Magnetic DNA-based microparticle as a hydrological tracer in river-water tracing experiments

<p>Recently an new microparticle tracer has been developed for investigating in stream-mass transport: a silica coated synthetic-DNA-tagged microparticles with a superparamagnetic core (SiDNAMag). SiDNAMag particles can be easily recovered by magnetic separation, with high DNA signal amplification by Quantitative Polymerase Chain Reaction (qPCR). However, with the presence of natural colloids, particulate matter and river bed sediments, SiDNAMag are likely to undergo complex interaction processes besides dispersion and advection. Moreover, little has been known for the possible sink sources of SiDNAMag tracer mass loss during transport in river waters.</p><p>In this research the focus is on investigating the transport behaviour of the SiDNAMag particle as a potential hydrological tracer. The behaviour of the SiDNAMag particles will be compared to those of solute tracers (NaCl) and silica microparticles in terms of breakthrough curves and mass recoveries, by performing open channel injection experiments in laboratory environment. The resulting breakthrough curves will be interpreted with a 1-D advection and dispersion model. Possible interactions and mass loss will be examined by performing batch and injection experiments in different river water types with the presence of river bottom sediments.</p>

TRACMASS 7.0 - A Lagrangian trajectory code for atmosphere and ocean sciences

<p>The latest version of the <strong>TRACMASS</strong> trajectory code, version 7.0 will be presented. The latest version includes several new features, e.g. water tracing in the atmosphere, generalisation of the tracer handling, and improvements to the numerical scheme. The code has also become more user friendly and easier to get started with. Previous versions of <strong>TRACMASS</strong> only allowed temperature, salinity and potential density to be calculated along the trajectories, but the new version allows any tracer to be followed e.g. biogeochemical tracers or chemical compounds in the atmosphere. </p><p><strong>TRACMASS</strong> calculates Lagrangian trajectories offline for both the ocean and atmosphere by using already stored velocity fields, and optionally tracer fields. The code supports most vertical coordinate systems, e.g. z-star, z-tilde, sigma, and hybrid sigma-pressure coordinates. Hence, <strong>TRACMASS</strong> supports a range of atmosphere and ocean models such as ECMWF IFS, NEMO, ROMS, MOM, as well as reanalysis products (e.g. ERA-5) or observations (e.g. geostrophic currents from AVISO satellite altimetry). The fact that the numerical scheme in <strong>TRACMASS</strong> is mass conserving allows us to associate each trajectory with a mass transport and calculate the Lagrangian mass transport between different regions as well as construct Lagrangian stream functions. </p><p>A short course on how to set up, configure and run the <strong>TRACMASS </strong>code will be given separately, <strong>SC5.17</strong>.</p>

TRACMASS - A mass conserving trajectory code for ocean and atmosphere general circulation models

<p>We present the latest version of the TRACMASS trajectory code, version 7.0. The new version includes new features such as water tracing in the atmosphere, parameterisation scheme for sub-grid scale turbulence, generalisation of the tracer handling, etc. The code has also become more user friendly and easier to get started with. Previous versions of TRACMASS only allowed temperature, salinity and potential density to be calculated along the trajectories, but the new version allows any tracer to be followed e.g. biogeochemical tracers or chemical compounds in the atmosphere. The new parameterisation of sub-grid turbulence will enhance the kinetic energy and dispersion of trajectories in the ocean so that results from eddy-permitting ocean models (dx ∼25km) resemble those from “eddy-resolving” models (dx ∼8km). We will demonstrate some use cases of these new capabilities for atmosphere and ocean sciences. </p><p>TRACMASS calculates Lagrangian trajectories offline for both the ocean and atmosphere by using already stored velocity fields, and optionally tracer fields. The velocity fields may be taken from ocean or atmosphere circulation models (e.g. NEMO, OpenIFS), reanalysis products (e.g. ERA-5) or observations (e.g. geostrophic currents from satellite altimetry). The fact that the numerical scheme in TRACMASS is mass conserving allows us to associate each trajectory with a mass transport and calculate the Lagrangian mass transport between different regions as well as construct Lagrangian stream functions. </p><p>A live demonstration on how to set up, configure and run the TRACMASS code will be given.</p>