GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Strong geologic methane emissions from discontinuous terrestrial permafrost in the Mackenzie Delta, Canada
    Springer Science and Business Media LLC ; 2017
    In:  Scientific Reports Vol. 7, No. 1 ( 2017-07-19)
    Details
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 7, No. 1 ( 2017-07-19)
    Abstract: Arctic permafrost caps vast amounts of old, geologic methane (CH 4 ) in subsurface reservoirs. Thawing permafrost opens pathways for this CH 4 to migrate to the surface. However, the occurrence of geologic emissions and their contribution to the CH 4 budget in addition to recent, biogenic CH 4 is uncertain. Here we present a high-resolution (100 m × 100 m) regional (10,000 km²) CH 4 flux map of the Mackenzie Delta, Canada, based on airborne CH 4 flux data from July 2012 and 2013. We identify strong, likely geologic emissions solely where the permafrost is discontinuous. These peaks are 13 times larger than typical biogenic emissions. Whereas microbial CH 4 production largely depends on recent air and soil temperature, geologic CH 4 was produced over millions of years and can be released year-round provided open pathways exist. Therefore, even though they only occur on about 1% of the area, geologic hotspots contribute 17% to the annual CH 4 emission estimate of our study area. We suggest that this share may increase if ongoing permafrost thaw opens new pathways. We conclude that, due to permafrost thaw, hydrocarbon-rich areas, prevalent in the Arctic, may see increased emission of geologic CH 4 in the future, in addition to enhanced microbial CH 4 production.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    URL: Article
    DOI: 10.1038/s41598-017-05783-2
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2017
    detail.hit.zdb_id: 2615211-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Space‐Scale Resolved Surface Fluxes Across a Heterogeneous, Mid‐Latitude Forested Landscape
    American Geophysical Union (AGU) ; 2022
    In:  Journal of Geophysical Research: Atmospheres Vol. 127, No. 23 ( 2022-12-16)
    Details
    In: Journal of Geophysical Research: Atmospheres, American Geophysical Union (AGU), Vol. 127, No. 23 ( 2022-12-16)
    Abstract: Substantial, persistent mesoscale surface‐atmospheric fluxes were measured across a heterogeneous mid‐latitude forested domain Measured fluxes show distinct seasonal and diurnal variations Measured mesoscale fractions of sensible and latent heat fluxes do not behave similarly
    Type of Medium: Online Resource
    ISSN: 2169-897X , 2169-8996
    URL: Article
    DOI: 10.1029/2022JD037138
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2022
    detail.hit.zdb_id: 710256-2
    detail.hit.zdb_id: 2016800-7
    detail.hit.zdb_id: 2969341-X
    SSG: 16,13
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Toward understanding the contribution of waterbodies to the methane emissions of a permafrost landscape on a regional scale—A case study from the Mackenzie Delta, Canada
    Wiley ; 2018
    In:  Global Change Biology Vol. 24, No. 9 ( 2018-09), p. 3976-3989
    Details
    In: Global Change Biology, Wiley, Vol. 24, No. 9 ( 2018-09), p. 3976-3989
    Abstract: Waterbodies in the arctic permafrost zone are considered a major source of the greenhouse gas methane ( CH 4 ) in addition to CH 4 emissions from arctic wetlands. However, the spatio‐temporal variability of CH 4 fluxes from waterbodies complicates spatial extrapolation of CH 4 measurements from single waterbodies. Therefore, their contribution to the CH 4 budget of the arctic permafrost zone is not yet well understood. Using the example of two study areas of 1,000 km² each in the Mackenzie Delta, Canada, we approach this issue (i) by analyzing correlations on the landscape scale between numerous waterbodies and CH 4 fluxes and (ii) by analyzing the influence of the spatial resolution of CH 4 flux data on the detected relationships. A CH 4 flux map with a resolution of 100 m was derived from two aircraft eddy‐covariance campaigns in the summers of 2012 and 2013. We combined the CH 4 flux map with high spatial resolution (2.5 m) waterbody maps from the Permafrost Region Pond and Lake Database and classified the waterbody depth based on Sentinel‐1 SAR backscatter data. Subsequently, we reduced the resolution of the CH 4 flux map to analyze if different spatial resolutions of CH 4 flux data affected the detectability of relationships between waterbody coverage, number, depth, or size and the CH 4 flux. We did not find consistent correlations between waterbody characteristics and the CH 4 flux in the two study areas across the different resolutions. Our results indicate that waterbodies in permafrost landscapes, even if they seem to be emission hot spots on an individual basis or contain zones of above average emissions, do currently not necessarily translate into significant CH 4 emission hot spots on a regional scale, but their role might change in a warmer climate.
