Am 27. März 2015 eröffnete Bundesministerin Barbara Hendricks den Neubau der Saatgutbank der Freien Universität Berlin. Sie übernimmt die Schirmherrschaft für Deutschlands älteste Wildpflanzen-Saatgutbank. Die Dahlemer Saatgutbank war bisher eher unscheinbar in den Räumen des Wirtschaftshofes im Botanischen Garten untergebracht und zieht nun in eigene Räumlichkeiten am Sumpf- und Wasserpflanzengarten. Die Saatgutbank des botanischen Gartens besteht seit 1994 und gehört damit zu den Ältesten in Deutschland und umfasst derzeit ca.7000 Saatguteinlagerungen. Die Saatgutbank sammelt, trocknet und lagert Saatgut aus der ganzen Welt, schwerpunktmäßig aber aus Europa und der Region Berlin-Brandenburg. Die Sammlung von Saatgut dient vor allem dem Schutz gefährdeter oder geschützter Arten zur Sicherung des Artenbestandes sowie der Wissenschaft und Forschung. Dazu werden auf Expeditionen die Samen gesammelt, gereinigt und aufbereitet, anschließend wird das Saatgut in einem Trockenraum bei 15° C und 15% relativer Luftfeuchte getrocknet und schließlich in einem Kühlraum bei -20 Grad eingelagert. Auf diese Weise kann die Keimfähigkeit der Samen Jahrzehnte, manchmal sogar Jahrhunderte erhalten werden!
Overview:
ERA5-Land is a reanalysis dataset providing a consistent view of the evolution of land variables over several decades at an enhanced resolution compared to ERA5. ERA5-Land has been produced by replaying the land component of the ECMWF ERA5 climate reanalysis. Reanalysis combines model data with observations from across the world into a globally complete and consistent dataset using the laws of physics. Reanalysis produces data that goes several decades back in time, providing an accurate description of the climate of the past.
Surface temperature:
Temperature of the surface of the Earth. The skin temperature is the theoretical temperature that is required to satisfy the surface energy balance. It represents the temperature of the uppermost surface layer, which has no heat capacity and so can respond instantaneously to changes in surface fluxes.
Processing steps:
The original hourly ERA5-Land data has been spatially enhanced from 0.1 degree to 30 arc seconds (approx. 1000 m) spatial resolution by image fusion with CHELSA data (V1.2) (https://chelsa-climate.org/). For each day we used the corresponding monthly long-term average of CHELSA. The aim was to use the fine spatial detail of CHELSA and at the same time preserve the general regional pattern and fine temporal detail of ERA5-Land. The steps included aggregation and enhancement, specifically:
1. spatially aggregate CHELSA to the resolution of ERA5-Land
2. calculate difference of ERA5-Land - aggregated CHELSA
3. interpolate differences with a Gaussian filter to 30 arc seconds
4. add the interpolated differences to CHELSA
The spatially enhanced daily ERA5-Land data has been aggregated on a weekly basis (starting from Saturday) for the time period 2016 - 2020. Data available is the weekly average of daily averages, the weekly minimum of daily minima and the weekly maximum of daily maxima of surface temperature.
File naming:
Average of daily average: era5_land_ts_avg_weekly_YYYY_MM_DD.tif
Max of daily max: era5_land_ts_max_weekly_YYYY_MM_DD.tif
Min of daily min: era5_land_ts_min_weekly_YYYY_MM_DD.tif
The date in the file name determines the start day of the week (Saturday).
Pixel values:
°C * 10 Example: Value 302 = 30.2 °C
The QML or SLD style files can be used for visualization of the temperature layers.
Coordinate reference system:
ETRS89 / LAEA Europe (EPSG:3035) (EPSG:3035)
Spatial extent:
north: 82N
south: 18S
west: -32W
east: 61E
Spatial resolution:
1 km
Temporal resolution:
weekly
Time period:
01/01/2016 - 12/31/2020
Format: GeoTIFF
Representation type: Grid
Software used:
GRASS 8.0
Original ERA5-Land dataset license:
https://cds.climate.copernicus.eu/api/v2/terms/static/licence-to-use-copernicus-products.pdf
CHELSA climatologies (V1.2):
Data used: Karger D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E, Linder, H.P., Kessler, M. (2018): Data from: Climatologies at high resolution for the earth's land surface areas. Dryad digital repository. http://dx.doi.org/doi:10.5061/dryad.kd1d4
Original peer-reviewed publication: Karger, D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E., Linder, P., Kessler, M. (2017): Climatologies at high resolution for the Earth land surface areas. Scientific Data. 4 170122. https://doi.org/10.1038/sdata.2017.122
Processed by:
mundialis GmbH & Co. KG, Germany (https://www.mundialis.de/)
Contact:
mundialis GmbH & Co. KG, info@mundialis.de
Acknowledgements:
This study was partially funded by EU grant 874850 MOOD. The contents of this publication are the sole responsibility of the authors and don't necessarily reflect the views of the European Commission.