Main menu

Navigation

CMIP5 CCSM4 Last Glacial Maximum dates

5 posts / 0 new
Last post
bdmorri2@...
CMIP5 CCSM4 Last Glacial Maximum dates

Hello,

I am currently using CMIP5 CCSM4 last glacial maximum data, but I am confused on the exact dates of the data. For example one of the files I am using is hurs_Amon_CCSM4_lgm_r1i1p1_180001-190012.nc. When I load the data and view the layers, I can see that there are around 1000 monthly averages for 100 years, but the date represented in the meta data says that it runs from 1800 - 1900, which is not LGM (should be around 20,000 years ago). However when I downloaded the file from ESGF, the "model documentation" says that it starts "around" 19000 and runs for 100 years. Does anyone know the actual dates for the CCSM4 lgm model runs?

 

 

Thank you,

Bailey Morrison

University of Illinois at Urbana Champaign

Global Environmental Analysis and Remote Sensing Lab

Bailey Morrison
University of Illinois at Urbana-Champaign
PhD Student
Global Environmental Analysis and Remote Sensing (GEARS) Laboratory

bdmorri2@...

Also, the files says that it has no coordinate reference system and I cannot figure out what the spatial units are. We believe they are in meters, but I cannot find that information any where since it spatially it is unit less. Reprojecting it has not helped. 

Bailey Morrison
University of Illinois at Urbana-Champaign
PhD Student
Global Environmental Analysis and Remote Sensing (GEARS) Laboratory

strandwg

The geographic axes are degrees east (for longitude) and degrees north (for latitude). The earth is treated a perfect sphere of 6.37122 * 10^6 m radius. There is no "coordinate reference system" as is commonly used in GIS applications.

You may want to contact the GIS group here

 

https://gisclimatechange.ucar.edu/

 

For guidance on how best to use CESM model output with GIS.

 

strandwg

The model's dates are somewhat arbitrary; in this instance they are merely a model time counter and not referenced to an absolute calendar.

 

You can treat this simulation as 100 years of model time under LGM conditions.

bdmorri2@...

Thank you very much for your help!

 

 

Bailey Morrison
University of Illinois at Urbana-Champaign
PhD Student
Global Environmental Analysis and Remote Sensing (GEARS) Laboratory

Log in or register to post comments

Who's new

  • opioronald123@...
  • shimura.tomoya....
  • rack.hun.son@...
  • nathalie.schall...
  • sf870222@...