    Type of Medium: Online Resource
    ISSN: 1354-1013 , 1365-2486
    URL: Issue
    URL: Article
    DOI: 10.1111/gcb.2018.24.issue-9
    DOI: 10.1111/gcb.14289
    Language: English
    Publisher: Wiley
    Publication Date: 2018
    detail.hit.zdb_id: 2020313-5
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Performance of the Landsat 8 Provisional Aquatic Reflectance Product for Inland Waters
    MDPI AG ; 2020
    In:  Remote Sensing Vol. 12, No. 15 ( 2020-07-27), p. 2410-
    Details
    In: Remote Sensing, MDPI AG, Vol. 12, No. 15 ( 2020-07-27), p. 2410-
    Abstract: Recently, the United States Geological Service (USGS) released a new provisional product which estimates aquatic reflectance from Landsat 8 Operational Land Imager (OLI), called Landsat 8 Provisional Aquatic Reflectance (L8PAR). However, as indicated in the product guide, the use of this product for inland waters needs further verification and improvements. The goal of this study was to determine how the novel L8PAR product performs for different small turbid and eutrophic lakes in Northern Germany compared to in situ measurements of above water remote sensing reflectance (Rrs). For several recent scenes during our monitoring, the L8PAR product failed to produce full data for the lakes of our interest. For the best scene with in situ spectra, L8PAR was not able to retrieve any information for band 1 and not all information for bands 2, 3 and 4. The pixels with valid values for reflectance showed a weak relationship for band 2 (R2 of 0.24) and a medium relationship for bands 3 and 4 (R2 of 0.68 and 0.72, respectively). Compared to other atmospheric correction routines (ACOLITE, C2RCC, C2X, iCOR and L8SR), L8PAR was the only product which was not able to retrieve Rrs for all match up samples. This work provides an evaluation of the L8PAR product for inland waterbodies. Although more analysis and validation need to be conducted, our study suggests that the L8PAR product cannot be used for small inland lakes in its current state and has to be used with care for inland waters in general.
    Type of Medium: Online Resource
    ISSN: 2072-4292
    URL: Article
    DOI: 10.3390/rs12152410
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2513863-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    The Use of Sentinel-2 for Chlorophyll-a Spatial Dynamics Assessment: A Comparative Study on Different Lakes in Northern Germany
    MDPI AG ; 2021
    In:  Remote Sensing Vol. 13, No. 8 ( 2021-04-16), p. 1542-
    Details
    In: Remote Sensing, MDPI AG, Vol. 13, No. 8 ( 2021-04-16), p. 1542-
    Abstract: Eutrophication of inland waters is an environmental issue that is becoming more common with climatic variability. Monitoring of this aquatic problem is commonly based on the chlorophyll-a concentration monitored by routine sampling with limited temporal and spatial coverage. Remote sensing data can be used to improve monitoring, especially after the launch of the MultiSpectral Instrument (MSI) on Sentinel-2. In this study, we compared the estimation of chlorophyll-a (chl-a) from different bio-optical algorithms using hyperspectral proximal remote sensing measurements, from simulated MSI responses and from an MSI image. For the satellite image, we also compare different atmospheric corrections routines before the comparison of different bio-optical algorithms. We used in situ data collected in 2019 from 97 sampling points across 19 different lakes. The atmospheric correction assessment showed that the performances of the routines varied for each spectral band. Therefore, we selected C2X, which performed best for bands 4 (root mean square error—RMSE = 0.003), 5 (RMSE = 0.004) and 6 (RMSE = 0.002), which are usually used for the estimation of chl-a. Considering all samples from the 19 lakes, the best performing chl-a algorithm and calibration achieved a RMSE of 16.97 mg/m3. When we consider only one lake chain composed of meso-to-eutrophic lakes, the performance improved (RMSE: 10.97 mg/m3). This shows that for the studied meso-to-eutrophic waters, we can reliably estimate chl-a concentration, whereas for oligotrophic waters, further research is needed. The assessment of chl-a from space allows us to assess spatial dynamics of the environment, which can be important for the management of water resources. However, to have an accurate product, similar optical water types are important for the overall performance of the bio-optical algorithm.
