ALBERT

Description: Appropriate field data are required to check the reliability of hydrodynamic models simulating the dispersion of soluble substances in the marine environment. This study deals with the collection of physical measurements and soluble tracer data intended specifically for this kind of validation. The intensity of currents as well as the complexity of topography and tides around the Cap de La Hague in the center of the English Channel makes it one of the most difficult areas to represent in terms of hydrodynamics and dispersion. Controlled releases of tritium - in the form of HTO - are carried out in this area by the AREVA-NC plant, providing an excellent soluble tracer. A total of 14 493 measurements were acquired to track dispersion in the hours and days following a release. These data, supplementing previously gathered data and physical measurements (bathymetry, water-surface levels, Eulerian and Lagrangian current studies) allow us to test dispersion models from the hour following release to periods of several years which are not accessible with dye experiments. The dispersion characteristics are described and methods are proposed for comparing models against measurements. An application is proposed for a 2 dimensions high-resolution numerical model. It shows how an extensive dataset can be used to build, calibrate and validate several aspects of the model in a highly dynamic and macrotidal area: tidal cycle timing, tidal amplitude, fixed-point current data, hodographs. This study presents results concerning the model's ability to reproduce residual Lagrangian currents, along with a comparison between simulation and high-frequency measurements of tracer dispersion. Physical and tracer data are available from the SISMER database of IFREMER (www.ifremer.fr/sismer/catal). This tool for validation of models in macro-tidal seas is intended to be an open and evolving resource, which could provide a benchmark for dispersion model validation.

Description: Content of Excel files: -- BASE calculation.xlsx: This is the core dataset for "Assessing the Efficiency of Land Use Changes for Mitigating Climate Change" using a 4% discount rate for all calculations. -- Sensitivity variant DISC 2%.xlsx Sensitivity variant DISC 6%.xlsx: Sensitivity calculations using 2% and 6% discount rates. -- Sensitivity variant GAIN.xlsx Calculations using the carbon gain method. -- Sensitivity variant HIGH.xlsx Sensitivity variant LOW.xlsx: Calculations using +/- 20% variations for native vegetation estimates and +/- 30% for soil carbon estimates under native vegetation. The HIGH variant uses 20% and 30% higher values for vegetation and soil carbon stocks in native vegetation, respectively, than the central scenario. The LOW variant uses 20% and 30% lower values for vegetation and soil carbon stocks in native vegetation, respectively,than the central scenario. --------------- Description of raster files: -- lpjml_anpp_avg_2001-2010.asc: Annual net primary productivity of potential native vegetation under current climate simulated with the LPJmL model. -- lpjml_vegc_avg_cor_2001-2010.asc: Above- and below-ground carbon stocks of potential natural vegetation under current climate simulated with the LPJmL model and adjusted at the biome level according to reference values from the literature (see Supplementary Information). -- lpjml_soilc_1m_avg_cor_2001-2010.asc: Soil carbon stocks of potential natural vegetation under current climate simulated with LPJmL and adjusted at the biome level according to reference values from the literature (see Supplementary Information).