New GHG feature

[msimmond]

2 GHG feature adds the following functionality to CALAND():

• partitions existing management-driven land to atmosphere C fluxes into burned and non-burned C pools based on c pool- and management-specific fractions that can be changed at the beginning of CALAND()
• partitions the burned C pools (including land to bioenergy) into CO2-C, CH4-C, and black carbon-C (Liu et al, 2014), while non-burned C pools is CO2-C
• adds the following additional land to atmosphere C fluxes: (a) net negative ecosystem C fluxes as CO2-C, and (b) CO2-C and CH4-C fluxes from fresh marshland (Knox et al, 2015)
• converts CO2-C, CH4-C, and black carbon-C to CO2-equivalents based on 100-y timespan
• adds tables to existing output excel file as additional sheets, including total GWP

[msimmond]

@aldivi Ok - that makes sense. I'll add in the other land types to account for CO2 uptake.

I changed the output file format to .xls because I was getting an error when trying to open the .xlsx file in Excel, saying the file was unreadable and needed to be repaired. This is a known issue, and changing it from ".xlsx" to ".xls" was a suggested fix. It worked and it also reduced the writing output time to less than a minute instead of ~15 mins.

[msimmond]

@aldivi the eco GHG C exchange is now included for all land types in the develop_GHG branch. All the internal checks and output numbers are looking good -- differences between various combinations of total GHG or CO2-eq and its components are either 0 or between -1 and 1 due to rounding errors.