    Type of Medium: Online Resource
    ISSN: 2072-4292
    URL: Article
    DOI: 10.3390/rs13081542
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2513863-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Germany: Renewables revolution
    Springer Science and Business Media LLC ; 2011
    In:  Nature Vol. 480, No. 7376 ( 2011-12), p. 279-280
    Details
    In: Nature, Springer Science and Business Media LLC, Vol. 480, No. 7376 ( 2011-12), p. 279-280
    Type of Medium: Online Resource
    ISSN: 0028-0836 , 1476-4687
    URL: Article
    DOI: 10.1038/nj7376-279a
    RVK:
    TA 1000
    RVK:
    UA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2011
    detail.hit.zdb_id: 120714-3
    detail.hit.zdb_id: 1413423-8
    SSG: 11
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    Evaluation of Two Energy Balance Closure Parametrizations
    Springer Science and Business Media LLC ; 2014
    In:  Boundary-Layer Meteorology Vol. 151, No. 2 ( 2014-5), p. 195-219
    Details
    In: Boundary-Layer Meteorology, Springer Science and Business Media LLC, Vol. 151, No. 2 ( 2014-5), p. 195-219
    Type of Medium: Online Resource
    ISSN: 0006-8314 , 1573-1472
    URL: Article
    DOI: 10.1007/s10546-013-9904-0
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2014
    detail.hit.zdb_id: 242879-9
    detail.hit.zdb_id: 1477639-X
    SSG: 16,13
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    Spatial and seasonal patterns of water isotopes in northeastern German lakes
    Copernicus GmbH ; 2022
    In:  Earth System Science Data Vol. 14, No. 4 ( 2022-04-19), p. 1857-1867
    Details
    In: Earth System Science Data, Copernicus GmbH, Vol. 14, No. 4 ( 2022-04-19), p. 1857-1867
    Abstract: Abstract. Water stable isotopes (δ18O and δ2H) were analyzed in samples collected in lakes, associated with riverine systems in northeastern Germany, throughout 2020. The dataset (Aichner et al., 2021; https://doi.org/10.1594/PANGAEA.935633) is derived from water samples collected at (a) lake shores (sampled in March and July 2020), (b) buoys which were temporarily installed in deep parts of the lake (sampled monthly from March to October 2020), (c) multiple spatially distributed spots in four selected lakes (in September 2020), and (d) the outflow of Müggelsee (sampled biweekly from March 2020 to January 2021). At shores, water was sampled with a pipette from 40–60 cm below the water surface and directly transferred into a measurement vial, while at buoys a Limnos water sampler was used to obtain samples from 1 m below the surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer, with a measurement uncertainty of 〈0.15 ‰ (δ18O) and 〈0.0 ‰ (δ2H). The data give information about the vegetation period and the full seasonal isotope amplitude in the sampled lakes and about spatial isotope variability in different branches of the associated riverine systems.
