82 results
Search Results
2. Analysis of monthly, winter, and annual temperatures in Zagreb, Croatia, from 1864 to 2010: the 7.7-year cycle and the North Atlantic Oscillation.
- Author
-
Sen, Asok and Ogrin, Darko
- Subjects
TEMPERATURE & the environment ,METEOROLOGICAL precipitation ,ATMOSPHERIC circulation ,NORTH Atlantic oscillation ,CLIMATE change - Abstract
Long instrumental records of meteorological variables such as temperature and precipitation are very useful for studying regional climate in the past, present, and future. They can also be useful for understanding the influence of large-scale atmospheric circulation processes on the regional climate. This paper investigates the monthly, winter, and annual temperature time series obtained from the instrumental records in Zagreb, Croatia, for the period 1864-2010. Using wavelet analysis, the dominant modes of variability in these temperature series are identified, and the time intervals over which these modes may persist are delineated. The results reveal that all three temperature records exhibit low-frequency variability with a dominant periodicity at around 7.7 years. The 7.7-year cycle has also been observed in the temperature data recorded at several other stations in Europe, especially in Northern and Western Europe, and may be linked to the North Atlantic Oscillation (NAO) and/or solar/geomagnetic activity. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
3. Anthropogenic forcings reverse a simulated multi-century naturally-forced Northern Hemisphere Hadley cell intensification.
- Author
-
Hess, Or and Chemke, Rei
- Subjects
ATMOSPHERIC models ,HYDROLOGIC cycle ,ATMOSPHERIC circulation ,CLIMATE change ,TROPICAL climate - Abstract
The Hadley circulation plays a central role in determining the location and intensity of the hydrological cycle in tropical and subtropical latitudes. Thus, the human-induced historical and projected weakening of the Northern Hemisphere Hadley circulation has considerable societal impacts. Yet, it is currently unknown how unparalleled this weakening is relative to the response of the circulation to natural forcings in past centuries. Here, using state-of-the-art climate models, we show that in contrast to the recent and future human-induced Hadley circulation weakening, natural forcings acted to intensify the circulation by cooling the climate over the last millennium. The reversal of a naturally-forced multi-centennial trend by human emissions highlights their unprecedented impacts on the atmospheric circulation. Given the amplifying effect of natural forcings on the Hadley circulation, our analysis stresses the importance of adequately incorporating natural forcings in climate model projections to better constrain future tropical climate changes. The authors find an unprecedented human-induced weakening of the Northern Hemisphere Hadley circulation in recent and coming decades, contrasting with the naturally-forced simulated strengthening over the preindustrial last millennium. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Spatio-temporal changes in atmospheric precipitation over south-western Poland between the periods 1891-1930 and 1981-2010.
- Author
-
Szymanowski, Mariusz, Wieczorek, Małgorzata, Namyślak, Marika, Kryza, Maciej, and Migała, Krzysztof
- Subjects
SPATIO-temporal variation ,METEOROLOGICAL precipitation ,ATMOSPHERIC circulation ,CLIMATE change ,PLUVIAL periods - Abstract
In this paper, we quantify the changes in precipitation distribution in south-western Poland between the periods 1891-1930 and 1981-2010. The average monthly precipitation totals available for 368 and 245 stations, respectively, are spatially interpolated and processed to calculate maps of differences and pluvial continentality indices for both periods. The maps are analysed against changes in atmospheric circulation and take into account the potential role of the mountain barrier of the Sudetes. The main findings are (1) winter totals generally increased in conjunction with a higher frequency of zonal circulation; it is more pronounced in the upper parts of the Sudetes due to orographic effects; (2) a decreased frequency of zonal circulation together with an increased frequency of southern flows has likely led to the reduction of precipitation in spring and autumn. These changes have led to a significant modification of the region's pluvial regime, mostly by decreasing continentality features (especially in the Sudetes and the western lowlands). In addition, the strong sheltering influence of the mountain barrier is observed, driving the preservation or even the enhancement of the continental pluvial characteristics in the north-eastern to eastern foregrounds of the Sudetes. This leads to the conclusion that in areas where long-term observed trends or future projections of precipitation are ambiguous, there may occur significant modifications in regional characteristics, especially as a result of changes in atmospheric circulation modified by local orography. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Assessing Global Warming Induced Changes in Summer Rainfall Variability over Eastern China Using the Latest Hadley Centre Climate Model HadGEM3-GC2.
- Author
-
Duan, Yawen, Wu, Peili, Chen, Xiaolong, and Ma, Zhuguo
- Subjects
METEOROLOGICAL precipitation ,RAINFALL anomalies ,RAINFALL ,CLIMATE change ,GLOBAL warming ,ATMOSPHERIC circulation - Abstract
Summer precipitation anomalies over eastern China are characterized spatially by meridionally banded structures fluctuating on interannual and interdecadal timescales, leading to regional droughts and floods. In addition to long-term trends, how these patterns may change under global warming has important implications for agricultural planning and water resources over this densely populated area. Using the latest Hadley Centre climate model, HadGEM3-GC2, this paper investigates the potential response of summer precipitation patterns over this region, by comparing the leading modes between a 4×CO
2 simulation and the model’s pre-industrial control simulation. Empirical Orthogonal Function (EOF) analyses show that the first two leading modes account for about 20% of summer rainfall variability. EOF1 is a monopole mode associated with the developing phase of ENSO events and EOF2 is a dipole mode associated with the decaying phase of ENSO. Under 4×CO2 forcing, the dipole mode with a south-north orientation becomes dominant because of a strengthened influence from excessive warming of the Indian Ocean. On interdecadal time scales, the first EOF looks very different from the control simulation, showing a dipole mode of east-west contrast with enhanced influence from high latitudes. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
6. Assessment and Assimilation of FY-3 Humidity Sounders and Imager in the UK Met Office Global Model.
- Author
-
Carminati, Fabien, Candy, Brett, Bell, William, and Atkinson, Nigel
- Subjects
HUMIDITY ,NUMERICAL weather forecasting ,WEATHER forecasting ,ATMOSPHERIC circulation ,CLIMATE change ,ENVIRONMENTAL monitoring ,CLIMATOLOGY - Abstract
China’s FengYun 3 (FY-3) polar orbiting satellites are set to become an important source of observational data for numerical weather prediction (NWP), atmospheric reanalyses, and climate monitoring studies over the next two decades. As part of the Climate Science for Service Partnership China (CSSP China) program, FY-3B Microwave Humidity Sounder 1 (MWHS-1) and FY-3C MWHS-2 observations have been thoroughly assessed and prepared for operational assimilation. This represents the first time observations from China’s polar orbiting satellites have been used in the UK’s global NWP model. Since 2016, continuous data quality monitoring has shown occasional bias changes found to be correlated to changes in the energy supply scheme regulating the platform heating system and other transient anomalies. Nonetheless, MWHS-1 and MWHS-2 significantly contribute to the 24-h forecast error reduction by 0.3% and 0.6%, respectively, and the combination of both instruments is shown to improve the fit to the model background of independent sounders by up to 1%. The observations from the Microwave Radiation Imager (MWRI) also are a potentially significant source of benefits for NWP models, but a solar-dependent bias observed in the instrument half-orbits has prevented their assimilation. This paper presents the bases of a correction scheme developed at the Met Office for the purpose of a future assimilation of MWRI data. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
