scholarly journals MJO simulation in a cloud-system-resolving global ocean-atmosphere coupled model

2016 ◽  
Vol 43 (17) ◽  
pp. 9352-9360 ◽  
Author(s):  
Wataru Sasaki ◽  
Ryo Onishi ◽  
Hiromitsu Fuchigami ◽  
Koji Goto ◽  
Shiro Nishikawa ◽  
...  
Keyword(s):  
Coupled Model ◽  
Global Ocean ◽  
Cloud System ◽  
Ocean Atmosphere

Improved air–sea flux algorithms in an ocean–atmosphere coupled model for simulation of global ocean SST and its tropical Pacific variability

2014 ◽  
Vol 44 (5-6) ◽  
pp. 1473-1485 ◽  
Author(s):  
Yimin Ma ◽  
Xiaobing Zhou ◽  
Daohua Bi ◽  
Zhian Sun ◽  
Anthony C. Hirst
Keyword(s):  
Coupled Model ◽  
Tropical Pacific ◽  
Global Ocean ◽  
Ocean Atmosphere

Performance of the OPA/ARPEGE-T21 global ocean-atmosphere coupled model

1997 ◽  
Vol 13 (2) ◽  
pp. 149-165 ◽  
Author(s):  
E. Guilyardi ◽  
G. Madec
Keyword(s):  
Coupled Model ◽  
Global Ocean ◽  
Ocean Atmosphere

scholarly journals Response to Filchner-Ronne Ice Shelf cavity warming in a coupled ocean–ice sheet model. Part I: The ocean perspective

2017 ◽  
Author(s):  
Ralph Timmermann ◽  
Sebastian Goeller
Keyword(s):  
World Ocean ◽  
Ice Sheet ◽  
Coupled Model ◽  
Freezing Temperature ◽  
Ocean Model ◽  
Climate Forcing ◽  
Global Ocean ◽  
Ice Shelf ◽  
Marginal Seas ◽  
Grounding Line

Abstract. A Regional Antarctic and Global Ocean (RAnGO) model has been developed to study the interaction between the world ocean and the Antarctic ice sheet. The coupled model is based on a global implementation of the Finite Element Sea-ice Ocean Model (FESOM) with a mesh refinement in the Southern Ocean, particularly in its marginal seas and in the sub-ice shelf cavities. The cryosphere is represented by a regional setup of the ice flow model RIMBAY comprising the Filchner-Ronne Ice Shelf and the grounded ice in its catchment area up to the ice divides. At the base of the RIMBAY ice shelf, melt rates from FESOM's ice-shelf component are supplied. RIMBAY returns ice thickness and the position of the grounding line. The ocean model uses a pre-computed mesh to allow for an easy adjustment of the model domain to a varying cavity geometry. RAnGO simulations with a 20th-century climate forcing yield realistic basal melt rates and a quasi-stable grounding line position close to the presently observed state. In a centennial-scale warm-water-inflow scenario, the model suggests a substantial thinning of the ice shelf and a local retreat of the grounding line. The potentially negative feedback from ice-shelf thinning through a rising in-situ freezing temperature is more than outweighed by the increasing water column thickness in the deepest parts of the cavity. Compared to a control simulation with fixed ice-shelf geometry, the coupled model thus yields a slightly stronger increase of ice-shelf basal melt rates.

scholarly journals A Moist Quasi-Geostrophic Coupled Model: MQ-GCM2.0

2021 ◽  
Author(s):  
Sergey Kravtsov ◽  
Ilijana Mastilovic ◽  
Andrew McC. Hogg ◽  
William Dewar ◽  
Jeffrey Blundell
Keyword(s):  
Mixed Layer ◽  
Decadal Variability ◽  
Coupled Model ◽  
Realistic Model ◽  
Model Parameters ◽  
Wind Component ◽  
Apparent Lack ◽  
Ocean Atmosphere ◽  
Atmospheric Mixed Layer ◽  
New Formulation