    Type of Medium: Online Resource
    ISSN: 1866-3516
    URL: Article
    DOI: 10.5194/essd-14-1857-2022
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2022
    detail.hit.zdb_id: 2475469-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    Upscaling surface energy fluxes over the North Slope of Alaska using airborne eddy-covariance measurements and environmental response functions
    Copernicus GmbH ; 2018
    In:  Atmospheric Chemistry and Physics Vol. 18, No. 13 ( 2018-07-13), p. 10007-10023
    Details
    In: Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 13 ( 2018-07-13), p. 10007-10023
    Abstract: Abstract. The objective of this study was to upscale airborne flux measurements of sensible heat and latent heat and to develop high-resolution flux maps. In order to support the evaluation of coupled atmospheric–land-surface models we investigated spatial patterns of energy fluxes in relation to land-surface properties. We used airborne eddy-covariance measurements acquired by the Polar 5 research aircraft in June–July 2012 to analyze surface fluxes. Footprint-weighted surface properties were then related to 21 529 sensible heat flux observations and 25 608 latent heat flux observations using both remote sensing and modeled data. A boosted regression tree technique was used to estimate environmental response functions between spatially and temporally resolved flux observations and corresponding biophysical and meteorological drivers. In order to improve the spatial coverage and spatial representativeness of energy fluxes we used relationships extracted across heterogeneous Arctic landscapes to infer high-resolution surface energy flux maps, thus directly upscaling the observational data. These maps of projected sensible heat and latent heat fluxes were used to assess energy partitioning in northern ecosystems and to determine the dominant energy exchange processes in permafrost areas. This allowed us to estimate energy fluxes for specific types of land cover, taking into account meteorological conditions. Airborne and modeled fluxes were then compared with measurements from an eddy-covariance tower near Atqasuk. Our results are an important contribution for the advanced, scale-dependent quantification of surface energy fluxes and they provide new insights into the processes affecting these fluxes for the main vegetation types in high-latitude permafrost areas.
    Type of Medium: Online Resource
    ISSN: 1680-7324
    URL: Article
    DOI: 10.5194/acp-18-10007-2018
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2018
    detail.hit.zdb_id: 2092549-9
    detail.hit.zdb_id: 2069847-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    New calibration procedures for airborne turbulence measurements and accuracy of the methane fluxes during the AirMeth campaigns
    Copernicus GmbH ; 2018
    In:  Atmospheric Measurement Techniques Vol. 11, No. 7 ( 2018-07-31), p. 4567-4581
    Details
    In: Atmospheric Measurement Techniques, Copernicus GmbH, Vol. 11, No. 7 ( 2018-07-31), p. 4567-4581
    Abstract: Abstract. Low-level flights over tundra wetlands in Alaska and Canada have been conducted during the Airborne Measurements of Methane Emissions (AirMeth) campaigns to measure turbulent methane fluxes in the atmosphere. In this paper we describe the instrumentation and new calibration procedures for the essential pressure parameters required for turbulence sensing by aircraft that exploit suitable regular measurement flight legs without the need for dedicated calibration patterns. We estimate the accuracy of the mean wind and the turbulence measurements. We show that airborne measurements of turbulent fluxes of methane and carbon dioxide using cavity ring-down spectroscopy trace gas analysers together with established turbulence equipment achieve a relative accuracy similar to that of measurements of sensible heat flux if applied during low-level flights over natural area sources. The inertial subrange of the trace gas fluctuations cannot be resolved due to insufficient high-frequency precision of the analyser, but, since this scatter is uncorrelated with the vertical wind velocity, the covariance and thus the flux are reproduced correctly. In the covariance spectra the -7/3 drop-off in the inertial subrange can be reproduced if sufficient data are available for averaging. For convective conditions and flight legs of several tens of kilometres we estimate the flux detection limit to be about 4 mg m−2 d−1 for w′CH4′‾, 1.4 g m−2 d−1 for w′CO2′‾ and 4.2 W m−2 for the sensible heat flux.
    Type of Medium: Online Resource
    ISSN: 1867-8548
    URL: Article
    DOI: 10.5194/amt-11-4567-2018
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2018
    detail.hit.zdb_id: 2505596-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...