A Brief Study on the Achievement of Syukuro Manabe, Awardee of 2021 Nobel Prize in Physics

2021 ◽  
Vol 30 (12) ◽  
pp. 10-15
Author(s):  
Kyung-Ja HA
Keyword(s):  
Global Warming ◽  
General Circulation ◽  
Climate Modeling ◽  
Thermal Structure ◽  
Circulation Model ◽  
First Results ◽  
Atmosphere General Circulation Model ◽  
Nobel Prize In Physics

Manabe Syukuro is well known as a father of climate modeling. He and his colleagues have achieved several important milestones in the research on global warming. In this article, two highly advanced subjects are described. In the early 1960s, he developed a radiative-convective model of the atmosphere and explored the role of greenhouse gases, such as water vapor, carbon dioxide, and ozone in maintaining and changing the thermal structure of the atmosphere. His study was the beginning of long-term research on global warming. In 1969, Manabe and Bryan published the first results from a coupled ocean-atmosphere general circulation model (OAGCM). However, this model used a highly idealized continent-ocean configuration. Results from the first coupled OAGCM with more realistic configurations were published in 1975, which eventually became a very powerful tool for the simulation of global warming.

scholarly journals Representation of Tropical Mesoscale Convective Systems in a General Circulation Model: Climatology and Response to Global Warming

2021 ◽  
pp. 1-40
Author(s):  
Wenhao Dong ◽  
Ming Zhao ◽  
Yi Ming ◽  
V. Ramaswamy
Keyword(s):  
Global Warming ◽  
General Circulation ◽  
Circulation Model ◽  
Mesoscale Convective Systems ◽  
Geophysical Fluid Dynamics Laboratory ◽  
Strongly Correlated ◽  
Event Scale ◽  
Convective Systems ◽  
Mesoscale Convective

AbstractThe characteristics of tropical mesoscale convective systems (MCSs) simulated with a finer-resolution (~50-km) version of the Geophysical Fluid Dynamics Laboratory (GFDL) AM4 model are evaluated by comparing with a comprehensive long-term observational dataset. It is shown that the model can capture the various aspects of MCSs reasonably well. The simulated spatial distribution of MCSs is broadly in agreement with the observations. This is also true for seasonality and interannual variability over different land and oceanic regions. The simulated MCSs are generally longer-lived, weaker and larger than observed. Despite these biases, an event-scale analysis suggests that their duration, intensity and size are strongly correlated. Specifically, longer-lived and stronger events tend to be bigger, which is consistent with the observations. The same model is used to investigate the response of tropical MCSs to global warming using time-slice simulations forced by prescribed sea surface temperatures (SST) and sea-ice. There is an overall decrease in occurrence frequency, and the reduction over land is more prominent than over ocean.

Long-term Surface Temperature (LoST) Database as a Complement for Transient and Control Preindustrial Simulations

2021 ◽  
Author(s):  
Francisco José Cuesta-Valero ◽  
Almudena García-García ◽  
Hugo Beltrami ◽  
Eduardo Zorita ◽  
Fernando Jaume Santero
Keyword(s):  
Surface Temperature ◽  
General Circulation ◽  
Climate Modeling ◽  
Ground Surface ◽  
Coupled Model ◽  
Circulation Model ◽  
Temperature Profiles ◽  
Intercomparison Project ◽  
Past Millennium

<div>Estimates of climate sensitivity from Atmosphere-Ocean Coupled General Circulation Model (GCM) simulations present a large spread despite the continued improvements in climate modeling since the 1970s. This variability is partially caused by the dependence of several long-term feedback mechanisms on the reference climate state. However, it is difficult to provide a reference to assess the climatology of preindustrial control simulations as there are no long-term preindustrial observations.<br>In the ground, recent changes in ground surface temperature are observed at shallow depths as perturbations to the quasi-steady state geothermal regime. However, if undisturbed by recent surface temperature changes, the deep ground temperatures vary linearly as a function of depth, and the extrapolation of this linear behavior to the surface can be interpreted as the past long-term surface temperature climatology.</div><div>We assemble a new gridded database of past long-term ground surface temperatures (LoST database) obtained from 514 borehole temperature profiles measured across North America, and we explore its use as a potential reference for the evaluation of GCM preindustrial control simulations and past millennium simulations. All temperature profiles are truncated at 300 m depth, allowing to estimate the ground surface climatology for the period 1300-1700 of the common era. We compare the LoST database with observations from the CRU database, as well as with five past millennium simulations and five preindustrial control simulations from the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3) and the fifth phase of the Coupled Model Intercomparison Project (CMIP5) archives. Our results suggest that LoST temperatures could be employed as a reference to narrow down the spread of surface temperature climatologies on GCM preindustrial control and past millennium simulations.</div>

scholarly journals Modelling Maastrichtian climate: investigating the role of geography, atmospheric CO<sub>2</sub> and vegetation

