scholarly journals Research Progress on Atmospheric Sulfur Cycle Model

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Jianjun Meng ◽  
Yuteng Xiao
Keyword(s):  
Resource Sharing ◽  
General Circulation ◽  
General Circulation Models ◽  
Sulfur Cycle ◽  
Research Progress ◽  
Observation Data ◽  
Cycle Model ◽  
Integrated Research ◽  
Sulfur Emission ◽  
Atmospheric Sulfur

We summarized the basic contents and the applicable conditions of typicalatmospheric sulfur cycle models, especially the classical atmospheric sulfur cycle model and the independent sulfur cycle model which is based on OsloCTM2 model.We introduced atmospheric sulfur cycle models which are coupled with some general circulation models such as ECHAM, LMDZ, CSIRO, MASINGAR, RCA2, NICAM and MIROC. Although there are many kinds of atmospheric sulfur cycle models, there are still some problems such as lack of relevant data support, comprehensive consideration of chemistry, radiation and dynamics, and interdisciplinary integrated research in the study of sulfur cycle models. To solve these problems, we proposed to optimize the quality of atmospheric sulfur emission and observation data, establish a shared database system, formulate relevant database usage regulations, strengthen the cooperation and resource sharing among subjects, and establish comprehensive high-resolution atmospheric sulfur cycle models.

scholarly journals DMS cycle in the marine ocean-atmosphere system – a global model study

2005 ◽  
Vol 2 (4) ◽  
pp. 1067-1126 ◽  
Author(s):  
S. Kloster ◽  
J. Feichter ◽  
E. Maier-Reimer ◽  
K. D. Six ◽  
P. Stier ◽  
...  
Keyword(s):  
General Circulation ◽  
Circulation Model ◽  
Surface Concentration ◽  
Ocean General Circulation Model ◽  
Sulfur Cycle ◽  
Biologically Active ◽  
Sea Surface ◽  
Aerosol Model ◽  
Ocean Atmosphere ◽  
Atmospheric Sulfur

Abstract. A global coupled ocean-atmosphere modeling system is established to study the production of Dimethylsulfide (DMS) in the ocean, the DMS flux to the atmosphere, and the resulting sulfur concentrations in the atmosphere. The DMS production and consumption processes in the ocean are simulated in the marine biogeochemistry model HAMOCC5, embedded in a ocean general circulation model (MPI-OM). The atmospheric model ECHAM5 is extended by the microphysical aerosol model HAM, treating the sulfur chemistry in the atmosphere and the evolution of the microphysically interacting internally- and externally mixed aerosol populations. We simulate a global annual mean DMS sea surface concentration of 1.8 nmol/l, a DMS emission of 28 Tg(S)/yr, a DMS burden in the atmosphere of 0.077 Tg(S), and a DMS lifetime of 1.0 days. To quantify the role of DMS in the atmospheric sulfur cycle we simulate the relative contribution of DMS-derived SO2 and SO4-2 to the total atmospheric sulfur concentrations. DMS contributes 25% to the global annually averaged SO2 column burden. For SO4-2 the contribution is 27%. The coupled model setup allows the evaluation of the simulated DMS quantities with measurements taken in the ocean and in the atmosphere. The simulated global distribution of DMS sea surface concentrations compares reasonably well with measurements. The comparison to SO4-2 surface concentration measurements in regions with a high DMS contribution to SO4-2 shows an overestimation by the model. This overestimation is most pronounced in the biologically active season with high DMS emissions and most likely caused by a too high simulated SO4-2 yield from DMS oxidation.

scholarly journals Evaluation of data-driven models to downscale rainfall parameters from global climate models outputs: the case study of Latyan watershed

2018 ◽  
Vol 11 (1) ◽  
pp. 200-216 ◽  
Author(s):  
Reza Haji Hosseini ◽  
Saeed Golian ◽  
Jafar Yazdi
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Climate Models ◽  
Fuzzy Inference ◽  
Global Climate ◽  
General Circulation Models ◽  
Global Climate Models ◽  
Data Driven ◽  
Observation Data ◽  
Inference System

