We have developed simulation output that is intended to be used as boundary conditions for regional modeling. We used CAM-chem at 0.9x1.25 horizontal resolution simulation with 56 vertical levels. Meteorology is driven by specified dynamics, by nudging with 50h relaxation (1%) to MERRA2 reanalysis. Data is saved as instantaneous fields every 6 hours. See a list of saved species. Files are collected as daily information (4 time-slices per file). Data coverage is January 2001 to June 2018. Anthropogenic emissions are from CMIP6, CMIP6 2014 anthropogenic emissions are repeated for dates past 2014. Biogenic emissions are from online MEGAN2.1, fire emissions are from QFED. Note that fire emitted DMS 2001-2015 is from CMIP6 and in 2016 and 2017 is from GFAS.

*** NOTE: The current version of output has incorrect HCN and O3S, please disregard these species ***

Get the data

1. Dates within the time period January 1, 2010 to June 30, 2018

A small subset of the boundary conditions are available via rapid access from the ACOM server:

Regional and temporal subsetting option can be found at:

2. All available dates January 1, 2001 to 2017

To access any of the complete dataset of shared files between January 2001 and June 2017 you will need a Globus account, which requires a Google account. Get Globus access here.

Once you can log into Globus, the boundary conditions are stored here:

Files can be transferred to another location using the Globus system. To set up a transfer point see the relevant page:


Note: direct download option from this site is in beta testing phase and should be available in the future.


Please use the following reference when using the data:

Emmons et al., in prep

Additionally, to cite the data directly, please use:

Buchholz, R., 2019. CESM2/CAM-chem instantaneous output for boundary conditions. National Center for Atmospheric Research, Atmospheric Chemistry Observations and Modeling Laboratory. DOI: TBD. Accessed dd mmm yyyy.

  Please fill in the "Accessed" date with the day, month, and year (e.g. - 5 Aug 2011) you last accessed the data

Other simulations

Other experimental output can be found here: Benchmarks and Production