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Datasets and protocols for including anomalous freshwater from melting ice sheets in climate simulations [Development and technical paper]
Get PDFAnomalous freshwater fluxes from the Greenland and Antarctic ice sheets and ice shelves are impacting the surrounding oceans, and we need to be able to account for these effects in climate model simulations over the historical period and in future projections. In previous phases of the Coupled Model Intercomparison Project (CMIP), models mostly either assumed that the ice sheets were in mass balance, or that discharge from the ice sheets was constant, but in neither case was the observed increasing discharge over the historical period properly represented. In this paper, we present data products of absolute and anomalous freshwater mass fluxes from both major ice sheets, and recommendations for their use in historical simulations. These fluxes can be implemented in climate simulations as a forcing for models that do not (yet) include interactive ice sheets, or used to evaluate models that do. We also make recommendations for how climatological and anomalous fluxes can be implemented in climate models that may have different approaches to interactions with the ice sheets. These forcings are available for CMIP7 simulations and should lead to more robust and coherent simulation of sea surface temperature, sea ice and regional sea level trends in the recent historical period and, as these data are extended, improve the credibility of projections
Breeding bird species richness and sensitivity to disturbance at Antarctic visitor sites
Get PDFTourism in Antarctica is increasing rapidly and is concentrated predominantly in ice-free areas in the Antarctic
Peninsula region, an area that holds globally important colonies of breeding birds. Since 2005, the Antarctic
Treaty Consultative Meeting (ATCM), which provides governance for the continent, has developed Visitor Site
Guidelines that detail practical information for visitor management. In parallel, the ATCM has worked to develop
methods to assess site sensitivity to inform visitor site management, but none have been formally agreed. With
the expansion of tourism operations, there is an urgent need for site-specific information to enable policymakers
to minimize disturbance at visitor sites, particularly to breeding seabirds. Responding to this need, we assessed
the sensitivity of bird species known to breed at each landing site with ATCM Visitor Site Guidelines. We collated
available data on breeding cycles for each site, identifying the most sensitive periods for individual bird species.
The information was combined to determine species richness and the periods of heightened sensitivity to
disturbance overall and for each visitor site. Our data showed that the most sensitive bird breeding stages
overlapped with the summer peak in tourist landings at visitor sites. We recommend that these site-specific data
be used to refine tourism management by the ATCM, including revision of existing and development of new
Visitor Site Guidelines. Future studies could help improve sensitivity assessment by collecting data on distribution and numbers of breeding birds and hauled-out seals within visited areas, and carrying out cross-species
comparisons of effects of disturbance
Advances and challenges in modelling the environmental fate and exposure of pharmaceuticals: a comprehensive review
No full textPharmaceutical contamination in the environment poses a global concern, raising questions about potential implications for both ecology and human health. Unravelling the fate and exposure of these contaminants is crucial, as it depends on various factors, including their physicochemical properties, metabolic pathways, breakdown processes ( e.g. , oxidation and hydrolysis), and environmental conditions. Applying model-based approaches to assess the fate and exposure of pharmaceuticals is essential for evaluating their potential risks and impacts on the environment and public health. This paper reviews the state-of-the-art models used to predict the environmental fate and exposure of pharmaceuticals, focusing on sources, theoretical frameworks, comparative analyses of existing models, and factors such as polarity, metabolism, and breakdown processes. Additionally, the paper identifies current challenges and outlines future directions in this field
Spatial and temporal variation in wave overtopping across a coastal structure based on one year of field observations
Get PDFCoastal managers worldwide must prepare for changes in annual wave overtopping events due to climate change and sea-level rise. Research often assesses overtopping discharges by extreme events at a sea wall crest, typically using data from physical models or empirical rules based on scaled experiments. Here, we analyse a unique 1-year field dataset of coastal wave overtopping, from SW England, to determine the number of individual waves, regardless of their size, overtopping two locations across a coastal structure. The coastal conditions causing the most frequent overtopping differ from those driving it landward, complicating hazard communications for multiuse infrastructure. These data are the first field observations covering a year of tide, wave and wind conditions that cause overtopping of a vertical sea wall. Storms have a minimal (<2%) contribution to the number of tides associated with overtopping and the prevailing wave direction was not that associated with most overtopping events. Overtopping histograms identify the variability in the most likely time of overtopping relative to high tide for different wave categories across the structure. Sea-level rise, beach lowering and climate change will influence the annual number of waves overtopping in future. Change will be a complex balance between overtopping by different wave categories due to their likelihood of coincidence with water levels that do not cause depth-limitation over the foreshore or (partial-)reflection off the structure. It is possible the number of waves overtopping will reduce at the crest of a sea wall, while more of those overtopping waves will travel further inland
Identifying biodiversity hotspots over time: stability, sampling bias, and conservation implications
