[CF-metadata] New standard names for OMIP biogeochemistry and chemistry

From: Jonathan Gregory <j.m.gregory>
Date: Thu, 29 Sep 2016 16:06:00 +0100

Dear Jim

Thanks for explaining. So "natural" is the opposite of "anthropogenic", in
a restricted sense. It includes the effect of anthropogenic climate change,
but not the anthropogenic emissions of CO2. Is that right? I think this is
potentially confusing in the context of CF, which has to cover a wide range of
applications. It is not hard to imagine people wanting to use natural in the
sense of *completely* unaffected by anthropogenic influence. (Obviously I'm
not commenting on the terminology used in OMIP - I'm sure that's clear in
that context.) I wonder if for CF we could think of something more explicit.

Actually I'm unclear quite what is meant by due_to_natural_component (in
several names). Component of what? Could you explain a bit more?

Also, what does sea_water_ph_reported_on_total_scale_due_to_X mean? Is it
perhaps a *change* in pH?

Best wishes

Jonathan

> For the biogeochemistry in OMIP, we've agreed on using the terms
> 'abiotic' and 'natural', neither synonyms nor antonyms for our
> purposes. The OMIP-BGC simulations will be run with 2 parallel
> simulations (or parallel tracers in the same simulation):
>
> * 'natural' means it will be maintained at same the CMIP6
> preindustrial CO2 level throughout the simulation, while the
>
> * 'total' simulation will have varying atmospheric CO2, but the same
> climate (e.g., forced in the OMIP ocean only run).
>
> The difference between the total and natural carbon tracers in the
> two will give us the anthropogenic carbon. The ocean's natural
> carbon cycle is considered in OMIP to change with climate change
> even though its simulated atmospheric CO2 is held constant.
>
> Regarding 'abiotic', the natural and the total simulation include
> both abiotic and biotic processes. To distinguish the two we also
> include an abiotic carbon tracer. Furthermore, we use a simplified
> abiotic approach to model C-14 in the ocean, e.g., to provide
> deep-ocean ventilation ages.
Received on Thu Sep 29 2016 - 09:06:00 BST