A CESM2-based LW and SW band-by-band cloud radiative kernel

by Xianglei Huang, Xiuhong Chen (Univ. of Michigan) and Qing Yue(JPL/Caltech)

Reference: Huang, X.L., X. H. Chen, Q. Yue, Band-by-band contributions to the longwave cloud radiative feedbacks, Geophysical Research Letters, doi.org/10.1029/2019GL083466, 2019.

All data are in NetCDF formats.

  • AMIP_CAM6_LW.tar.gz (link) contains the monthly longwave (LW) cloud radiative kernels (CRKs) derived from the 3-hourly output of the CESM2 AMIP run (F_2000 forced with observed SST; the year 2003-2013). 16 RRTMG LW bands are used. To get the broadband LW kernel, just need to sum over all the bands
  • AMIP_CAM6_SW.tar.gz (link) contains the monthly shortwave (SW) cloud radiatve kernels (CRKs) derived in from the 3-hourly output of the CESM2 AMIP run (F_2000 forced with observed SST; the year 2003-2013). 14 RRTMG SW bands are used. To get the broadband SW kernel, just need to sum over all the bands
  • Readme file for further information.

To get cloud radiative feedback: use the monthly CRKs multiplying with monthly cloud fraction change between two climate states delta_C(y,x,i,j) in %, and then divided by surface temperature change.The monthly cloud fraction output should be the output from COSP simulator, which is on the tau/CTP diagram already. If you need a separate code to compute this, please contact us.

  • All simulations were done using the CESM version 1.1.1.
  • The unit for all kernels is W per square meter per 1% change of cloud fraction.

Dimensional Information:

  • 192 latitudes: -90:0.9424:90
  • 288 longitudes: 0:1.25:357.5
  • 7 CTP bins: 1100-800, 800-680, 680-560, 560-440, 440-310, 310-180, 180-50 hPa
  • 7 tau bins: 0-0.3, 0.3-1.3, 1.3-3.6, 3.6-9.4, 9.4-23, 23-60, 60-380 (note: as in COSP or ISCCP simualtors, tau here refers to the visible optical depth at 0.55 um
  • 16 RRTMG-LW bands (in cm-1): 10-350, 350-500, 500-630, 630-700, 700-820, 820-980, 980-1080,1080-1180, 1180-1390, 1390-1480, 1480-1800, 1800-2080, 2080-2250,2250-2380, 2380-2600, 2600-3000
  • 14 RRTMG-SW bands (in cm-1): 2600-3250, 3250-4000, 4000-4650, 4650-5150, 5150-6150, 6150-7700, 7700-8050,8050-12850, 12850-16000, 16000-22650, 22650-29000, 29000-38000, 38000-50000,820-2600

Acknowledgements: The results here were based on the findings from a research project awarded to Qing Yue and Xianglei Huang by the NASA CloudSat/CALIPSO program.

If you have questions, please contact Xianglei Huang.