Get PDFThe conservation of biodiversity is a major challenge facing society. In order to design effective conservation strategies, we must be able to identify the areas in which biodiversity is concentrated (i.e., biodiversity hotspots). However, observed patterns of species richness are often heavily biased by sampling effort, undermining the reliability of hotspot detection. Therefore, it is important to understand how the location of identified hotspots varies over time as knowledge about the identity and distribution of species increases. Using what is likely the most comprehensive insect database in the world (the butterflies of Great Britain), we examine the survey effort achieved over time, estimating the degree of congruence in the identification of butterfly biodiversity hotspots at different time intervals. This congruence is low over much of the 215-year period studied, remaining so for hotspots based on a rarity metric even after 1980, when the inventories were already relatively complete. The location of hotspots based on species richness has been more stable in recent decades, reflecting one the more complete sampling coverage in these years. These results highlight the risk of misidentifying biodiversity hotspots based on inadequate data and point to the need for greater sampling effort for insects to improve inventories before identifying and proposing areas for conservation. This study has significant implications for biodiversity conservation, as it provides insights into the usefulness of identifying priority areas based on incomplete inventories, such as those we currently have worldwide
Mapping potential water repellency of Danish topsoil
Get PDFSoil water repellency (SWR) is a natural process and affects water dynamics from nano to ecosystem scales. However, the spatial distribution of SWR at the ecosystem scale, as well as the underlying drivers across diverse habitats, land uses and soil textures, remain underexplored. This study presents a comprehensive survey of SWR in Denmark and its predicted spatial distribution, using approximately 7,500 samples. We used digital soil mapping methods (Quantile Random Forest model) to map and identify the relationship between SWR and various environmental variables, including vegetation (via satellite imagery), soil properties (texture and soil organic carbon), and landforms (slope and wetness index). The predicted maps at 10 m resolution revealed that SWR varies across different land uses and vegetation types, with higher values in areas of natural vegetation (e.g., heathlands and coniferous forests) compared to grasslands and croplands (mostly hydrophilic). The analysis also identified soil organic carbon, Sentinel band 3 (Green band − Chlorophyll absorption) and soil texture as key drivers of spatial variation in SWR at the national extent. We found that soil texture influences SWR intensity, which generally decreases as clay content increases across most land use types, except for heathlands. While the predicted maps provided valuable insights into SWR distribution and its environmental drivers, further research is needed to explore the spatio-temporal dynamics of SWR within each habitat, particularly in relation to soil moisture changes. This study highlights the potential of combining machine learning and remote sensing to provide crucial spatial information for managing water resources and enhancing ecosystem resilience in the face of climate change
Tracing the biogeographic history of the world's most isolated insular floras
Get PDFInferring general biogeographic patterns in the sub-Antarctic region has been challenging due to the disparate geological origins of its islands and archipelagos—ranging from Gondwanan fragments to uplifted seafloor and more recently formed volcanic islands—and the remoteness of these island systems, spread around the austral continental landmasses. Here, we conduct phylogenetic reconstruction, divergence time estimation, and Bayesian Island Biogeographic analyses to reconstruct the spatio–temporal colonization histories of seven vascular plant lineages, which are either widespread across the sub-Antarctic region (Acaena magellanica, Austroblechnum penna-marina, Azorella selago, Notogrammitis crassior) or restricted to an extremely remote sub-Antarctic province (Colobanthus kerguelensis, Polystichum marionense, Pringlea antiscorbutica). Our results reveal high biological connectivity within the sub-Antarctic region, with southern landmasses (Australia, New Zealand, South America) as key sources of sub-Antarctic plant diversity since the Miocene, supporting long-distance dispersal as the primary colonization mechanism rather than tectonic vicariance. Despite the geographic isolation of the sub-Antarctic islands, eastward and westward colonization events have maintained this connectivity, likely facilitated by eastward-moving marine and wind currents, short-term weather systems, and/or dispersal by birds. Divergence time estimates indicate that most species diverged within the Plio–Pleistocene, with crown ages predating the Last Glacial Maximum, suggesting that sub-Antarctic archipelagos acted as refuges for biodiversity. Our findings highlight the role of one of the most remote sub-Antarctic archipelagos as both a refugium and a source of (re)colonization for continental regions. These results underscore the urgent need for establishing priority conservation plans in the sub-Antarctic, particularly in the face of climate change
A new versatile dropsonde for atmospheric soundings – the KITsonde
Get PDFA new modular multi-sensor aerological dropsonde system for high and fast-flying research aircraft has been developed for studying atmospheric processes. This new system allows us to drop release containers with up to four sondes inside, and data from up to 30 sondes can be transmitted simultaneously. After separation from the release container, the sondes enable high-resolution spatio-temporal profiling of temperature, humidity, and pressure with a time resolution of 1.12 s and wind of 1 s, corresponding to approximately 10 m vertical resolution. The modular design ensures simple integration of additional sensors without extensive flight tests and recertification for e.g. particle measurements and radioactivity.
