Mercury

Hello Team-Hg

Here's the list of things I *think* we came up with on Friday regarding cleaning up the code (feel free to add/comment):

1) Standardize the solver. Everyone should use the solver Chris developed for the Hg chemistry
(located at ~cdh/GC/RevisedChem.v7-04-06/mercury_mod.f)

• outstanding issue - dry dep of Hg0* <- currently working on this (eds)

2) Catalog all emissions options and develop clear flagging system to choose your own adventure. This will include:

• different anthropogenic emissions scenarios/corrections (i.e Jaffe vs. Streets) <- going to work on the anthro emissions soon (eds),
  
• different land emissions. <- nvd will work on this

3) Diagnostics. We didn't get to discuss this, but we need to decide what should be included in the diagnostics.
4) Comment everything in the code. Remove old bits of code that are hanging around & commented out.
5) GEOS-5
6) Get the land stuff out of ocean_mercury_mod.f and into it's own module <- nvd will work on this

Chemistry 'issues'

1) Oxidant. Chris has a simulation with Hg-Br chemistry and SS aerosol deposition; the global budget is ok, but the Br concentrations in the BL are too low to generate diurnal cycles. (cdh working on it)
2) Snow/ice scavenging of HgII
3) Dry deposition of "aqueous HgII. (Explanation from Chris: We calculate the fraction of HgII, Fg, which is gas phase. But we're currently applying the dry deposition velocity to both gas and aqueous fractions. I think it would be better to deposit the aqueous fraction at the velocity of HgP; this would be slower dep, but I don't know how much. This is definitely up for discussion.)