APCC Data Report I: Black carbon and organic carbon dataset from atmosphere, glaciers, snow cover, precipitation, and lake sediment cores over the Third Pole

The Tibetan Plateau (TP) and its surroundings, known as the Third Pole, play an important role in the regional and global climate and hydrological cycle. Carbonaceous aerosols (CAs), including black carbon (BC) and organic carbon (OC), can directly/indirectly absorb and scatter solar radiation, and change the energy balance on Earth. CAs, along with other atmospheric pollutants (e.g., mercury), can frequently be transported over long distances into the inland TP. During the last decade, a coordinated monitoring network and research program on Atmospheric Pollution and Cryospheric Change (APCC) has been gradually setup and continuously operated within the Third Pole regions to investigate the linkage between atmospheric pollutants and cryospheric change. This paper presents a systematic dataset of BC, OC, water soluble organic carbon (WSOC), and water insoluble organic carbon (WIOC) from aerosols (19 stations), glaciers (17 glaciers, including samples from surface snow/ice, snowpit, and two ice cores), snow cover (2 stations continuous observed, and 138 sites surveyed), precipitation (6 stations), and lake sediment cores (7 lakes) collected across the TP and its surroundings, as the first dataset released from this APCC program. These data were created based on online (in-situ) and laboratory measurements. High-resolution (daily scale) atmospheric equivalent BC (eBC) concentrations were obtained by using an aethalometer (AE-33) in the Mt. Everest (Qomolangma) region, which can provide a 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 TP, which were mostly influenced by emission sources, transport, and deposition processes. Several hundred years of refractory BC (rBC) records from ice cores and BC from lake sediment cores revealed the strength of human activities 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 Himalayas and TP. Mass absorption cross section 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. These files are available to download from the State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences at Lanzhou (https://doi.org/10.12072/ncdc.NIEER.db0114.2021, Kang and Zhang, 2021). In the future, datasets of mercury, heavy metals, and POPs will be reported.

Cryogenic cave carbonate and implications for thawing permafrost at Winter Wonderland Cave, Utah, USA

Winter Wonderland Cave contains perennial ice associated with two types of cryogenic cave carbonate (CCC) formed during the freezing of water. CCCfine is characterized by relatively high δ13C values, whereas CCCcoarse exhibits notably low δ18O values indicating precipitation under (semi)closed-system conditions in a pool of residual water beneath an ice lid. Previous work has concluded that CCCcoarse forms during permafrost thaw, making the presence of this precipitate a valuable indicator of past cryospheric change. Available geochronologic evidence indicates that CCC formation in this cave is a Late Holocene or contemporary process, and field observations suggest that the cave thermal regime recently changed in a manner that permits the ingress of liquid water. This is the first documented occurence of CCCcoarse in the Western Hemisphere and one of only a few locations where these minerals have been found in association with ice. Winter Wonderland Cave is a natural laboratory for studying CCC genesis.

Reframing Antarctica’s ice loss: impacts of cryospheric change on local human activity

Physical scientists, social scientists, humanities scholars, and journalists have all framed Antarctica as a place of global importance—as a laboratory for scientific research, as a strategic site for geopolitical agendas, and more recently as a source of melting ice that could catastrophically inundate populations worldwide. Yet, the changing cryosphere impacts society within Antarctica as well, and this article expands the focus of Antarctic ice research to include human activities on and around the continent. It reframes Antarctica as a place with human history and local activities that are being affected by melting ice, even if the consequences are much smaller in scale than the effects of global sea level rise. Specifically focused on tourism and conservation along the west Antarctica Peninsula (wAP), this article demonstrates the impacts of changing glaciers and sea ice on the timing, location, and type of tourism as well as the ability of changing ice to mediate human experiences through conservation agendas. As future ice conditions influence Antarctic tourism and conservation, an attention to issues emerging within the wAP region offers a new perspective on climate change impacts and the management of Antarctic activities in the 21st-century Anthropocene.

Winter Wonderland Cave, Utah, USA: A Natural Laboratory for the Study of Cryogenic Cave Carbonate and Thawing Permafrost

Winter Wonderland Cave contains perennial ice associated with two types of cryogenic cave carbonate (CCC) formed during the freezing of water. CCCfine is characterized by relatively enriched δ13C values, whereas CCCcoarse exhibits notably depleted δ18O values indicating precipitation under (semi)closed-system conditions in a pool of residual water beneath an ice lid. Previous work has concluded that CCCcoarse forms during permafrost thaw, making the presence of this precipitate a valuable indicator of past cryospheric change. Available geochronologic evidence indicates that CCC formation in this cave is a Late Holocene or contemporary process, and field observations suggest that the cave thermal regime recently changed in a manner that permits the ingress of liquid water. This is the first documented occurence of CCCcoarse in the Western Hemisphere and one of only a few locations where these minerals have been found in association with ice. Winter Wonderland Cave is a natural laboratory for studying CCC genesis.

Fostering multidisciplinary research on interactions between chemistry, biology, and physics within the coupled cryosphere-atmosphere system

The cryosphere, which comprises a large portion of Earth’s surface, is rapidly changing as a consequence of global climate change. Ice, snow, and frozen ground in the polar and alpine regions of the planet are known to directly impact atmospheric composition, which for example is observed in the large influence of ice and snow on polar boundary layer chemistry. Atmospheric inputs to the cryosphere, including aerosols, nutrients, and contaminants, are also changing in the anthropocene thus driving cryosphere-atmosphere feedbacks whose understanding is crucial for understanding future climate. Here, we present the Cryosphere and ATmospheric Chemistry initiative (CATCH) which is focused on developing new multidisciplinary research approaches studying interactions of chemistry, biology, and physics within the coupled cryosphere – atmosphere system and their sensitivity to environmental change. We identify four key science areas: (1) micro-scale processes in snow and ice, (2) the coupled cryosphere-atmosphere system, (3) cryospheric change and feedbacks, and (4) improved decisions and stakeholder engagement. To pursue these goals CATCH will foster an international, multidisciplinary research community, shed light on new research needs, support the acquisition of new knowledge, train the next generation of leading scientists, and establish interactions between the science community and society.

Vegetation phenology in Greenland and links to cryospheric change

ABSTRACTRecent greening of vegetation across the Arctic is associated with warming temperatures, hydrologic change and shorter snow-covered periods. Here we investigated trends for a subset of arctic vegetation on the island of Greenland. Vegetation in Greenland is unique due to its close proximity to the Greenland Ice Sheet and its proportionally large connection to the Greenlandic population through the hunting of grazing animals. The aim of this study was to determine whether or not longer snow-free periods (SFPs) were causing Greenlandic vegetation to dry out and become less productive. If vegetation was drying out, a subsequent aim of the study was to determine how widespread the drying was across Greenland. We utilized a 15-year time-series obtained by the MODerate Resolution Imaging Spectroradiometer (MODIS) to analyze the Greenland vegetation by deriving descriptors corresponding with the SFP, the number of cumulative growing degree-days and the time-integrated Normalized Difference Vegetation Index. While the productivity of most vegetated areas increased in response to longer growing periods, there were localized regions that exhibited signs consistent with the drying hypothesis. In these areas, vegetation productivity decreased in response to longer SFPs and more accumulated growing degree-days.