7. Three-dimensional fusion of spaceborne and ground radar reflectivity data using a neural network-based approach.
- Author
-
Kou, Leilei, Wang, Zhuihui, and Xu, Fen
- Subjects
SPACE-based radar ,ARTIFICIAL neural networks ,METEOROLOGICAL precipitation ,ATMOSPHERIC circulation ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
8. Data assimilation method based on the constraints of confidence region.
- Author
-
Li, Yong, Li, Siming, Sheng, Yao, and Wang, Luheng
- Subjects
CONFIDENCE regions (Mathematics) ,KALMAN filtering ,OCEANOGRAPHY ,ATMOSPHERIC circulation ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
9. Dynamical downscaling of regional climate over eastern China using RSM with multiple physics scheme ensembles.
- Author
-
Peishu, Zong, Jianping, Tang, Shuyu, Wang, Lingyun, Xie, Jianwei, Yu, Yunqian, Zhu, Xiaorui, Niu, and Chao, Li
- Subjects
DOWNSCALING (Climatology) ,CLIMATE change ,METEOROLOGICAL precipitation ,ATMOSPHERIC temperature ,ATMOSPHERIC circulation - Abstract
The parameterization of physical processes is one of the critical elements to properly simulate the regional climate over eastern China. It is essential to conduct detailed analyses on the effect of physical parameterization schemes on regional climate simulation, to provide more reliable regional climate change information. In this paper, we evaluate the 25-year (1983-2007) summer monsoon climate characteristics of precipitation and surface air temperature by using the regional spectral model (RSM) with different physical schemes. The ensemble results using the reliability ensemble averaging (REA) method are also assessed. The result shows that the RSM model has the capacity to reproduce the spatial patterns, the variations, and the temporal tendency of surface air temperature and precipitation over eastern China. And it tends to predict better climatology characteristics over the Yangtze River basin and the South China. The impact of different physical schemes on RSM simulations is also investigated. Generally, the CLD3 cloud water prediction scheme tends to produce larger precipitation because of its overestimation of the low-level moisture. The systematic biases derived from the KF2 cumulus scheme are larger than those from the RAS scheme. The scale-selective bias correction (SSBC) method improves the simulation of the temporal and spatial characteristics of surface air temperature and precipitation and advances the circulation simulation capacity. The REA ensemble results show significant improvement in simulating temperature and precipitation distribution, which have much higher correlation coefficient and lower root mean square error. The REA result of selected experiments is better than that of nonselected experiments, indicating the necessity of choosing better ensemble samples for ensemble. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
10. Attributing Venice Acqua Alta events to a changing climate and evaluating the efficacy of MoSE adaptation strategy.
- Author
-
Faranda, Davide, Ginesta, Mireia, Alberti, Tommaso, Coppola, Erika, and Anzidei, Marco
- Subjects
CLIMATE change ,ATMOSPHERIC circulation ,GLOBAL warming ,CITIES & towns ,SEA level ,CYCLONES - Abstract
We use analogues of atmospheric patterns to investigate changes in four devastating Acqua Alta (flooding) events in the lagoon of Venice associated with intense Mediterranean cyclones occurred in 1966, 2008, 2018 and 2019. Our results provide evidence that changes in atmospheric circulation, although not necessarily only anthropogenically driven, are linked to the severity of these events. We also evaluate the cost and benefit of the MoSE system, which was designed to protect against flooding. Our analysis shows that the MoSE has already provided protection against analogues of the most extreme event, which occurred in 1966. These findings have significant implications for the future of Venice and other coastal cities facing similar challenges from rising sea levels due to extreme events. This study also provides a pathway to evaluate the effectiveness of adaptation in a scenario more frequent and intense extreme events if higher global warming levels will be reached. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
11. Preface to Special Issue on Climate Science for Service Partnership China.
- Author
-
Belcher, Stephen, Stott, Peter, Song, Lianchun, Chao, Qingchen, Lu, Riyu, and Zhou, Tianjun
- Subjects
CLIMATE change ,CLIMATOLOGY ,ATMOSPHERIC models ,ATMOSPHERIC sciences ,ATMOSPHERIC circulation - Published
- 2018
- Full Text
- View/download PDF
12. Analysis of climate change in Northern Ethiopia: implications for agricultural production.
- Author
-
Hadgu, Gebre, Tesfaye, Kindie, and Mamo, Girma
- Subjects
CLIMATE change ,AGRICULTURAL productivity ,AGRICULTURE ,ATMOSPHERIC temperature ,ATMOSPHERIC circulation - Abstract
The impact of climatic change can be on specific locations. However, the broader the affected area coverage, in mind, the higher would be the chance in missing critical details. In this light, this paper attempts to assess the possible climatic changes and their corresponding implications on agricultural production in northern Ethiopia. The analysis is based on the future (2030 and 2050) temperature and rainfall data, downscaled as ensemble of four general circulation models (GCMs) using the A2 and B1 emission scenarios for ten meteorological stations located in different agroecological zones of the study region. The result indicates that, based on emission scenarios, the mean maximum and minimum temperature would increase by 2-2.3 and 0.8-0.9 °C in 2030 and by 2.2-2.7 and 1.4-1.7 °C in 2050, respectively. This will be accompanied by an increase in the frequency of hot days and nights and a decrease in cool days and nights. While annual rainfall totals will remain unchanged, main rainy season ( kiremt) rainfall total would increase on average in 12.9 and 14.2 % under A2 and 9.5 and 11.2 % under B1 by 2030 and 2050, respectively. Owing to an increase in kiremt rainfall, the yield of maize and sorghum may increase at some sites under future climatic conditions, and the increase would be higher under CO fertilization. The results suggest the need for site-specific adaptation strategies to reduce the impact and/or exploit the opportunities of climate change. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
13. A review of seasonal climate prediction research in China.
- Author
-
Wang, Huijun, Fan, Ke, Sun, Jianqi, Li, Shuanglin, Lin, Zhaohui, Zhou, Guangqing, Chen, Lijuan, Lang, Xianmei, Li, Fang, Zhu, Yali, Chen, Hong, and Zheng, Fei
- Subjects
WEATHER forecasting ,CLIMATE change ,ATMOSPHERIC temperature ,ATMOSPHERIC circulation ,DISASTERS - Abstract
The ultimate goal of climate research is to produce climate predictions on various time scales. In China, efforts to predict the climate started in the 1930s. Experimental operational climate forecasts have been performed since the late 1950s, based on historical analog circulation patterns. However, due to the inherent complexity of climate variability, the forecasts produced at that time were fairly inaccurate. Only from the late 1980s has seasonal climate prediction experienced substantial progress, when the Tropical Ocean and Global Atmosphere project of the World Climate Research program (WCRP) was launched. This paper, following a brief description of the history of seasonal climate prediction research, provides an overview of these studies in China. Processes and factors associated with the climate variability and predictability are discussed based on the literature published by Chinese scientists. These studies in China mirror aspects of the climate research effort made in other parts of the world over the past several decades, and are particularly associated with monsoon research in East Asia. As the climate warms, climate extremes, their frequency, and intensity are projected to change, with a large possibility that they will increase. Thus, seasonal climate prediction is even more important for China in order to effectively mitigate disasters produced by climate extremes, such as frequent floods, droughts, and the heavy frozen rain events of South China. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
14. Climatological drivers of changes in flood hazard in Germany.
- Author
-
Hattermann, Fred, Kundzewicz, Zbigniew, Huang, Shaochun, Vetter, Tobias, Gerstengarbe, Friedrich-Wilhelm, and Werner, Peter
- Subjects
CLIMATOLOGY ,CLIMATE change ,FLOOD damage prevention ,ATMOSPHERIC circulation ,HUMIDITY - Abstract
Since several destructive floods have occurred in Germany in the last decades, it is of considerable interest and relevance ( e.g., when undertaking flood defense design) to take a closer look at the climatic factors driving the changes in flood hazard in Germany. Even if there also exist non-climatic factors controlling the flood hazard, the present paper demonstrates that climate change is one main driver responsible for the increasing number of floods. Increasing trends in temperature have been found to be ubiquitous in Germany, with impact on air humidity and changes in (intense) precipitation. Growing trends in flood prone circulation pattern and heavy precipitation are significant in many regions of Germany over a multi-decade interval and this can be translated into the rise of flood hazard and flood risk. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
15. Extra-tropical cyclones in the present and future climate: a review.
- Author
-
Ulbrich, U., Leckebusch, G. C., and Pinto, J. G.
