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Tropical Cyclone Initialization with Dynamical Retrieval from a Modified UWPBL Model
Journal of the Meteorological Society of Japan, Vol.88 No.5. Ma Lei-Ming; Tan Zhe-Min - Meteorological Society of Japan, 2010A new scheme, termed Vortex Initialization with the Assimilation of Retrieved Variables (VIRV), is presented to improve the initialization of regional numerical model for Tropical Cyclone (TC) prediction. In this scheme, the horizontal winds in Planetary Boundary Layer (PBL) and the sea level pressure (SLP), retrieved from Quick Scatterometer (QuikSCAT) data obtained using a modified University of Washington Planetary Boundary Layer (UWPBL) model, are assimilated with a cycled three-dimensional variational (3DVAR) technique to produce the initialized analysis. The procedures of retrieval are i ...
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Available online: http://dx.doi.org/10.2151/jmsj.2010-504
in Journal of the Meteorological Society of Japan > Vol.88 No.5 (October 2010) . - p.827-846A new scheme, termed Vortex Initialization with the Assimilation of Retrieved Variables (VIRV), is presented to improve the initialization of regional numerical model for Tropical Cyclone (TC) prediction. In this scheme, the horizontal winds in Planetary Boundary Layer (PBL) and the sea level pressure (SLP), retrieved from Quick Scatterometer (QuikSCAT) data obtained using a modified University of Washington Planetary Boundary Layer (UWPBL) model, are assimilated with a cycled three-dimensional variational (3DVAR) technique to produce the initialized analysis. The procedures of retrieval are implemented under the joint dynamical constraints of the gradient wind, secondary circulation, and thermal stratification. Moreover, in order to improve the analysis of TC intensity, the roughness parameterization in the UWPBL model was modified for the case of strong surface wind. The sensitivities of the structure, intensity, and track of TC to the VIRV are then examined by two numerical experiments for TC Bilis (2006) and TC Fung-wong (2008).
The maximum Wind Speed (MWS) and minimum Sea Level Pressure (MSLP) retrieved from the QuikSCAT data obtained using the modified UWPBL model show more agreement with the observations relative to those derived from the analysis of the National Center for Environmental Prediction (NCEP global model). The analysis of TC intensity cfm enhanced using VIRV by modifying the low-level (upper-level) convergence (divergence), vertical shear of horizontal wind, transportation of moisture. Significant improvement on 48-h TC simulation is identified in the MWS, with 22.8% error reduction. In particular, the Modification of Roughness Parameterization (MRP) enhanced the simulation of MWS by 6.9%. Finally, the VIRV also reduces the simulation error in the track of TC by affecting the steering flow throughout the troposphere.Language(s): English; Other Languages: Japanese
Format: Digital (Free), Hard copyTags: Tropical cyclone ; Modelling ; Observations ; Natural hazards ; Numerical simulation ; Japan
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Has the Drake Passage Played an Essential Role in the Cenozoic Cooling?
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Zhang Zi-Yin; Gong Zhong-Shi; Yan Qing; et al. - Science Press, 2010The Drake Passage is the seaway between South America and Antarctica. It is widely believed that the thermal isolation effects caused by the opening of the Drake Passage played an important role in the abrupt cooling that occurred at the Eocene-Oligocene boundary in the Cenozoic. These effects are also thought to be independent of the geometry of the passage. Here, the authors demonstrate that the climate impacts of the Drake Passage depend on the passage geometry by comparing the climate’s sensitivity to the opening of the Drake Passage under the present and the Early Eocene land-sea configur ...
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10054
in Atmospheric and Oceanic Science Letters > Volume 3 Number 5 (16 September 2010) . - p.288-292The Drake Passage is the seaway between South America and Antarctica. It is widely believed that the thermal isolation effects caused by the opening of the Drake Passage played an important role in the abrupt cooling that occurred at the Eocene-Oligocene boundary in the Cenozoic. These effects are also thought to be independent of the geometry of the passage. Here, the authors demonstrate that the climate impacts of the Drake Passage depend on the passage geometry by comparing the climate’s sensitivity to the opening of the Drake Passage under the present and the Early Eocene land-sea configurations. These experiments show that the thermal isolation effects caused by the passage are much stronger under the present land-sea configuration. In comparison, under the Early Eocene land-sea configuration, the weak anomalies in heat transport caused by the opening of the narrow and shallow Drake Passage are not strong enough to thermally insulate Antarctica. The climate effects of the Drake Passage on the Cenozoic cooling have been overestimated in previous sensitivity studies carried out using the present land-sea configuration. Thus, it is unlikely that the opening of the Drake Passage played an essential role in the abrupt Cenozoic cooling, especially in the abrupt cooling at the Eocene-Oligocene boundary.
