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The application of a photovoltaic (PV) system for zero energy buildings is crucial to balance energy consumption. This paper investigated the potential of PV systems for buildings in different climate zones of China. The tilt angle, orientation, plot ratio, PV conversion efficiency and location were selected to study their influences on electricity production. The performance of the PV system was analyzed based on a residential building, and employed RETScreen in combination with TRNSYS. The results indicate that southwest China is the best place to develop zero energy buildings. Low-rise residential buildings can realize zero energy in China when the PV conversion efficiency is higher than 20%. However, an energy balance only occurs in the southwest when the PV conversion efficiency is 10%. For different building heights, with a high conversion efficiency (20%), the energy consumptions rates are less than 15 kW h/m2a all over China. In the southeast, the effect of the building shape on energy generation can be ignored due to the high solar elevation angle in the summer. Although the optimal tilt angle varies for different cities, the energy deviations are less than 10% when tilt angle is within 10° of the optimal angle. This study proposed a formula to evaluate the potential of a building PV system. The maximum difference between the simulated and calculated results is approximately 10%, which is reasonable and acceptable. This paper provides some references for the application of PV systems in zero energy buildings. [ABSTRACT FROM AUTHOR]

Recently there has been growing interest in regenerative evaporative coolers (REC), which can reduce the temperature of the supply air to below the wet-bulb of intake air and approach its dew-point. In this paper, we designed, fabricated and experimentally tested a counter-flow REC in laboratory. The REC’s core heat and mass exchanger was fabricated using stacked sheets composed of high wicking evaporation (wickability of available materials was measured) and waterproof aluminium materials. The developed REC system has a much higher cooling performance compared to conventional indirect evaporative cooler. However, the decision to use the REC for China buildings depends on a dedicated evaluation of the net energy saved against the capital expended. Such an evaluation requires the hourly-based data on the availability of cooling capacity provided by the REC for various climates. The paper used an experiment-based method to estimate the cooling capacity and energy savings provided by the proposed REC for China’s various climates. By using the experimental results and regional hourly-based weather data, the energy saving potential of the REC against an equivalent-sized mechanical air conditioner alone was analysed. The results indicate that, for all selected regions, the REC could reduce 53–100% of cooling load and 13–58% of electrical energy consumption annually. [ABSTRACT FROM AUTHOR]

Aiming at the current situation in China with vast territory, diverse climate, and a big difference on thermal adaptation of the indoor thermal environment among the people in different regions, the paper analyzes the typical model research of thermal adaptation, and points out the features of three representative models and the ignored reason of physiological thermal adaptation, summarizes some results on field studies of thermal adaptation in China, induces three research directions about physiological indexes selection research, physiological thermal adaptation research and multivariate evaluation model research of thermal comfort based on the physical, psychological and behavioral adjustments. The paper proposes to explain the differences of physiological thermal adaptation in these different climatic regions and to further finds out the relations between all these differences and the physiological indexes. The goal is to establish physiological index to evaluate thermal comfort and to perfect the climate adaptation model which can give some advises to the architecture designers on how to realize the comfortable and energy-saving thermal environment. [ABSTRACT FROM AUTHOR]

The underground cave dwelling located in loess plateau of China is known for its use of natural and passive environment control systems for a comfortable indoor environment. However, it has not been proved by a detailed and quantitative analysis so far. This paper conducts qualitative and quantitative evaluations on the thermal performance of ancient cave dwellings. Firstly, the authors conducted a qualitative analysis on the passive strategies of vernacular underground cave dwellings by field investigations. The orientation of building, the presence of underground courtyard, use of biomass massive building envelope, etc. Formed the indoor environment. Secondly, a quantitative analysis was also carried out based on long-term remote monitoring experiments by recording thermal environment parameters in a selected building. The analysis results were very much in agreement with the inferences drawn from the qualitative analysis. Finally, in order to evaluate the whole annual thermal performance, numerical simulations on the Yaodong models was also conducted using the software Energyplus. The study provided positive results confirming that climate responsive strategies employed in underground cave dwellings were highly effective in providing methods and implications to create more comfortable indoor environments for rural residences. Image 1 • A vernacular underground cave dwelling presented for cold climates. • Climate responsive strategies of underground cave dwellings was obtained. • A long-term remote monitoring was carried out. • Annual thermal performance of the cave dwelling was evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Vegetation is one of the most important components of the global ecosystem. It plays a vital role for global energy balances and climate modulations. Timely and precisely monitoring vegetation changes has become an increasing need. Among various satellite-based earth observation systems, the Landsat and ASTER sensors are most commonly used in mesoscale vegetation observations. Nevertheless, the quantitative relationship between the two sensors in measuring vegetation has not been investigated in detail. Therefore, this paper aims to investigate how well ASTER vegetation measurements replicate ETM+ vegetation measurements, and more important, how much difference there is in the measurements between the two sensors. The study utilised three date-coincident image pairs of the two sensors, covering the subtropical coastal areas of southeastern China. The approach was achieved by evaluating the consistence of the normalised difference vegetation index (NDVI) data and the NDVI-estimated vegetation area between the two sensors. A further inter-type comparison among forest, paddy and grass has also been carried out to examine whether there is any variation in the consistence between different vegetation types. Results suggest that the ASTER sensor produces similar vegetation measurements to ETM+ in the study areas. Nevertheless, differences have also been observed. The study found an overall lower spectral NDVI measurement of ASTER than ETM+ based on their differences in mean NDVI value and estimated vegetation area. This suggests that the ASTER sensor is less sensitive to vegetation characteristics. Compared with ETM+, the ASTER sensor produces lower NDVI values by up to 8.1% and estimates less vegetation area by up to 4.1%. Inter-type analysis indicates that among the three test vegetation types, forest has the highest degree of agreement in NDVI measurements between the two sensors, whereas grass has the greatest difference in mean NDVI value between both sensors. All these differences are worth considering when the vegetation measurement results of ASTER have to be used together with those of ETM+ for a synergistic scientific application. This often occurs when using the ASTER sensor data for Landsat data continuity in scientific applications in order to fill the gaps in observation. As such, a data conversion between the two sensors is recommended. This paper demonstrated that the conversion using the model equations obtained in this study could reduce the root mean square errors and improve data agreement between the two sensor NDVIs. The study shows that the revealed differences in vegetation measurements between both sensors are due largely to the difference in the relative spectral response functions of the NDVI-related near-infrared bands between the two sensors. [Copyright &y& Elsevier]