Abstract Assessment of climate change in future periods is considered necessary, especially with regard to probable changes to water resources. One of the methods for estimating climate change is the use of the simulation outputs of general circulation models (GCMs). However, due to the low resolution of these models, they are not applicable to regional and local studies and downscaling methods should be applied. The purpose of the present study was to use GCM models' outputs for downscaling precipitation measurements at Amameh station in Latyan dam basin. For this purpose, the observation data from the Amameh station during the 1980–2005 period, 26 output variables from two GCM models, namely, HadCM3 and CanESM2 were used. Downscaling was performed by three data-driven methods, namely, artificial neural network (ANN), nonparametric K-nearest neighborhood (KNN) method, and adaptive network-based fuzzy inference system method (ANFIS). Comparison of the monthly results showed the superiority of KNN compared to the other two methods in simulating precipitation. However, all three, ANN, KNN, and ANFIS methods, showed satisfactory results for both HadDCM3 and CanESM2 GCM models in downscaling precipitation in the study area.

scholarly journals DMS cycle in the marine ocean-atmosphere system – a global model study

2006 ◽  
Vol 3 (1) ◽  
pp. 29-51 ◽  
Author(s):  
S. Kloster ◽  
J. Feichter ◽  
E. Maier-Reimer ◽  
K. D. Six ◽  
P. Stier ◽  
...  
Keyword(s):  
General Circulation ◽  
Circulation Model ◽  
Surface Concentration ◽  
Ocean General Circulation Model ◽  
Sulfur Cycle ◽  
Biologically Active ◽  
Sea Surface ◽  
Aerosol Model ◽  
Ocean Atmosphere ◽  
Atmospheric Sulfur

Abstract. A global coupled ocean-atmosphere modeling system is established to study the production of dimethylsulfide (DMS) in the ocean, the DMS flux to the atmosphere, and the resulting sulfur concentrations in the atmosphere. The DMS production and consumption processes in the ocean are simulated in the marine biogeochemistry model HAMOCC5, embedded in a ocean general circulation model (MPI-OM). The atmospheric model ECHAM5 is extended by the microphysical aerosol model HAM, treating the sulfur chemistry in the atmosphere and the evolution of the microphysically interacting internally- and externally mixed aerosol populations. We simulate a global annual mean DMS sea surface concentration of 1.8 nmol l−1, a DMS emission of 28 Tg(S) yr−1, a DMS burden in the atmosphere of 0.077 Tg(S), and a DMS lifetime of 1.0 days. To quantify the role of DMS in the atmospheric sulfur cycle we simulate the relative contribution of DMS-derived SO2 and SO42− to the total atmospheric sulfur concentrations. DMS contributes 25% to the global annually averaged SO2 column burden. For SO42− the contribution is 27%. The coupled model setup allows the evaluation of the simulated DMS quantities with measurements taken in the ocean and in the atmosphere. The simulated global distribution of DMS sea surface concentrations compares reasonably well with measurements. The comparison to SO42− surface concentration measurements in regions with a high DMS contribution to SO42− shows an overestimation by the model. This overestimation is most pronounced in the biologically active season with high DMS emissions and most likely caused by a too high simulated SO42− yield from DMS oxidation.

scholarly journals Evaluating the effects of climate change on groundwater level in the Varamin plain

2021 ◽  
Author(s):  
Hamidreza Azizi ◽  
Hossein Ebrahimi ◽  
Hossein Mohammad Vali Samani ◽  
Vida Khaki
Keyword(s):  
Groundwater Level ◽  
General Circulation ◽  
Climate Model ◽  
Three Dimensional ◽  
General Circulation Models ◽  
Annual Rainfall ◽  
Observation Data ◽  
Base Period ◽  
The Future ◽  
Varamin Plain

Abstract In this research, a number of paired three-dimensional Atmosphere-Ocean General Circulation Models (AOGCM) from CMIP (Climate Model Inter Comparison Project) 5 group with the base period of 1989–2005 have been evaluated and the output of these models was micro-scaled and calibrated by LARS-WG software. The appropriate model was selected to simulate temperature and rainfall data under the emission scenarios of RCP (Representative Concentration Pathway) 2.6, RCP4.5 and RCP8.5 for the future period of 2020–2050, and then to model the groundwater level of the region, GMS software for both stable and transient states for one water year was calibrated and then was validated by observation data. The results in the future periods showed an increase of 1–1.5 degrees in temperature and an increase in rainfall in the early months of the year to late spring season and a decrease in rainfall in autumn season. Generally, the RCP4.5 scenario showed slightly more annual rainfall increase over the next 30 years compared to the base period than the other two scenarios. The time series investigation of the average of groundwater level shows that the implementation of RCP 2.6, RCP 4.5 and RCP 8.5 scenarios respectively leads to an average monthly increase of 4.2, 4.3 and 4.6 cm of the groundwater level.