Abstract. This paper contains a description of recent changes to the formulation and numerical implementation of the Quasi-Geostrophic Coupled Model (Q-GCM), which constitute a major update of the previous version of the model (Hogg et al., 2014). The Q-GCM model has been designed to provide an efficient numerical tool to study the dynamics of multi-scale mid-latitude air–sea interactions and their climatic impacts. The present additions/alterations were motivated by an inquiry into the dynamics of mesoscale ocean–atmosphere coupling and, in particular, by an apparent lack of Q-GCM atmosphere’s sensitivity to mesoscale sea-surface temperature (SST) anomalies, even at high (mesoscale) atmospheric resolutions, contrary to ample theoretical and observational evidence otherwise. Major modifications aimed at alleviating this problem include an improved radiative-convective scheme resulting in a more realistic model mean state and associated model parameters, a new formulation of entrainment in the atmosphere, which prompts more efficient communication between the atmospheric mixed layer and free troposphere, as well as an addition of temperature-dependent wind component in the atmospheric mixed layer and the resulting mesoscale feedbacks. The most drastic change is, however, the inclusion of moist dynamics in the model, which may be key to midlatitude ocean–atmosphere coupling. Accordingly, this version of the model is to be referred to as the MQ-GCM model. Overall, the MQ-GCM model is shown to exhibit a rich spectrum of behaviours reminiscent of many of the observed properties of the Earth’s climate system. It remains to be seen whether the added processes are able to affect in fundamental ways the simulated dynamics of the mid-latitude ocean–atmosphere system’s coupled decadal variability.

scholarly journals Experimental and diagnostic protocol for the physical component of the CMIP6 Ocean Model Intercomparison Project (OMIP)

2016 ◽  
Author(s):  
Stephen M. Griffies ◽  
Gokhan Danabasoglu ◽  
Paul J. Durack ◽  
Alistair J. Adcroft ◽  
V. Balaji ◽  
...  
Keyword(s):  
Sea Ice ◽  
Global Climate ◽  
Coupled Model ◽  
Companion Paper ◽  
Ocean Model ◽  
Global Ocean ◽  
Model Intercomparison ◽  
Experimental Protocol ◽  
Diagnostic Protocol ◽  
Intercomparison Project

Abstract. The Ocean Model Intercomparison Project (OMIP) aims to provide a framework for evaluating, understanding, and improving the ocean and sea-ice components of global climate and earth system models contributing to the Coupled Model Intercomparison Project Phase 6 (CMIP6). OMIP addresses these aims in two complementary manners: (A) by providing an experimental protocol for global ocean/sea-ice models run with a prescribed atmospheric forcing, (B) by providing a protocol for ocean diagnostics to be saved as part of CMIP6. We focus here on the physical component of OMIP, with a companion paper (Orr et al., 2016) offering details for the inert chemistry and interactive biogeochemistry. The physical portion of the OMIP experimental protocol follows that of the interannual Coordinated Ocean-ice Reference Experiments (CORE-II). Since 2009, CORE-I (Normal Year Forcing) and CORE-II have become the standard method to evaluate global ocean/sea-ice simulations and to examine mechanisms for forced ocean climate variability. The OMIP diagnostic protocol is relevant for any ocean model component of CMIP6, including the DECK (Diagnostic, Evaluation and Characterization of Klima experiments), historical simulations, FAFMIP (Flux Anomaly Forced MIP), C4MIP (Coupled Carbon Cycle Climate MIP), DAMIP (Detection and Attribution MIP), DCPP (Decadal Climate Prediction Project), ScenarioMIP (Scenario MIP), as well as the ocean-sea ice OMIP simulations. The bulk of this paper offers scientific rationale for saving these diagnostics.

scholarly journals Strongly Coupled Assimilation of a Hypothetical Ocean Current Observing Network within a Regional Ocean-Atmosphere Coupled Model: An OSSE Case Study of Typhoon Hato

2021 ◽  
Author(s):  
Luke Phillipson ◽  
Yi Li ◽  
Ralf Toumi
Keyword(s):  
Coupled Model ◽  
Ocean Currents ◽  
Hf Radar ◽  
Ocean Current ◽  
Coastal Current ◽  
Strongly Coupled ◽  
Ocean Atmosphere ◽  
Atmospheric Observations ◽  
Surface Drifters ◽  
The Impact

