The data set contains the off-line sampling data of medium flow aerosols from Shiquanhe national climate station (32 ° 30'n, 80 ° 05'e, altitude 4278.6 m) in Ali Region. The measuring instrument is Laoying 2030 medium flow sampler. The quartz filter membrane samples of PM2.5, PM10 and TSP with a diameter of 90 mm are collected. The samples will be used for chemical components such as elemental carbon, organic carbon, water-soluble ions and metal elements analysis. The sampling period is from July 7, 2019 to August 2, 2019, starting at 09:00 every day, with a total of 81 samples for 23 hours each time. The data is stored in Excel file.
The data set contains the scattering coefficients of PM2.5 (particles less than 2.5 μ m) at 450nm, 550nm and 700nm at Shiquanhe national climate station (32 ° 30'n, 80 ° 05'e, altitude 4278.6 m). The measuring instrument is tsi-3563 integral turbidimeter, the observation period is from July 8, 2019 to August 2, 2019, and the time resolution is 10 seconds. It can be used to study the dependence of PM2.5 scattering coefficient on the wavelength of incident light, which can reflect the particle size distribution of PM2.5.
The data set contains the scattering and absorption coefficients of PM2.5 (particles with particle size less than 2.5 μ m) in the atmosphere of Shiquanhe national reference climate station (32 ° 30'n, 80 ° 05'e, altitude 4278.6 m) in Ali Region. The measurement instrument is photoacoustic extinctiomer (pax), the observation period is from July 13, 2019 to August 2, 2019, and the time resolution is 1 minute. The data set can be used to study the scattering and absorption characteristics of PM2.5 over the Tibetan Plateau.
The data set contains the mass concentration of PM2.5 (particulate matter less than 2.5 μ m) in the atmosphere of Shiquanhe national reference climate station (32 ° 30'n, 80 ° 05'e, altitude 4278.6 m). The measuring instrument is RP 1400A vibrating balance micro balance (TEOM). The observation period is from July 8, 2019 to August 2, 2019, and the time resolution is 1 minute. The data is stored in TXT format.
The data set contains the number concentration and size distribution spectrum of particles in the atmosphere of Shiquanhe national climate station (32 ° 30'n, 80 ° 05'e, elevation 4278.6 m) in Ali Region. The instrument is tsi-3321 aerodynamic particle size spectrometer (APS), with 52 particle size channels. The observation period is from July 7, 2019 to August 2, 2019, and the time resolution is 5 minutes. The size distribution spectra of aerosol volume concentration and mass concentration can be obtained by using the data, aerosol spherical hypothesis and aerosol density, and then the characteristics of aerosol particle size distribution in the northwest of Qinghai Tibet Plateau can be studied.
The measurement data of the sun spectrophotometer can be directly used to perform inversion on the optical thickness of the non-water vapor channel, Rayleigh scattering, aerosol optical thickness, and moisture content of the atmospheric air column (using the measurement data at 936 nm of the water vapor channel). The aerosol optical property data set of the Tibetan Plateau by ground-based observations was obtained by adopting the Cimel 318 sun photometer, and both the Mt. Qomolangma and Namco stations were involved. The temporal coverage of the data is from 2009 to 2016, and the temporal resolution is one day. The sun photometer has eight observation channels from visible light to near infrared. The center wavelengths are 340, 380, 440, 500, 670, 870, 940 and 1120 nm. The field angle of the instrument is 1.2°, and the sun tracking accuracy is 0.1°. According to the direct solar radiation, the aerosol optical thickness of 6 bands can be obtained, and the estimated accuracy is 0.01 to 0.02. Finally, the AERONET unified inversion algorithm was used to obtain aerosol optical thickness, Angstrom index, particle size spectrum, single scattering albedo, phase function, birefringence index, asymmetry factor, etc.
This dataset includes the concentrations and spatial pattern of organic carbon (OC) and Elemental carbon (EC) in the carbonaceous aerosol (CA) of the Tibetan Plateau and surroundings. OC and EC were measured by Desert Research Institute Model 2001 Thermal/Optical Carbon Analyzer. The limit of detection (LOD) for OC and EC were 0.43 and 0.12 ug/cm2, respectively. In addition, MAC was also calculated for assessing the effect of EC. This dataset will provide the informations of CA contamination and background values over the Tibetan Plateau and surroundings.
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
Wildfires can strongly affect the frozen soil environment by burning surface vegetation and soil organic matter. Vegetation affected by fire can take many years to return to mature pre-fire levels. In this data set, the effects of fires on vegetation regrowth in a frozen-ground tundra environment in the Anaktuvuk River Basin on the North Slope of Alaska were studied by quantifying changes in C-band and L-band SAR backscatter data over 15 years (2002-2017). After the fire, the C- and L-band backscattering coefficients increased by 5.5 and 4.4 dB, respectively, in the severe fire area compared to the unburned area. Five years after the fire, the difference in C-band backscattering between the fire zone and the unburned zone decreased, indicating that the post-fire vegetation level had recovered to the level of the unburned zone. This long recovery time is longer than the 3-year recovery estimated from visible wavelength-based NDVI observations. In addition, after 10 years of vegetation recovery, the backscattering of the L-band in the severe fire zone remains approximately 2 dB higher than that of the unburned zone. This continued difference may be caused by an increase in surface roughness. Our analysis shows that long-term SAR backscattering data sets can quantify vegetation recovery after fire in an Arctic tundra environment and can also be used to supplement visible-wavelength observations. The temporal coverage of the backscattering data is from 2002 to 2017, with a time resolution of one month, and the data cover the Anaktuvuk River area on the North Slope of Alaska. The spatial resolution is 30~100 m, the C- and L-band data are separated, and a GeoTIFF file is stored every month. For details on the data, see SAR Backscattering Data of the Anaktuvuk River Basin on the North Slope of Alaska - Data Description.