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--- pmip3:design:bc:index [2009/01/27 17:56] – Added ~~DISCUSSION~~ jypeter
+++ pmip3:design:bc:index [2025/05/15 17:37] (current) – jypeter
@@ Line 1: / Line 1: @@
-~~DISCUSSION~~
+~~ODT~~
 ====== PMIP3 Boundary Conditions ======
@@ Line 12: / Line 13: @@
 ==== Ice sheets ====
+Modern
 ==== Topography, coastlines ====
+Modern
 ==== Greenhouse gases ====
-CO<sub>2</sub> = ppm
+//Pre-industrial concentrations (around 1750)//
+CO<sub>2</sub> = 280 ppm
-CH<sub>4</sub> = ppb
+CH<sub>4</sub> = 760 ppb
-N<sub>2</sub>0 = ppb
+N<sub>2</sub>0 = 270 ppb
-CFC =
+CFC = 0
-<sub>3</sub> =
+<sub>3</sub> = Modern - 10 DU
 ==== Insolation ====
-Solar constant = W m-2
+Solar constant = 1365 W m-2
-Eccentricity =
+Eccentricity = 0.016724
-Obliquity = °
+Obliquity = 23.446 °
-Angular precession = °
+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 =====
@@ Line 47: / Line 60: @@
 ==== Vegetation ====
-**OA** = fixed
+**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> = ppm
+CO<sub>2</sub> = 280 ppm
-CH<sub>4</sub> = ppb
+CH<sub>4</sub> = 650 ppb
-N<sub>2</sub>0 = ppb
+N<sub>2</sub>0 = 270 ppb
-CFC =
+CFC = 0
-<sub>3</sub> =
+<sub>3</sub> = Same as control run
 ==== Insolation ====
-Solar constant = W m-2
+Solar constant = 1365 W m-2 (Same as control run)
-Eccentricity =
+Eccentricity = 0.018682
-Obliquity = °
+Obliquity = 24.105 °
-Angular precession = °
+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
@@ Line 88: / Line 107: @@
 ==== Vegetation ====
-**OA** = fixed
+**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> = ppm
+CO<sub>2</sub> = 185 ppm
-CH<sub>4</sub> = ppb
+CH<sub>4</sub> = 350 ppb
-N<sub>2</sub>0 = ppb
+N<sub>2</sub>0 = 200 ppb
-CFC =
+CFC = 0
-<sub>3</sub> =
+<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 = W m-2
+Solar constant = 1365 W m-2 (Same as control run)
-Eccentricity =
+Eccentricity = 0.018994
-Obliquity = °
+Obliquity = 22.949 °
-Angular precession = °
+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.