The New Baseline Ground Radiation (NBSR) system was established in 2013 at the Global Atmospheric Monitoring Station (GAW) in the Shangdianzi (SDZ) region to observe nine broadband radiation components, namely global, direct, diffuse, and upwelling shortwave irradiance (GSWI, DSWI, DifSWI, and UpSWI); Photosynthetically active radiation (PAR); Ultraviolet irradiance (UVAI and UVBI); And sinking and upwelling longwave irradiance (DnLWI and UpLWI). In order to test 1-minute raw radiation data, this study proposes a hybrid algorithm for radiation data quality control (HARDQC) based on mature methods, combined with solar irradiance datasets and spectral characteristics of instrument bands. Subsequently, an NBSR dataset consisting of radiation data from multiple time scales (i.e. 1-minute, hourly, daily, monthly, monthly average hourly, and monthly average daily) from 2013 to 2022 was established and evaluated.
Basic meteorological elements, such as near ground temperature, air pressure, wind direction/speed, relative humidity, and visibility, are also measured at 1-minute intervals using automatic weather stations (AWS) in SDZ and stored in the HY3000 data logger. The air temperature and relative humidity are detected by the humidity and temperature probe HMP-115 installed inside the instrument protective cover. The air pressure is detected by a PTB110 barometer, and the wind speed/direction is monitored by a cup anemometer installed at the top of a 10 meter high MOF tower. The visibility measurement used a DNQ1 visibility meter installed on the MOF. The raw data of meteorological elements are carefully processed by experienced engineers according to the standards of the World Meteorological Organization to obtain high-quality meteorological datasets.
The NBSR dataset consists of five multi temporal resolution datasets, namely the 1-minute dataset (L1B), hourly dataset (L2A), daily dataset (L2B), monthly average hourly dataset (L3A), and monthly average daily dataset (L3B). Firstly, the HARDQC method is applied together with 1-minute raw data of irradiance and meteorological elements to generate the L1B dataset. The L1B dataset contains a title record and six sets of actual data. Secondly, use statistical methods to obtain the hourly dataset (L2A) from the L1B dataset. It should be noted that when calculating hourly statistical data (i.e. hourly mean, minimum value, maximum value, and standard deviation), only 1-minute radiation data with QC_flag ≤ 2 was selected, rather than the ideal QC_flag=0. This indicates a compromise between retaining as many hourly data samples as possible and ensuring that the hourly data has relatively high quality. Thirdly, the daily dataset (L2B) is derived from the L2A dataset. When the actual amount of data per hour in a day exceeds 90% of its maximum value, each day's data is calculated based on the hourly data. Finally, taking the L2A and L2B datasets as inputs, when the number of valid L2A and L2B files in a month exceeds 25, the monthly average hourly dataset (L3A) and monthly average daily dataset (L3B) can be obtained respectively.
In theory, the maximum number of 1-minute raw data for longwave radiation components is 525600 in normal years and 527040 in leap years, while the number of shortwave radiation component data is about half of the former because the shortwave radiation recorded at night is null. However, due to interference factors such as instrument malfunctions, incorrect operations, and weather events, the actual number of measurements of radiation is less than the theoretical value. Throughout the entire period, NBSR observed DnLWI almost continuously, with data quantities ranging from 480148 to 527035. However, in 2015, 2016, and 2017, UpLWI was severely lacking. In addition, effective data for PARI ranged from 132939 (2021) to 182273 (2016), and data for UVAI/UVBI ranged from 81162 (2014) to 146007/144 830 (2017). On the other hand, due to the influence of data logger error settings, UpSWI had less data in 2016 (0), 2015 (11409), and 2017 (79053), but exceeded 185666 in other years.
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CSTR:11738.11.NCDC.PANGAEA.DB6464.2024
10.1594/PANGAEA.963330