PAR008 Optical disdrometer data at Lutjewad

<strong>Description:</strong> In-situ measurements of raindrop size distributions, fall velocities, drop number concentrations and surface rain rates recorded by an OTT Parsivel2 disdrometer named "PAR008" 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. The rural landscape to the south consists mainly of pasture and cropland with patches of forested land with livestock dominated by dairy cows and sheep. Set up directly behind the Wadden Sea dike, the site features a 60 meter tall sampling tower, a 10 meter platform, a laboratory building, and an aerosol laboratory container. The station monitors greenhouse gases and trace gas species, sampling aerosol number, size, and composition at different altitudes. Lutjewad is part of the European research infrastructure ICOS, providing continuous greenhouse gas concentrations. 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><strong>Format:</strong> Each NetCDF file covers a full month of observations. The temporal resolution is 1 minute. Data are provided "as is", without any post-processing. The NetCDF files contain all relevant information about all the variables, attributes and units. The global attributes of the NetCDF files contain important information about the type of sensor, logging software, project contributors and history of the dataset. If a monthly file is missing, no data are available for this month.<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.<br><strong>Note:</strong> On April 7, 2022, PAR008 was blown over by the wind during a big storm. The concrete ballast at the base of the 3 meter pole was not heavy enough to sustain the high winds and the sensor fell to the ground and got damaged in the process. On June 3, 2022, another Parsivel disdrometer named "PAR009_Lutjewad" was installed on the same site to replace the broken sensor.

<strong>描述：</strong>本数据集包含荷兰北部海岸吕特耶瓦德（Lutjewad）大气观测站的原位观测数据，观测变量涵盖雨滴尺寸分布、下落速度、雨滴数浓度及地面降雨率，由编号为“PAR008”的OTT Parsivel2型雨滴谱仪在3米高度处采集。该观测站距离格罗宁根市东北约30公里，紧邻瓦登海海堤后方；其南侧为乡村景观，以牧场与农田为主，夹杂小片林地，当地畜禽养殖以奶牛和绵羊为主。观测场配套60米高采样塔、10米高观测平台、实验室大楼及气溶胶实验室集装箱。该站同时开展温室气体与痕量气体监测，在不同海拔高度采样气溶胶的数量、粒径与组成。吕特耶瓦德观测站是欧洲综合碳观测系统（Integrated Carbon Observation System，ICOS）的组成部分，可提供连续的温室气体浓度监测数据。由于地处沿海区域，当风向为北风时，站点采集的是相对清洁的海洋背景大气；而当风向为东南风或西南风时，则会采集到污染程度更高的气团。
<strong>格式：</strong>每个NetCDF文件覆盖一整月的观测数据，时间分辨率为1分钟。数据按原样提供，未经过任何后处理。NetCDF文件包含所有相关变量、属性与单位的完整信息。NetCDF文件的全局属性中存储了传感器类型、记录软件、项目贡献者及数据集历史等重要元数据。若某一月份的NetCDF文件缺失，则代表该月无可用观测数据。
<strong>应用价值：</strong>光学雨滴谱仪数据可用于从地面固定观测者的视角研究降水的类型、动力学特征与微物理过程。该数据可用于辅助校准天气雷达、改进定量降水估测算法、计算电磁信号在大气中的吸收/衰减/传播特性，以及量化液态水含量、降雨量、降雨强度与动能等重要物理量。
<strong>备注：</strong>2022年4月7日，编号为PAR008的传感器在强风暴中被风吹倒。由于3米高立杆底部的混凝土压舱物配重不足，该传感器坠地并受损。2022年6月3日，另一台编号为“PAR009_Lutjewad”的Parsivel型雨滴谱仪被安装至同一观测站点，以替换损坏的传感器。