Objectives
(1) To update multi-media Hg models based on current knowledge and any new findings generated in WP 1-2-3 during the course of the project. (2) Improve the representation of inter-compartmental Hg exchange processes. (3) To model the complete Hg cycle from emissions to bioaccumulation on a regional scale for Europe and other selected areas (e.g. polar regions). (4) To determine the current level of Hg pollution in Europe and, in collaboration with WP6, determine the effectiveness of European and global emission reductions on Hg cycling and bioaccumulation in Europe based on emission scenarios developed in WP6.
Description of Work
Modelling will be done in collaboration with the project partners from the WPs 1-3 for red-ox reactions (CNRS and JSI), marine Hg chemistry (AMU), methylation reactions (CNRS), and bioaccumulation processes (IFREMER). The computational capacity and IT support for the ESRs model studies will be provided by Hereon locally and via the German Climate Computing Centre (DKRZ). Datasets for model evaluation will be obtained from atmospheric long-term observations (Hereon), aircraft campaigns (Hereon), marine cruises (AMU), coastal sites (WP2 and 3) and observations from the Global Mercury Observation System (CNR-IIA) (collaboration with ESR14).
Task 5.1: ESR12 will use regional atmospheric and air-sea exchange modelling with WRF-Chem (CNR-IIA), COSMO-CMAQ (Hereon), and MECOSMO (Hereon) to improve Hg exchange processes, implement new red-ox schemes into atmospheric models and investigate the impact of ocean-atmosphere coupling on the regional Hg cycle. This work will be closely linked to ESR13, 14 and the global atmospheric modeling (ESR15, GESO-Chem Harvard, GLEMOS MSC-E).
Task 5.2: ESR13 will investigate marine methylation and bioaccumulation using marine ecosystem and chemistry models (Hereon) and determine the impact of policy scenarios from WP6 on MeHg concentration and accumulation in Europe. Mechanisms for marine Hg chemistry and bio-accumulation will be improved, global (GEOS-Chem, Harvard; GLEMOS, MSC-E) and regional (Hereon) models will be updated and harmonized according to current knowledge.
Expected Results
ESR12
Updated Hg red-ox chemistry in regional models. Quantification of the impact of oceanic sources on observed Hg concentrations and on regional deposition patterns. Clarification to what extent reductions in anthropogenic Hg emissions will be visible in reduced atmospheric concentrations and depositions (2 papers).
ESR13
Improved regional ocean-ecosystem model which can be used to evaluate the impact of emission changes in the Hg burden in sea food (2 papers).
Deliverables
| Del. | Deliverable Title – Science deliverables | WP | Lead | Type | Diss. | Due |
| D5.1 | ESR12: 2 papers on (i) redox chemistry and air-sea exchange and in coupled 3D ocean-atmosphere models; (ii) impact of future emissions changes if Hg transport in Europe; additional co-authorship in papers submitted by the ESRs in WP1-3. | 5, 1, 2, 3 | CNR-IIA | R | PU | 31 Oct 2024 |
| D5.2 | ESR13: 2 papers (i) model results and sensitivity of marine methylation processes; (ii) source receptor study for bio-accumulation of Hg in sea food | 5,2 | Hereon | R | PU | 31 Oct 2024 |
Milestones
| No | Title | WP(s) | Lead Benef. | Due Date | Means of Verification |
| 4 | New field observations on atmospheric Hg speciation | 1, 5 | UGA | M26 | Field survey completed and data quality validated, ESR1 |
| 5 | New kinetic data for redox chemistry available | 1, 5 | JSI | M48 | Reactions verified and reported (ESR2) |
| 12 | New cruises and data on marine Hg speciation | 2, 5 | AMU | M42 | Cruises completed, data verified |
| 13 | New data on coastal Hg speciation | 2, 5 | UPPA | M36 | Measurements completed and validated |
| 15 | Long-term databases compiled | 5, 6 | Hereon | M26 | Data availability (US, CNR-IIA, UGA, Hereon) |
| 16 | Emission perturbation scenarios | 5, 6 | CNR-IIA | M30 | CNR-IIA/Hereon: Emission datasets for policy scenarios done |
| 20 | Compilation of spatially-resolved terrestrial databases completed | 3, 5 | JSI | M32 | Data available at AMAP, UNEP, CNR-IIA, Hereon. GEO |
| 21 | Revised regional and global 3D Hg model available | 3, 5 | Hereon | M38 | Validation of models using new kinetic data and filed observations |
| 22 | Regional high-resolution model study on impact of red-ox chemistry | 5, 1 | Hereon | M48 | Modelling and field data comparison for validation |
| 23 | Update of methylation processes in the marine model and bio-accumulation modelling | 5 | Hereon | M38 | Modelling and field data comparison for validation |
| 24 | PhD thesis submitted | 1-6 | JSI | M48 | All beneficiaries: PhD thesis approved by (co)supervisors |