Skip to: [content] [navigation]

The primary goals of this meeting were to update everyone on code status and present results from the second attempt at a fully exchanging CO2 in the ESM, and discuss diagnostics issues

A) Code Status report:

1) After many bug-fixes and tunings, we have currently put together a hacked - pre-Lima version of the ESM2.1 code including the latest LM3v and Ocean biogeochemistry modules to test fidelity (the so-called third trial run)

2) Formal integration of code versions for a post-Lima code-base to replace the main FMS trunk is ongoing - Fei Liu is heading this, and estimates that this will take approximately one month.

B) Results of third trial run

In this run, the bottom atmospheric condition if over-ridden in the flux exchange code so that land and ocean "feel" 278 ppm CO2. However, an atmospheric CO2 tracer is included that responds to the resultant fluxes to confirm fidelity.

Click here to see an animation of CO2 Air-Land/Sea Fluxes over the first six years!

Here are the global averaged CO2 Fluxes (Total - black; land - green; ocean - blue) from the first 6 years of the model


Here is the global averaged surface CO2 concentration from the first 6 years of the model



Model is continuing to run. Results can be found at:

/archive/jpd/khartoum/CM2.1U_co2_ov_v2

C) Diagnostics for the Earth System Model: A preliminary discussion

The primary objective of this discussion was to ascertain if the frequency (mponthly) and content (17Gb, mostly ocean-based) of the current diagnostic set was approriate for this phase of model development. It was generally agreed that this was appropriate for the development stage, but excessive for the spinup stage. One concern was that in order to compare the CO2 fluxes and concentrations with field observations, we will need to save out these parameters at a very high frequency (at least 4-hourly). This can wait, however, until after spinup, and probably would only be necessary for brief periods.

...Presentation by Gnanadesikan:

Currently we are saving ~17 Gb of output per year (before we go into preprocessing)
~11 in ocean_bgc
~5 in ocean_month
~0.5 in atmos_month
~0.3 in ocean_grid
~0.05 in land diagnostics

Number gets multiplied by 3-4 if we include postprocessing.

What gets saved in ocean_bgc?

65 Three-dimensional fields: Phytoplankton cell quotas of key elements (8):
N (small, large, diazotroph), Si (large), iron (small, large, diazotroph),
P (large)
Compounds involved in the nutrient cycle (13)

NO3, NH4, PO4, SiO4, Dissolved and particulate Fe, Semilabile DON, Semilabile DOP, Labile DON, O2, DIC, Alk, Chl
Irradiance (1)
Production (broken down by element, +CaCO3) (11)
Grazing terms (8)
Water column processes (broken down by element, process) (20)
Particulate fluxes (4)

Why do we save all of these fields?

Comparisons with data:
PO4, NO3, Alkalinity, SiO4, O2 are available as monthly, gridded datasets.
DIC is available as an annual average global gridded dataset.
Some hydrographic data for Fe, DON, DOP.
Globally gridded estimates of primary productivity, export of N,C,P, Ca available on monthly timescales. (2D)
Large-scale averaged rates of remineralization.
Individual rates (size and origin-fueled productivity, silicification, calcification, grazing rates, export, particle flux) available at a number of sites.
Example: Mean and annual cycle of phosphate (Year 5, ESM)

Possible way of reducing output

Average production, grazing fields over top 100m
Integrate some processes that occur at the bottom (denitrification, bottom sources)
Saves 18-20 three-dimensional fields.

Why do we save all these variables?

To understand why the model fields drift away from data.
Requires doing more detailed budgets.
May require saving more fields. (Phytoplankton state variables- limitation terms).

C) Action items from previous meeting:

1) Ascertain whether carbon is conserved in the model -
Further tests are necessary.

2) Establishment of Standard Diagnostic Suite -
Discussed below.
3) Get model working in concurrent mode to bump up to 150pes -
Done
4) Wait for LM3v to be frozen. -
Done - LM3v incorporated into Lima release
5) Spin up land model with fixed CO2 atmosphere -
Done
6) Spin up ocean model with spun-up land and fixed CO2 atmosphere -
Done.
7) Develop code to allow radiation code to "feel" the atmospheric CO2 tracer -
Version of code is complete and in testing.
8) Start running on Altix when it frees up -
Done
9) have a frozen rts checkout.
Hack exists, but official version waiting for merged code in Lima
10) A third attempt at running the full system to test physical fidelity and CO2 conservation -
In progress - discussed below
11) Finalization of ocean carbon system initialization plan -
Waiting for implementation plan from Toggweiler/Dunne
12) Establishment of diagnostic suite -
Discussed below
13) Write up of technical description -
Waiting for documentation from Maleshev and Slater

E) Plans for next two months/continuing action items.

1) Achieve frozen rts checkout based on Lima that is capable of reproducing CM2.1

2) Analysis of current ESM2.1 run

3) Finalization of ocean carbon system initialization plan.

• About us
  • Welcome
  • Visiting GFDL
  • Overview
  • Tour
  • Gallery
  • People
  • Employment
  • Help
  • Notices
• Research
  • Atmospheric Physics and Chemistry
  • Biospheric Processes
  • Climate Diagnostics
  • Climate Dynamics and Prediction
  • Oceans and Climate
  • Weather and Atmospheric Dynamics
• Products and Services
  • Flexible Modeling System
  • Our Data Portal
  • Our GForge
  • Technical Services
  • Visualization
• Reference
  • Our Online Bibliography
  • Our Meetings and Seminars
  • Our Library
• GFDL Only
  • External forms and links
  • External web mail
  • Help Desk
  • Internal Administrative Services
  • Internal Technical Services
  • NOAA's Hot Items
  • webTA Login

smaller bigger reset