scholarly journals Causes for decadal variations of wind speed over land: Sensitivity studies with a global climate model

2012 ◽  
Vol 39 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. Bichet ◽  
M. Wild ◽  
D. Folini ◽  
C. Schär
Keyword(s):  
Wind Speed ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Decadal Variations ◽  
Sensitivity Studies

Impact of heterogeneous chemistry on the distribution of Glyoxal and Methylglyoxal in the troposphere

2021 ◽  
Author(s):  
Ramiro Checa-Garcia ◽  
Didier Didier Hauglustaine ◽  
Yves Balkanski ◽  
Paola Formenti
Keyword(s):  
Atmospheric Chemistry ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Experimental Simulation ◽  
Heterogeneous Chemistry ◽  
Closed Set ◽  
Sensitivity Studies ◽  
The Tropics

<p>Glyoxal (GL) and methylglyoxal (MGL) are the smallest di-carbonyls present in the atmosphere. They hydrate easily, a process that is followed by an oligomerisation. As a consequence, it is considered that they participate actively in the formation of secondary organic aerosols (SOA) and therefore, they are being introduced in the current climate models with interactive chemistry to assess their importance on atmospheric chemistry. In our study we present the introduction of glyoxal in the INCA global model. A new closed set of gas-phase  reactions is analysed first with a box model. Then the simulated global distribution of glyoxal by the global climate model is compared with satellite observations. We show that the oxidation of volatile organic compounds and acetylene, together with the photolysis of more complex di-carbonyls allows us to reproduce well glyoxal seasonal cycle in the tropics but it requires an additional sink in several northern hemispheric regions. Additional sensitivity studies are being conducted by introducing  GL and MGL interactions with dust and SOA according to new uptake  coefficients obtained by dedicated experiments in the CESAM instrument (Chamber of Experimental Simulation of Atmospheric Multiphases). The effects of these heterogeneous chemistry processes will be quantified in the light of the new chamber measurements  and also evaluated in terms of optical properties of aged dust aerosol  and the changes in direct radiative effects  of the involved aerosol species.</p>

scholarly journals Sensitivity studies of different aerosol indirect effects in mixed-phase clouds

2009 ◽  
Vol 9 (4) ◽  
pp. 15045-15081
Author(s):  
U. Lohmann ◽  
C. Hoose
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Mixed Phase ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Activation Effect ◽  
Aerosol Effect ◽  
Sensitivity Studies ◽  
Mixed Phase Clouds

Abstract. Aerosols affect the climate system by changing cloud characteristics. Using the global climate model ECHAM5-HAM, we investigate different aerosol effects on mixed-phase clouds: The glaciation effect, which refers to a more frequent glaciation due to anthropogenic aerosols, versus the de-activation effect, which suggests that ice nuclei become less effective because of an anthropogenic sulfate coating. The glaciation effect can partly offset the indirect aerosol effect on warm clouds and thus causes the total anthropogenic aerosol effect to be smaller. It is investigated by varying the parameterization for the Bergeron-Findeisen process and the threshold coating thickness of sulfate (SO4-crit), which is required to convert an externally mixed aerosol particle into an internally mixed particle. Differences in the net radiation at the top-of-the-atmosphere due to anthropogenic aerosols between the different sensitivity studies amount up to 0.5 W m−2. This suggests that the investigated mixed-phase processes have a major effect on the total anthropogenic aerosol effect.

scholarly journals Sensitivity studies of different aerosol indirect effects in mixed-phase clouds

2009 ◽  
Vol 9 (22) ◽  
pp. 8917-8934 ◽  
Author(s):  
U. Lohmann ◽  
C. Hoose
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Mixed Phase ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Activation Effect ◽  
Aerosol Effect ◽  
Sensitivity Studies ◽  
Mixed Phase Clouds

Abstract. Aerosols affect the climate system by changing cloud characteristics. Using the global climate model ECHAM5-HAM, we investigate different aerosol effects on mixed-phase clouds: The glaciation effect, which refers to a more frequent glaciation due to anthropogenic aerosols, versus the de-activation effect, which suggests that ice nuclei become less effective because of an anthropogenic sulfate coating. The glaciation effect can partly offset the indirect aerosol effect on warm clouds and thus causes the total anthropogenic aerosol effect to be smaller. It is investigated by varying the parameterization for the Bergeron-Findeisen process and the threshold coating thickness of sulfate (SO4-crit), which is required to convert an externally mixed aerosol particle into an internally mixed particle. Differences in the net radiation at the top-of-the-atmosphere due to anthropogenic aerosols between the different sensitivity studies amount up to 0.5 W m−2. This suggests that the investigated mixed-phase processes have a major effect on the total anthropogenic aerosol effect.