2008 ◽  
Vol 4 (4) ◽  
pp. 981-1019 ◽  
Author(s):  
S. J. Hunter ◽  
P. J. Valdes ◽  
A. M. Haywood ◽  
P. J. Markwick
Keyword(s):  
General Circulation ◽  
General Pattern ◽  
Circulation Model ◽  
Atmospheric Co2 ◽  
High Latitudes ◽  
Industrial Experiment ◽  
Co2 Levels ◽  
Modelling Studies ◽  
Atmosphere General Circulation Model

Abstract. In this paper we describe the results from an ensemble of palaeoclimate simulations of the Maastrichtian using the fully-coupled dynamic ocean-atmosphere General Circulation Model, HadCM3L. Using appropriate Maastrichtian boundary conditions, we investigate the sensitivity of the predicted palaeoclimate to changing atmospheric CO2 levels and modelled vegetation treatment. In addition, we explore the climatic response to the changed geography using a comparison with a pre-industrial experiment. We describe our results alongside the findings of previous modelling studies in particular with consideration to concepts of climate equability. Our findings demonstrate increased global temperatures compared with the pre-industrial experiment, with a 5.9°C increase in temperatures associated with the change to 1×CO2 Maastrichtian conditions and a further 3.9°C warming associated with a quadrupling of atmospheric CO2 levels. Compared to the pre-industrial we find a latitudinal temperature profile that is reduced in gradient and shifted to higher temperatures. Our control 4×CO Maastrichtian experiment exceeds the pre-industrial by 6.5–8.6°C, 7.4–11.2°C, and 10.1–32.4°C in the equatorial, mid and high latitudes respectively. We also find a general pattern of increased thermal seasonality in the high latitudes. In terms of global mean annual temperatures we find a range of 18.1–23.6°C for our 1–6×atmospheric CO2 envelope. Other than in the northern high latitudes we find satisfactory levels of agreement between the ensemble temperature envelope and estimates from palaeotemperature proxies. The inclusion of a dynamic vegetation model (TRIFFID) leads to a further increase in the thermal seasonality at high latitudes, warming in the mid to high latitudes and increased precipitation in the low and mid latitudes.

scholarly journals Long-term Surface Temperature (LoST) Database as a complement for GCM preindustrial simulations

2018 ◽  
Author(s):  
Francisco José Cuesta-Valero ◽  
Almudena García-García ◽  
Hugo Beltrami ◽  
Eduardo Zorita ◽  
Fernando Jaume-Santero
Keyword(s):  
Surface Temperature ◽  
General Circulation ◽  
Climate Modeling ◽  
Ground Surface ◽  
Coupled Model ◽  
Circulation Model ◽  
Large Spread ◽  
Intercomparison Project ◽  
Past Millennium

Abstract. Estimates of climate sensitivity from General Circulation Model (GCM) simulations still present a large spread despite the continued improvements in climate modeling since the 1970s. This variability is partially caused by the dependence of several long-term feedback mechanisms on the reference climate state. Indeed, state-of-the-art GCMs present a large spread of control climate states probably due to the lack of a suitable reference for constraining the climatology of preindustrial simulations. We assemble a new gridded database of long-term ground surface temperatures (LoST database) obtained from geothermal data over North America, and we explore its use as a potential reference for the evaluation of GCM preindustrial simulations. We compare the LoST database with observations from the CRU database, as well as with five past millennium transient climate simulations and five preindustrial control simulations from the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3) and the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The database is consistent with meteorological observations as well as with both types of preindustrial simulations, which suggests that LoST temperatures can be employed as a reference to narrow down the spread of surface temperature climatologies on GCM preindustrial control and past millennium simulations.

scholarly journals Estimating the Continental Response to Global Warming Using Pattern-Scaled Sea Surface Temperatures and Sea Ice

2016 ◽  
Vol 29 (24) ◽  
pp. 9125-9139 ◽  
Author(s):  
Adeline Bichet ◽  
Paul J. Kushner ◽  
Lawrence Mudryk
Keyword(s):  
Global Warming ◽  
Sea Ice ◽  
General Circulation ◽  
Circulation Model ◽  
Tropical Indian Ocean ◽  
Sea Surface ◽  
Climate Projections ◽  
Western Boundary ◽  
Sea Ice Concentration ◽  
Continental Climate

