Lake Vanda is a perennially ice-covered, meromictic, endorheic lake located in the McMurdo Dry Valleys of Antarctica, and an exceptional sentinel of climate change within the region. Lake levels rose 15 m over the past 68 years in response to climate-driven variability in ice-cover sublimation, meltwater production, and annual discharge of the Onyx River, the main source of water to the lake. Evidence from a new bathymetric map and water balance model combined with annual growth laminations in benthic mats suggest that the most recent filling trend began abruptly 80 years ago, in the early 1930's. This change increased lake volume by >50%, triggered the formation of a new, upper, thermohaline convection cell, and cooled the lower convection cell cooled by at least 2°C and the bottom-most waters by at >4°C. Additionally, the depth of the deep chlorophyll a maximum rose by >2 m, and deep-growing benthic algal mats declined while shallow benthic mats colonized freshly inundated areas. We attribute changes in hydrology to regional variations in air flow related to the strength and position of the Amundsen Sea Low (ASL) pressure system which have increased the frequency of down-valley, föhn winds associated with surface air temperature warming in the McMurdo Dry Valleys. The ASL has also been implicated in the recent warming of the Antarctic Peninsula, and provides a common link for climate-related change on opposite sides of the continent. If this trend persists, Lake Vanda should continue to rise and cool over the next 200 years until a new equilibrium lake level is achieved. Most likely, future lake rise will lead to isothermal conditions not conducive to thermohaline convection, resulting in a drastically different physical, biogeochemical, and biological structure than observed today.3

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Analysis and synthesis of large and complex datasets are increasingly important components of scientific research. To expose undergraduate students to these datasets and to develop valuable data analysis skills, a team of environmental scientists and education researchers created Project EDDIE (Environmental Data-Driven Inquiry and Exploration). Project EDDIE is a pedagogical collaborative that develops and assesses flexible modules that use publicly-available, large datasets that allow students to explore a range of concepts in the biological, earth, and environmental sciences. Modules have been implemented in a range of courses, class sizes, and institutions. We assessed six modules over eight courses, which were taught to total of 1,380 students. EDDIE modules led to significant improvements in students' competence using spreadsheet software and as well as their conceptual understanding of how to use large complex datasets to address scientific problems. Furthermore, students reported positive and informative experiences using large datasets to explore open-ended questions.

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Regulators often require mining companies to monitor the water quality of pit lakes during closure. Aerial drones, or unmanned aerial vehicles (UAVs), are poised to revolutionise pit lake monitoring and management by: (i) reducing risks associated with water sampling, (ii) lowering costs associated with sampling, and (iii) increasing the frequency of data acquisition. This paper demonstrates how in situ profiles of temperature and specific conductance collected by aerial drones in advance of water sampling can be used to select optimal sampling depths and to inform samplers of the physical state of the pit lake. We provide case studies of drone water sampling at two pit lakes located 295 km apart in the northwest United States. These pit lakes have similar maximum depths, latitudes, and surface elevations, and both require drone water sampling. The Montana Tunnels Pit Lake near Jefferson City, Montana is inaccessible to both foot and vehicle traffic due to previous pit wall failures. The Thompson Creek Pit Lake near Clayton, Idaho has unstable pit walls that as recently as 2016 generated a large landslide that entered the pit lake and produced a tsunami. The health and safety risks associated with future tsunamis have suspended boat-based water sampling. Both pit lakes were sampled during a three-week period in autumn 2018 when most temperate-zone lakes in North America undergo complete top-to-bottom circulation, called 'turnover'. The aerial drone first suspended a conductivity-temperature-depth (CTD) probe capable of measuring in situ parameters to a depth of 100 m, and then suspended a water sampling device capable of collecting 2 L water samples up to 120 m deep. On 23 October 2018, in situ profiles collected in the Montana Tunnels Pit Lake showed that complete turnover had occurred and informed samplers that a minimum number of water samples would be sufficient to characterise the geochemistry of the water column. The sampling team collected three water samples from 0, 28 and 56 m depths, and subsequent lab results confirmed homogeneous conditions. State and federal regulators observed the sampling event and accepted the water samples for compliance purposes. In contrast, on 13 November at the Thompson Creek Pit Lake, in situ profiles indicated variable water chemistry with depth and the persistence of summer stratification. As a result of this complexity, samplers collected eight water samples from 3, 8, 15, 17, 36, 40, 55, and 83 m depths. In both studies, the aerial drone methods presented herein provided pit lake managers with important information about pit lake behaviour and water quality which could not have been obtained with boat-based methods owing to access and health and safety risks. These studies highlight the potential for future aerial drone water sampling applications during closure.