scholarly journals Lagrangian Analysis of Tropical Cyclone Genesis Simulated by General Circulation Models Compared with Observations

2020 ◽  
Vol 33 (11) ◽  
pp. 4489-4511 ◽  
Author(s):  
Chanwoo Song ◽  
Sungsu Park ◽  
Jihoon Shin
Keyword(s):  
Environmental Conditions ◽  
Environmental Variables ◽  
General Circulation ◽  
General Circulation Models ◽  
Vertical Shear ◽  
Tropical Cyclone Genesis ◽  
Observation Data ◽  
Lagrangian Analysis ◽  
Model Version ◽  
Atmosphere Model

AbstractAs a contribution to understanding the genesis of tropical cyclones (TCs), we compared TC genesis processes simulated by the Seoul National University Atmosphere Model version 0 with a Unified Convection Scheme (SAM0) and the Community Atmosphere Model version 5 (CAM5) with those from the ERA-Interim reanalysis (ERA-Interim, hereafter ERAI) and best track observations. In contrast to previous studies that estimated the TC genesis potential using the Eulerian mean environmental conditions, we calculated the probability of a pre-existing weak cyclonic embryo vortex (EV) developing into a TC by analyzing changes in the environmental conditions along the EV trajectories. Our analysis indicates that the spatial distribution and annual cycles of TCs obtained from the SAM0 and ERAI are similar to those obtained from the best track observation data. With the exception of the mesoscale convective organization and associated variables, most environmental variables along the trajectories of DEVs (EVs developing into TCs) showed monotonic variations. When EVs were born, environmental conditions of DEVs were significantly different from those of nondeveloping EVs, allowing for the prediction of TC genesis. In general, TC genesis probability increased as the environment became more cyclonic, moist, unstable, and with a weaker wind shear. Rapidly strengthening EVs were more likely to develop into TCs. SAM0 and ERAI have the same combination of environmental variables with the best prediction skill for TC genesis—absolute vorticity at 850 hPa, column saturation deficit, sea surface temperature, vertical shear of horizontal winds between 200 and 850 hPa, and latitude—with similar sensitivities to individual environmental variables, indicating that SAM0 well simulates the observed TC genesis processes.

scholarly journals Improving Detectability of Seafloor Deformation From Bottom Pressure Observations Using Numerical Ocean Models

2021 ◽  
Vol 8 ◽  
Author(s):  
Yoichiro Dobashi ◽  
Daisuke Inazu
Keyword(s):  
Atmospheric Pressure ◽  
General Circulation ◽  
Subduction Zones ◽  
Nankai Trough ◽  
General Circulation Models ◽  
Japan Trench ◽  
Observation Data ◽  
Bottom Pressure ◽  
Seafloor Deformation ◽  
Ocean Models

We investigated ocean bottom pressure (OBP) observation data at six plate subduction zones around the Pacific Ocean. The six regions included the Hikurangi Trough, the Nankai Trough, the Japan Trench, the Aleutian Trench, the Cascadia Subduction Zone, and the Chile Trench. For the sake of improving the detectability of seafloor deformation using OBP observations, we used numerical ocean models to represent realistic oceanic variations, and subtracted them from the observed OBP data. The numerical ocean models included four ocean general circulation models (OGCMs) of HYCOM, GLORYS, ECCO2, and JCOPE2M, and a single-layer ocean model (SOM). The OGCMs are mainly driven by the wind forcing. The SOM is driven by wind and/or atmospheric pressure loading. The modeled OBP was subtracted from the observed OBP data, and root-mean-square (RMS) amplitudes of the residual OBP variations at a period of 3–90 days were evaluated by the respective regions and by the respective numerical ocean models. The OGCMs and SOM driven by wind alone (SOMw) contributed to 5–27% RMS reduction in the residual OBP. When SOM driven by atmospheric pressure alone (SOMp) was added to the modeled OBP, residual RMS amplitudes were additionally reduced by 2–15%. This indicates that the atmospheric pressure is necessary to explain substantial amounts of observed OBP variations at the period. The residual RMS amplitudes were 1.0–1.7 hPa when SOMp was added. The RMS reduction was relatively effective as 16–42% at the Hikurangi Trough, the Nankai Trough, and the Japan Trench. The residual RMS amplitudes were relatively small as 1.0–1.1 hPa at the Nankai Trough and the Chile Trench. These results were discussed with previous studies that had identified slow slips using OBP observations. We discussed on further accurate OBP modeling, and on improving detectability of seafloor deformation using OBP observation arrays.

