Biome-BGC模型的模拟分两步实现：
- 第一步是获得模拟的初始状态，初始状态的获得有两种途径
- 一是直接输入长期定点观察数据最初的观测值
- 二是运行模型自带的Spin-up程序。在Spin-up过程中, 将模拟起点时的碳氮存量设为极低的值(叶片的碳存量为0.001 kg C/m2, 其它库的碳氮存量均为0 kg C/m2), 反复模拟数千年, 直到连续两年土壤碳含量的差异小于0.0005 kg C/m2, 默认系统达到稳定状态, Spin-up过程结束
- 第二步是正式运行模拟程序。
spin-up: 在没有观测数据的情况下，根据工业革命前的CO2浓度和氮沉降值进行反复模拟，直到碳氮含量达到稳定，模拟出的参数供正常模拟使用。如果有观测数据就不用spin-up模拟。
输入数据：
- ini 各站点文件中主要不同的地方有：SITE_CONTROL, EPC_FILE, IO prefix ``` ini Biome-BGC v4.1 initialization file template
MET_INPUT metdata/1.mtc43 气象数据文件 4 (int) 气象数据文件头行数
RESTART spin-up 阶段写 restart file，正常模拟阶段读 restart file 0 (flag) 1 = read restart file 0 = do not read restart file 1 (flag) 1 = write restart file 0 = do not write restart file 1 (flag) 1 = use restart metyear 0 = reset metyear restart/1.endpoint input restart filename restart/1.endpoint output restart filename
TIME_DEFINE 输入数据的时间配置 32 (int) 气象数据年数 32 (int) 模拟的年数 1982 (int) 起始模拟年份 1 (flag) 1 = spinup simulation 0 = normal simulation 6000 (int) maximum number of spinup years (if spinup simulation)
CLIM_CHANGE 气象数据的尺度和偏移因子 0.0 (deg C) offset for Tmax 0.0 (deg C) offset for Tmin 1.0 (DIM) multiplier for Prcp 1.0 (DIM) multiplier for VPD 1.0 (DIM) multiplier for shortwave radiation
CO2_CONTROL spin-up 阶段为常量，正常模拟为年度变化量 0 (flag) 0=constant 1=vary with file 2=constant, file for Ndep 294.842 (ppm) constant atmospheric CO2 concentration xxxxxxxxxxx (file) 历年 CO2 浓度
SITE 站点物理常量 1.0 (m) 土壤深度 80 (percentage) 沙含量 15 (percentage) 淤泥含量 5 (percentage) 黏土含量 500.0 (m) 高程 -54.75 (degrees) 纬度 0.2 (DIM) 短波反射率 0.0001 (kgN/m2/yr) wet+dry atmospheric deposition of N 0.0008 (kgN/m2/yr) symbiotic+asymbiotic fixation of N
RAMP_NDEP
0 (flag) do a ramped N-deposition run? 0=no, 1=yes
2099 (int) reference year for industrial N deposition
0.0001 (kgN/m2/yr) industrial N deposition value
EPC_FILE 生态常量文件：每种植被类型的生态常量不同，比如常绿灌木、常绿针叶林、常绿阔叶林、落叶阔叶林、草地等 epc/shrub.epc (file) shrub ecophysiological constants
W_STATE (keyword) 模拟初始的水存量，spin-up 阶段才用，正常模拟阶段从 restart.endpoint 中读 0.0 (kg/m2) 积雪水含量 0.5 (DIM) 初始土壤水分占饱和的比例
C_STATE (keyword) 模拟初始的碳存量，同 W_STATE 0.001 (kgC/m2) first-year maximum leaf carbon 0.0 (kgC/m2) first-year maximum stem carbon 0.0 (kgC/m2) coarse woody debris carbon 0.0 (kgC/m2) litter carbon, labile pool 0.0 (kgC/m2) litter carbon, unshielded cellulose pool 0.0 (kgC/m2) litter carbon, shielded cellulose pool 0.0 (kgC/m2) litter carbon, lignin pool 0.0 (kgC/m2) soil carbon, fast microbial recycling pool 0.0 (kgC/m2) soil carbon, medium microbial recycling pool 0.0 (kgC/m2) soil carbon, slow microbial recycling pool 0.0 (kgC/m2) soil carbon, recalcitrant SOM (slowest)
N_STATE (keyword) 模拟初始的氮存量，同 W_STATE 0.0 (kgN/m2) litter nitrogen, labile pool 0.0 (kgN/m2) soil nitrogen, mineral pool
OUTPUT_CONTROL 输出配置 outputs/1 (text) prefix for output files 1 (flag) 1 = write daily output 0 = no daily output 0 (flag) 1 = monthly avg of daily variables 0 = no monthly avg 0 (flag) 1 = annual avg of daily variables 0 = no annual avg 1 (flag) 1 = write annual output 0 = no annual output 1 (flag) for on-screen progress indicator
DAILY_OUTPUT 日输出配置 7 (int) number of daily variables to output 177 0 summary.leafc_to_litr1c; 178 1 summary.leafc_to_litr2c; 179 2 summary.leafc_to_litr3c; 180 3 summary.leafc_to_litr4c; 509 4 summary.proj_lai; 510 5 summary.all_lai; 626 6 summary.daily_hr;
ANNUAL_OUTPUT 年输出配置 7 (int) number of annual output variables 177 0 summary.leafc_to_litr1c; 178 1 summary.leafc_to_litr2c; 179 2 summary.leafc_to_litr3c; 180 3 summary.leafc_to_litr4c; 509 4 summary.proj_lai; 510 5 summary.all_lai; 626 6 summary.daily_hr;
END_INIT ```
- CO2 含量: 全球年平均值
- epc 生态常量，因植被类型而异
- met 气象数据: tmax, tmin, tday, prcp, VPD, srad, daylen
- restart: spin-up 输出的一些参数
输出数据：
- annual output: leafc_to_litr1c, leafc_to_litr2c, leafc_to_litr3c, leafc_to_litr4c, proj_lai, all_lai, daily_hr
- daily output: leafc_to_litr1c, leafc_to_litr2c, leafc_to_litr3c, leafc_to_litr4c, proj_lai, all_lai, daily_hr
