The ceilometer CL51 employs a pulsed diode laser LIDAR technology, where short, powerful laser pulses are sent out in a vertical or near-vertical direction. The reflection of light (backscatter) caused by clouds, precipitation or other obscuration is analysed and used to determine the cloud base height, the cloud layer height and the amount of clouds (in octas) in different layers.

Hail products are derived from the observed vertical profiles of radar reflectivity and the NWP vertical profiles of temperature. Three types of products are generated. poh : probability of hail of any size (larger than 0.5 cm diameter)expressed in %. posh : probability of severe hail(larger than 2cm)expressed in %. mesh : maximum expected size of hailexpressed in mm of hailstone diameter. All products are generated every 5 minutes. This product is not publically available yet.

A climate normal is an average over a 30-years period. The period 1981-2010 is the current reference period recommended by the World Meteorological Organization (WMO). Recent climate normals are available for any locations in Belgium and several parameters including air temperature, precipitations and solar radiation. Climate normals for the reference period 1981-2010 are available for air temperature, precipitation and derived parameters (e.g., annual number of summer days, annual number of precipitation days, etc.). For solar radiation, the reference period had to be adjusted to 1984-2013 because of data availability. These climate normals are available as maps and as table for each Belgian municipality.

The DTM 1m, digital terrain model at 1m-resolution, is a homogeneous and regular point grid indicating the height of the ground level in order to model its surface, without taking into account objects on the surface such as buildings and vegetation. DTM 1m is achieved by interpolating in Lambert 2008 source data in Lambert 72 and at a 1m-resolution from the Flemish (2013-2015) and Brussels (2021) Regions, and by adding Lambert 2008 data at 1m-resolution from the Walloon Region (2021-2022).

Points Of Interest - patrimonial elements contains point elements relating to the patrimony, namely (water and wind)mill, (historic, commemoration, fortified) building, historic mound, ice house, castle, kiosk, shoring, non-religious monument, monumental stairs in Belgium.

Summer and winter maximum daily precipitation given in mm/day that occur once in a year and once in 5, 10, 15 and 30 years (i.e. return periods of 1 year and 5, 10, 15, 30 years). The precipitation extremes are available for the future target year 2085, which corresponds to the middle of the 30-year period 2071-2100, and for mean and high impact scenarios corresponding respectively to the 50th and 95th percentiles of the change factors.

Total lightning observations, i.e., cloud-to-ground (CG) strokes and intra/inter-cloud (IC) pulses, in Belgium. BELLS data is given in Universal Time! (local time winter = UT +1; local time summer = UT + 2). Each record contains following fields: 1. Network type, 0 = LF, 1 = VHF-TOA, 2 = VHF-ITF, 3 = VLF 2. Year, 1970 to 2032. 3. Month, with January as 1 and December as 12. 4. Day of the month, 1 to 31. 5. Hour, 0 to 23. 6. Minute, 0 to 59. 7. Second, 0 to 60. 8. Nanosecond, 0 to 999999999. 9. Latitude of the calculated location in decimal degrees, to 4 decimal places, -90.0 to 90.0. 10. Longitude of the calculated location in decimal degrees, to 4 decimal places, -180.0 to 180.0. 11. Altitude in meters, -4950 to +60535. This field will be 0 if the altitude is not provided in the lightning data. 12. The altitude uncertainty in meters. This field will be 0 if the altitude uncertainty is not provided in the lightning data. 13. Estimated peak current in kiloamps, -9999 to 9999. 14. VHF Range normalized power, -9999.0 to 9999.0 15. Multiplicity for flash data (1 to 99) or 0 for strokes. 16. Cloud pulse count for the lightning record. This field will be -1 if the lightning did not contain the cloud pulse count attribute. 17. Number of sensors participating in the solution, 2 to 99. 18. Degrees of freedom when optimizing location, 0 to 99. 19. The error ellipse angle as a clockwise bearing from 0 degrees north, 0 to 180.0 degrees 20. The error ellipse semi-major axis length in kilometers, 0 to 50.0km. 21. The error ellipse semi-minor axis length in kilometers, 0 to 50.0km. 22. Chi-squared value from location optimization, 0 to 999.99 23. Rise time of the waveform in microseconds, 0 to 99.9 24. Peak-to-zero time of the waveform in microseconds, 0 to 999.9 25. Maximum rate-of-rise of the waveform in kA/usec (will be a negative rate if discharge is negative), -999.9 to 999.9 26. Cloud indicator, 1 if Cloud-to-cloud discharge, 0 for Cloud-to-ground 27. Angle indicator, 1 if sensor angle data used to compute position, 0 otherwise 28. Signal indicator, 1 if sensor signal data used to compute position, 0 otherwise 29. Timing indicator, 1 if sensor timing data used to compute position, 0 otherwise 30. Flash ID, a unique integer value identifying the flash grouping a stroke belongs to or 0 if not set. This product is not publically available yet.

RADQPE provides high resolution radar-based quantitative precipitation estimation in realtime for Belgium and its surroundings. This product is not publically available yet.

This dataset is part of the 2018 Belgian submission for the Marine Strategy Framework Directive (MSFD) linked to descriptor 5, criterion 1. This dataset contains the nutrient concentrations (ammonia, nitrate, nitrite, total nitrogen, phosphorus) measured on water samples taken in the BPNS between 2011 and 2016. The analysis of nutrients (N and P) is ensured by the national monitoring programme at ten sampling locations that are representative for the surrounding water masses. Based on all 2011-2016 results, the relationship with the salt content was calculated and, for each year, the value derived corresponding to a salt content of 33.5. The surface of the area where the nutrient concentrations exceed the respective thresholds was calculated on the basis of the relationship with the winter salt content and a climatology of the spatial distribution of the salt content (see annex D5 of the Belgian MSFD report). The resulting maps give a good overview of nutrient concentrations in the Belgian zone. In order to take into account the coastal-sea gradient and to illustrate the temporal trends in detail, the concentrations were also evaluated in three different areas of the BPNS: the coastal zone, the territorial zone and the open-sea zone. The long-term trends of nutrient concentrations in the three zones were assessed statistically.

The reference list in Belgium for the unique abbreviations of all Belgian cities and municipalities. It also includes the submunicipalities, which do not have a clear definition.