- Subjects
TROPICAL cyclones ,CLIMATE change ,WEATHER forecasting ,ATMOSPHERIC circulation ,GENERAL circulation model - Abstract
Based on the availability of hemispheric gridded data sets from observations, analysis and global climate models, objective cyclone identification methods were developed and applied to these data sets. Due to the large amount of investigation methods combined with the variety of different datasets, a multitude of results exist, not only for the recent climate period but also for the next century, assuming anthropogenic changed conditions. Different thresholds, different physical quantities, and considerations of different atmospheric vertical levels add to a picture that is difficult to combine into a common view of cyclones, their variability and trends, in the real world and in GCM studies. Thus, this paper will give a comprehensive review of the actual knowledge on climatologies of mid-latitude cyclones for the Northern and Southern Hemisphere for the present climate and for its possible changes under anthropogenic climate conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
16. Reconstruction of long-term precipitation records for Edinburgh: an examination of the mechanisms responsible for temporal variability in precipitation.
- Author
-
Macdonald, N., Phillips, I. D., and Thorpe, J.
- Subjects
PRECIPITATION variability ,METEOROLOGICAL precipitation ,CLIMATE change ,PRECIPITATION normals ,ATMOSPHERIC circulation ,SYNOPTIC climatology ,GROSSWETTERLAGEN ,STRATOSPHERIC circulation - Abstract
Recent dry years (combined dry winter and summer months) within the UK (2005 and 2006) have enhanced concerns relating to long term water resources and future water provision in large conurbations. This paper examines the mechanisms responsible for precipitation variability for five different areas in Edinburgh (precipitation regions) using composite historic precipitation records for the period 1861–2005. Trend analysis and principal component analysis (PCA) were undertaken to examine precipitation variability over time and space. Annual correlation co-efficients were derived for relationships between precipitation areas, atmospheric–oceanographic variations and geographic parameters. Stepwise regression models were constructed to specify annual precipitation, through atmospheric variations, for each of the precipitation areas. Significant downward trends in precipitation ( p < 0.05) were noted in two out of the five precipitation areas, with one principal component representing precipitation variability over Edinburgh and the Pentland Hills. Precipitation variability is best explained by fluctuations in pressure, altitude and proximity to coast. Precipitation trends cannot be explained by changes in atmospheric circulation patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
17. Volcanic contribution to the 1990s North Pacific climate shift in winter.
- Author
-
Wu, Chi-Hua, Lee, Shih-Yu, Tsai, I-Chun, Shiu, Chein-Jung, and Chen, Yi-Ying
- Subjects
VOLCANIC eruptions ,STRATOSPHERIC aerosols ,ATMOSPHERIC circulation ,JET streams ,WINTER ,CLIMATE change - Abstract
It is debatable whether external forcing can change the state of the climate. By investigating decadal changes with and without including the 1990s stratospheric volcanic aerosols, we explored the volcanic eruptions contribution to decadal climate regime shifts occurring in boreal winter over the North Pacific. The volcanic eruptions contribution can be characterized as a series of rapid changes, including the strengthening and poleward shift of the midlatitude westerly jet stream. In addition to the short-lived radiative effects primarily induced by the 1991 Mount Pinatubo eruption, the volcanically driven decadal change can be observed in the mid-to-late 1990s, suggesting a time-lagged characteristic of the volcanic climate impact. Compared with the decadal change irrelevant to volcanic eruption, the decadal state more dramatically enters into the next phase when volcanic forcing is included. The climate oscillation-related pattern shifts that occurred across the 1990s can provide insights into volcanically induced changes in decadal atmospheric circulation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Methodology for the historical and synoptic analysis of snows: its application to the region of Castilla y León (Spain).
- Author
-
Ortega, Mª Teresa and Morales, Carlos G.
- Subjects
ATMOSPHERIC circulation ,HISTORICAL analysis ,DATABASES ,CLIMATE change ,COMMUNITIES - Abstract
A methodology is proposed for the study of snowfall, applied to the region and autonomous community of Castilla y León (Spain). It is based on two major pillars: the elaboration of a Snowfall Catalogue from the consultation of documentary sources (press) between 1979 and 2021, which allows cataloging all the episodes that occurred from October to May, and the synoptic study of the atmospheric dynamics in those 43 years, identifying the different types of weather as a means of validating the cataloged episodes. The database created provides information on its intensity, duration, and frequency, as well as its genesis, distribution, typology, and climatic hazard. All this has been analyzed and has allowed to recognize different stages in its way of occurring and to estimate trends and behaviors in both the number of episodes and the number of snow days and their assessment in the current situation of climate change. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Unprecedented Heatwave in Western North America during Late June of 2021: Roles of Atmospheric Circulation and Global Warming.
- Author
-
Wang, Chunzai, Zheng, Jiayu, Lin, Wei, and Wang, Yuqing
- Subjects
ATMOSPHERIC circulation ,GLOBAL warming ,ATMOSPHERIC models ,HEAT waves (Meteorology) ,NATURAL gas pipelines ,GREENHOUSE gases - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
20. Enhanced spring warming in a Mediterranean mountain by atmospheric circulation.
- Author
-
Bruley, E., Mouillot, F., Lauvaux, T., and Rambal, S.
- Subjects
SPRING ,ATMOSPHERIC temperature ,HUMIDITY ,WATER vapor ,CLIMATE change ,GRASSLANDS ,ATMOSPHERIC circulation - Abstract
We analyzed trends of air temperature across the Cévennes National Park in Southern France, a mid-altitude coastal mountain experiencing a rapid spread of forests at the expense of rangelands and submitted to Mediterranean Sea influences and so, impacted by local and regional processes of climate change. Since 1980, April to June warming trend reached a maximum temperature increase of + 0.124 °C year
−1 and uniform whatever the altitude. Minimum temperature increased by + 0.058 °C year−1 at 500 m altitude and + 0.089 °C year−1 at 1500 m. Concomitantly, forest cover is increasing by + 0.51% year−1 . Using an intrinsic biophysical mechanism model, we demonstrated that, at monthly scale, the forest surface is 1.7–3.1 °C cooler than that of nearby grasslands. As a result, the decrease in albedo corresponding to the conversion from grasslands to dense forests, translates into a cooling of maximum air temperatures of 0.023 °C year−1 which contributes to slow down the warming rate enhancement. Spring warming trends co-varied with negative WeMO phases associated with a low in the Gulf of Cádiz and an anticyclone in Central Europe. An east to west pressure gradient increases atmospheric humidity leading to a strong water vapor feedback, enhancing the forcing of thermal long wave radiations and hence the rise in temperature. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