AbstractThe forecast of tropical cyclone (TC) intensity is a significant challenge. In this study, we showcase the impact of strongly coupled data assimilation with hypothetical ocean currents on analyses and forecasts of Typhoon Hato (2017). Several observation simulation system experiments were undertaken with a regional coupled ocean-atmosphere model. We assimilated combinations of (or individually) a hypothetical coastal current HF radar network, a dense array of drifter floats and minimum sea-level pressure. During the assimilation, instant updates of many important atmospheric variables (winds and pressure) are achieved from the assimilation of ocean current observations using the cross-domain error covariance, significantly improving the track and intensity analysis of Typhoon Hato. As compared to a control experiment (with no assimilation), the error of minimum pressure decreased by up to 13 hPa (4 hPa / 57 % on average). The maximum wind speed error decreased by up to 18 knots (5 knots / 41 % on average). By contrast, weakly coupled implementations cannot match these reductions (10% on average). Although traditional atmospheric observations were not assimilated, such improvements indicate there is considerable potential in assimilating ocean currents from coastal HF radar, and surface drifters within a strongly coupled framework for intense landfalling TCs.

The Flexible Global Ocean–Atmosphere–Land System Model, Grid-Point Version 2: FGOALS-g2

2013 ◽  
pp. 39-43 ◽  
Author(s):  
Lijuan Li ◽  
Pengfei Lin ◽  
Yongqiang Yu ◽  
Bin Wang ◽  
Tianjun Zhou ◽  
...  
Keyword(s):  
Grid Point ◽  
System Model ◽  
Global Ocean ◽  
Land System ◽  
Ocean Atmosphere

Evaluating Met Office uncoupled and coupled forecasts during the Iceland Greenland Seas Project field campaign in 2018

2021 ◽  
Author(s):  
Chris Barrell ◽  
Ian Renfrew ◽  
Steven Abel ◽  
Andrew Elvidge ◽  
John King
Keyword(s):  
Sea Ice ◽  
Ocean Circulation ◽  
Rapid Change ◽  
Coupled Model ◽  
Vital Role ◽  
Meridional Overturning Circulation ◽  
Global Ocean ◽  
Near Surface ◽  
Field Campaign ◽  
Important Region

<div> <p>During a cold-air outbreak (CAO) a cold polar airmass flows from the frozen land or ice surface, over the marginal ice zone (MIZ), then out over the comparatively warm open ocean. This constitutes a dramatic change in surface temperature, roughness and moisture availability, typically causing rapid change in the atmospheric boundary layer. Consequently, CAOs are associated with a range of severe mesoscale weather phenomena and accurate forecasting is crucial. Over the Nordic Seas CAOs also play a vital role in global ocean circulation, causing densification and sinking of ocean waters that form the headwaters of the Atlantic meridional overturning circulation. </p> </div><div> <p>To tackle the lack of observations during wintertime CAOs and improve scientific understanding in this important region, the Iceland Greenland Seas Project (IGP) undertook an extensive field campaign during February and March 2018. Aiming to characterise the atmospheric forcing and the ocean response, particularly in and around the MIZ, the IGP made coordinated ocean-atmosphere measurements, involving a research vessel, a research aircraft, a meteorological buoy, moorings, sea gliders and floats.  </p> </div><div> <p>The work presented here employs these novel observational data to evaluate output from the UK Met Office global operational forecasting system and from a pre-operational coupled ocean-ice-atmosphere system. The Met Office aim to transition to a coupled operational forecast in the coming years, thus verification of model versions in development is essential. Results show that this coupled model’s sea ice is generally more accurate than a persistent field. However, it can also suffer from cold-biased sea surface temperatures around the MIZ, which influences the modelled near-surface meteorology. Both these effects demonstrate the crucial importance of accurate sea ice simulation in coupled model forecasting in the high latitudes. Hence, an ice edge metric is then used to quantify the accuracy of the coupled model MIZ edge at two ocean grid resolutions. </p> </div>

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