The acceleration of urbanization and the growth of population are considered to be the reasons of increasing demands for construction, life quality and energy consumption. This leads to more research in climate adaptive strategies such as traditional design methods, construction techniques and building materials. Traditional dwelling has been successful in achieving harmony between dwelling and climatic environment, which is one of the most important conditions for sustainability. Firstly, this paper focused on analyzing the characteristics of traditional dwellings in Qinba mountainous areas to adapt to the climatic environment. Secondly, two typical dwellings constructed respectively with brick and earth materials were selected for monitoring and simulating of its indoor thermal, luminous and ventilation environment in summer and winter. In addition, the research summarized the advantages and disadvantages of the dwelling's physical environment in response to climatic characteristics. It revealed that the traditional earth dwelling is well adapted to the local climate during summer, although the indoor thermal comfort is not fully satisfactory during winter. Finally, we prompted effective climate adaptive strategies of traditional earth dwelling, such as natural ventilation, thermal insulation and thermal buffer space. We want to provide guidance and reference for the development of traditional dwellings in the mountainous areas. [ABSTRACT FROM AUTHOR]

• Both the combination and temperature-based ET 0 estimating equations were compared for four main climatic regions across China. • The most accurate method of ET 0 estimating was recommended for each climate region. • The Penman-Monteith Forecast and Temperature Penman-Monteith equations usually provided the most accurate ET 0 estimation. • The Thornthwaite and McCloud would not be recommended for ET 0 estimating in China. Accurate estimation of daily reference evapotranspiration (ET 0) are vital for water resource management and irrigation decision-making. Based on the public weather forecasts, numerous models have been successfully used for daily ET 0 estimating, while too many models available for selection, which causes confusion regarding model selection for specific climate regions. In this paper, the estimating performances of six ET 0 equations using public weather forecast for a lead time of 1–7 days were compared for four main climatic region across China, and then, the most accurate equation was recommended for each climate region. Meanwhile, the applicability of every equation was assessed in relation to four climates, including subtropical monsoon climate (Cwa), temperate continental climate (Dfc), temperate monsoon climate (Dwa) and mountain plateau climate (HG). The Penman-Monteith Forecast (PMF) equation, which consisting of an adaptation of FAO56-PM equation using temperature and weather type forecast as inputs, provided the best ET 0 estimation performance in Cwa and HG climates; and the Temperature Penman-Monteith (PMT) equation using only the temperature data, obtained the most accurate average results for the Dwa and Dfc climates. The best and the second best estimation performance for each climate usually provided by PMF and PMT equations, since they both have the same advantage of following the conceptual approach of the FAO56-PM equation; further the third and the fourth choice would be the Hargreaves-Samani (HS) and the Blaney-Criddle (BC), respectively, while the Thornwaite (TH) and the McCloud (MC) yielded high errors and may not be applicable for ET 0 estimation for most climatic regions. As a whole, the PMF and PMT equations were better than the other equations and thus these two equations were recommended for daily ET 0 estimation for the near-future at all climate regions across China. [ABSTRACT FROM AUTHOR]

In this paper, correlation between modern leaf physiognomy and climate in China are examined, to optimize the use of leaf characters as a palaeoclimate proxy. A large dataset was compiled, recording the distribution of leaf physiognomic characters among 3166 native dicot trees species across 732 calibration grids on a county level. Grids span a range of ecological environments (tropical rainforests to alpine shrubs) across humid areas. Thirteen climatic parameters were included for each grid and 22 leaf physiognomic characters were scored for each tree species. The correlation between leaf physiognomic characters and climatic parameters were calculated based on single linear regressions (SLR) and multiple linear regressions (MLR). Results indicate clear spatial distribution patterns, linked to latitude, exist for all leaf characters, with temperature (Coldest Month Mean Temperature, CMMT) and precipitation (Growing Season Precipitation, GSP) being the main climate controls. Moreover, because leaf characters are more closely correlated with Precipitation during the Three Wettest Consecutive Months (P3WET), rather than with Precipitation during the Three Driest Consecutive Months (P3DRY), seasonal variations in rainfall associated with the Asian Monsoon might especially influence leaf physiognomic characters. Closer correlations between leaf physiognomy and climate are seen using MLR compared with SLR; therefore Mean Annual Temperature (MAT) and Mean Annual Precipitation (MAP) based on MLR equations provide the most promising basis for palaeoclimate reconstructions in China. • Spatial distribution of 21 leaf physiognomic characters in China is established. • Relationships between leaf physiognomic characters and climatic parameters are established. • The seasonal variations in rainfall under the Asian monsoon climate shapes leaf physiognomic characters. • Paleoclimate can be reconstructed based on such large-scale modern dataset. [ABSTRACT FROM AUTHOR]

