 |
| Titel |
A sensitivity study of radiative fluxes at the top of atmosphere to cloud-microphysics and aerosol parameters in the community atmosphere model CAM5 |
| VerfasserIn |
C. Zhao, X. Liu, Y. Qian, J. Yoon, Z. Hou, G. Lin, S. McFarlane, H. Wang, B. Yang, P.-L. Ma, H. Yan, J. Bao |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 21 ; Nr. 13, no. 21 (2013-11-08), S.10969-10987 |
| Datensatznummer |
250085806
|
| Publikation (Nr.) |
 copernicus.org/acp-13-10969-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| In this study, we investigated the sensitivity of net
radiative fluxes (FNET) at the top of atmosphere (TOA) to 16 selected
uncertain parameters mainly related to the cloud microphysics and aerosol
schemes in the Community Atmosphere Model version 5 (CAM5). We adopted a
quasi-Monte Carlo (QMC) sampling approach to effectively explore the high-dimensional parameter space. The output response variables (e.g., FNET) are
simulated using CAM5 for each parameter set, and then evaluated using the
generalized linear model analysis. In response to the perturbations of these
16 parameters, the CAM5-simulated global annual mean FNET ranges from −9.8
to 3.5 W m−2 compared to 1.9 W m−2 with the default parameter
values. Variance-based sensitivity analysis is conducted to show the
relative contributions of individual parameter perturbations to the global
FNET variance. The results indicate that the changes in the global mean FNET
are dominated by changes in net cloud forcing (CF) within the parameter
ranges being investigated. The threshold size parameter related to
auto-conversion of cloud ice to snow is identified as one of the most
influential parameters for FNET in CAM5 simulations. The strong
heterogeneous geographic distribution of FNET variance shows that parameters
have a clear localized effect over regions where they are acting. However,
some parameters also have non-local impacts on FNET variance. Although
external factors, such as perturbations of anthropogenic and natural
emissions, largely affect FNET variance at the regional scale, their impact
is weaker than that of model internal parameters in terms of simulating
global mean FNET. The interactions among the 16 selected parameters
contribute a relatively small portion to the total FNET variance over most
regions of the globe. This study helps us better understand the parameter
uncertainties in the CAM5 model, and thus provides information for further
calibrating uncertain model parameters with the largest sensitivity. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|