21. Changes of Meiyu system in the future under A1B scenario simulated by MIROC_Hires model.
- Author
-
Zhu, Jian, Huang, Danqing, and Yang, Tao
- Subjects
RAINFALL anomalies ,CLIMATE change ,ATMOSPHERIC circulation ,ATMOSPHERIC water vapor - Abstract
The Meiyu/Baiu/Changma is an important and unique persistent rainfall over East Asian during the northward progress of the East Asian summer monsoon (EASM) from late spring to middle summer. In this study, changes of Meiyu system under global warming are examined by MIROC_Hires coupled model. The results reveal that the Meiyu system becomes weaker in the warmer future: the large precipitation center shifts to northern China; ratio of Meiyu rainfall to total summer precipitation ratio decreases. For the three-dimensional atmospheric circulation, the configuration of upper and lower jets benefits the heavy rainfall located over the northern China, associated with abundant water vapor transporting to northern China. The heterogeneous warming over land and sea may be a possible reason for the changes of Meiyu system. Larger thermal contrast is indicated between the Asian continent and the western Pacific during the Meiyu period, which may result in the enhanced southerly with abundant water vapor arriving at northern China. Therefore, rainfall over Meiyu region may be suspended. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
22. Understanding Third Pole Atmospheric Dynamics and Land Surface Processes and Their Associations with the Cryosphere, Air Quality, and Climate Change: Preface to the Special Issue on Third Pole Atmospheric Physics, Chemistry, and Hydrology.
- Author
-
Qian, Yun, Wang, Hailong, Zhao, Chuanfeng, Zhao, Chun, Chen, Siyu, Hu, Xiao-Ming, and Kang, Shichang
- Subjects
ATMOSPHERIC physics ,ATMOSPHERIC circulation ,HYDROLOGY ,CLIMATE change ,EARTH system science ,MONSOONS - Published
- 2022
- Full Text
- View/download PDF
23. A simple model of blocking action over a hemisphere.
- Author
-
Kurgansky, M. V.
- Subjects
ATMOSPHERIC circulation ,STATISTICAL equilibrium ,ATMOSPHERIC models ,GLOBAL warming ,CLIMATE change - Abstract
A two-zone model of the atmospheric circulation over a hemisphere is considered. The latitude φ of the boundary between the zone of the Rossby circulation regime at mid and high latitudes and the zone of the Hadley circulation regime at low latitudes serves as a model variable. The principle of maximum of the (information) entropy of the eddy regime within the Rossby regime zone is used to determine a statistical (climatic) equilibrium value of φ. Based on the proposed model, the question of atmospheric blocking action over the hemisphere is addressed. An attempt has been made to represent a blocking phenomenon as a necessary attribute of the atmospheric circulation in statistical equilibrium. The model suggests that long-term climate change related either to the (significant) global warming or to the (significant) global cooling, both respective to the current climate state, and quantified in terms of changes in latitude φ, leads to an increase in the probability of blocking action. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. Estimates of Direct Radiative Forcing Impact on Surface Air Temperature Changes in the Modern Period.
- Author
-
Semenov, V. A. and Aleshina, M. A.
- Subjects
ATMOSPHERIC temperature ,RADIATIVE forcing ,SURFACE temperature ,ATMOSPHERIC circulation ,OCEAN temperature ,GENERAL circulation model - Abstract
Estimates of the contribution of direct radiative forcing (DRF) to the surface air temperature trends over the Northern Hemisphere (NH) continents for the period 1979–2012 have been obtained based on an ensemble of numerical experiments with an atmospheric general circulation model using the prescribed historical sea surface temperature and sea ice concentration data with and without time-varying concentrations of greenhouse gases and aerosols in the atmosphere. The contribution of DRF to the simulated ensemble mean temperature variations over land in the NH in winter and summer is approximately 30% or 0.3°С and 0.2°С, respectively. The maximum warming associated with DRF was found, in particular, in winter and summer over the eastern part of the European territory of Russia. The results indicate that the response of atmosphere circulation to DRF may lead to a nonlinear DRF contribution to the temperature changes in the NH, in particular mitigating the temperature increase in the winter season. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. Influence of the Arctic on the Predictability of Eurasian Winter Extreme Weather Events.
- Author
-
Dai, Guokun and Mu, Mu
- Subjects
WEATHER ,ATMOSPHERIC circulation ,FORECASTING ,INFLUENCE ,CLIMATE extremes ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
- Full Text
- View/download PDF
26. Seasonal division of 850 hPa South China Sea based on multi-element atmospheric condition similarity.
- Author
-
Wang, Zheng, Feng, Guolin, Zhi, Rong, and Hu, Po
- Subjects
WEATHER ,ATMOSPHERIC circulation ,MONSOONS ,HOT springs ,CLIMATE change ,CLIMATE change forecasts - Abstract
Comprehensive consideration of multiple meteorological elements for the objective identification and division of seasonal changes is important in the field of climate monitoring and diagnostic analysis. The development of relevant identification and classification methods will help us better understand the new characteristics of seasonal transitions against the background of climate change. Based on reanalysis data from the National Centers for Environmental Prediction from 1950 to 2015, we used the multi-element atmospheric condition similarity method to seasonally divide the average climatological conditions at 850 hPa over the South China Sea, and analyzed the annual mean results of the onset of seasons and annual mean seasonal variations of meteorological elements in this region. The results show the following. First, the seasonal division results based on multi-element atmospheric condition similarity coincide with the seasonal variation times of each meteorological element with atmospheric conditions comprising five meteorological elements. When the four seasons change, the meteorological elements at 850 hPa in the South China Sea have obvious seasonal variation, and atmospheric circulation and surface upward long-wave radiation change conspicuously with seasonal transformation. This confirms the validity of the method as applied to seasonal divisions in the South China Sea. Second, when the climate system translates from winter to summer in the South China Sea, thermal elements change greatly and rapidly. Changes to thermal elements in spring provide climate conditions for the onset of summer and the onset of the summer monsoon in the South China Sea. Third, when the climate system shifts from summer to winter in the South China Sea, changes to wind elements are obvious and rapid. In autumn, changes in thermal conditions between the Eurasian continent and the Pacific Ocean lead to major changes in atmospheric circulation and wind. In addition, seasonal divisions are no longer just nodes of time. Rather, they can be used as important indicators for further studies of atmospheric circulation changes, short-term climate predictions, and seasonal changes of other climate systems. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