Abstract Elucidating the vertical structures of clouds is key to reducing the uncertainty in cloud-induced climate forcing; however, we do not yet know explicitly about the cloud structures that form over Beijing, China, and how they vary. In this paper, we document vertically resolved cloud structures and their climatological variation based on three-year (1 January 2015 to 31 December 2017) ground-based Ka-band (35 GHz) millimeter-wave cloud radar (MMCR) measurements. Cloud top height (CTH) and radar reflectivity are higher in summer and autumn than in spring and winter. We verified the MMCR measurements of the CTH and cloud base height (CBH) independently based on observations from the Himawari-8 and CL51 ceilometer at the same station, respectively. The CTH decreased as the thickness of the cloud layer increased. This may have been due to the mechanism used to determine the CTH, which was based on data from the satellite infrared channel. There were two peaks in the CBH distribution, located at 0–1 km and 5–6 km, whereas the frequency of the CTH peaked at an altitude of 9–10 km, between 1200 and 1800 LST. Precipitating clouds tended to be located at lower altitudes and exhibited stronger radar reflectivities than non-precipitating clouds. The cloud frequency tended to peak in autumn and reached a minimum in winter. In terms of the seasonality of clouds at various levels, middle- and high-level clouds were dominant over Beijing, with high and low (precipitating) clouds concentrated between May and October. Mid-altitude clouds occurred more frequently in winter and spring. CTH peaked in summer due to the strong solar radiation received by the surface. In contrast, minimum CBH occurred in winter. The cloud heights were higher and radar reflectivities larger than reported in previous studies. These results are correlated with urban warming effects. Understanding the properties of clouds will not only be of benefit to researchers carrying out cloud forcing studies, but will also provide key validation data for climate model simulations. Graphical abstract Unlabelled Image Highlights • The cloud vertical structures in Beijing are elucidated using 3-year observations • Cloud structures from MMCR, Himawari-8 and ceilometer agree with each other very well • Cloud top heights are shown to decrease as the cloud layer thickness increases [ABSTRACT FROM AUTHOR]

Abstract: The paper investigates a single-sided naturally ventilated buildings potential model considering number of factors in China. This model can be used to estimate potential of natural ventilation via local climate data and building parameters. The main goal of the model is to predict natural ventilation hours and hourly ventilation flow rate. In fluid model, formula of single-sided natural ventilation by coupling wind pressure and temperature difference was used to calculate air flow rate. Accordingly, the paper analyzed four typical cities in different climate region in China and calculated pressure difference Pascal hours (PDPH). The results show that single-sided ventilation has fewer adaptive comfort hours than two-sided ventilation and much less ventilation volume. This model provided quantitative information for early stage architectural natural ventilation design and building energy efficiency evaluation. [ABSTRACT FROM AUTHOR]

Abstract: Arid and semiarid China have experienced multiple arid phases throughout the Quaternary, and over the past five decades, there have been several periods with relatively high or low rates of desertification and rehabilitation. The causes of these changes and their historical trends have been debated by scientists because of their potentially huge significance for China, as well as for the global ecology and food supply. This paper reviews recent studies of desertification in different regions of arid and semiarid China. In general, the results of systematic monitoring, and analyses of the causes of desertification and the contemporaneous human impacts, suggest that desertification in China has been primarily caused by climate change, and particularly by strong wind regimes (with high sand transport potential) accompanied by decreased spring precipitation. Unfortunately, although numerous scientists have claimed that desertification in China is primarily due to human impacts; there is surprisingly little unassailable evidence to support this claim. The review presented in this paper show that desertification in China is likely to be controlled by climate change and geomorphological processes, even though human impacts have undeniably exacerbated their effects. Our arguments for both climate change and human activity as factors responsible for the observed changes in desertification rely primarily on inferences based on correlations between trends, thus future research must seek stronger and more direct evidence for the causal relationships that we have proposed as possibilities. This improved information is essential to provide a firm basis for future policy decisions on how best to combat desertification. [Copyright &y& Elsevier]

Based on the numerical simulation in this paper, the local climate of the Majianglong traditional villages in the Lily Town city is analyzed, the influence of the village layout in the traditional villages on the wind environment and the adaptability of Lingnan traditional village layout to the regional climate is studied. The layout characteristics of Majianglong traditional village is the former pond after the village and comb layout. The results show that the traditional grid layout of MajiangLong village obviously influence the microclimate of residential street. The traditional grid layout and relative position of residential plays an important role to the micro-environment of indoor and courtyard. In summer, the area close to the entrance of the cold lane and the edge of residential buildings is a more comfortable wind environment. However, the residential space in the middle of traditional building layout maintains a better thermal comfort environment because of the isolation of street space. [ABSTRACT FROM AUTHOR]

