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pmip3:design:lm:index [2009/09/11 23:35] gavin |
pmip3:design:lm:index [2009/12/23 13:40] jypeter Closed the discussion |
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~~ODT~~ | ~~ODT~~ | ||
- | ~~DISCUSSION~~ | + | ~~DISCUSSION:closed~~ |
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^ ^ PMIP3 ^ Alternative solution ^ | ^ ^ PMIP3 ^ Alternative solution ^ | ||
- | | Orbital parameters | Annually varying (Table provided (for years 0-2100 CE/AD) if not internally calculated) | 1850 values [ **ecc** = 0.01676 ] - [ **obl** = 23.459° ] - [ **peri-180°** = 100.327° ] or same as Pre-Ind CMIP5 control | | + | | Orbital parameters | Annually varying\\ [[index#orbital_forcing|Table provided (0-2100 CE/AD), if not internally calculated]] | 1850 values\\ [ **ecc** = 0.01676 ]\\ [ **obl** = 23.459° ]\\ [ **peri-180°** = 100.327° ]\\ or same as Pre-Ind CMIP5 control | |
- | | Date of vernal equinox | Mar 21 hr 0 | same as CMIP5 control | | + | | Date of vernal equinox | Mar 21 hr 0 | same as CMIP5 control | |
- | | Trace gases | Annually varying (850-1850) ([[index#reconstructed_evolution_of_trace_gases|Table provided]]) | constant at CMIP5 control levels [ **CO<sub>2</sub>** = ppm ] - [ **CH<sub>4</sub>** = ppb ] - [ **N<sub>2</sub>O** = ppb ] - [ **CFC** = ] - [ **O<sub>3</sub>** = ] | | + | | Trace gases | Annually varying (850-1850) ([[index#reconstructed_evolution_of_trace_gases|Table provided]]) | constant at CMIP5 control levels\\ [ **CO<sub>2</sub>** = ppm ]\\ [ **CH<sub>4</sub>** = ppb ]\\ [ **N<sub>2</sub>O** = ppb ]\\ [ **CFC** = ]\\ [ **O<sub>3</sub>** = ] | |
| Volcanic Aerosols | Multiple reconstructions (of AOD, Effective Radius, Mass) | | | | Volcanic Aerosols | Multiple reconstructions (of AOD, Effective Radius, Mass) | | | ||
| Solar irradiance | Multiple reconstructions (default TBD) | | | | Solar irradiance | Multiple reconstructions (default TBD) | | | ||
| Ozone | solar related variations (parameterised as function of change in solar irradiance - Drew Shindell) | same as pre-Ind control | | | Ozone | solar related variations (parameterised as function of change in solar irradiance - Drew Shindell) | same as pre-Ind control | | ||
| Aerosols | biomass burning changes???? | same as pre-Ind control | | | Aerosols | biomass burning changes???? | same as pre-Ind control | | ||
- | | Vegetation | Land use conversion (forests to C3/C4 crops) (Pongratz, 2009, Foley and Ramunkutty). Available from WDCC-Hamburg (http://cera-www.dkrz.de/WDCC/ui/Entry.jsp?acronym=LAND_COV_scen_800_1699) | No change from Pre-Ind control | | + | | Vegetation | Land use conversion (forests to C3/C4 crops) (Pongratz, 2009, Foley and Ramunkutty)\\ Available from WDCC-Hamburg\\ (http://cera-www.dkrz.de/WDCC/ui/Entry.jsp?acronym=LAND_COV_scen_800_1699) | No change from Pre-Ind control | |
| Ice sheets | No changes from Pre-Ind control | | | | Ice sheets | No changes from Pre-Ind control | | | ||
| Topography and coastlines | No change from Pre-Ind control | | | | Topography and coastlines | No change from Pre-Ind control | | | ||
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==== Orbital forcing ==== | ==== Orbital forcing ==== | ||
- | Calculation from Berger (1978), annually varying. | + | The following orbital parameters parameters should be used, if they are not internally calculated. |
- | Note that over the period 0-2100 CE, the parameters are well approximated by linear regressions | + | |
- | ECC = 0.017475 - 0.000000382*Year | + | |
- | OBL = 23.697 - 0.000128*Year | + | Note: calculation from Berger (1978), annually varying. |
- | PERI-180= 68.79 + 0.0170*Year | + | === Precomputed table === |
+ | |||
+ | The {{:pmip3:design:lm:pmip3_lm_orbital_parameters.txt|parameters' table}} has been supplied by | ||
+ | [[gschmidt@giss.nasa.gov|Gavin Schmidt]] (GISS). | ||
+ | |||
+ | === Linear regressions === | ||
+ | |||
+ | Over the period 0-2100 CE, the parameters are well approximated by the following linear regressions: | ||
+ | |||
+ | ^ Parameter ^ Linear approximation ^ | ||
+ | | ECC | 0.017475 - 0.000000382 * Year | | ||
+ | | OBL | 23.697 - 0.000128 * Year | | ||
+ | | PERI-180 | 68.79 + 0.0170 * Year | | ||