Data of Semi-Arid Climate and Environment Observatory Station of Lanzhou University (SACOL) (2019.12.09-2021.12.31)

Data Description

The PM_2.5 mass concentrations were observed by using a tapered element oscillating microbalance machine (TEOM, Model RP-1400A, Thermo Scientific, USA) with a temporal resolution of 1 minute. An aethalometer (Model AE31, Magee Scientific, USA) with a PM_2.5 inlet was used to measure the aerosol light absorption coefficients at 370, 470, 520, 590, 660, 880, and 950 nm. Aerosol scattering coefficients of PM_2.5 at 450, 550, and 700 nm wavelengths were observed by using an integrating nephelometer (Model 3563, TSI, USA) with a time resolution of 10 seconds. The micro-pulse lidar was installed approximately 50 m north of the tethered balloon observation site and used to observe atmospheric echoes within 20 km vertically and then invert parameters such as the aerosol σ and aerosol optical depth. The detailed parameters of lidar are shown in Table 1.

A tethered balloon (volume: 10 m³; payload: 8 kg) was used to carry the following equipment: (1) MA200 micro-aethalometer (Magee Scientific, USA), (2) TSI 9306 optical particle counter (OPC, TSI, USA), (3) KZXLT-II sounding system from the Institute of Atmospheric Physics, and (4) GPSMAP 639sc GPS (GARMIN, USA). Sounding observations were made at 02:00, 08:00, 11:00, 14:00, 17:00, and 20:00 each day from December 9 to 31, 2019. A total of 91 vertical profiles were obtained for each of the available absorbing aerosols, particle number concentrations, and meteorological parameters.

The MA200 measures light absorption at 5 wavelengths (375, 470, 528, 625 and 880 nm), and a dual-spot® compensation for loading effect correction is available. The MA200 observations have been converted to 550 nm in this data based on the AAE during the observation period. OPC was used to measure the particle number concentrations and particle number size distribution in the 0–10 μm size range. The temporal resolutions of MA200 and OPC were ~ 10 s, and their vertical resolutions were ~ 10 m. KZXLT-II sounding system was used to measure the vertical distribution of meteorological elements. GPS was used to measure real-time altitude.

Table 1. Main parameters of micro-pulse lidar