Abstract
Many climate models struggle with a poor simulation of the Madden-Julian Oscillation (MJO), especially its propagation across the Maritime Continent (MC). This study quantitatively evaluates the robustness of MJO propagation over the MC in climate models that participated in Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 6 (CMIP6) with a newly developed MC propagation metric. The results show that the CMIP6 models simulate MJO propagation over the MC more realistically than the CMIP5 models. Lower free-tropospheric moisture budget analysis highlights that the greater horizontal moisture advection is responsible for the enhanced MJO propagation over the MC. The increase in horizontal moisture advection in the CMIP6 models is mainly attributed to the steeper horizontal mean state moisture gradient around the MC, which is associated with the reduction of the equatorial dry bias.
Original language | English |
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Article number | e2020GL087250 |
Journal | Geophysical Research Letters |
Volume | 47 |
Issue number | 11 |
DOIs | |
State | Published - 16 Jun 2020 |
Bibliographical note
Funding Information:Constructive and valuable comments from the reviewers are greatly appreciated. M.-S. A., D. Kim, and D. Kang were supported by the NOAA CVP program (NA18OAR4310300), the U.S. DOE RGMA program (DE-SC0016223), and the NASA MAP program (80NSSC17K0227). D. Kim, H. K., and Y.-G. H. were also supported by KMA R&D program (KMI2018-03110). J. L., K. S., and P. G.'s work was performed under the auspices of the U.S. DOE (BER, RGMA Program) by LLNL under Contract DE-AC52-07NA27344. X. J. acknowledges support by the NOAA Climate Program Office under awards NA17OAR4310261. We thank DOE's RGMA program area, the Data Management program, and NERSC for making this coordinated CMIP6 analysis activity possible. For CMIP, the U.S. DOE's PCMDI provides coordinating support and led development of the software infrastructure in partnership with the Global Organization for Earth System Science Portals. The ESGF provided the CMIP model data (https://esgf-node.llnl.gov/projects/esgf-llnl). The TRMM provided the precipitation data (https://pmm.nasa.gov/data-access/downloads/trmm). The CMORPH provided the precipitation data (https://www.cpc.ncep.noaa.gov/products/janowiak/cmorph_description.html). The ECMWF provided the fifth generation of ECMWF reanalysis (ERA5, https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5).
Funding Information:
Constructive and valuable comments from the reviewers are greatly appreciated. M.‐S. A., D. Kim, and D. Kang were supported by the NOAA CVP program (NA18OAR4310300), the U.S. DOE RGMA program (DE‐SC0016223), and the NASA MAP program (80NSSC17K0227). D. Kim, H. K., and Y.‐G. H. were also supported by KMA R&D program (KMI2018‐03110). J. L., K. S., and P. G.'s work was performed under the auspices of the U.S. DOE (BER, RGMA Program) by LLNL under Contract DE‐AC52‐07NA27344. X. J. acknowledges support by the NOAA Climate Program Office under awards NA17OAR4310261. We thank DOE's RGMA program area, the Data Management program, and NERSC for making this coordinated CMIP6 analysis activity possible. For CMIP, the U.S. DOE's PCMDI provides coordinating support and led development of the software infrastructure in partnership with the Global Organization for Earth System Science Portals. The ESGF provided the CMIP model data ( https://esgf-node.llnl.gov/projects/esgf-llnl ). The TRMM provided the precipitation data ( https://pmm.nasa.gov/data-access/downloads/trmm ). The CMORPH provided the precipitation data ( https://www.cpc.ncep.noaa.gov/products/janowiak/cmorph_description.html ). The ECMWF provided the fifth generation of ECMWF reanalysis (ERA5, https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 ).
Publisher Copyright:
© 2020. The Authors.