Abstract Better constraining the continental climate response to anthropogenic forcing is essential to improve climate projections. In this study, pattern scaling is used to extract, from observations, the patterned response of sea surface temperature (SST) and sea ice concentration (SICE) to anthropogenically dominated long-term global warming. The SST response pattern includes a warming of the tropical Indian Ocean, the high northern latitudes, and the western boundary currents. The SICE pattern shows seasonal variations of the main locations of sea ice loss. These SST–SICE response patterns are used to drive an ensemble of an atmospheric general circulation model, the National Center for Atmospheric Research (NCAR) Community Atmosphere Model, version 5 (CAM5), over the period 1980–2010 along with a standard AMIP ensemble using observed SST—SICE. The simulations enable attribution of a variety of observed trends of continental climate to global warming. On the one hand, the warming trends observed in all seasons across the entire Northern Hemisphere extratropics result from global warming, as does the snow loss observed over the northern midlatitudes and northwestern Eurasia. On the other hand, 1980–2010 precipitation trends observed in winter over North America and in summer over Africa result from the recent decreasing phase of the Pacific decadal oscillation and the recent increasing phase of the Atlantic multidecadal oscillation, respectively, which are not part of the global warming signal. The method holds promise for near-term decadal climate prediction but as currently framed cannot distinguish regional signals associated with oceanic internal variability from aerosol forcing and other sources of short-term forcing.

scholarly journals Sensitivity of the tropical climate to an interhemispheric thermal gradient: the role of tropical ocean dynamics

2018 ◽  
Vol 9 (1) ◽  
pp. 285-297 ◽  
Author(s):  
Stefanie Talento ◽  
Marcelo Barreiro
Keyword(s):  
Seasonal Cycle ◽  
General Circulation ◽  
Southern Oscillation ◽  
Circulation Model ◽  
Ocean Dynamics ◽  
Thermocline Depth ◽  
Thermal Forcing ◽  
Tropical Ocean ◽  
Slab Ocean

Abstract. This study aims to determine the role of the tropical ocean dynamics in the response of the climate to extratropical thermal forcing. We analyse and compare the outcomes of coupling an atmospheric general circulation model (AGCM) with two ocean models of different complexity. In the first configuration the AGCM is coupled with a slab ocean model while in the second a reduced gravity ocean (RGO) model is additionally coupled in the tropical region. We find that the imposition of extratropical thermal forcing (warming in the Northern Hemisphere and cooling in the Southern Hemisphere with zero global mean) produces, in terms of annual means, a weaker response when the RGO is coupled, thus indicating that the tropical ocean dynamics oppose the incoming remote signal. On the other hand, while the slab ocean coupling does not produce significant changes to the equatorial Pacific sea surface temperature (SST) seasonal cycle, the RGO configuration generates strong warming in the central-eastern basin from April to August balanced by cooling during the rest of the year, strengthening the seasonal cycle in the eastern portion of the basin. We hypothesize that such changes are possible via the dynamical effect that zonal wind stress has on the thermocline depth. We also find that the imposed extratropical pattern affects El Niño–Southern Oscillation, weakening its amplitude and low-frequency behaviour.

scholarly journals Coupled ice sheet–climate modeling under glacial and pre-industrial boundary conditions

2014 ◽  
Vol 10 (5) ◽  
pp. 1817-1836 ◽  
Author(s):  
F. A. Ziemen ◽  
C. B. Rodehacke ◽  
U. Mikolajewicz
Keyword(s):  
Boundary Conditions ◽  
General Circulation ◽  
Climate Modeling ◽  
Ice Sheets ◽  
Ice Sheet ◽  
General Circulation Models ◽  
Quasi Equilibrium ◽  
Ice Streams ◽  
Ice Stream ◽  
First Results

Abstract. In the standard Paleoclimate Modelling Intercomparison Project (PMIP) experiments, the Last Glacial Maximum (LGM) is modeled in quasi-equilibrium with atmosphere–ocean–vegetation general circulation models (AOVGCMs) with prescribed ice sheets. This can lead to inconsistencies between the modeled climate and ice sheets. One way to avoid this problem would be to model the ice sheets explicitly. Here, we present the first results from coupled ice sheet–climate simulations for the pre-industrial times and the LGM. Our setup consists of the AOVGCM ECHAM5/MPIOM/LPJ bidirectionally coupled with the Parallel Ice Sheet Model (PISM) covering the Northern Hemisphere. The results of the pre-industrial and LGM simulations agree reasonably well with reconstructions and observations. This shows that the model system adequately represents large, non-linear climate perturbations. A large part of the drainage of the ice sheets occurs in ice streams. Most modeled ice stream systems show recurring surges as internal oscillations. The Hudson Strait Ice Stream surges with an ice volume equivalent to about 5 m sea level and a recurrence interval of about 7000 yr. This is in agreement with basic expectations for Heinrich events. Under LGM boundary conditions, different ice sheet configurations imply different locations of deep water formation.

scholarly journals Sensitivity of the tropical climate to an interhemispheric thermal gradient: the role of tropical ocean dynamics

