There are two types of aerosol data in the Tibetan Plateau. Aerosol type data products are the results of aerosol type data fusion by using Meera 2 assimilation data and active satellite CALIPSO products through a series of data preprocessing, quality control, statistical analysis and comparative analysis. The key of the algorithm is to judge the CALIPSO aerosol type. According to CALIPSO aerosol types and quality control, and referring to merra 2 aerosol types, the final aerosol type data (12 kinds) and quality control results were obtained. Considering the vertical and spatial distribution of aerosols, it has high spatial resolution (0.625 ° × 0.5 °) and temporal resolution (month). Aerosol optical depth (AOD) is a visible band remote sensing inversion method developed by ourselves, combined with merra-2 model data and NASA's official product mod04. The data coverage time is from 2000 to 2019, with daily temporal resolution and spatial resolution of 0.1 degree. The retrieval method mainly uses the self-developed APRs algorithm to retrieve the aerosol optical depth over the ice and snow. The algorithm takes into account the BRDF characteristics of the ice and snow surface, and is suitable for the inversion of aerosol optical thickness on the ice and snow. The results show that the relative deviation of the data is less than 35%, which can effectively improve the coverage and accuracy of the polar AOD.
The data of aerosol optical depth were daily collected at Qomolangma Station for Atmospheric and Environmental Observation and Research with An automatic sun/sky scanning radiometer (Cimel 318), over the period from Jan. to Dec. The data were measured at 2020. 340, 380, 440, 500, 675, 870 and 1020 nm channel with uncertainty of 0.01 - 0.02.
As the “water tower of Asia”, Tibetan Plateau (TP) are the resource of major rivers in Asia. Black carbon (BC) aerosol emitted from surrounding regions can be transported to the inner TP by atmospheric circulation and consequently deposited in snow, which can significantly influence precipitation and mass balance of glaciers. Five Aethalometers are used to mornitoring black carbon concentration at 5 stations on the Tibetan Plateau. It can provide basic dataset to study the effects of BC to the environment and climate over the Tibetan Plateau, as well as the pollutants transport.
(1) Daily average of atmospheric black carbon concentration(ng/m3) at the NASDE. (2) Instruments: Aethalometer (AE33). This instrument collected data with a resolution of one minute. The abnormal data collected at the start-up or faulty stage were manually excluded before analysis further. We generated daily average based on the National Ambient Air Quality Standard of China (GB 3095-2012). (3) From May to November, 2018, a wildlife Conservation Station nearby was constructed, which frequentlyexposed largeamounts of particles, thus the BC concentration was far beyond that collected in the same season of other years. The data in this period shouldbeusedwith greatcaution. Due to problems in the instrument or electric power supply, thedata was lost in other periods. (4) The instrument was placed at the Ngari Station for Desert Environment Observation and Research (79.70° E, 33.39°N, 4270 m above sea level).
The data set is the observation of Shiquanhe town in Ali area. The altitude, longitude and latitude of Ali area are 32.50, 80.10 and 4360m respectively. The mass concentration of black carbon in the atmosphere was continuously observed. Ae31 (aethalometer) is used as the measuring instrument. Its observation period is from 12:00:00 on July 13, 2019 to 21:35:00, July 17, 2020. The time resolution is 5 minutes. There is data missing due to instrument failure. The data file includes instrument information, flow parameter setting (LPM) and specific observed concentration. Funded project: Research Fund for the second comprehensive investigation of Qinghai Tibet Plateau, 2019qzkk0602.
Black carbon(BC) is a carbonaceous aerosol that mainly emitted from the incomplete combustion of fossil fuels or biomass. As fine particles in the atmosphere with light-absorbing characteristic, BC can significantly reduce the surface albedo when deposits on snow and ice and accelerate the melting of glaciers and snow cover. New Aethalometer model AE-33 acquires the real-time BC concentration according to the light absorption and attenuation characteristics from the different wavelengths. In addition, AE-33 uses dual-spot measurements, which can compensate for the “spot loading effect” and obtain high-quality BC concentrations. By using the real-time observation data measured by AE-33 at Mt. Everest Station, we analyzed the seasonal and diurnal variations of BC and its sources and transport processes, and we also investigated the transport mechanisms of serious polluted episodes. That can provide basis for future works on assessment of climate effects caused by BC in this region.
