ICBM, the Introductory Carbon Balance Model 

ICBM is a simple soil carbon model suitable for making projections of soil C dynamics in temperate and tropical land-use systems, originally for agricultural land. It has been used for IPCC greenhouse gas reporting on arable land in Sweden, USA and Norway. The model is based on two state equations and five parameters describing two compartments, Young and Old soil C (see Fig) and can be downloaded as a simple Excel spreadsheet, but also be a component in very complex simulation systems describing daily soil carbon dynamics in soils, cropping systems, climates, regions for a whole country during 30 years or more.

2013 News

2013-10-14 New  mother archive - corrected a serious bug in ICBM_mother_sim_3 - now ver 4 - should be correct . Now also included ICBM as an R function: ICBM_mother_sim_func_4. And a new R program for calculating Et0.

2013-10-08 New mother archive - corrected Et0calc.r that had a bug in radiation calculations.

2013-05-22 Now a zip archive, mother_archive_20130522,  with 'mother' versions of ICBM: R, SAS, Excel. Including base ICBM, re_clim calculations, conversion of weather data (Penman-Monteith, Allen et al. -98, etc.), ICBM with driving variables... (ca 5 MB). The latest versions should be here. Also download manual from 2012 below. Also now Excel version of ICBM for simulation.

 ICBM now available in R! Climate calculations, ICBM in pure form and with driving variables here (ZIP ARCHIVE) Enclosed is also a SAS program that is the 'mother' program re_clim calculations - now v. 2 - used for checking other programming and for calibration.

The Excel file for re calculations below (2012) has some flaws, does not give exactly the same results as the SAS and R files. I may make a new version soon...but the current version is still useful.

2012 News

Download a manual and Excel programs - a complete set for simple calculations of soil C balances. Developed for long-term soil C balances in Africa - but can be used anywhere.

Zip Archive (9 Mb) Manual Input (Excel) Climate calcs (8 Mb) ICBM Background paper

 Suggestion: Click on 'ICBM' above and play with the Excel ICBM model!

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Read a presentation and find links here (PDF)! Excel and SAS programs for download or interactive testing. Also routines for calculation of soil activity from weather station data.

Test an Excel program interactively here!

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