• Online Coupled Atmosphere and Ocean Model for Mercury

One drawback of the previous models for mercury air-sea exchange is that the atmosphere and the ocean are not "talking" with each other. Therefore, they have issues to capture the feedback and interactions among atmosphere, marine boundary layer, ocean mixed layer, and subsurface ocean. They can not thus simulate the influence of short time scale variabilities in wind speed and ocean mixed layer depth change. I'm currently working on online coupling of atmosphere (GEOS-Chem) and ocean (MITgcm). Here are some prelimilary resuts:

Hourly Atmospheric Elemental Mercury Concentrations in the Marine Boundary Layer

Hourly Atmospheric Deposition Fluxes

Hourly Ocean Evasion Fluxes

  • MITgcm-Hg Ocean Mercury Model

This model includes the mercury cyle in the global ocean based on the MITgcm model. It simulates the transport, biogeochemical transformation, partitioning, air-sea exchange, and particle sinking processes of both inorganic mercury and methylmercury. It also includes the bioaccumulation and biomagnification of methylmercury in the marine plankton foodweb. For more details of this model, please refer to my previous publications: [Zhang et al. 2015][Zhang et al., 2014][Zhang et al., 2014].

The model results are available upon request. The following figures show the modeled concentrations in the surface ocean for multiple mercury chemical species:

Daily Mercury Concentrations at top 10m of global ocean by MITgcm-Hg Model

Also, the concentrations in different phytoplankton types (Note, not based on wet or dry weight of cells, but the mass of MeHg in phytoplankton cells per unit volume of seawater):

MeHg concentrations in different phytoplankton

  • Global Health Effects of Future Atmospheric Mercury Emissions


The calculated Methylmercury exposure risk for individual countries as plotted in Figure 1 of Zhang et al. Nature Communications, [2021] [Data].

The python codes to calculate these risk are also available [Codes].