In recent years, climate extreme events have caused increasing direct economic and social losses in the arid region of northwestern China. Based on daily temperature and precipitation data from 1960 to 2010, this paper discussed the linear trend and abrupt changes of climate indices. The general evolution was obtained by the empirical orthogonal function (EOF), the Mann-Kendall test, and the distribution-free cumulative sum chart (CUSUM) test. The results are as follows: (1) climate showed a warming trend at annual and seasonal scale, with all temperature indices exhibiting statistically significant changes. The warm indices have increased, with 1.37%days/decade of warm days (TX90p), 0.17 °C/decade of warmest days (TXx) and 1.97 days/decade of warm spell duration indicator (WSDI), respectively. The cold indices have decreased, with − 1.89%days/decade, 0.65 °C/decade and − 0.66 days/decade for cold nights (TN10p), coldest nights (TNn) and cold spell duration indicator (CSDI), respectively. The precipitation indices have also increased significantly, coupled with the changes of magnitude (max 1-day precipitation amount (RX1day)), frequency (rain day (R0.1)), and duration (consecutive dry days (CDD)). (2) Abrupt changes of the annual regional precipitation indices and the minimum temperature indices were observed around 1986, and that of the maximum temperature indices were observed in 1996. (3) The EOF1 indicated the overall coherent distribution for the whole study area, and its principal component (PC1) was also observed, showing a significant linear trend with an abrupt change, which were in accordance with the regional observation results. EOF2 and EOF3 show contrasts between the southern and northern study areas, and between the eastern and western study areas, respectively, whereas no significant tendency was observed for their PCs. Hence, the climate indices have changed significantly, with linear trends and abrupt changes noted for all climate indices, which will have serious impacts on water resources and ecological environment in the arid region of China. [ABSTRACT FROM AUTHOR]

There is a strong inter-annual and inter-decadal variability in time series of variables related to water abundance, such as intense precipitation, high river discharge, flood magnitude, and flood loss in China. Part of this variability can be random or chaotic, but it may well be that climate variability track plays an important role in the interpretation of the variability of water abundance. The principal aim of this review paper is to create a summary of literature-based information on links of various climate-variability drivers, i.e. natural oscillations in the ocean–atmosphere system, and the variability of characteristics of destructive water abundance in China, at a range of spatial scales (national, provincial, basin-based, municipal). The present paper reviews extensive pool of literature discussing the links between the two modes of oscillation in the ocean-atmosphere system (ENSO - El Niño -Southern Oscillation and PDO – Pacific Decadal Oscillation) and variability in time series of variables related to water abundance in China. This paper also reviews examples of extension of the database, with the help of proxies. It reviews interpretation of possible link of particular large flood events (e.g. the 1998 and the 2016 deluges) to climate variability. Also a range of issues of relevance to water management are reviewed, such as seasonal forecasting and non-stationarity of flood frequency. [ABSTRACT FROM AUTHOR]

Although visibility is a widely-used indicator to quantify the aerosol loadings, only a few studies have been analyzed the representativeness of visibility in deriving Aerosol Optical Thickness (AOT). In this paper, ground-based visibility, MODerate-resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging SpectroRadiometer (MISR) monthly AOT products between July 2002 and December 2014 were analyzed in order to extract the dominant modes of variability using the Singular Value Decomposition (SVD) method. The method has significant merit to reduce data dimension and examine both spatial and temporal variability simultaneously. Results indicated that the satellite retrieved AOTs agreed well with ground-based visibility in terms of inter-annual variability. The correlation coefficients in the first deseasonalized mode are greater than 0.65 between visibility and satellite AOT products. However, large differences were observed in the seasonal variability between ground-based visibility and AOT. In addition, Aerosol vertical distribution from LIdar climatology of Vertical Aerosol Structure for space-based lidar simulation studies (LIVAS) and cloud data from ground-based meteorological station were used to investigate the seasonal variability disagreement. The AOT values derived from LIVAS extinction coefficients between 0 and 500 m above surface have a stronger relationship with visibility, than total column AOT with visibility. It also indicates that seasonal variation of aerosol vertical distribution is the main cause of the disagreement between two parameters, and the uncertainties of satellite products also contribute to the disagreement. Results in this study highlighted that the visibility observation could only be used to depict the inter-annual AOT and more ancillary information could be used for studying seasonal AOT variation. [ABSTRACT FROM AUTHOR]

• This method integrates uncertainty analysis and cluster analysis methods. • Proposed novel zoning indicators are statistically significant. • Moves from traditional weather-based approaches to a performance-based approach. • Robust tool to tackle complex relation between climate and building energy efficiency. • Provide evidence for the rationality of decision making in energy policy. Climatic zoning is an important tool in building energy policy and regulations, smaller and more homogeneous climate zones could help enhance the rationality of energy policymaking. In most countries, climate zoning is based on simplified climate models, and it is difficult to accurately represent the energy demand characteristics of buildings. Therefore, this paper proposes a novel climate subdivision method that tackles the complex relations between climate and building energy-efficient, which move from traditional weather-based approaches to a performance-based approach. Integrate the uncertainty analysis method and the building dynamic performance simulation to extract a novel statistically significant index as the basis for classification. The K -means clustering method and discriminant analysis method are used to obtain and verify the clustering results, respectively. Furthermore, the comparison with clustering results based on degree days confirms the superiority of the new method proposed in this paper in identifying building energy demand. The method is applied to the cold climate zone of China as a showcase. The results show significant differences in building energy demand and the order of key features affecting building performance between each region in the climatic zones. The zone can be further sub-divided into four groups considering the climate factor and building feature uncertainty, and clustering results have been verified by several evaluation indicators. [ABSTRACT FROM AUTHOR]