As the "water tower" of Asia, the Qinghai Tibet Plateau provides water resources for the main rivers in Asia. BC aerosol emitted from biomass and fossil fuel combustion has a strong absorption effect on radiation, and has an important impact on the energy budget and distribution of the earth system. It is an important influence factor of climate and environmental change. The black carbon aerosols emitted from the surrounding areas of the Qinghai Tibet Plateau can be transported to the interior of the plateau through the atmospheric circulation, and settle on the surface of snow and ice, which has an important impact on precipitation and glacier mass balance. Black carbon meters were set up at five stations on the Qinghai Tibet Plateau, and aethalometer was used to measure the black carbon content in the atmosphere online. The time resolution of the data was day by day. This data is an update of the previously released "observational data of black carbon content in the atmosphere of the Qinghai Tibet Plateau (2018)". The information of the five sites is as follows: Namco: 30 ° 46'N, 90 ° 59'e, 4730 ma.s.l Mt. Everest: 28.21 ° n, 86.56 ° e, 4276 ma. S.l Southeast Tibet: 29 ° 46'N, 94 ° 44'e, 3230 ma.s.l Ali station: 33.39 ° n, 79.70 ° e, 4270 ma. S.l Mostag: 38 ° 24'n, 75 ° 02'e, 3650 ma.s.l
This data set includes PM2.5 mass concentrations (unit: μ g / m3) of atmospheric aerosol particles from South-East Tibetan plateau Station, Ngari Station, Muztagh Ata Station, Qomolangma station and Namco station. Aerosol PM2.5 fine particles refer to the particles with aerodynamic equivalent diameter less than or equal to 2.5 μ m in ambient air. It can be suspended in the air for a long time, which has an important impact on air quality and visibility. The higher its concentration in the air, the more serious the air pollution. The concentration characteristic data of PM2.5 were calculated every 5 The analysis of aerosol mass concentration in different time scales, such as hour, day and night, season and inter annual, can be achieved by obtaining a group of data frequency for output. This provides important data support for the analysis of aerosol mass concentration changes in different time scales and its influencing factors in different locations of the Qinghai Tibet Plateau, as well as the evaluation of local air quality. The data is an update of the published data set of aerosol PM2.5 concentration at different stations on the Qinghai Tibet Plateau (2018).
The dataset of ground truth measurement synchronizing with Envisat ASAR was obtained in the arid region hydrological experimental area on Sep. 19, 2007 during the pre-observation period. One scene of Envisat ASAR image was captured on Sep. 19. The data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:29 BJT. Those provide reliable ground data for remote sensing retrieval and validation of soil moisture from Envisat ASAR image. Observation items included: (1) soil moisture measured by the cutting ring method in Linze reed land, Zhangye farmland, Zhangye gobi, Linze maize land, Linze alfalfa land, Zhangye weather station, and Linze wetland. (2) GPS measured by GARMIN GPS 76 (3) vegetation measurements including the vegetation height, the green weight, the dry weight, the sampling method, and descriptions on the land type, uniformity and dry and wet conditions (4) atmospheric parameters at Daman Water Management office measured by CE318 (produced by CIMEL in France). The total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, particle size spectrum and phase function were then retrieved from these observations. The optical depth in 1020nm, 936nm, 870nm, 670nm and 440nm were all acquired by CE318. Those data include the raw data in .k7 and can be opened by ASTPWin. ReadMetext files (.txt) is attached for detail. Processed data (after retrieval of the raw data) archived as Excel files are on optical depth, rayleigh scattering, aerosol optical depth, the horizontal visibility, the near surface air temperature, the solar azimuth, zenith, solar distance correlation factors, and air column mass number. (5) roughness measured by the roughness plate together with the digital camera. The coordinates of the sample would be got with the help of ArcView; and after geometric correction, surface height standard deviation (cm) and correlation length (cm) could be acquired based on the formula listed on pages 234-236, Microwave Remote Sensing (Vol. II). The roughness data were initialized by the sample name, which was followed by the serial number, the name of the file, standard deviation and correlation length. Each text files (.txt) file is matched with one sample photo and standard deviation and correlation length represent the roughness. In addition, the length of 101 radius is also included for further checking.
The dataset of ground truth measurements synchronizing with Landsat TM was obtained in the Linze grassland and Linze station foci experimental area on Sep. 23, 2007 during the pre-observation periods, and one scene was captured well. These data can provide reliable ground data for retrieval and validation of land surface temperatures with EO-1 Hyperion remote sensing approaches. Observation items included: (1) the land surface radiative temperature by the hand-held infrared thermometer, which was calibrated; (2) GPS by GARMIN GPS 76; (3) atmospheric parameters at Daman Water Management office measured by CE318 (produced by CIMEL in France). The total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, particle size spectrum and phase function were then retrieved from these observations. The optical depth in 1020nm, 936nm, 870nm, 670nm and 440nm were all acquired by CE318. These data include the raw data in .k7 format and can be opened by ASTPWin software. ReadMe.txt is attached for detail. Processed data (after retrieval of the raw data) in Excel contain optical depth, rayleigh scattering, aerosol optical depth, the horizontal visibility, the near surface air temperature, the solar azimuth, zenith, solar distance correlation factors, and air column mass number. (4) ground-based land surface temperature measurements by the thermal imager in the Heihe gobi, west of Zhangye city.