Monthly time series of spatially enhanced relative humidity for Europe at 30 arc seconds resolution (2000 - 2023) derived from ERA5-Land data

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.


Processing steps:

The original hourly ERA5-Land air temperature 2 m above ground and dewpoint temperature 2 m 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


Subsequently, the temperature time series have been aggregated on a daily basis. From these, daily relative humidity has been calculated for the time period 01/2000 - 12/2023.


Relative humidity (rh2m) has been calculated from air temperature 2 m above ground (Ta) and dewpoint temperature 2 m above ground (Td) using the formula for saturated water pressure from Wright (1997):


maximum water pressure = 611.21 * exp(17.502 * Ta / (240.97 + Ta))


actual water pressure = 611.21 * exp(17.502 * Td / (240.97 + Td))


relative humidity = actual water pressure / maximum water pressure


The resulting relative humidity has been aggregated to monthly averages.


Resultant values have been converted to represent percent * 10, thus covering a theoretical range of [0, 1000].


File naming scheme (YYYY = year; MM = month):

ERA5_land_rh2m_avg_monthly_YYYY_MM.tif


Projection + EPSG code:

Latitude-Longitude/WGS84 (EPSG: 4326)


Spatial extent:

north: 82:00:30N

south: 18N

west: 32:00:30W

east: 70E


Spatial resolution:

30 arc seconds (approx. 1000 m)


Temporal resolution:

Monthly


Pixel values:

Percent * 10 (scaled to Integer; example: value 738 = 73.8 %)


Software used:

GDAL 3.2.2 and GRASS GIS 8.0.0/8.3.2

Original ERA5-Land dataset license:

https://apps.ecmwf.int/datasets/licences/copernicus/


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/ )


Reference: Wright, J.M. (1997): Federal meteorological handbook no. 3 (FCM-H3-1997). Office of Federal Coordinator for Meteorological Services and Supporting Research. Washington, DC


Data is also available in EU LAEA (EPSG: 3035) projection: https://data.mundialis.de/geonetwork/srv/eng/catalog.search#/metadata/ab06ed25-84af-43c9-b1c3-57e3b6ad8d29


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.

INSPIRE

Identification

File identifier
b9ce7dba-4130-428d-96f0-9089d8b9f4a5 XML
Hierarchy level
Dataset
Online resource
Protocol

WWW:DOWNLOAD-1.0-http--download
Resource identifier
code

dataset
Metadata language
English
Spatial representation type
Grid
Encoding
Format

GeoTIFF
Projection
code
EPSG:4326
 

Classification of data and services

Topic category
  • Geoscientific information
  • Climatology, meteorology, atmosphere
 

Classification of data and services

Coupled resource

Coupled resource
 
 

Classification of data and services

Coupled resource

Coupled resource
 
 

Keywords

GEMET - INSPIRE themes, version 1.0

  • Atmospheric conditions

  • Meteorological geographical features

Other keywords

Theme

  • relative humidity

  • geospatial analysis

  • environment

  • meteorology

  • ERA5-Land

  • CHELSA
Place

  • Europe
Theme

  • MOOD-H2020

  • Tularaemia

  • Lyme

  • TBE

  • WNV

  • USUTU

  • Mosquito borne Flaviviruses
 
 

Geographic coverage

N
S
E
W
thumbnail


 

Temporal reference

Temporal extent
Begin
2000-01-01
End
2023-12-31
Temporal extent
Date (Publication)
2024-07-11
 

Quality and validity

Lineage

derived from ERA5-Land reanalysis data, spatially enhanced by image fusion with CHELSA data
Distance
30  arc-seconds
 

Conformity

Conformity
Conformity
 

Conformity

Conformity
Conformity
Explanation

See specified reference
 

Restrictions on access and use

Access constraints
no limitations to public access
Access constraints

Creative Commons Namensnennung – 4.0 International (CC BY 4.0)
Access constraints

{ "id": "cc-by/4.0", "name": "Creative Commons Namensnennung – 4.0 Internationa", "url": " http://creativecommons.org/licenses/by/4.0/ ", "quelle": "Source: mundialis GmbH & Co. KG" }

 

Responsible organization (s)

Contact for the resource
Organisation name

mundialis GmbH & Co. KG
Email

info@mundialis.de

 

Responsible organization (s)

Contact for the resource
Organisation name

mundialis GmbH & Co. KG
Email

info@mundialis.de

 

Metadata information

Contact for the metadata
Organisation name

mundialis GmbH & Co. KG
Email

info@mundialis.de

Date stamp
2024-07-11T06:54:02
Metadata language
English
Character set
UTF8
 
 

SDS

Conformance class 1: invocable

Access Point URL
Endpoint URL
Technical specification
 

Conformance class 2: interoperable

Access constraints

Limitation
 

Use constraints

Limitation
 

Responsible custodian

Contact for the resource
 
 
 

Overviews

overview

Spatial extent

N
S
E
W
thumbnail


Keywords

CHELSA ERA5-Land Lyme MOOD-H2020 Mosquito borne Flaviviruses TBE Tularaemia USUTU WNV environment geospatial analysis meteorology relative humidity
GEMET - INSPIRE themes, version 1.0
Atmospheric conditions Meteorological geographical features

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