DMI has published a plugin for the free software program QGIS. With this plugin, users can easily access, visualize, analyze and interpret almost all of DMIs Open Data. The plugin only requires an API key for the different data types, and once this has been loaded, a simple User Interface will allow the user to point and click on the data of interest. Data will be visualised as shape or tiff files in QGIS, and can also be downloaded as CSV files if selected. The plugin can also be viewed and downloaded on QGIS' official plugin site here.
¶ Installation
The plugin can be downloaded in QGIS. Go to Plugins → Manage and Install Plugins and search for DMI Open Data and click on Install Plugin.
The plugin will be located in the plugin toolbar as showed in the image.
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Activate your API Keys
In order to use the plugin, the user must obtain and activate their API Keys. API Keys can freely be created here. Once the API Keys have been created and saved, go to Settings → Options → DMI Open Data.
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Meteorological Observations
The first tab is Meteorological Observations. It is possible to filter meteorological observations on date and time, parameters and stations. Furthermore the plugin allows the user to download data as a CSV file. It is not possible to only pick a station and not a parameter, or only picking a parameter and no station. Not all stations measure all parameters. Be sure to check which stations measure what parameter in the Stations and parameters tab or read about it here.
The output is a point shapefile (.shp) located at the coordinates of the station. The point's attribute table can be accessed by right clicking the layer. Parameter values, time of observation and stationId can be viewed.
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Climate Data
The second tab is Climate Data. Climate data has 5 types of data available. Data from stations, data in 10x10km resolution, data in 20x20km resolution, data for municipalities and data for Denmark as a whole country. Since climate data has 5 different types of data, it is possible to change between these by clicking on the radio buttons. Temporal resolution is also available in climate data. It is possible to switch between hour, day, month, and year. Not all parameters are available in all temporal- or spatial resolutions. Read about which parameters are measured in which temporal- and spatial resolutions here. The division of cellIds are based on the national grid. 10x10 and 20x20km cell values are calculated by DMI, based on surrounding stations. Read more about it here. The cell division can be found here and downloaded into QGIS as a shapefile here: /10x10km-grid.zip /20x20km-grid.zip
Stations, municipality and country is a point feature. Grid 10x10 and 20x20 is a polygon feature. Each output has 4 fields containing the parameter value, a from and to value and a name.
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Radar Data
The third tab is Radar Data which allows you to import radar images from the last six months. There are two types of radar data; Composite and Pseudo CAPPI. With Composite you can sort the data on the scan type. With Pseudo CAPPI you can sort the data on stations. Read more about the different types here. Furthermore you can sort the radar data on a BBOX and date and time. BBOX must be written as a CSV file, as in the following example: 7.76,54.51,15.23,57.82. An easy way to find BBOX coordinates can found here.
The resulting file is a H5 file, and will be downloaded onto the computers temporary file folder. The files are automatically set to be temporal, so you can automatically use the Temporal Controller Panel to browse the different radar images based on the time.
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Lightning Data
The fourth tab is Lightning Data which shows lightnings observed by DMIs lightning sensors. DMI has 6 sensors located around Denmark, that measures cloud to ground (positive), cloud to ground (negative) and cloud to cloud. Lightning data has been measured since 2002. Read more about lightning data here.
Lightning data has three ways to sort data: BBOX (Bounding Box), lightning type and datetime. BBOX allows the user to find lightning observed within a square of coordinates. BBOX must be written as minimum longitude, minimum latitude, maximum longitude and maximum latitude separated by commas, as in the following example: 7.76,54.51,15.23,57.82. An easy way to find BBOX coordinates can found here.
The output is a point shapefile that has a time of observation, a lightning type, sensors, stroke and an amplitude.
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Oceanographic Observations
The fifth tab is Oceanographic Observations. Oceanographic observations are very similar to Meteorological observations. You can only filter on parameters, stations and date and time.
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Forecast Data
The sixth tab is Forecast Data. Forecast data in the plugin is limited to the Wave Model (WAM) and the Storm Surge Model (DKSS). The plugin can not import HARMONIE data. Like radar data, forecast data will be downloaded onto the temp folder, and will be imported from there. The file is GRIB1 format.
It is possible to sort data based on time, model, parameters and area. When the forecast file is loaded into QGIS, it will be located in a layer group. It is the chosen parameter that will be displayed "on top", but all parameters are downloaded and are located in the different bands. You can find an overview of the bands and their corresponding parameters for the WAM here and for the DKSS here. It is possible to chose depth in the DKSS. Each band thereby represent a parameter (and a depth if DKSS is chosen), that can be visualized. You can access the different bands by right clicking on the layer and choosing Properties → Symbology → Gray Band and then clicking on the band that is desired.
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Stations and Parameters
This tab allows you to get an overview of the stations and what parameters are measured. It is possible to choose between meteorological- and oceanographic stations, choosing what parameter are desired and date and time. Parameters in the meteorological stations tab are only climate data. However if you are interested in a parameter measured in the meteorological observations, it is likely that a similar parameter is measured in climate data. E.g. if you want to find all stations that measure the meteorological observations parameter precip_past1h you can choose the parameter acc_precip . All of these stations will likely also measure precip_past_1h, since it is a parameter concerning precipitation in both cases. A list of meteorological stations and their parameter measured for climate data can be found here, for meteorological observations here and for oceanographic stations here.
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Tips and tricks
All layers that are inserted into QGIS are compatible with the Temporal Controller Panel. The Temporal Controller Panel is a great way to create cool dynamic maps that shows the development of e.g. temperature, radar images, waves at sea, etc. Meteorological Observations, Climate Data, Lightning Data and Oceanographic Observations must have their datetime fields defined in the temporal controller first. Right click on the layer and go to Properties → Temporal. Check the box next to Temporal. If you are using Meteorological Observations, Lightning Data or Oceanographic Observations choose Single Field with Date/Time under Configuration. If you are using Climate Data pick Separate Fields for Start and End Date/Time. Pick the fields that fits the description and click on OK.
Click on this icon:
located in the top panel and define your start time and end time. Use the controller to visualize your data. To make the maps even better, use Labels and Graduated Symbology. See the two following examples, of how you can use the plugin to visualize and analyze data.
The first is an example of radar images together with meteorological observations, on a day of a heavy rainfall in Jutland.
The second is an example of a temperature map from 2016 to 2022 from the 20x20km grid cells from Climate Data.
When importing data into QGIS, try downloading it as a .csv file also. This can be used to analyze, visualize and interpret the data. Below is an example of two graphs made of data imported into Excel directly from the plugin.
