Black carbon and organic carbon dataset over the Third Pole

The Tibetan Plateau and its surroundings, also known as the Third Pole, play an important role in the global and regional climate and hydrological cycle. Carbonaceous aerosols (CAs), including black carbon (BC) and organic carbon (OC), can directly or indirectly absorb and scatter solar radiation and change the energy balance on the Earth. CAs, along with the other atmospheric pollutants (e.g., mercury), can be frequently transported over long distances into the inland Tibetan Plateau. During the last decades, a coordinated monitoring network and research program named “Atmospheric Pollution and Cryospheric Changes” (APCC) has been gradually set up and continuously operated within the Third Pole regions to investigate the linkage between atmospheric pollutants and cryospheric changes. This paper presents a systematic dataset of BC, OC, water-soluble organic carbon (WSOC), and water-insoluble organic carbon (WIOC) from aerosols (20 stations), glaciers (17 glaciers, including samples from surface snow and ice, snow pits, and 2 ice cores), snow cover (2 stations continuously observed and 138 locations surveyed once), precipitation (6 stations), and lake sediment cores (7 lakes) collected across the Third Pole, based on the APCC program. These data were created based on online (in situ) and laboratory measurements. High-resolution (daily scale) atmospheric-equivalent BC concentrations were obtained by using an Aethalometer (AE-33) in the Mt. Everest (Qomolangma) region, which can provide new insight into the mechanism of BC transportation over the Himalayas. Spatial distributions of BC, OC, WSOC, and WIOC from aerosols, glaciers, snow cover, and precipitation indicated different features among the different regions of the Third Pole, which were mostly influenced by emission sources, transport pathways, and deposition processes. Historical records of BC from ice cores and lake sediment cores revealed the strength of the impacts of human activity since the Industrial Revolution. BC isotopes from glaciers and aerosols identified the relative contributions of biomass and fossil fuel combustion to BC deposition on the Third Pole. Mass absorption cross sections of BC and WSOC from aerosol, glaciers, snow cover, and precipitation samples were also provided. This updated dataset is released to the scientific communities focusing on atmospheric science, cryospheric science, hydrology, climatology, and environmental science. The related datasets are presented in the form of excel files. BC and OC datasets over the Third Pole are available to download from the National Cryosphere Desert Data Center (10.12072/ncdc.NIEER.db0114.2021; Kang and Zhang, 2021)

The impacts of temperature averages, variabilities and extremes on China’s winter wheat yield and its changing rate

China is the world’s largest producer and consumer of wheat. The impact of temperature averages, variabilities, and extremes on winter wheat yield changes is still not very clear. The annual production data for winter wheat in China’s provinces and municipalities and NCEP-NCAR Reanalysis-1 data were used from November to April in the period 1949–2018, to investigate the impact of temperature-related variables, such as the winter average temperature ( $\overline{{{\rm{T}}}_{2{\rm{m}}}}$ ), winter variance of temperature ( ${{\rm{T}}}_{2{\rm{m}}\_{\rm{var}}}$ ), extreme hot days (EHD), and extreme cold days (ECD), on China’s winter wheat yield. Ensemble Empirical Mode Decomposition (EEMD) analysis showed that winter wheat yield has an in-phase relationship with average temperature but an out-of-phase relationship with variance of temperature, extreme hot days, and extreme cold days on timescales greater than 20 years. The changing rates of winter wheat yield and temperature-related variables were well measured by their sliding trends. At the overwintering growth stage, the increasing rate of average temperature and extreme hot days (temperature variance and extreme cold days) exhibit negative (positive) correlations with the rate of winter wheat yield change, with the strongest correlation observed in southeast China. During the tillering growth stage, the changing rates of average temperature exhibited a positive correlation with the rate of winter wheat yield change, whereas negative associations were observed with temperature variance, extreme hot days, and extreme cold days. Among the regions, Central China showed the weakest correlations. At the reviving growth stage, however, the relationship of changing rates of temperature-related variables with that of winter wheat yield was much weaker. These observational results are important and can be used as a reference in climate models for improving the climatic impacts on the winter wheat yield