LMDZ5B: the atmospheric component of the IPSL climate model with revisited parameterizations for clouds and convection
By Frederic Hourdin, J. Grandpeix, C. Rio, Sandrine Bony, A. Jam, Frédérique Cheruy, N. Rochetin, L. Fairhead, A. Idelkadi, I. Musat and 4 more. Climate Dynamics, 2013
272 citations recorded by the source corpus.
Based on a decade of research on cloud processes, a new version of the LMDZ atmospheric general circulation model has been developed that corresponds to a complete recasting of the parameterization of turbulence, convection and clouds. This LMDZ5B version includes a mass-flux representation of the thermal plumes or rolls of the convective boundary layer, coupled to a bi-Gaussian statistical cloud scheme, as well as a parameterization of the cold pools generated below cumulonimbus by re-evaporation of convective precipitation. The triggering and closure of deep convection are now controlled by lifting processes in the sub-cloud layer. An available lifting energy and lifting power are provided both by the thermal plumes and by the spread of cold pools. The individual parameterizations were carefully validated against the results of explicit high resolution simulations. Here we present the work done to go from those new concepts and developments to a full 3D atmospheric model, used in particular for climate change projections with the IPSL-CM5B coupled model. Based on a series of sensitivity experiments, we document the differences with the previous LMDZ5A version distinguishing the role of parameterization changes from that of model tuning. Improvements found previously in single-column simulations of case studies are confirmed in the 3D model: (1) the convective boundary layer and cumulus clouds are better represented and (2) the diurnal cycle of convective rainfall over continents is delayed by several hours, solving a longstanding problem in climate modeling. The variability of tropical rainfall is also larger in LMDZ5B at intraseasonal time-scales. Significant biases of the LMDZ5A model however remain, or are even sometimes amplified. The paper emphasizes the importance of parameterization improvements and model tuning in the frame of climate change studies as well as the new paradigm that represents the improvement of 3D climate models under the control of single-column case studies simulations.
Subfields: Atmospheric Science, Global and Planetary Change
View Paper: https://www.semanticscholar.org/paper/0496536216ff2fd0021c25a6ff891cb16733731a
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Atmospheric Science
In Global and Planetary Change
Citations in the corpus
- Presentation and Evaluation of the IPSL‐CM6A‐LR Climate Model (2020, methodology): “The jets, which are located too close to the equator in most CMIP models, are known to generally move poleward when the horizontal resolution is increased (Hourdin et al., 2013a).”
- Mixed-phase clouds cause climate model biases in Arctic wintertime temperature inversions (2014, unknown): “0.9941 exp(0.003102 T2) IPSL-CM5A LMDZ5A 39 Hourdin et al. (2012) Linear between 0 and -15 MIROC-ESM MIROC-AGCM 80 Watanabe et al. (2011) f = 1 - exp[(-((268.91K -”
- Climate change projections using the IPSL-CM5 Earth System Model: from CMIP3 to CMIP5 (2013, methodology): “The reasons for this difference may be related to the reduction of the southern westerlies biases in IPSL- CM5A-MR compared to IPSL-CM5A-LR (see Hourdin et al. 2013a) and its impact on oceanic carbon uptake as demonstrated in Swart and Fyfe (2012).”
- Evaluation of CMIP6 DECK Experiments With CNRM‐CM6‐1 (2019, methodology): “…that atmospheric processes are better represented by this drastic change in atmospheric parameterizations; however, this may not result in a general improvement of the model as experienced by other models, as shown, for example, by the version 5B of the IPSL‐CM model (Hourdin et al., 2013).”