Can mussels be used as sentinel organisms for characterization of pollution in urban water systems? Hydrology and Earth System Sciences DOI 10.5194/hess-20-2679-2016 8 July 2016 We assessed if nitrogen stable isotopes in mussels are a suitable indicator, capable of resolving spatial and temporal variability of nutrient pollution in an urban estuary. Our results highlight the value of using stable isotope analysis as an integrative tool to establish an understanding of local processes and pollution levels in theses urban aquatic systems. We suggest that mussels can become a robust tool for the detection of emerging anthropogenic pollutants of concern in urban water systems. Read more
Multi-scale statistical analysis of coronal solar activity Nonlinear Processes in Geophysics DOI 10.5194/npg-23-175-2016 8 July 2016 We use temperature maps of the solar corona for three regions and use a technique that separates multiple timescales and space scales to show that the small-scale temperature fluctuations appear more frequently prior to the occurrence of a solar flare, in comparison with the same region after the flare and with a quiet region. We find that, during the flare, energy flows from large to small scales and heat transport associated with a heat front is convective along and diffusive across the front. Read more
The impact of ancestral heath management on soils and landscapes: a reconstruction based on paleoecological analyses of soil records in the central and southeastern Netherlands SOIL DOI 10.5194/soil-2-311-2016 4 July 2016 Soil records provide information about 5 millennia of heath management in cultural landscapes on sandy soils. Deforestations and the introduction of the deep, stable economy in the 18th century resulted in sand drifting and heath degradation. After the introduction of chemical fertilizers more than 90 % of the heaths were transformed into productive arable field or forests. Currently the last heaths are preserved as part of the cultural heritage. Read more
Impacts of Tibetan Plateau uplift on atmospheric dynamics and associated precipitation δ18O Climate of the Past DOI 10.5194/cp-12-1401-2016 28 June 2016 We use an isotope-equipped GCM and develop original theoretical expression for the precipitation composition to assess δ18O of paleo-precipitation changes with the Tibetan Plateau uplift. We show that δ18O of precipitation is very sensitive to climate changes related to the growth of mountains, notably changes in relative humidity and precipitation amount. Topography is shown to be not an exclusive controlling factor δ18O in precipitation that have crucial consequences for paleoelevation studies. Read more
Spatial and temporal variations in plant water-use efficiency inferred from tree-ring, eddy covariance and atmospheric observations Earth System Dynamics DOI 10.5194/esd-7-525-2016 28 June 2016 Our analysis allows us to infer maps of changing plant water-use efficiency (WUE) for 1901–2010, using atmospheric observations of temperature, humidity and CO2. Our estimated increase in global WUE is consistent with the tree-ring and eddy covariance data, but much larger than the historical WUE increases simulated by Earth System Models (ESMs). We therefore conclude that the effects of increasing CO2 on plant WUE are significantly underestimated in the latest climate projections. Read more
Increasing the accuracy and temporal resolution of two-filter radon–222 measurements by correcting for the instrument response Atmospheric Measurement Techniques DOI 10.5194/amt-9-2689-2016 28 June 2016 Surface-based two-filter radon detectors monitor the ambient concentration of atmospheric radon-222, a natural tracer of mixing and transport. They are sensitive, but respond slowly to ambient changes in radon concentration. In this paper, a deconvolution method is used to successfully correct observations for the instrument response. Case studies demonstrate that it is beneficial, sometimes necessary, to account for the detector response, especially when studying near-surface mixing. Read more
Which are the highest peaks in the US Arctic? Fodar settles the debate The Cryosphere DOI 10.5194/tc-10-1245-2016 23 June 2016 We measured the heights of the five tallest peaks in the US Arctic using fodar, a new airborne photogrammetric technique using structure-from-motion software. The highest peaks are Mt Isto (2735.6 m), Mt. Hubley (2717.6 m), Mt. Chamberlin (2712.3 m), Mt. Michelson (2698.1 m), and an unnamed peak (2694.9 m). We found fodar suitable for topographic change detection on the centimeter scale in steep mountain terrain, such as for measuring snow depths. Read more
Growth of nucleation mode particles in the summertime Arctic: a case study Atmospheric Chemistry and Physics DOI 10.5194/acp-16-7663-2016 23 June 2016 We present a case study focused on an aerosol growth event observed in the Canadian High Arctic during summer. Using measurements of aerosol chemical and physical properties we find evidence for aerosol growth into cloud condensation nuclei-active sizes, through marine-influenced secondary organic aerosol formation. Understanding the mechanisms that control the formation and growth of aerosol is crucial for our ability to predict cloud properties, and therefore radiative balance and climate. Read more
Greenland Ice Sheet seasonal and spatial mass variability from model simulations and GRACE (2003–2012) The Cryosphere DOI 10.5194/tc-10-1259-2016 20 June 2016 We compared satellite-derived estimates of spatial and seasonal variations in Greenland Ice Sheet mass with a set of model simulations, revealing an agreement between models and satellite estimates for the ice-sheet-wide seasonal fluctuations in mass, but disagreement at finer spatial scales. The model simulations underestimate low-elevation mass loss. Improving the ability of models to capture variations and trends in Greenland Ice Sheet mass is important for estimating future sea level rise. Read more
A 7-year dataset for driving and evaluating snow models at an Arctic site (Sodankylä, Finland) Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-5-219-2016 16 June 2016 Physically based models that predict the properties of snow on the ground are used in many applications, but meteorological input data required by these models are hard to obtain in cold regions. Monitoring at the Sodankyla research station allows construction of model input and evaluation datasets covering several years for the first time in the Arctic. The data are used to show that a sophisticated snow model developed for warmer and wetter sites can perform well in very different conditions. Read more