27. Performance of the general circulation models in simulating temperature and precipitation over Iran.
- Author
-
Abbasian, Mohammadsadegh, Moghim, Sanaz, and Abrishamchi, Ahmad
- Subjects
GENERAL circulation model ,METEOROLOGICAL precipitation ,CLIMATE change ,ATMOSPHERIC models ,ATMOSPHERIC circulation - Abstract
General Circulation Models (GCMs) are advanced tools for impact assessment and climate change studies. Previous studies show that the performance of the GCMs in simulating climate variables varies significantly over different regions. This study intends to evaluate the performance of the Coupled Model Intercomparison Project phase 5 (CMIP5) GCMs in simulating temperature and precipitation over Iran. Simulations from 37 GCMs and observations from the Climatic Research Unit (CRU) were obtained for the period of 1901–2005. Six measures of performance including mean bias, root mean square error (RMSE), Nash-Sutcliffe efficiency (NSE), linear correlation coefficient (r), Kolmogorov-Smirnov statistic (KS), Sen's slope estimator, and the Taylor diagram are used for the evaluation. GCMs are ranked based on each statistic at seasonal and annual time scales. Results show that most GCMs perform reasonably well in simulating the annual and seasonal temperature over Iran. The majority of the GCMs have a poor skill to simulate precipitation, particularly at seasonal scale. Based on the results, the best GCMs to represent temperature and precipitation simulations over Iran are the CMCC-CMS (Euro-Mediterranean Center on Climate Change) and the MRI-CGCM3 (Meteorological Research Institute), respectively. The results are valuable for climate and hydrometeorological studies and can help water resources planners and managers to choose the proper GCM based on their criteria. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
28. Temperature difference relationship among precipitation, dry days, and spells in Turkey.
- Author
-
Dabanli, Ismail
- Subjects
ATMOSPHERIC temperature ,METEOROLOGICAL precipitation ,CLIMATE change ,ATMOSPHERIC circulation ,STANDARD deviations - Abstract
Strong logical relationships exist between temperature difference and hydro-meteorological variables such as precipitation, dry days, and dry spells. These relationships can be used for knowing how the differences of total and top 10% heavy precipitations, dry days, and dry spells will change with respect to temperature differences? Here, daily precipitation and temperature records over Turkey are considered from 1971 to 2010, inclusive. First 30-year (1971-2000) data are used for training for temperature difference function (ΔT) and the remaining 10-year (2001-2010) is reserved for validation. The temperature difference function is validated by mean relative error, and the results are calculated for total and top 10% heavy precipitation, dry days, and spells as 14.60%, 6.14%, 2.81%, and 11.89%, respectively. The strong relationship exists between temperature difference function and standard deviation of corresponding climatic variables. Results show that standard deviation and mean relative error (MRE) have linear correlation. Also, ΔT model predictions are compared with CMIP5 RCPs projections from 2020 to 2100. The suggested model predictions fall within the range of various atmosphere-ocean global circulation (climate) model (AOGCM) scenario RCP 4.5 and RCP 8.5 projections, in addition to model predictions cross-correlation for RCP 2.6 and RCP 6.0. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
29. Further-Adjusted Long-Term Temperature Series in China Based on MASH.
- Author
-
Li, Zhen, Yan, Zhongwei, Cao, Lijuan, and Jones, Phil D.
- Subjects
EARTH temperature ,ATMOSPHERIC circulation ,ATMOSPHERIC sciences ,ATMOSPHERIC temperature ,CLIMATE change ,CLIMATOLOGY - Abstract
A set of homogenized monthly mean surface air temperature (SAT) series at 32 stations in China back to the 19th century had previously been developed based on the RHtest method by Cao et al., but some inhomogeneities remained in the dataset. The present study produces a further-adjusted and updated dataset based on the Multiple Analysis of Series for Homogenization (MASH) method. The MASH procedure detects 33 monthly temperature records as erroneous outliers and 152 meaningful break points in the monthly SAT series since 1924 at 28 stations. The inhomogeneous parts are then adjusted relative to the latest homogeneous part of the series. The new data show significant warming trends during 1924-2016 at all the stations, ranging from 0.48 to 3.57°C (100 yr)
−1 , with a regional mean trend of 1.65°C (100 yr)−1 ; whereas, the previous results ranged from a slight cooling at two stations to considerable warming, up to 4.5°C (100 yr)−1 . It is suggested that the further-adjusted data are a better representation of the large-scale pattern of climate change in the region for the past century. The new data are available online athttp://www.dx.doi.org/10.11922/sciencedb.516. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
30. Reduced Sensitivity of Tropical Cyclone Intensity and Size to Sea Surface Temperature in a Radiative-Convective Equilibrium Environment.
- Author
-
Wang, Shuai and Toumi, Ralf
- Subjects
OCEAN temperature ,TROPICAL cyclones ,GLOBAL temperature changes ,GLOBAL warming ,ATMOSPHERIC models ,ATMOSPHERIC circulation ,CLIMATE change ,CLIMATOLOGY - Abstract
It has been challenging to project the tropical cyclone (TC) intensity, structure and destructive potential changes in a warming climate. Here, we compare the sensitivities of TC intensity, size and destructive potential to sea surface warming with and without a pre-storm atmospheric adjustment to an idealized state of Radiative-Convective Equilibrium (RCE). Without RCE, we find large responses of TC intensity, size and destructive potential to sea surface temperature (SST) changes, which is in line with some previous studies. However, in an environment under RCE, the TC size is almost insensitive to SST changes, and the sensitivity of intensity is also much reduced to 3% °C
−1 -4% °C−1 . Without the pre-storm RCE adjustment, the mean destructive potential measured by the integrated power dissipation increases by about 25% °C−1 during the mature stage. However, in an environment under RCE, the sensitivity of destructive potential to sea surface warming does not change significantly. Further analyses show that the reduced response of TC intensity and size to sea surface warming under RCE can be explained by the reduced thermodynamic disequilibrium between the air boundary layer and the sea surface due to the RCE adjustment. When conducting regional-scale sea surface warming experiments for TC case studies, without any RCE adjustment the TC response is likely to be unrealistically exaggerated. The TC intensity-temperature sensitivity under RCE is very similar to those found in coupled climate model simulations. This suggests global mean intensity projections under climate change can be understood in terms of a thermodynamic response to temperature with only a minor contribution from any changes in large-scale dynamics. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
31. Interannual Variability of Late-spring Circulation and Diabatic Heating over the Tibetan Plateau Associated with Indian Ocean Forcing.
- Author
-
Zhao, Yu, Duan, Anmin, and Wu, Guoxiong
- Subjects
ATMOSPHERIC circulation ,OCEAN temperature ,SEASONAL temperature variations ,METEOROLOGICAL precipitation ,CLIMATE change ,HEAT flux - Abstract
The thermal forcing of the Tibetan Plateau (TP) during boreal spring, which involves surface sensible heating, latent heating released by convection and radiation flux heat, is critical for the seasonal and subseasonal variation of the East Asian summer monsoon. Distinct from the situation in March and April when the TP thermal forcing is modulated by the sea surface temperature anomaly (SSTA) in the North Atlantic, the present study shows that it is altered mainly by the SSTA in the Indian Ocean Basin Mode (IOBM) in May, according to in-situ observations over the TP and MERRA reanalysis data. In the positive phase of the IOBM, a local Hadley circulation is enhanced, with its ascending branch over the southwestern Indian Ocean and a descending one over the southeastern TP, leading to suppressed precipitation and weaker latent heat over the eastern TP. Meanwhile, stronger westerly flow and surface sensible heating emerges over much of the TP, along with slight variations in local net radiation flux due to cancellation between its components. The opposite trends occur in the negative phase of the IOBM. Moreover, the main associated physical processes can be validated by a series of sensitivity experiments based on an atmospheric general circulation model, FAMIL. Therefore, rather than influenced by the remote SSTAs of the northern Atlantic in the early spring, the thermal forcing of the TP is altered by the Indian Ocean SSTA in the late spring on an interannual timescale. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
32. Statistics-based optimization of the polarimetric radar hydrometeor classification algorithm and its application for a squall line in South China.
