| 1. |
Toshihiko Takemura, Development of a global aerosol climate model SPRINTARS, CGER’s Supercomputer Monograph Report, Vol.24, pp.1-88, 2018.01. |
| 2. |
Ocean spray : An outsized influence on weather and climate. |
| 3. |
Development of Seamless Chemical Assimilation System and Its Application for Atmospheric Environmental Materials(Introduction of Results from the MEXT "Research Program on Climate Change adaptation (RECCA)"). |
| 4. |
Utilization of numerical atmospheric dispersion models for environmental emergency response
筆頭. |
| 5. |
Overview of Aerosol Forecasting System and Recent Transboundary Air Pollution. |
| 6. |
Wind for Transporting Materials : Transport Processes of Aerosols in the Atmosphere. |
| 7. |
A report of the special topic session "Current status and issues of numerical models for the transport of radioactive substances" at the 2011 Autumn Meeting. |
| 8. |
Toshihiko Takemura, Simulation of distributions and radiative impacts of biomass-burning aerosols, Global Environmental Research, Vol.15, pp.77-81, 2011.09. |
| 9. |
Atmospheric Environment in East Asia (A Report on the Symposium of the 2009 Fall Assembly of the Meteorological Society of Japan). |
| 10. |
2. Estimating Aerosol Effects on Climate System(Introduction to Cross-Cutting Discussion on "Water Cycle Environmental Science"). |
| 11. |
Estimation of aerosol effects on climate by modeling studies. |
| 12. |
Coupled effects of land use and aerosols changes and their impacts on Asian climate
This study assesses the roles of aerosols in the past/present changes in Asian climate and monsoon, isolating impacts of individual aerosol components in the framework of the CCSR/NIES/FRCGC climate model (MIROC). Many recent studies suggest that increases in anthropogenic aerosols such as black carbon and sulfate may play a crucial role in Asian climate change as observed. Our previous studies also demonstrate the significance of aerosol increases (sulfate and carbonaceous aerosols) in the simulated precipitation changes in Asia (e.g., Arai et al., 2009). In this study, we particularly focus on the changes of nitrate and secondary organic aerosols (SOA) which are tightly linked to land use change in regions like Asia, but not treated in our previous aerosol studies. We newly introduced simulation of nitrate aerosol in our climate model. Our simulation shows that there are anomalously high concentrations of nitrate aerosol in South Asia (particularly around India and Bangladesh), coming from abundant ammonium and less sulfate components in this region. In India, free tropospheric mixing ratio and number concentration of nitrate in fine mode are both larger than those of sulfate in. |
| 13. |
Review and Future Studies of Estimating Aerosol Effects on Climate System
The aerosol effects on the climate system are roughly divided into three categories: direct, indirect, and semi-direct effects. Observations from satellites and ground with remote sensing and numerical models have been developed to understand and estimate aerosol effects on a global scale. In the latest assessment report of the Intergovernmental Panel on Climate Change (IPCC) , however, there are still large uncertainties in their radiative forcings in comparison with the estimation of long-lived greenhouse gases. To reduce the uncertainties, we have to study the three-dimensional aerosol distributions and the cloud-aerosol interaction more accurately. It is important to observe aerosol vertical profiles with lidar, one of the active sensors, to understand the three-dimensional aerosol distributions as well as to continue observations with passive sensors. The data assimilation, which harmonizes numerical models with observations, is also an effective method to reduce the uncertainties. A cloud resolving model coupled with an aerosol transport model is a useful tool to better understand the cloud-aerosol interaction. Efforts to analyze the aerosol climate effects quantitatively will result in more reliable projection of the future climate change and elucidating climate system.. |
| 14. |
Data Assimilation with Aerosol Transport Model
Data assimilation has been developed in numerical weather prediction (NWP) and modeling of oceanography. Recently, store and expansion of observations and development of numerical modeling have enabled data assimilation techniques to be applied to aerosol transport models. In this paper, we introduce information about applications (e.g., forecast, inverse modeling, reanalysis, sensitivity analysis) and recent studies about data assimilation with atmospheric aerosol observations and numerical models. We also show a preliminary experiment of ensemble-based data assimilation with global aerosol climate model (SPRINTARS) and Aerosol Optical Thickness (AOT) measured by MODIS/AQUA. In the experiment, the data assimilation improves under-estimates in East Asia, North Pacific Ocean, Central America, Middle East and Central Africa, and over-estimates in oceans over the southern hemisphere. Root mean square difference (RMSD) between SPRINTARS and MODIS AOT is reduced by 21 %, and long-wave aerosol direct forcing at the tropopause increased where dust and carbon aerosol are increased by the data assimilation.. |
| 15. |
Introduction to the Feature Articles: Studies on Reducing Uncertainties of Estimation of Aerosol Effects on Climate System. |
| 16. |
MI02 : Clouds, Aerosols, Radiation and Climate Symposium(Report on the XXIII General Assembly of the International Union of Geodesy and Geophysics (IUGG2003) (2)). |
| 17. |
A study of aerosol distribution and radiative forcing with a global three-dimensional aerosol transport-radiation model. |
| 18. |
S Kinne, B Holben, T Eck, A Smirnov, O Dubovik, Slutsker, I, D Tanre, G Zibozdi, U Lohmann, S Ghan, R Easter, M Chin, P Ginoux, T Takemura, Tegen, I, D Koch, R Kahn, E Vermote, L Stowe, O Torres, M Mishchenko, Geogdzhayev, I, A Hiragushi, How well do aerosol retrievals from satellites and representation in global circulation models match ground-based AERONET aerosol statistics?, Remote Sensing and Climate Modeling: Synergies and Limitations, Vol.7, pp.103-158, 2001.04, Statistics from sky/sunphotometers at AERONET sites throughout the world provide the background for a comparison of monthly or seasonally averaged aerosol optical depths to retrievals by operational satellites and to representations in global models. Available data-sets, however, rarely relate to the same year(s). With strong year-to-year variations even for monthly averaged aerosol optical depths and open issues on sampling biases and regional representation by local measurements only larger discrepancies are investigated. Aerosol optical depths retrievals of five different satellites and five different global models are compared. Quantitative accurate satellite retrievals over land remain a challenge and even their relative difference cannot provide clear answers on regional representation. Model predicted aerosol optical depth averages are usually smaller than AERONET. The behavior of models is further explored on a component basis. For sulfate, dust, carbon and sea-salt optical depths, mass and assumed aerosol sizes are compared. For the conversion of the column (dry) component mass in optical depth in models, assumptions for component aerosol size and aerosol humidification are critical. Statistical comparisons to ground-based monitoring will be more useful, if temporal differences are removed. This requires data from the same time-period and the use of sampling screens, to accommodate less frequent measurements. For the understanding of regional representation by local measurements, satellite data play a key role. Necessities to validate critical aerosol assumptions in models or satellite retrievals require field- experiments that focus on individual aerosol components plus continued and additional monitoring (e.g. AERONET) at sites, where a particular aerosol component dominates.. |
| 19. |
Nakajima, T, A. Higurashi, K. Kawamoto, T. Takemura, Effects of man-made air pollution on the climate, Present and Future of Modeling Global Environmental Change Toward Integrated Modeling, pp.77-87, 2001.01. |
| 20. |
Nozawa, T, S. Emori, A. Numaguti, Y. Tsushima, T. Takemura, T. Nakajima, A. Abe-Ouchi, M. Kimoto, Projections of future climate change in the 21st century simulated by the CCSR/NIES CGCM under the IPCC SRES scenario, Present and Future of Modeling Global Environmental Change Toward Integrated Modeling, pp.15-28, 2001.01. |