Understanding the lightning climatological distribution is of great significance but remains challenging which is in part due to the lack of continuous and uniform lightning observations. In this paper, for the first time, an 11-year ground-based cloud-to-cloud lightning dataset of China National Lightning Detection Network from 2010 to 2020 is used to investigate the lightning climatology over China's land area in terms of spatial distribution, seasonal, monthly and diurnal variations. Lightning activity in China's land area generally decreases from south to north and from east to west. The mean cloud-to-ground lightning density of China's land area is 0.9 fl km−2 yr−1, with the average maximums (exceeding 10 fl km−2 yr−1) are found in the south and east coastal provinces, such as Guangdong, Hainan, Fujian and Zhejiang Province. The lightning activity in spring, summer and autumn seems consistent throughout the daytime cycle, with the lightning activity is rather weak in the morning and most active in the afternoon, while winter lightning appears to be more active in the nighttime and in the very early morning produced from nocturnal thunderstorms. The cloud-to-ground lightning activity in the tropical and subtropical areas within 15–25°N is mainly concentrated in the late spring and early summer, with two weak peaks in May and August, while lightning in mid latitudes within 25–55°N mainly occurs in the summer (June–July-August). The percentage of positive cloud-to-ground lightning flashes with peak current higher than 75 kA is more than 3 times than that of negative cloud-to-ground lightning flashes. Meanwhile, the mean peak current of cloud-to-ground lightning flashes shows an inverse diurnal pattern to the cloud-to-ground lightning activity. • Cloud-to-ground lightning climatology over Chinese continent is first investigated. • Lightning activity generally decreases from south to north and from east to west. • More lightning occurs in the summer in mid latitudes within 25–55°N. • Winter lightning is unique, usually produced from nocturnal thunderstorms. [ABSTRACT FROM AUTHOR]

Abstract: With the concern about the issues of global environments and climates, the green power development is drawing increasing attention. Although the government of our country attaches great importance to renewable energy power generation industry and certain industry foundation has been established, the generating costs of green power obviously lack competitive advantages comparing with those of the tradition power. As a result, the developing speed is relatively slow. This paper analyzes the existing barriers in the green power development of our country and puts up the suggestions of developing strategies for the future green power of our country, combined with the actual situations of our power industry. [Copyright &y& Elsevier]

Abstract: This paper introduces a new model for regional climate simulation-Star model, and explains the scheme, the usage and the application of the Star model. Taking the “Temperature of 2m” and “Precipitation” as the characteristic variables of climate, the model is calculated and tested by taking Huailai climate station of China as practical example. [Copyright &y& Elsevier]

Summary: The paper discusses a number of key conceptual issues related to the role of energy in development and its potential synergies and tradeoffs with climate change. The relationship between economic development and energy over time is discussed and illustrated by data from China, India and South Africa, and some other countries. It concludes that energy plays an important role as a productivity enhancing factor in economic development and in human well being. Several policy goals related to sustainable development, energy, and climate can be integrated. However, meeting all these policy goals requires a special effort and has significant cost implications. [ABSTRACT FROM AUTHOR]

Abstract: Long-term high-resolution climate proxies are essential for understanding climate variability on the Tibetan Plateau (TP), where few long-term climate records are available. In this paper, we describe a summer (August) temperature reconstruction over the period 1385–2002 based on a tree-ring width chronology of Balfour spruce (Picea likiangensis var. balfouriana) on the southeastern TP created using the Regional Curve Standardization method. The reconstruction explains 44.7% of the variance in the instrumental temperature records during the calibration period (1962–2002), and captures temperature variability over a broad region of the TP. Warmer than average Augusts were found during the periods 1446–1494, 1509–1522, 1553–1567, 1797–1812, 1845–1905 and 1918–2002. Cooler than average Augusts occurred from 1385–1416, 1426–1445, 1495–1508, 1523–1552, 1568–1686, 1695–1718, 1725–1796, 1813–1844 and 1906–1917. A warming trend in the 20th century was unprecedented during the past six centuries. The reconstruction closely matched other tree-ring summer temperature reconstructions from neighboring regions, as well as patterns from ice-core δ18O data, and fluctuated in synchrony with Northern Hemisphere temperature reconstructions. [Copyright &y& Elsevier]

Abstract: Accurate prediction of building energy performance requires precise information of the local climate. Typical weather year files like typical meteorological year (TMY) are commonly used in building simulation. They are also essential for numerical analysis of sustainable and renewable energy systems. The present paper presents the generation of typical meteorological year (TMY) for eight typical cities representing the major climate zones of China. The data set, which includes global solar radiation data and other meteorological parameters referring to dry bulb temperature, relative humidity, wind speed, has been analyzed. The typical meteorological year is generated from the available meteorological data recorded during the period 1995–2004, using the Finkelstein-Schafer statistical method. The cumulative distribution function (CDF) for each year is compared with the CDF for the long-term composite of all the years in the period. Typical months for each of the 12 calendar months from the period of years are selected by choosing the one with the smallest deviation from the long-term CDF. The 12 typical months selected from the different years are used for the formulation of a TMY. [Copyright &y& Elsevier]

Abstract: The design and operation of combined cooling, heating and power (CCHP) systems are greatly dependent upon the seasonal atmospheric conditions, which determine thermal and power demands of buildings. This paper presents a mathematical analysis of CCHP system in comparison to separate system. The corresponding primary energy consumption in thermal demand management (TDM) and electrical demand management (EDM) operation modes are deduced. Three relative criteria, primary energy saving (PES), CO2 emission reduction (CO2ER), and annual total cost saving (ATCS) are employed to evaluate the respective performances of CCHP systems for a hypothetical building in five different climate zones from the technical, environmental and economic aspects. The results indicate that CCHP system in TDM mode in the cold area, where the building requires more heating during the year, achieves more benefit over separate system while CCHP system in EDM mode suits the building having stable thermal demand in mild climate zone. [Copyright &y& Elsevier]

