In:
Geoscientific Model Development, Copernicus GmbH, Vol. 15, No. 14 ( 2022-07-20), p. 5529-5546
Abstract:
Abstract. A one-column, turbulent, and kinetic-energy-type ocean mixed-layer model
(snow–ice–thermocline, SIT), when coupled with three atmospheric general
circulation models (AGCMs), yields superior Madden–Julian oscillation (MJO)
simulations. SIT is designed to have fine layers similar to those observed
near the ocean surface; therefore, it can realistically simulate the diurnal
warm layer and cool skin. This refined discretization of the near-surface ocean
in SIT provides accurate sea surface temperature (SST) simulation, and
thus facilitates realistic air–sea interaction. Coupling SIT with
the European Centre/Hamburg Model version 5, the Community Atmosphere Model
version 5, and the High-Resolution Atmospheric Model significantly improved MJO
simulation in three coupled AGCMs compared to the AGCM driven by a
prescribed SST. This study suggests two major improvements to the coupling
process. First, during the preconditioning phase of MJO over the Maritime
Continent (MC), the often underestimated surface latent heat bias in AGCMs
can be corrected. Second, during the phase of strongest convection over the MC,
the change in intraseasonal circulation in the meridional circulation
enhancing near-surface moisture convergence is the dominant factor in the
coupled simulations relative to the uncoupled experiments. The study results
show that a fine vertical resolution near the surface, which better captures
temperature variations in the upper few meters of the ocean, considerably
improves different models with different configurations and physical
parameterization schemes; this could be an essential factor for accurate MJO
simulation.
Type of Medium:
Online Resource
ISSN:
1991-9603
DOI:
10.5194/gmd-15-5529-2022
DOI:
10.5194/gmd-15-5529-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2456725-5
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