~~DISCUSSION~~
~~ODT~~

====== PMIP3 Boundary Conditions ======

===== Pre-industrial control run =====

==== Vegetation ====

**OA** = fixed

**OAV** = interactive

==== Ice sheets ====

Modern

==== Topography, coastlines ====

Modern

==== Greenhouse gases ====

//Pre-industrial concentrations (around 1750)//

CO<sub>2</sub> = 280 ppm

CH<sub>4</sub> = 760 ppb

N<sub>2</sub>0 = 270 ppb

CFC = 0

0<sub>3</sub> = Modern - 10 DU

==== Insolation ====

Solar constant = 1365 W m-2

Eccentricity = 0.016724

Obliquity = 23.446 °

Angular precession = 102.04 °

==== Initial ocean state ====

Modern

Initialize 3-D ocean temperature and salinity from the Levitus 1998 datasets

==== Model spinup ====

Each group has its own spinup methodology, which we ask they document.

The model should be run long enough for any trends to be small, and the control run should be at least as long as any anomaly integrations.

===== Mid-holocene =====

==== Vegetation ====

**OA** = Same as control run

**OAV** = interactive

==== Ice sheets ====

Same as control run

==== Topography, coastlines ====

Same as control run

==== Greenhouse gases ====

CO<sub>2</sub> = 280 ppm

CH<sub>4</sub> = 650 ppb

N<sub>2</sub>0 = 270 ppb

CFC = 0

0<sub>3</sub> = Same as control run

==== Insolation ====

Solar constant = 1365 W m-2 (Same as control run)

Eccentricity = 0.018682

Obliquity = 24.105 °

Angular precession = 0.87 °

==== Initial ocean state ====

Initialize 3-D ocean temperature and salinity either from the Levitus 1998  datasets or from year 100 of the control run 

==== Model spinup ====

Same as control run


===== Last glacial maximum =====

==== Vegetation ====

**OA** = Same as control run

**OAV** = interactive

==== Ice sheets ====

ICE-5G v1.1

==== Topography, coastlines ====

From ICE-5G v1.1 data set 

==== Greenhouse gases ====

CO<sub>2</sub> = 185 ppm

CH<sub>4</sub> = 350 ppb

N<sub>2</sub>0 = 200 ppb

CFC = 0

0<sub>3</sub> = Same as control run

==== River outflow ====

Modified according to a river pathway map

==== Ice sheet melt ====

Same as control run, or add excess LGM freshwater

==== Insolation ====

Solar constant = 1365 W m-2 (Same as control run)

Eccentricity = 0.018994

Obliquity = 22.949 °

Angular precession = 114.42 °

==== Initial ocean state ====

Mean ocean salinity = Same as control run 

  * Option 1: same as for control run (warm ocean state)
but see model spinup below
  * Option 2: cold ocean state from existing LGM simulation 

==== Model spinup ====

If initializing from modern conditions (Option 1):

   - Option 1a: we recommend doing a 100-year Haney forced run, restoring the SSTs to those of a slab model LGM anomaly SSTs.
   - Option 1b: or 100-year Haney forced run, restoring to CLIMAP LGM anomaly SSTs.
   - Option 1c: or ocean-only stage restoring SSTs to slab or CLIMAP LGM
   - Option 1d: or just run it (brute force approach)!

For both Options 1 and 2:

Run the OAGCM (initialized from either the end of Option 1, or from the cold state of an existing LGM simulation) for long enough for any trends to be small.


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