Abstract: The relationships between climate, topography, and erosion are significant in understanding landscape evolution. In order to study this relationship in a tectonically active landscape, the details of 11 drainage basins were collected from Qilian Shan Mountains. Decadal-scale erosion rates, including the mechanical load and solute load contributions, are estimated in natural conditions. The calculated erosion rates show that the average erosion rate of Qilian Shan Mountains is about 0.08mm/yr, while the variation of annual erosion rates within each basin is significant. The changes of topography and climate, which potentially control erosion rates, are also employed in this paper for correlating analyses. Correlation analyses indicate that erosion rates are more closely correlated with topographic variables, such as mean local relief and mean slope, than all of the climatic variables; and mean local relief and decadal-scale erosion rates show a linear relationship in these tectonically active mountains. However, some topographic variables like basin area and elongation ratio exert limited influence on erosion rates; while others, such as basin elevation, basin relief and basin roughness, show poor correlation. The results indicate that topographic control, like aspects of the local terrain steepness, plays the most important role in spatial distribution of decadal-scale erosion rates throughout Qilian Shan Mountains. Under topographic control, some climatic variables, like discharge and runoff, however, could account for the significant variation of annual erosion rates in individual basin. When comparing erosion rates on different timescales, we found that the decadal-scale erosion rates are lower than the long-term river incision rates, as well as the exhumation rates during early and middle Miocene. The change to more arid climatic condition since the middle Miocene combining with tectonic uplift should attribute to the inconsistent erosion rates over different timescales in Qilian Shan Mountains. [Copyright &y& Elsevier]

Abstract: Shanghai as the largest city in China has been suffering from the ever-worsening thermal environment due to the explosive urbanization rate. As an indication of urbanization impact, urban heat islands (UHI) can give rise to a variety of problems. This paper reports the results of an empirical study on the summertime UHI patterns in three high-rise residential quarters in the inner-city Shanghai. Site-means of UHI intensity are compared; case studies are carried out on strategically located measurement points; and regression analysis is followed to examine the significance of the on-site design variables in relation to UHI intensity. It is found that site characteristics in plot layout, density and greenery have different impacts on UHI-day and UHI-night patterns. Day-time UHI is closely related to site shading factor. Total site factor (TSF) as an integrated measure on solar admittance shows a higher explanatory power in UHI-day than sky view factor (SVF) does under a partially cloudy sky condition. Night-time UHI cannot be statistically well explained by the on-site variables in use, indicating influences from anthropogenic heat and other sources. Evaporative cooling by vegetation plays a more important role at night than it does at day. Considered diurnally, the semi-enclosed plot layout with a fairly high density and tree cover has the best outdoor thermal condition. Design implication based on the findings, with consideration on other important environmental design issues, is briefly discussed. [Copyright &y& Elsevier]

Abstract: Buildings and their related activities are responsible for a large portion of the energy consumed in China. It is therefore worthwhile to investigate methods for improving the energy efficiency of buildings. This paper describes a low energy building design in Hangzhou, south China. A hybrid ventilation system which employs both natural and mechanical ventilation was used for the building due to the severity of the climate. The passive ventilation system was tested using computational fluid dynamics (CFD) and the results showed that, in the mid-seasons, natural ventilation for the building is viable. The likely thermal performance of the building design throughout the year was evaluated using dynamic thermal simulation (DTS) with local hourly standard weather data. It is evident from the modelling results that the hybrid ventilation system is a feasible, low energy approach for building design, even in sub-tropical climates such as south China. [Copyright &y& Elsevier]

This paper studies the impact of pragmatic and optimal transfer schemes on the incentives for regions to join international climate agreements. With an applied model that comprises twelve world regions we investigate: (i) a benchmark without transfers, (ii) scenarios with allocation-based rules where coalition members receive tradable emission permits proportional to initial or future emissions, (iii) scenarios with outcome-based rules where the coalition surplus is distributed proportional to emissions, and (iv) a scenario based on an optimal sharing rule where the coalition surplus is distributed proportional to outside option payoffs. We find that well-designed transfer schemes can stabilise larger coalitions and increase global abatement levels. In our applied setting we find that for allocation-based and outcome-based rules only small coalitions are stable, and, in the case of grandfathered emission permits, there is no stable coalition at all. Some obstacles associated with grandfathered emission permits can be overcome by incorporating the expected growth of emissions in developing countries in the distribution of emission permits. For the optimal transfer scheme we find that larger coalitions, which include key players such as the United States and China, can be stable, but no transfer scheme is capable of stabilising the Grand Coalition. [Copyright &y& Elsevier]

Abstract: The zonal displacement of the western Pacific subtropical high remarkably influences the climate anomalies in China. In this paper, a new zonal index of the subtropical high is defined by modifying previous indices, and is used to investigate the relationship between the zonal displacement of the subtropical high and the dominant modes of 850-hPa circulations. It is found that the zonal displacement of the subtropical high is significantly correlated with the first two leading modes of circulations. In particular, the correlation coefficient between the index and the time series associated with the second mode is as high as 0.78 in 1958–2003 (46years). Since the second mode is not associated with significant anomalies of sea surface temperatures, the above results imply the difficulty in seasonal forecasting of the zonal displacement of the subtropical high. In addition, the interannual variability in the zonal displacement of the subtropical high has been considerably enhanced since 1978, due to the effects of both dominant modes, especially the second mode. This is likely to account for the frequent occurrence of anomalous climate in China during the recent two decades. [Copyright &y& Elsevier]

