TU Delft optical disdrometer data - PAR009 at Lutjewad

<strong>Description:</strong>In-situ measurements of raindrop size distributions, fall velocities, drop number concentrations and surface rain rates recorded by a Parsivel2 optical disdrometer named "PAR009_Lutjewad" at a height of 3 meters at the Lutjewad atmospheric measurement station on the northern coast of the Netherlands, approximately 30 km northeast from the city of Groningen. Set up directly behind the Wadden Sea dike, the Lutjewad site is part of the European research infrastructure ICOS, providing continuous measurements of greenhouse and trace gas concentrations. It features a 60 meter tall sampling tower, a 10 meter platform, a laboratory building, and an aerosol laboratory container. The coastal location means that the site samples relatively clean marine background air in conditions of northerly winds and more polluted air masses during conditions of south-easterly and south-westerly winds. <br>This dataset is part of a larger collection of datasets published by the Dept. of Geoscience and Remote Sensing (GRS) at TU Delft within the framework of the Ruisdael Observatory (https://ruisdael-observatory.nl/).<br>The Parsivel2 optical disdrometer, manufactured by OTT Hydromet, is a widely used precipitation sensor which measures the size and velocity of raindrops as they pass through a horizontal laser beam. These measurements are aggregated over fixed intervals (typically 60 seconds) to produce a matrix of drop counts across 32 size and velocity classes, which is then used to approximate the raindrop size distribution (DSD) per unit volume of air. At the Ruisdael observatory, all Parsivel2 disdrometers are operated with a temporal sampling resolution of 60 seconds.<br><strong>List of variables:</strong>* latitude, longitude and altitude of measurement site* time (in UTC), both in numeric and text format* rainfall intensity* weather codes (synop 4677, synop 4680, metar 4678, NWS)* meteorological optical range in precipitation* radar reflectivity* number of hydrometeors per minute at the surface, grouped according to 32 diameter and 32 velocity classes* number concentrations of raindrop sizes (for 32 diameter classes), per unit volume of air * total number of detected hydrometeors per minute* kinetic energy of hydrometeors* laser amplitude and laser status* internal temperature of sensor<br><strong>Relevance:</strong>Optical disdrometer data are useful for studying the type, dynamics and microphysics of precipitation from the perspective of a fixed observer on the ground. The data can be used to help calibrate weather radars, improve quantitative precipitation estimates, calculate the absorption/attenuation/propagation of electromagnetic signals through the atmosphere, and quantify important physical quantities such as liquid water content, rain amount, intensity and kinetic energy.