Language(s): English
Format: Digital (Free), Hard copyTags: Antarctica ; Melting Ice ; Paleoclimatology ; Research
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Statistical Reconstruction of the Antarctic Oscillation Index Based on Multiple Proxies
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Zhang Zi-Yin; Gong Dao-Yi; He Xue-Zhao; et al. - Science Press, 2010Based on multiple proxies from the Southern Hemisphere, an austral summer (December-January-February: DJF) Antarctic Oscillation Index (AAO) since 1500 A.D. was reconstructed with a focus on interannual to interdecadal variability (< 50 a). By applying a multivariate regression method, the observational AAO-proxy relations were calibrated and cross-validated for the period of 1957-89. The regressions were employed to compute the DJF-AAO index for 1500-1956. To verify the results, the authors checked the explained variance (r2), the reduction of error (RE), and the standard error (SE). Cross-va ...
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10053
Zi-Yin Zhang ; Dao-Yi Gong ; Xue-Zhao He ; Yang-Na Lei ; Sheng-Hui Feng
in Atmospheric and Oceanic Science Letters > Volume 3 Number 5 (16 September 2010) . - p.283-287Based on multiple proxies from the Southern Hemisphere, an austral summer (December-January-February: DJF) Antarctic Oscillation Index (AAO) since 1500 A.D. was reconstructed with a focus on interannual to interdecadal variability (< 50 a). By applying a multivariate regression method, the observational AAO-proxy relations were calibrated and cross-validated for the period of 1957-89. The regressions were employed to compute the DJF-AAO index for 1500-1956. To verify the results, the authors checked the explained variance (r2), the reduction of error (RE), and the standard error (SE). Cross-validation was performed by applying a leave-one-out validation method. Over the entire reconstruction period, the mean values of r2, RE, and SE are 59.9%, 0.47, and 0.67, respectively. These statistics indicate that the DJF-AAO reconstruction is relatively skillful and reliable for the last ~460 years. The reconstructed AAO variations on the interannual and interdecadal timescales compare favorably with those of several shorter sea level pressure (SLP)-based AAO indices. The leading periods of the DJF-AAO index over the last 500 years are ~2.4, ~2.6, ~6.3, ~24.1, and ~37.6 years, all of which are significant at the 95% level as estimated by power spectral analysis.
Language(s): English
Format: Digital (Free), Hard copyTags: Meteorology ; Antarctic Oscillation (AAO) ; Research ; Numerical simulation
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Ensemble Simulations of a Nonlinear Barotropic Model for the North Atlantic Oscillation
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Zhang Dong-Bin; Jin Fei-Fei; Li Jian-Ping; et al. - Science Press, 2010A numerical ensemble-mean approach was employed to solve a nonlinear barotropic model with stochastic basic flows to analyze the nonlinear effects in the formation of the North Atlantic Oscillation (NAO). The nonlinear response to external forcing was more similar to the NAO mode than the linear response was, indicating the importance of nonlinearity. With increasing external forcing and enhanced low-frequency anomalies, the effect of nonlinearity increased. Therefore, for strong NAO events, nonlinearity should be considered.
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10052
Dong-Bin Zhang ; Fei-Fei Jin ; Jian-Ping Li ; Rui-Quiang Ding
in Atmospheric and Oceanic Science Letters > Volume 3 Number 5 (16 September 2010) . - p.277-282A numerical ensemble-mean approach was employed to solve a nonlinear barotropic model with stochastic basic flows to analyze the nonlinear effects in the formation of the North Atlantic Oscillation (NAO). The nonlinear response to external forcing was more similar to the NAO mode than the linear response was, indicating the importance of nonlinearity. With increasing external forcing and enhanced low-frequency anomalies, the effect of nonlinearity increased. Therefore, for strong NAO events, nonlinearity should be considered.
Language(s): English
Format: Digital (Free), Hard copyTags: Meteorology ; North Atlantic Oscillation (NAO) ; Research ; Numerical simulation
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Analysis of South Asian Monsoons within the Context of Increasing Regional Black Carbon Aerosols
Atmospheric and Oceanic Science Letters, Volume 3 Number 4. Mahmood Rashed; Yao Jin-Feng - Science Press, 2010South Asian monsoons were analyzed within the context of increasing emissions of black carbon (BC) aerosols using a global atmospheric general circulation model. The BC aerosols were allowed to increase only over the south Asian domain to analyze the impacts of regional black carbon over the climatological patterns of monsoons. The black carbon significantly absorbed the incoming short wave radiation in the atmosphere, a result that is consistent with previous studies. Pre-monsoon (March-April-May) rainfall showed positive anomalies, particularly for some coastal regions of India. The summer ( ...