scholarly journals Performance of Global Climate Model (GCMs) for Wind Data Analysis

2019 ◽  
Vol 117 ◽  
pp. 00006
Author(s):  
Chutipat Foyhirun ◽  
Duangrudee K. Kongkitkul ◽  
Chaiwat Ekkawatpanit
Keyword(s):  
Wind Speed ◽  
Wave Height ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Andaman Sea ◽  
Future Climate Change ◽  
Observation Data ◽  
Efficiency Coefficient ◽  
Wind Speed Data

The surface wind speed is an important climate variable for study of ocean wave energy and coastal erosion. The wind speed and wave height variations are caused by global warming. In the future, climate change impacts on changes of direction and wind speed which affect on wave height and wave period. The global climate model (GCMs) were developed by various institutions so each GCM has different GCM output. Then, the aim of this study is to evaluation the performance of GCMs for wind speed analysis in the area of Gulf of Thailand and Andaman Sea. In this study, the daily wind speed data was analyzed with a total of 15 GCMs and daily wind speed data of NCEP-NCAR was used as observation data to compare with wind speed data from GCMs over the period 1986-2005 (20 years). Moreover, the wind speed data was evaluated by efficiency coefficient which are root mean square error (RMSE) and mean absolute error (MAE). It was found tht MRI-CGCM3, GFDL-ESM2M, IPSL-CM5A-LR, and IPSL-CM5A-MR are consistent with the most of observation data from NCEP-NCAR.

scholarly journals Changes in Surface Wind Speed over North America from CMIP5 Model Projections and Implications for Wind Energy

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sujay Kulkarni ◽  
Huei-Ping Huang
Keyword(s):  
Wind Speed ◽  
North America ◽  
Greenhouse Gas ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Current Estimate

The centennial trends in the surface wind speed over North America are deduced from global climate model simulations in the Climate Model Intercomparison Project—Phase 5 (CMIP5) archive. Using the 21st century simulations under the RCP 8.5 scenario of greenhouse gas emissions, 5–10 percent increases per century in the 10 m wind speed are found over Central and East-Central United States, the Californian Coast, and the South and East Coasts of the USA in winter. In summer, climate models projected decreases in the wind speed ranging from 5 to 10 percent per century over the same coastal regions. These projected changes in the surface wind speed are moderate and imply that the current estimate of wind power potential for North America based on present-day climatology will not be significantly changed by the greenhouse gas forcing in the coming decades.

Wind resource assessment of Cuba in future climate scenarios

2018 ◽  
Vol 43 (3) ◽  
pp. 311-326
Author(s):  
Yoandy Alonso Díaz ◽  
Arnoldo Bezanilla ◽  
Alfredo Roque ◽  
Abel Centella ◽  
Israel Borrajero ◽  
...  
Keyword(s):  
Wind Speed ◽  
General Circulation ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Circulation Model ◽  
Wind Farms ◽  
Northern Coast ◽  
The Future ◽  
Wind Resource

The future climatic behavior of the wind resource in Cuba has not been studied in the past. This study presents a preliminary analysis of the behavior of wind speed using the regional climate model PRECIS (Providing Regional Climates for Impacts Studies) in high-resolution scenarios of climate change SRES A1B (Special Report on Emissions Scenarios), driven with boundary conditions from the General Circulation Model ECHAM5 (European Centre/HAMburg climate model) and 6 of the 16 members of the set of perturbed physics HadCM3 (Hadley Center Coupled Model, version 3) global climate model. Changes in the distribution of wind speed for three periods of 30 years in the future—2011–2040, 2041–2070, and 2071–2099—are analyzed. The PRECIS model was also run with reanalysis data during the period of 1 January 1989 to 31 December 2002. It was found that changes in wind speed will be larger in the eastern and northern coast, becoming statistically significant for the second half of this century with an increase in wind magnitude between 0.1 and 0.4 m s−1. These areas of increased wind power match with the current projection of the Cuban wind program where the construction of 13 new wind farms are contemplated. Finally, this increase is added to the wind speed outputs of the numerical wind atlas of Cuba to estimate the values of wind speed over the three future periods.

High bit rate ACTS experiments for performing global science - Keck Telescope and global climate model

1996 ◽  
Author(s):  
Larry Bergman ◽  
J. Gary ◽  
Burt Edelson ◽  
Neil Helm ◽  
Judith Cohen ◽  
...  
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Bit Rate ◽  
Global Science ◽  
High Bit Rate
Sign in / Sign up

Export Citation Format

Share Document