Based on daily observation records of fog and atmospheric visibility from 24 meteorological stations in the Yangtze Delta in the period from 1954 to 2005, the identification standard of dense fog events (DFE) has been proposed in this paper, a quite complete time series of DFEs for the delta constructed, and the climate characteristics of these events analyzed sequentially. Preliminary results showed that there were 564 typical DFEs in the delta from 1954 to 2005. The most frequent season for DFEs was from October to next April, when the number of the events accounted for 89. 9% of the annual total, while the least frequent season was summer, when the number only accounted for 1.6% of the total due to higher temperature and more convective weather in the season. In the Yangtze Delta, DFEs occurred less and were weaker in the 1960s, but turned to increase from the end of the 1970s to the beginning of the 1980s, with an abrupt change in 1978. Afterwards, DFEs occurred more frequently, intensively, and indeterministically, and in particular, most frequently in the 1980s and intensively in the 1990s. However both the frequency and intensity of DFEs decline apparently in the period of 2000-2005 in the delta. [ABSTRACT FROM AUTHOR]

Abstract: Climate prediction under impact of anthropological greenhouse-gas emission is impossible to validate, but it can be inferred from past climate and modeling. In East Asia, a general warm–wet period at late Marine Isotope Stage 3, ca. 30–40 ky BP has been identified based upon extensive geological records; this provides an arid/humid reference for possible future warming caused by human activities. Based upon syntheses of geological evidence and the AGCM+SSiB modeling, this paper presents climate simulations focused on 35 ky BP, using forcing of insolation, glaciation and land surface conditions for East Asia. Results of the simulation can be compared with geological records and show that (1) the climate patterns of 35 ky BP were warm–wet conditions in northern China, but with warm–dry conditions in southern China compared to today; (2) mean annual temperatures were higher in most mid-low latitude areas, mainly contributed to by increased winter temperatures, suggesting that insolation has generated significant climate effects through the coupling in atmospheric circulation with land surface patterns; (3) Quaternary ice sheets in the Northern Hemisphere played an important role in temperature decrease at the mid-high-latitudes, and also enhanced the south–north temperature gradients, which in turn, increased moisture transport from low to high latitudes and increased monsoonal precipitation over the Tibetan Plateau; and (4) Vegetation changes in East Asia resulted from an increased temperature in the low latitudes, extended rain-belt northwards into China, and an enlarged area of increased precipitation inland. [Copyright &y& Elsevier]

Abstract: A method for surface modeling of land cover change (SMLC) is developed on the basis of establishing transition probability matrixes between land cover types and HLZ types. SMLC is used to simulate land cover scenarios of China for the years 2039, 2069 and 2099, for which HLZ scenarios are first simulated in terms of HadCM3 climatic scenarios that are downscaled in zonal model of spatial climate change in China. This paper also analyzes spatial distribution of land cover types, area change and mean center shift of each land cover type, ecotope diversity, and patch connectivity under the land cover scenarios. The results show that cultivated land would decrease and woodland would expand greatly with climatic change, which coincides with consequences expected by implementation of Grain-for-Green policy. Nival area would shrink, and desertification area would expand at a comparatively slow rate in future 100 years. Climate change would generally cause less ecotope diversity and more patch connectivity. Ecosystems in China would have a pattern of beneficial cycle after efficient ecological conservation and restoration. However, if human activities would exceed regulation capacity of ecosystems themselves, the ecosystems in China might deteriorate more seriously. [Copyright &y& Elsevier]

Abstract: China has undertaken two of the world''s largest ecological rehabilitation projects—the Natural Forest Protection Program and the Sloping Land Conversion Program. This paper presents our historic perspective on the two projects, reports their preliminary impacts, and discusses the challenges in carrying them out, including the “top–down” administration, lack of interagency cooperation and long-term planning, and neglect of appropriate technical practices and market-based approaches. We argue that if properly implemented, these projects can contribute to China and the world in combating the pressing environmental problems of soil erosion, flooding, and desertification as well as climate change and loss of biodiversity. To implement the projects properly, however, major policy and technical changes must be made. [Copyright &y& Elsevier]

Abstract: Weather data can vary significantly from year to year. There is a need to derive typical meteorological year (TMY) data to represent the long-term typical weather condition over a year, which is one of the crucial factors for successful building energy simulation. In this paper, various types of typical weather data sets including the TMY, TMY2, WYEC, WYEC2, WYEC2W, WYEC2T and IWEC were reviewed. The Finkelstein–Schafer statistical method was applied to analyze the hourly measured weather data of a 25-year period (1979–2003) in Hong Kong and select representative typical meteorological months (TMMs). The cumulative distribution function (CDF) for each year was compared with the CDF for the long-term composite of all the years in the period for four major weather indices including dry bulb temperature, dew point temperature, wind speed and solar radiation. Typical months for each of the 12 calendar months from the period of years were selected by choosing the one with the smallest deviation from the long-term CDF. The 12 TMMs selected from the different years were used for formulation of a TMY for Hong Kong. [Copyright &y& Elsevier]

Desertification in Qinghai-Xizang (Tibet) Plateau is part of Chinese desertification. In the past decades, due to the climate warming, the climate condition in Qinghai-Xizang (Tibet) Plateau has been relatively dry. This has resulted in permafrost degradation and other environmental problems. In addition, the vegetation and the soil layer were also destroyed by unreasonable economic activities. Cultivated and grassland lands have become deserted. Nowadays, the desertification is still expending. In this paper, the factors affecting the desertification in Qinghai-Xizang (Tibet) Plateau were examined, and the desertification as well as its relationship with permafrost degradation was also discussed. [Copyright &y& Elsevier]