- Author
-
Wu, Chong, Liu, Liping, Wei, Ming, Xi, Baozhu, and Yu, Minghui
- Subjects
POLARIMETRIC remote sensing ,SQUALL lines ,ATMOSPHERIC circulation ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
33. New method for estimating daily global solar radiation over sloped topography in China.
- Author
-
Shi, Guoping, Qiu, Xinfa, and Zeng, Yan
- Subjects
MEASUREMENT of solar radiation ,MODIS (Spectroradiometer) ,ATMOSPHERIC circulation ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
34. Anomalous western Pacific subtropical high during El Niño developing summer in comparison with decaying summer.
- Author
-
Xue, Feng, Dong, Xiao, and Fan, Fangxing
- Subjects
SUMMER ,EL Nino ,PRECIPITATION anomalies ,ATMOSPHERIC circulation ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
35. Asymmetric variations in the tropical ascending branches of Hadley circulations and the associated mechanisms and effects.
- Author
-
Sun, Bo
- Subjects
ATMOSPHERIC circulation ,MERIDIONAL overturning circulation ,CYCLONES ,CLIMATE change - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
36. Role of extratropical cyclones in the recently observed increase in poleward moisture transport into the Arctic Ocean.
- Author
-
Villamil-Otero, Gian, Zhang, Jing, He, Juanxiong, and Zhang, Xiangdong
- Subjects
CYCLONES ,ATMOSPHERIC water vapor ,ATMOSPHERIC temperature ,ATMOSPHERIC circulation - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
37. Remarkable link between projected uncertainties of Arctic sea-ice decline and winter Eurasian climate.
- Author
-
Cheung, Hoffman, Keenlyside, Noel, Omrani, Nour-Eddine, and Zhou, Wen
- Subjects
SEA ice ,CLIMATE change ,ATMOSPHERIC circulation ,SINGULAR value decomposition - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
38. Assessment of prediction and predictability of short rains over equatorial East Africa using a multi-model ensemble.
- Author
-
Bahaga, T., Kucharski, F., Tsidu, G., and Yang, Hongwei
- Subjects
RAINFALL anomalies ,CLIMATE change ,METEOROLOGICAL precipitation ,ATMOSPHERIC circulation ,ECOLOGY - Abstract
In this study, the performance of dynamical seasonal forecast systems is evaluated for the prediction of short rain anomalies over equatorial East Africa. The evaluation is based on observational datasets and the Asia-Pacific Climate Center (APCC) Ocean-Atmosphere coupled multi-model ensemble (MME) retrospective forecasts (hindcasts). These forecast systems have different hindcast periods; here, we have selected common years from 1982 to 2005. The ensembles of individual models and their MME mean are evaluated. Hindcasts initialized on the 1st of August from each year alone are considered, as these are the most relevant to short rain predictions. The coupled climate model ensemble reproduces the spatial distribution of mean September-October-November (SON) rainfall and seasonal climate variations over equatorial East Africa with further improvement in MME mean. Individual coupled models and MME mean also show statistically significant skill in forecasting sea surface temperatures anomalies (SSTAs) over the western and eastern parts of the equatorial Indian Ocean, giving significant correlation at 99 % confidence level for Indian Ocean dipole (IOD). Moreover, five out of ten coupled models and MME mean show statistically significant skill in predicting equatorial East Africa short rains. The fidelity of hindcasts is further measured by anomaly correlation coefficient (ACC) and four models as well as MME mean show significant skill over East Africa. It is shown that the reproduction of the observed variability in the East African region is mainly due to a realistic relationship of East African rainfall with the Indian Ocean dipole. Overall, the skill of the dynamical models is attributed to the fact that slowly evolving SSTs are the primary source of predictability and to the fact that coupled climate models produce skillful predictions of SON SST anomalies over the tropical Indian Ocean. This information opens the possibility of using readily available seasonal forecasts as skillful predictions of equatorial East Africa short rains. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
39. Projecting yield changes of spring wheat under future climate scenarios on the Canadian Prairies.
- Author
-
Qian, Budong, De Jong, Reinder, Huffman, Ted, Wang, Hong, and Yang, Jingyi
- Subjects
ATMOSPHERIC carbon dioxide ,CLIMATE change ,AGRICULTURAL productivity ,CROP yields ,ATMOSPHERIC circulation - Abstract
The potential impact of the rise in atmospheric CO concentration and associated climatic change on agricultural productivity needs assessment. Projecting crop yield changes under climate change requires future climate scenarios as input to crop yield models. It is widely accepted that downscaling of climate data is required to bridge the gap between large-scale global climate models (GCMs) and climate change impact models, such as crop growth models. Regional climate models (RCMs) are often used to dynamically downscale GCM simulations to smaller regional scales, while statistical methods, such as regression-based transfer functions and stochastic weather generators, are also widely employed to develop future climate scenarios for this purpose. The methods used in developing future climate scenarios often contribute to uncertainties in the projected impacts of climate change, in addition to those associated with GCMs and forcing scenarios. We employed climate scenarios from the state-of-the-art RCMs in the North American Regional Climate Change Assessment Program (NARCCAP), along with climate scenarios generated by a stochastic weather generator based on climate change simulations performed by their driving GCMs, to drive the CERES-Wheat model in DSSAT to project changes in spring wheat yield on the Canadian Prairies. The future time horizon of 2041-2070 and the baseline period of 1971-2000 were considered. The projected changes showed an average increase ranging from 26 to 37 % of the baseline yield when the effects of the elevated CO concentration were simulated, but only up to 15 % if the elevated CO effect was excluded. In addition to their potential use in climate change impact assessment, the results also demonstrated that the simulated crop yield changes were fairly consistent whether future climate scenarios were derived from RCMs or they were generated by a stochastic weather generator based on the simulated climate change from the GCMs that were used to drive the RCMs, in this case, when they were compared for regional averages. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
40. A downscaling technique to simulate changes in western North Pacific tropical cyclone activity between two types of El Niño events.
- Author
-
Zhao, Haikun
- Subjects
TROPICAL cyclones ,CLIMATE change ,ATMOSPHERIC circulation ,TYPHOONS ,ECOLOGY - Abstract
Changes in tropical cyclone (TC) activity over the western North Pacific (WNP) basin between the Modoki and canonical El Niño years have been simulated and examined in this study based on a downscaling technique. The downscaling technique is used for generating synthetic TCs based on TC formation, TC track, and TC intensity models. Results suggest that the downscaling technique can well simulate the spatial distribution of TC activity during the two types of El Niño years and their differences. It is found that the observed changes in TC tracks during the two types of El Niño years are mainly due to the combined effects of changes in TC formation locations and large-scale steering flows. Further examinations have shown that changes in large-scale steering flows play a more important role than changes in TC formation locations. These results are in accordance with the cyclonic circulation anomaly found during the Modoki El Niño years compared to that during the canonical El Niño years. Numerical simulations further suggest that changes in TC tracks between the two types of El Niño years appear to be the most important factor affecting the TC intensity change. Compared to that during the Modoki El Niño years, TC formation is enhanced in the south quadrant of the WNP basin and more TCs take a northwestward track during the canonical El Niño years, leading to a longer TC lifespan and greater TC intensity. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