2017 ◽  
Author(s):  
Stefanie Talento ◽  
Marcelo Barreiro
Keyword(s):  
Seasonal Cycle ◽  
General Circulation ◽  
Southern Oscillation ◽  
Circulation Model ◽  
Ocean Dynamics ◽  
Thermocline Depth ◽  
Thermal Forcing ◽  
Tropical Ocean ◽  
Slab Ocean

Abstract. This study aims to determine the role of the tropical ocean dynamics in the response of the climate to an extratropical thermal forcing. We analyse and compare the outcomes of coupling an atmospheric general circulation model (AGCM) with two ocean models of different complexity. In the first configuration the AGCM is coupled with a slab ocean model while in the second a Reduced Gravity Ocean (RGO) model is additionally coupled in the tropical region. We find that the imposition of an extratropical thermal forcing (warming in the Northern Hemisphere and cooling in the Southern Hemisphere with zero global mean) produces, in terms of annual means, a weaker response when the RGO is coupled, thus indicating that the tropical ocean dynamics opposes the incoming remote signal. On the other hand, while the slab ocean coupling does not produce significant changes to the equatorial Pacific sea surface temperature (SST) seasonal cycle, the RGO configuration generates a strong warming in the centre-east of the basin from April to August balanced by a cooling during the rest of the year, strengthening the seasonal cycle in the eastern portion of the basin. We hypothesize that such changes are possible via the dynamical effect that zonal wind stress has on the thermocline depth. We also find that the imposed extratropical pattern affects El Niño Southern Oscillation, weakening its amplitude and low-frequency behaviour.

scholarly journals The GCM Response to Current Parameterizations of Nonorographic Gravity Wave Drag

2005 ◽  
Vol 62 (7) ◽  
pp. 2394-2413 ◽  
Author(s):  
Charles McLandress ◽  
John F. Scinocca
Keyword(s):  
Gravity Wave ◽  
General Circulation ◽  
Critical Level ◽  
Climate Modeling ◽  
Circulation Model ◽  
Wave Drag ◽  
Nonlinear Dissipation ◽  
Additional Experiment ◽  
Identical Response ◽  
Dissipation Mechanism

Abstract A comparison is undertaken of the response of a general circulation model (GCM) to the nonorographic gravity wave drag parameterizations of Hines, Warner and McIntyre, and Alexander and Dunkerton. The analysis is restricted to a comparison of each parameterization’s nonlinear dissipation mechanism since, in principle, this is the only component that differs between the schemes. This is achieved by developing a new, more general parameterization that can represent each of these dissipation mechanisms, while keeping all other aspects of the problem identical. The GCM simulations reveal differences in the climatological response to the three dissipation mechanisms. These differences are documented for both tropopause and surface launch elevations of the parameterized waves. The simulations also reveal systematic differences in the height at which momentum is deposited. This behavior is investigated further in a set of experiments designed to reduce these systematic differences, while leaving the details of the dissipation mechanisms unaltered. These sensitivity experiments demonstrate that it is possible to obtain nearly identical responses from all three mechanisms, which indicates that the GCM response is largely insensitive to the precise details of the dissipation mechanisms. This finding is supported by an additional experiment in which the nonlinear dissipation mechanisms are turned off and critical-level filtering is left to act as the only source of dissipation. In this experiment, critical-level filtering effectively replaces the nonlinear dissipation mechanism, producing a nearly identical response. The results of this study suggest that climate modeling efforts would potentially benefit more from the refinement of other aspects of the parameterization problem, such as the properties of the launch spectrum, than they have benefited from the refinement of dissipation mechanisms.

scholarly journals The FAMOUS climate model (versions XFXWB and XFHCC): description update to version XDBUA

2011 ◽  
Vol 4 (4) ◽  
pp. 3047-3065
Author(s):  
R. S. Smith
Keyword(s):  
Water Budget ◽  
General Circulation ◽  
Climate Model ◽  
Circulation Model ◽  
Model Description ◽  
Model Intercomparison ◽  
Ocean Atmosphere ◽  
Atmosphere General Circulation Model ◽  
Intercomparison Project ◽  
The Uk

Abstract. FAMOUS is an ocean-atmosphere general circulation model of low resolution, based on version 4.5 of the UK MetOffice Unified Model. Here we update the model description to account for changes in the model as it is used in the CMIP5 EMIC model intercomparison project (EMICmip) and a number of other studies. Most of these changes correct errors found in the code. The EMICmip version of the model (XFXWB) has a better-conserved water budget and additional cooling in some high latitude areas, but otherwise has a similar climatology to previous versions of FAMOUS. A variant of XFXWB is also described, with changes to the dynamics at the top of the model which improve the model climatology (XFHCC).

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