兰州大学寒旱区科学观测网络CARN（敦煌站气象要素梯度观测系统-2019）

该数据集包含了2019年1月1日至2019年12月31日兰州大学兰州大学寒旱区科学观测网络敦煌站气象要素梯度观测系统数据。站点位于甘肃敦煌西湖，下垫面是湿地。观测点的经纬度是93.709E，40.348N，海拔993m。二维超声风速/风向传感器和空气温湿度传感器分别架设在4m、8m处，朝向正北；气压计安装在1m采集箱内；翻斗式雨量计安装在塔4m处；红外温度计安装在4m处，朝向正南，探头朝向垂直向下；土壤热通量板（自校正式）（2块）依次埋设在塔南侧植被下5cm和10cm处；土壤温/湿/电导率传感器和土壤水势传感器埋设在塔南侧植被下5cm和20cm处；光合有效辐射传感器、日照时数传感器以及四分量辐射仪安装在4m处，朝向正南。 观测项目有：风速（WS_4m、WS_8m）(单位：米/秒)、风向（WD_4m、WD_8m）(单位：度)、空气温湿度（Ta_4m、Ta_8m和RH_2m、RH_4m、RH_8m）(单位：摄氏度、百分比)、气压（PA）(单位：百帕)、降水量（P）(单位：毫米)、四分量辐射（SWIN、SWOUT、LWIN、LWOUT、Rn）(单位：瓦/平方米)、地表辐射温度（TC）(单位：摄氏度)、土壤热通量（SHF）(单位：瓦/平方米)、土壤水分（SWC）(单位：百分比)、土壤温度（Ts）(单位：摄氏度) 、土壤水势（SWP）（单位：千帕）、土壤电导率（EC）（单位：微西门子/厘米）光合有效辐射（PPFD）(单位：微摩尔/平方米秒)、日照时数（Sun_time）（单位：小时）。 观测数据的处理与质量控制：（1）确保每天48个数据（每30min）；由于程序故障，空气湿度采集错误；（2）剔除有重复记录的时刻；（3）删除了明显超出物理意义或超出仪器量程的数据；（4）数据中以红字标示的部分为有疑问的数据；（5）日期和时间的格式统一，并且日期、时间在同一列。如，时间为：2019-06-10 10:30。

This dataset contains meteorological element gradient observation system data from the Dunhuang Station of the Cold and Arid Regions Science Observation Network of Lanzhou University, spanning from January 1, 2019 to December 31, 2019. The station is located in Dunhuang West Lake, Gansu Province, with a wetland underlying surface. The coordinates of the observation site are 93.709°E, 40.348°N, and the elevation is 993 m. Two-dimensional ultrasonic wind speed/direction sensors and air temperature and humidity sensors are installed at 4 m and 8 m respectively, facing due north. A barometer is installed inside the 1 m-height data acquisition cabinet. A tipping bucket rain gauge is installed at 4 m on the tower. An infrared thermometer is installed at 4 m, facing due south with the probe facing vertically downward. Two self-calibrating soil heat flux plates are sequentially buried at 5 cm and 10 cm below vegetation on the south side of the tower. Soil temperature, moisture, and electrical conductivity sensors and soil water potential sensors are buried at 5 cm and 20 cm below vegetation on the south side of the tower. Photosynthetically active radiation sensors, sunshine duration sensors, and four-component radiometers are installed at 4 m, facing due south.

Observation items include: wind speed (WS_4m, WS_8m) (unit: meters per second), wind direction (WD_4m, WD_8m) (unit: degrees), air temperature and humidity (Ta_4m, Ta_8m, RH_2m, RH_4m, RH_8m) (units: degrees Celsius, percentage), atmospheric pressure (PA) (unit: hectopascals), precipitation (P) (unit: millimeters), four-component radiation (SWIN, SWOUT, LWIN, LWOUT, Rn) (unit: watts per square meter), surface radiation temperature (TC) (unit: degrees Celsius), soil heat flux (SHF) (unit: watts per square meter), soil moisture (SWC) (unit: percentage), soil temperature (Ts) (unit: degrees Celsius), soil water potential (SWP) (unit: kilopascals), soil electrical conductivity (EC) (unit: microSiemens per centimeter), photosynthetically active radiation (PPFD) (unit: micromoles per square meter per second), and sunshine duration (Sun_time) (unit: hours).

Data processing and quality control: (1) Ensure 48 daily records (one per 30 minutes); air humidity collection errors occurred due to program failures; (2) Remove records with duplicate timestamps; (3) Delete data that obviously exceeds physical limits or instrument measurement ranges; (4) Parts marked in red in the dataset indicate questionable data; (5) Unify the date and time formats, with date and time in the same column. For example, the time format is: 2019-06-10 10:30.