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Available online: http://www.iapjournals.ac.cn/aosl/ch/reader/view_abstract.aspx?file_no=AOSL10037
in Atmospheric and Oceanic Science Letters > Volume 3 Number 4 (16 July 2010) . - p.224-231South Asian monsoons were analyzed within the context of increasing emissions of black carbon (BC) aerosols using a global atmospheric general circulation model. The BC aerosols were allowed to increase only over the south Asian domain to analyze the impacts of regional black carbon over the climatological patterns of monsoons. The black carbon significantly absorbed the incoming short wave radiation in the atmosphere, a result that is consistent with previous studies. Pre-monsoon (March-April-May) rainfall showed positive anomalies, particularly for some coastal regions of India. The summer (June-July-August) rainfall anomalies were negative over the northern Himalayas, Myanmar, southern China and most of the regions below 20°N due to the decrease in temperature gradients induced by the absorption of BC aerosols. The vertical wind speed anomalies indicated that these regions experienced less convection, which reduces the precipitation efficiency of the monsoon system in South Asia.
Language(s): English
Format: Digital (Free), Hard copyTags: Aerosols ; Atmosphere ; Climate ; Monsoon ; Acid rain ; Research ; Region II - Asia ; South East Asia
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UNDP - Green LECRDS Guidance Manuals and Toolkits, 7. Technology Needs Assessment for Climate Change Handbook
UNDP, 2010This updated handbook provides hands-on guidance for identifying the most effective technology options for poverty reduction and climate change mitigation and adaptation. By drawing on decades of experience and inputs from leading experts and practitioners, it brings novel insights for carrying out needs assessments and creating actionable plans as part of national climate change strategies.
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Climate change, hydroconflicts and human security : achievements of and gaps in current policies
CLICO, 2010In contrast with the ubiquitousness of the headlines, empirically‐based research on the relationship between climate change, resource scarcity and conflict is often absent. The new EU project “Climate Change, Hydro‐conflicts and Human Security” (CLICO) will address this research gap. This policy brief presents CLICO’s research agenda regarding policy responses to climate change‐induced hydro‐conflicts. This policy brief is the first in a series of briefs presenting results of the CLICO project, which is funded by the 7th EU Framework Programme.
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WWRP, 04. WWRP 2010-4 - 2nd WMO International Workshop on Tropical Landfall Processes (IWTCLP-II)
Severe calamities and fatalities have arisen from landfalling tropical cyclones (TC) around the world in recent years, such as Morakot (August 2009) in western North Pacific, Nargis (May 2008) in Bay of Bengal, Gonu (June 2007) in North Arabian Sea, Bilis (July 2006) in western North Pacific, Katrina (August 2005) in Gulf of Mexico, and Catarina (March 2004) in South Atlantic etc. Transferring the advancements from the research community to operational forecast centers in NMHSs would be helpful for improving the landfalling tropical cyclone (LTC) forecasts and for mitigation of high-impact tro ...
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Assessing the role of economic instruments in a policy mix for biodiversity conservation and ecosystem services provision : a review of some methodological challenges
In the context of the EU 2010 goal of halting biodiversity loss, researchers have been called upon to evaluate the role of economic instruments for cost-effective decision-making, as well as non-market methods to assess their benefits. This paper reviews a number of methodological challenges of evaluating and designing economic instruments aimed at biodiversity conservation and ecosystem services provision in an existing policy mix. The study draws on experiences from Brazil and Costa Rica.
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IOM Report, 104. Papers presented at the WMO Technical Conference on Meteorological and Environmental Instruments and Methods of Observation (TECO-2010)
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Warming not due to urban heating says research : In Reporting Climate Science
Clifford Leon - 2010Surface temperature increases appear to be independant of wind speed suggesting that urban heating is not responsible for the long-term observed surface warming trend, according to new research that is to be published shortly.
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Guidelines for converting between various wind averaging periods in tropical cyclone conditions
World Meteorological Organization (WMO) ; Kepert Jeffrey David; Ginger J.D. - WMO, 2010 (WMO/TD-No. 1555)
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Manual para realizar una: evaluación de necesidades en materia de tecnología para el cambio climático
PNUD, 2010Esta Guía actualizada de Evaluación de necesidades en materia de tecnología ha sido diseñada para ayudar a los países a adoptar decisiones informadas en sus elecciones de tecnología. Basándose en lecciones de esfuerzos de ENT anteriores de la última década, ofrece un enfoque sistemático para realizar evaluaciones de necesidades en materia de tecnología a fin de identificar, evaluar y establecer prioridades de medios tecnológicos para mitigación y adaptación. También proporciona procesos y metodologías para revelar brechas en capacidades y marcos favorecedores, y para formular un plan de acción ...
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手册: 应对气候 变化技术需求评估
UNDP, 2010新版手册是与来自联合执行网络、英国爱丁堡大学环境变化与可持续发展研究中心和 斯德哥尔摩环境研究所(美国波士顿)的专家密切合作的结果。他们对手册的撰写都 做出了巨大的贡献。技术变化专家组的成员也在本书的写作过程中给予了宝贵的意见 和指导。
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