41. Prediction of precipitation in Golestan dam watershed using climate signals.
- Author
-
Ruigar, Hossein and Golian, Saeed
- Subjects
ATMOSPHERIC circulation ,OCEAN temperature ,CLIMATE change ,OSCILLATIONS ,ARTIFICIAL neural networks ,RAINFALL anomalies - Abstract
Global and regional scale climate teleconnection signals, including sea level pressure (SLP) and sea surface temperature (SST), are the main factors influencing the earth's climate oscillations and are among the most important indices used to predict climatic variables. In this research, the effect of teleconnection signals on monthly maximum 1-day precipitation is examined using artificial neural network (ANN) and 40 years of rainfall data for the Madarsoo watershed located at the upstream of Golestan dam in Northern Iran. The Pearson correlation coefficient was used to determine the correlation between monthly maximum 1-day precipitation and climate signals with different lags. Different ANN models with various combinations of inputs, i.e., correlated SLP and SST with different lags, were then used for forecasting precipitation. Results revealed acceptable performance of ANN in forecasting monthly maximum 1-day precipitation using SST/SLP datasets. For instance, the performance indices including root mean square error (RMSE), correlation ( R), and Nash-Sutcliffe (CNS) coefficients for monthly maximum 1-day precipitation of Tangrah rain gauge in August were found to be 6.12, 0.95, and 0.945 mm, respectively, for the test period. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
42. Variations in extreme temperature and precipitation for a Caribbean island: Trinidad.
- Author
-
Beharry, Sharlene, Clarke, Ricardo, and Kumarsingh, Kishan
- Subjects
TEMPERATURE measurements ,CLIMATOLOGY -- Social aspects ,CLIMATE change ,RAINFALL measurement ,ATMOSPHERIC circulation - Abstract
Temperature and precipitation in situ datasets for the Caribbean island, Trinidad for 1961-2010 were statistically analyzed using the RClimDex software and the Mann-Kendall test for trends. The annual, seasonal, and monthly findings were compared with regional projections; Providing Regional Climates for Impact Studies (PRECIS) and a 20 km atmospheric global circulation model, and a global projection of the Coupled Model Intercomparison Project Phase 3 (CMIP3). Overall, the seasonal and decadal results revealed patterns different from the annual warming. All the temperature indices were found to have warming patterns with the wet season, June to December, generally greater than the dry season, January to May. The warmest decade was 1980s, whereas globally, the decade 2001-2010 was the warmest. There was an increase in the annual maximum 5 day precipitation, RX5day, at the UWI station. During the dry season (1973-2010) at the UFS and UWI stations, the RX5day increased by 8.60 and 7.76 mm per decade, respectively, while the maximum 1-day precipitation, RX1day, increased by 2.92 and 8.90 mm per decade for the UFS and UWI, respectively. The 1980s was the wettest, and during the decade 2001-2010, there were above averages for the consecutive dry days (CDD) and the simple daily intensity index (SDII). The projections on both the regional and global outlooks suggest that this warming pattern will continue in the future. This small-scale study supports that seasonal and decadal analyses, in addition to the annual assessments, are significant for the understanding of the climate variability which is required for vulnerability and adaptation studies for small island states. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
43. Spatial variability of the trends in climatic variables across China during 1961-2010.
- Author
-
Yang, Hanbo, Yang, Dawen, Hu, Qingfang, and Lv, Huafang
- Subjects
CLIMATE change ,SPATIAL variation ,SOLAR radiation ,SURFACE temperature ,ATMOSPHERIC aerosols ,ATMOSPHERIC circulation - Abstract
Distribution of meteorological stations is not uniform in many regions of the world, especially in developing countries like China. To eliminate the effect of uneven stations, this study produced a data set of areal average precipitation, air temperature, solar radiation, and wind speed from 736 meteorological station observations during 1961-2010 using an inverse-distance weighted technique. Based on the data set, this study detected the trends in climatic variables. Precipitation has a slight but no significant ( p = 0.78) trend for the whole of China and has a significant increase trend in northwest China. Surface air temperature has a significant ( p < 0.001) accelerating warming trend of 0.032 °C/a for the whole of China, and spatially larger in northern China than that in southern China. Solar radiation has a significant ( p < 0.001) dimming trend of −0.14 W/(m · a) for the whole of China, and the largest dimming trend appears in eastern China, the possible cause for which is a high-aerosol concentration. Surface wind speed has a significant ( p < 0.001) stilling trend of −0.012 m/(s·a) for the whole of China, the causes for which were speculated the changes in atmospheric circulation and surface roughness, as well as increases in aerosol concentration and the decrease in the south-north temperature gradient in China. In addition, three large-scale instrument replacements increase uncertainties of the trend analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
44. Recent advances in monsoon studies in China.
- Author
-
Xue, Feng, Zeng, Qingcun, Huang, Ronghui, Li, Chongyin, Lu, Riyu, and Zhou, Tianjun
- Subjects
MONSOONS ,LAND surface temperature ,RAINFALL ,METEOROLOGISTS ,ATMOSPHERIC circulation ,CLIMATE change ,EL Nino - Abstract
This review provides a synopsis of the major progress that has been made in monsoon studies in China and to further bridge the gap between the Chinese and international meteorological community. It consists of seven major sections. After the introduction, the second section begins with the global monsoon systems and their seasonal variation, based on some new methods proposed in recent years. Besides, some major intraseasonal features of East Asian monsoon, including the onset of South China Sea summer monsoon are discussed. In the third section, we review the interactions between ENSO and the East Asian monsoon, focusing in particular on the results of Chinese meteorologists that indicate the influence of ENSO on the East Asian summer monsoon (EASM) is obviously different from that on the tropical monsoon. Besides the tropical Pacific, other ocean basins, such as the Indian Ocean and the Atlantic Ocean, are also important to the East Asian monsoon, and this topic is discussed in the fourth section. In the fifth section, we address the role of land surface processes in East Asian monsoon. For example, we describe work that has shown more snow cover in spring on the Tibetan Plateau is followed by a weakened EASM and more summer rainfall in the Yangtze River valleys. The sixth section focuses on the influence of atmospheric circulation in the Southern Hemisphere (SH) on EASM, demonstrating how the signal from the SH is likely to provide new clues for the seasonal forecasting of summer rainfall in China. Finally, in the seventh section, we concentrate on the interdecadal variations of EASM. In particular, we look at a significant interdecadal variation that occurred at the end of the 1970s, and how our understanding of this feature could affect forecasting ability. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
45. Aless or more dusty future in the Northern Qinghai-Tibetan Plateau?
- Author
-
Xingqi Liu, Zhitong Yu, Hailiang Dong, and Huei-Fen Chen
- Subjects
DUST & the environment ,CLIMATE change ,ATMOSPHERIC circulation ,HYDROLOGIC cycle ,BIOGEOCHEMICAL cycles ,GLOBAL warming - Abstract
Dust plays an important role in climate changes as it can alter atmospheric circulation, and global biogeochemical and hydrologic cycling. Many studies have investigated the relationship between dust and temperature in an attempt to predict whether global warming in coming decades to centuries can result in a less or more dusty future. However, dust and temperature changes have rarely been simultaneously reconstructed in the same record. Here we present a 1600-yr-long quantitative record of temperature and dust activity inferred simultaneously from varved Kusai Lake sediments in the northern Qinghai-Tibetan Plateau,NWChina. At decadal time scale, our temperature reconstructions are generally in agreement with tree-ring records from Karakorum of Pakistan, and temperature reconstructions of China and North Hemisphere based on compilations of proxy records. A less or more dusty future depends on temperature variations in the Northern Qinghai-Tibetan Plateau, i.e. weak and strong dust activities at centennial time scales are well correlated with low and high June-July-August temperature (average JJA temperature), respectively. This correlation means that stronger summer and winter monsoon should occur at the same times in the northern Qinghai-Tibetan Plateau. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
