to be the most vulnerable and least drought-resistant of all investigated tree species. Likewise, Norway spruce (Picea abies) and European beech (Fagus sylvatica) revealed a higher drought sensitivity over the past 25 years, even though an extended growing season partially improved tree growth at high-elevation sites. In conclusion, all studied tree species were affected by drought events, even at humid high-elevation sites. Correlations with daily climate variables confirmed that even short-term weather conditions could strongly influence trees’ radial growth. Tree responses to climate conditions have shifted significantly between past and present periods but vary considerably among sites and are generally stronger in humid regions than in already dry areas.

22 March 2024 in Communications Earth & Environment
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JFJohannes J. Fürst
Johannes J. Fürst
DFDavid Farías-Barahona
David Farías-Barahona
NBNorbert Blindow
Norbert Blindow
GCGino Casassa
Gino Casassa
GGGuisella Gacitúa
Guisella Gacitúa
MSMarius Schaefer
Marius Schaefer
The two vast Patagonian icefields are a global hotspot for ice-loss. However, not much is known about the total ice volume they store - let alone its spatial distribution. One reason is that the abundant record of direct thickness measurements has never been systematically exploited. Here, this record is combined with remotely-sensed information on past ice thickness mapped from glacier retreat. Both datasets are incorporated in a state-of-the-art, mass-conservation approach to produce a well-informed map of the basal topography beneath the icefields. Its major asset is the reliability increase of thicknesses values along the many marine- and lake-terminating glaciers. For these, frontal ice-discharge is notably lower than previously reported. This finding implies that direct climatic control was more influential for past ice loss. We redact a total volume for both icefields in 2000 of 5351 km3. Despite the wealth of observations used in this assessment, relative volume uncertainties remain elevated.

29 March 2019 in Geosciences
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Jussi GrießingerJussi Grießinger
Jussi Grießinger
Achim BräuningAchim Bräuning
Achim Bräuning
GHGerhard Helle
Gerhard Helle
GSGerhard H Schleser
Gerhard H Schleser
PHPhilipp Hochreuther
Philipp Hochreuther
Haifeng ZhuHaifeng Zhu
Haifeng Zhu
Tree-rings are recorders of environmental signals and are therefore often used to reconstruct past environmental conditions. In this paper, we present four annually resolved, multi-centennial tree-ring isotope series from the southeastern Tibetan plateau. The investigation site, where juniper and spruce trees jointly occur, is one of the highest known tree-stands in the world. Tree ring cellulose oxygen (δ18O) and carbon (δ13C) isotopes were analyzed for a common period of 1685–2007 AD to investigate climate–isotope relationships. Therefore, various climate parameters from a local meteorological station and from the CRU 4.02 dataset were used. Tree-ring δ18O of both species revealed highly significant sensitivities with a high degree of coherence to hydroclimate variables during the growing season. The obtained δ18O–climate relationships can even be retained using a species mean. In contrast, the individual δ13C series indicated a weaker and non-uniform response to the tested variables. Underlying species-specific responses and adaptations to the long-term trend in atmospheric CO2 bias even after a trend correction identified dominant environmental factors triggering the tree-ring δ13C at our site. However, analysis of individual intrinsic water-use efficiency in juniper and spruce trees indicated a species-specific adaptation strategy to climate change.

3 August 2019 in Geosciences
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WMWolfgang Meier
Wolfgang Meier
JAJuan-Carlos Aravena
Juan-Carlos Aravena
Jussi GrießingerJussi Grießinger
Jussi Grießinger
PHPhilipp Hochreuther
Philipp Hochreuther
Pamela Soto-RogelPamela Soto-Rogel
Pamela Soto-Rogel
MBMatthias Braun
Matthias Braun
The Magallanes–Tierra del Fuego region, Southern Patagonia (53–56° S) features a plethora of fjords and remote and isolated islands, and hosts several thousand glaciers. The number of investigated glaciers with respect to the multiple Neoglacial advances is based on a few individual studies and is still fragmentary, which complicates the interpretation of the glacial dynamics in the southernmost part of America. Schiaparelli Glacier (54°24′ S, 70°50′ W), located at the western side of the Cordillera Darwin, was selected for tree-ring-based and radiocarbon dating of the glacial deposits. One focus of the study was to address to the potential dating uncertainties that arise by the use of Nothofagus spp. as a pioneer species. A robust analysis of the age–height relationship, missing the pith of the tree (pith offset), and site-specific ecesis time revealed a total uncertainty value of ±5–9 years. Three adjacent terminal moraines were identified, which increasingly tapered towards the glacier, with oldest deposition dates of 1749 ± 5 CE, 1789 ± 5 CE, and 1867 ± 5 CE. Radiocarbon dates of trunks incorporated within the terminal moraine system indicate at least three phases of cumulative glacial activity within the last 2300 years that coincide with the Neoglacial phases of the Southern Patagonian Icefield and adjacent mountain glaciers. The sub-recent trunks revealed the first evidence of a Neoglacial advance between ~600 BCE and 100 CE, which so far has not been substantiated in the Magallanes–Tierra del Fuego region.