The standard meteorological sonde comprises sensor elements of a commercial Graw DFM-17 radiosonde, a 400 to 406 MHz band communication link to the aircraft, and an optional satellite communication module. By means of the satellite link, the data can be made available worldwide in near-real time, and data loss is avoided when the dropping aircraft leaves the telemetry range.
The main feature of the new system is the release container, which allows for dropping through standard dropsonde dispensers of both mid-size turbo-prop aircraft (e.g. Dornier Do 128-6) and jet aircraft (e.g. the Gulfstream 550 “High Altitude and Long Range Research Aircraft” HALO). The release container ensures safe separation from the aircraft and protects its payload during deceleration from aircraft speed to fall speed before the sondes are released by an electro-mechanical mechanism. Operations in different campaigns have confirmed the reliability of the entire system and the quality of acquired data. Feasibility of the technical and operational approach for targeted observations of a mesoscale convective system in Argentina was demonstrated by HALO measurements during the SouthTRAC (TRAnsport and Composition of the southern hemisphere UTLS (upper troposphere–lower stratosphere) campaign) campaign. Moreover, a configuration consisting of a meteorological sonde coupled with an optical counter for particle sizing was tested during a Saharan dust episode over Germany using a Dornier Do 128-6 aircraft. Secondly, a meteorological sonde together with a radioactivity sensor was successfully dropped from a Learjet 35A
Moisture Source Controls on Water Isotopes in Antarctic Precipitation—Insights From Water Tracers in ECHAM6-Wiso
Get PDFThe interpretation of water isotope records in Antarctic ice cores is crucial for our understandingof past climate changes. Here we use novel water tracers in an ECHAM6‐wiso simulation to investigatemoisture source controls on deuterium excess in Antarctic precipitation, particularly the logarithmic variant dln.The simulation captures the amplitude of seasonal changes in observed δD and dln of precipitation. There are,however, some model biases that cannot be resolved through adjustments to kinetic fractionation parameters orthe model resolution. These may reflect issues in the hydrological cycle representation or the representation ofisotope processes. The simulated dln in Antarctic precipitation reliably reflects moisture source sea surfacetemperature (SST): dln shows a higher correlation than traditionally defined deuterium excess. Ocean surfacerelative humidity with respect to SST (RHsst) influences dln during evaporation, however, this influenceweakens above the ocean surface. 79% of the variance in dln of annual precipitation at Dome C is due to changesin moisture source SST. dln is more sensitive to source SST in inland Antarctica than in coastal regions, makingit a robust proxy for reconstructing past SST at the inland ice core sites. The explained variance of dln by sourceSST for daily precipitation at Dome C is lower at 28%, which increases to 59% after excluding very lowprecipitation days (<0.02 mm). Finally, we find reversed relationships between source SST and dln in the vaporabove the Southern Ocean, potentially driven by cold air outbreaks or precipitation processes
Daily turnover of airborne bacterial communities in the sub-Antarctic
Get PDFColonization of remote ecosystems by new microorganisms poses a significant threat to the diversity and function of native microbial communities. In the polar regions, including Antarctica, airborne microbial communities are shaped by environmental and climatic factors, which are changing rapidly. However, the specific drivers of microbial community composition and diversity in these regions remain poorly understood. This study explores the daily dynamics of airborne bacterial communities over South Georgia, a large and remote sub-Antarctic Island, and evaluates the influence of environmental factors, local microbiomes, and sampling methodology. Over two weeks, near-surface air samples were collected from coastal and higher-altitude (200 m a.s.l) sites using different air samplers. The Coriolis Compact sampler, run for longer durations, captured higher diversity, while the Coriolis Micro provided high-quality snapshots during shorter sampling windows. Results showed rapid daily turnover in community composition (up to 90%) alongside a stable core microbiome (10–20%). Coastal microbial communities were shaped by local microbiomes, especially wildlife-associated taxa, whereas high-altitude communities were more variable, suggesting influence from long-range microbial dispersal. Environmental factors, including wind direction, temperature, and rainfall, also significantly shaped community structure. These findings highlight the dynamic nature of airborne microbiomes in the sub-Antarctic
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