46. Transition of the annual cycle of precipitation from double-peak mode to single-peak mode in South China.
- Author
-
Gao, Hui, Jiang, Wei, and Li, WeiJing
- Subjects
RAINFALL ,CLIMATE change ,OCEAN temperature ,TYPHOONS ,SCIENTIFIC observation ,ATMOSPHERIC circulation ,GLOBAL warming - Abstract
Previous studies revealed the double-peak mode (DPM) in South China precipitation, corresponding to the two stages in the rainy season, i.e. the first rainy stage (FRS) and the second rainy stage (SRS). But observations in recent two decades show that the DPM has changed to a single-peak mode (SPM). Both the precipitation amount and the heavy rainfall event frequency enhanced significantly in the gap between the FRS and the SRS in 1991–2010, compared to those in 1961-1990. This change can be linked to the effects of the global warming. During the warmer period, the July sea surface temperature over the western Pacific has greater increases than that over the central and eastern Pacific, especially west of 140°E. It may generate more tropical cyclones (TCs) in the inshore areas and then more typhoon rainfall over South China. On the other hand, the increments of the air temperature over the East Asian continent are greater than those of the SST over the western Pacific under the global warming, which enlarges the land-ocean temperature/pressure contrast and leads to a trend of the earlier onset dates of the Asian summer monsoon (ASM) in recent two decades. Then, the earlier ASM will facilitate the western Pacific subtropical high (WPSH) to retreat earlier from the South China Sea and enhance the convective precipitation in South China between the FRS and the SRS. Also, due to the warmer ocean, the WPSH locates more westward in July, and more moisture will be transported to South China from the southwest side to the WPSTH. All these influences favor a remarkably increasing precipitation in the gap in the warmer period and changes the seasonal cycle from double-peak mode to single-peak mode. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
47. Projected evolution of circulation types and their temperatures over Central Europe in climate models.
- Author
-
Plavcová, Eva and Kyselý, Jan
- Subjects
ATMOSPHERIC circulation ,ATMOSPHERIC models ,EARTH temperature ,GENERAL circulation model ,CLIMATE change - Abstract
The study deals with changes in large-scale atmospheric circulation (represented by circulation types) and associated surface air temperatures as projected in an ensemble of regional climate models (RCMs) from the ENSEMBLES project. We examine changes of circulation type frequencies and means of daily maximum and minimum temperatures within circulation types in individual seasons for two time slices of transient runs under the SRES A1B scenario (2021–2050 and 2071–2100) with respect to the control period (1961–1990). To study the influence of driving data, simulations of the driving general circulation models (GCMs) also are evaluated. We find that all models project changes of atmospheric circulation that are statistically significant for both future time slices. The models tend to project strengthening of the westerly circulation in winter and its weakening in summer. We show that increases of daily maximum and minimum temperatures in all seasons differ for individual circulation types. There are, however, only few features of the projected changes in the future circulation–temperature links that are common among the models, in particular relatively smaller warming for westerly types. Only in winter, projected changes in circulation types tend to contribute to the projected overall warming. This effect is negligible and mostly opposite in the other seasons. We also detect a strong influence of driving data on RCMs’ simulation of atmospheric circulation and temperature changes. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
48. Reconstruction of the Holocene climate of Transbaikalia: Evidence from the oxygen isotope analysis of fossil diatoms from Kotokel Lake.
- Author
-
Kostrova, S., Meyer, H., Chapligin, B., Bezrukova, E., Tarasov, P., and Kuz'min, M.
- Subjects
OXYGEN isotopes ,FOSSIL diatoms ,MARINE sediments ,CLIMATE change ,ATMOSPHERIC circulation - Abstract
The article discusses the oxygen isotope analysis results of fossil diatoms or Bacillariophyta from Katokel Lake in Transbaikalia, Russia. It states that fossil diatoms consists two separate valves that are significant in lake and marine sedimentation. It mentions that the information obtained from the analysis of oxygen isotopes serves as way to retrace the climatic change mechanism in the region, which is mainly controlled by the changes in atmospheric circulation.
- Published
- 2013
- Full Text
- View/download PDF
49. Two modes of the silk road pattern and their interannual variability simulated by LASG/IAP AGCM SAMIL2.0.
- Author
-
Song, Fengfei, Zhou, Tianjun, and Wang, Lu
- Subjects
OCEAN-atmosphere interaction ,ATMOSPHERIC models ,CLIMATE change ,OCEAN circulation ,ENERGY conversion ,ATMOSPHERIC circulation ,BAROCLINICITY ,SILK Road - Abstract
In this study, two modes of the Silk Road pattern were investigated using NCEP2 reanalysis data and the simulation produced by Spectral Atmospheric Circulation Model of IAP LASG, Version 2 (SAMIL2.0) that was forced by SST observation data. The horizontal distribution of both modes were reasonably reproduced by the simulation, with a pattern correlation coefficient of 0.63 for the first mode and 0.62 for the second mode. The wave train was maintained by barotropic energy conversion (denoted as CK) and baroclinic energy conversion (denoted as CP) from the mean flow. The distribution of CK was dominated by its meridional component (CK) in both modes. When integrated spatially, CK was more efficient than its zonal component (CK) in the first mode but less in the second mode. The distribution and efficiency of CK were not captured well by SAMIL2.0. However, the model performed reasonably well at reproducing the distribution and efficiency of CP in both modes. Because CP is more efficient than CK, the spatial patterns of the Silk Road pattern were well reproduced. Interestingly, the temporal phase of the second mode was well captured by a single-member simulation. However, further analysis of other ensemble runs demonstrated that the successful reproduction of the temporal phase was a result of internal variability rather than a signal of SST forcing. The analysis shows that the observed temporal variations of both CP and CK were poorly reproduced, leading to the low accuracy of the temporal phase of the Silk Road pattern in the simulation. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
50. Projected change in extreme rainfall events in China by the end of the 21st century using CMIP5 models.
- Author
-
Chen, HuoPo
- Subjects
RAINFALL ,CLIMATE change ,TWENTY-first century ,ENVIRONMENTAL impact analysis ,COMPARATIVE studies - Abstract
Projection of future climate changes and their regional impact is critical for long-term planning at the national and regional levels aimed at adaptation and mitigation. This study assesses the future changes in precipitation in China and the associated atmospheric circulation patterns using the Couple Model Intercomparison Project 5 Phase (CMIP5) simulations under the RCP4.5 and RCP8.5 scenarios. The results consistently indicate that the annual precipitation in China is projected to significantly increase at the end of the 21st century compared to the present-day levels. The number of days and the intensity of medium rain, large rain and heavy rain are obviously increased, while the number of trace rain days is projected to decrease over the entire area of China. Further analysis indicates that the significant increase of annual precipitation in Northwest China is primarily due to the increase of light rain and the increases in North and Northeast China are primarily due to the increase of medium rain. In the region of southern China, the increases of large rain and heavy rain play an important role in the increase of annual precipitation, while light rain events play a negative role. Analysis of the changes in atmospheric circulation indicates that the East Asian summer monsoon circulation is projected to be considerably stronger, and the local atmospheric stratification is projected to be more unstable, all of which provide a background benefit for the increase of precipitation and extreme rainfall events in China under global warming scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.