Successive Modulation of ENSO to the Future Greenhouse Warming

2008 ◽  
Vol 21 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Yoo-Geun Ham ◽  
In-Sik Kang
Keyword(s):  
General Circulation ◽  
Southern Oscillation ◽  
General Circulation Models ◽  
Tropical Pacific ◽  
Greenhouse Warming ◽  
Delayed Response ◽  
Subsurface Temperature ◽  
Climate System Model ◽  
The Mean ◽  
The Tropical Pacific

Abstract The multidecadal modulation of the El Niño–Southern Oscillation (ENSO) due to greenhouse warming has been analyzed herein by means of diagnostics of Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) coupled general circulation models (CGCMs) and the eigenanalysis of a simplified version of an intermediate ENSO model. The response of the global-mean troposphere temperature to increasing greenhouse gases is more likely linear, while the amplitude and period of ENSO fluctuates in a multidecadal time scale. The climate system model outputs suggest that the multidecadal modulation of ENSO is related to the delayed response of the subsurface temperature in the tropical Pacific compared to the response time of the sea surface temperature (SST), which would lead a modulation of the vertical temperature gradient. Furthermore, an eigenanalysis considering only two parameters, the changes in the zonal contrast of the mean background SST and the changes in the vertical contrast between the mean surface and subsurface temperatures in the tropical Pacific, exhibits a good agreement with the CGCM outputs in terms of the multidecadal modulations of the ENSO amplitude and period. In particular, the change in the vertical contrast, that is, change in difference between the subsurface temperature and SST, turns out to be more influential on the ENSO modulation than changes in the mean SST itself.

scholarly journals Contributors to linkage between Arctic warming and East Asian winter climate

2021 ◽  
Author(s):  
Xinping Xu ◽  
Shengping He ◽  
Yongqi Gao ◽  
Botao Zhou ◽  
Huijun Wang
Keyword(s):  
Sea Ice ◽  
General Circulation ◽  
Initial Conditions ◽  
Wave Train ◽  
East Asian ◽  
Surface Air Temperature ◽  
General Circulation Models ◽  
The Arctic ◽  
Winter Climate ◽  
Arctic Warming

AbstractPrevious modelling and observational studies have shown discrepancies in the interannual relationship of winter surface air temperature (SAT) between Arctic and East Asia, stimulating the debate about whether Arctic change can influence midlatitude climate. This study uses two sets of coordinated experiments (EXP1 and EXP2) from six different atmospheric general circulation models. Both EXP1 and EXP2 consist of 130 ensemble members, each of which in EXP1 (EXP2) was forced by the same observed daily varying sea ice and daily varying (daily climatological) sea surface temperature (SST) for 1982–2014 but with different atmospheric initial conditions. Large spread exists among ensemble members in simulating the Arctic–East Asian SAT relationship. Only a fraction of ensemble members can reproduce the observed deep Arctic warming–cold continent pattern which extends from surface to upper troposphere, implying the important role of atmospheric internal variability. The mechanisms of deep Arctic warming and shallow Arctic warming are further distinguished. Arctic warming aloft is caused primarily by poleward moisture transport, which in conjunction with the surface warming coupled with sea ice melting constitutes the surface-amplified deep Arctic warming throughout the troposphere. These processes associated with the deep Arctic warming may be related to the forcing of remote SST when there is favorable atmospheric circulation such as Rossby wave train propagating from the North Atlantic into the Arctic.

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