Abstract
Shortwave and longwave 2D radiative transfer calculations were performed using Monte Carlo radiative transfer models and output from a global climate model (GCM) that employed, in each of its columns, a 2D cloud system-resolving model (CSRM) with a horizontal gridspacing Δx of 4 km. CSRM output were sampled every 9 hours for December 2000. Radiative fluxes were averaged to the GCM's grid. Monthly-mean top of atmosphere (TOA) shortwave flux differences between 2D radiative transfer and the Independent Column Approximation (ICA) are at most 5 W m-2 in the tropics with a zonal-average of 1.5 W m-2. These differences are 2 to 10 times smaller than those stemming from the maximum-random overlap model and neglect of horizontal variability of cloud. Corresponding longwave differences are approximately 3 times smaller than their shortwave counterparts. Use of CSRM data with Δx < 4 km may roughly double the reported differences between 2D and ICA TOA SW fluxes.
Original language | English (US) |
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Article number | L19817 |
Pages (from-to) | 1-5 |
Number of pages | 5 |
Journal | Geophysical Research Letters |
Volume | 32 |
Issue number | 19 |
DOIs | |
State | Published - Oct 16 2005 |
All Science Journal Classification (ASJC) codes
- Geophysics
- General Earth and Planetary Sciences