In studying solar energy and daylight availability, particularly the sky luminance distributions, the required data are always analysed under various sky types which are categorised by some climatic parameters. Overcast days are important because they are used in more general sky models and appear quite frequent in some places. This paper studies some common climatic parameters including cloud cover, sunshine hour, solar irradiance, daylight illuminance and sky luminance and their applications in the classification of sky conditions. Frequency of occurrence of each parameter under overcast skies in Hong Kong has been established. It has been found that no single parameter can effectively describe the fully overcast skies and hybrid indices should be adopted. The general luminance distribution formula for the overcast sky with various luminance distribution parameter values has been used to test the selected sky luminance databases. The analysis indicates that the CIE standard overcast sky shows a good agreement with the overcast sky luminance distributions obtained in Hong Kong. [Copyright &y& Elsevier]

A Holocene loess profile to the west of Xi''an China was studied multi-disciplinarily to investigate the relationships between soil erosion and monsoonal climatic change. The proxy data obtained from this aeolian loess and palaeosol sequence indicate large-scale variations of climate in the southern Loess Plateau since the last glaciation. A rainwash bed, indicative of a wetter climate, excessive runoff and erosion on the loess tablelands, was identified relating to the early Holocene before the onset of the “climatic optimum”. This is synchronous with the early Holocene physiographic erosional stage identified in the valleys in North China. It means that severe erosion took place when the region was undergoing climatic amelioration during the early Holocene. The evidence presented in this paper shows that the erosion occurred as a regional response to a monsoonal climatic shift in the southern Loess Plateau. During the last glaciation, prior to the erosion phase, the land surface on the tablelands had been largely stable except for the rapid accumulation of aeolian dust and the resultant increase in its elevation. Relatively slow dust accumulation and intensive bio-pedogenesis responding to the Holocene “climatic optimum” followed the erosion phase. The loess tablelands were most vulnerable to erosion during the large-scale monsoonal climatic shift from dry-cold glacial to humid-warm post-glacial conditions in the southern Loess Plateau. [Copyright &y& Elsevier]

With a high-carbon fuel mix and enormous space for efficiency potential, the power sector is critical to cope with global emission mitigation targets. The climate targets of less than 2 °C and even ambitious 1.5 °C confront China's power sector due to the rising momentum of power demand and the power mix dominated by coal power. Considering the potential carbon-emissions space of the power sector in China, this paper sets the alternative high-share renewable power, 1.5 and 2 °C scenarios that necessitate the zero-emissions and even negative-emissions for the power sector by 2050, and then proposes the pathways and outlines challenges to demonstrate the arduousness and uncertainty of the mega-project of power transition. The results indicate that a package of options is needed for the transition while unconventional bio-energy is the key to a 1.5 °C scenario. Notably, the coal power represents the largest barrier to low-carbon transition owing to the rising installation and massive stranded assets during the long-term reconfiguration of the power sector. • Set transition scenarios for China's power sector. • Discuss the pathways and challenges. • Comment China's transition policy. [ABSTRACT FROM AUTHOR]

• A comprehensive performance of R134a-TCS, R744-TCS and R744-PC-TCS is compared. • Five typical representative cities are selective to represent five major climate zones in China. • The seasonal performance of three systems in different climates is analyzed. • The proposed R744-PC-TCS has a great potential for the supermarket refrigeration application. In this paper, a R744 Partial Cascaded Two-stage Compression Refrigeration System (R744-PC-TCS) was proposed and evaluated in terms of coefficient of performance (COP) and seasonal energy efficiency ratio (SEER) when it operated in five typical climate representative cities in China. R134a and CO 2 are used as refrigerants in this study. The results show that the SEER of the supermarket refrigeration system in the severe cold zone and the mild zone is higher than that of the other climate zones. The performance of the R134a Two-stage Compression Refrigeration System (R134a-TCS) performs better than the R744 Two-stage Compression Refrigeration System (R744-TCS). However, both COP and SEER of the CO 2 system can be improved significantly by adding a parallel compressor, as well as using the single-stage vapor compression partial cascade cycle for subcooling under the practical working conditions (such as R744-PC-TCS). The greatest improvement of R744-PC-TCS can be achieved in the areas with poor climatic conditions, in which COP increases by 48.9% at an ambient temperature of 39 °C, and SEER increases by the maximum of 21.5% in hot summer and warm winter zones, compared with that of R744-TCS. Compared with R134a system, the R744-PC-TCS basically achieves the comparable or even higher energy efficiency. It can be concluded that the proposed R744-PC-TCS has a great potential to replace the existing R134a refrigeration system for the supermarket refrigeration application. [ABSTRACT FROM AUTHOR]

Load matching is an inevitable problem that restricts the development of photovoltaic (PV) system used in buildings. The objective of this paper is to solve this problem by conducting a load matching assessment and optimization of PV system in different climate zones of China. The influences of the tilt angle, orientation, PV plot ratio and building height on the achievement of zero energy buildings (ZEBs) were evaluated. The PV potentials of roofs and facades were analyzed and optimized based on self-sufficiency and self-consumption. Net load variance and the maximum electricity import were employed as indices to evaluate the performance of PV systems in different climate zones of China. The results of the load matching assessment show that electricity generations from roof PV systems in low-rise buildings can meet most of the energy demand (at least 70%) in all climate zones of China. East and west facades of mid-rise buildings have an advantage over south façades in Kunming and Guangzhou in terms of load matching. It is necessary to combine roofs, south, east and west facades to meet the ZEBs requirement of for high-rise building. When the heating/cooling demand is dominant, the tilt angle should be higher/lower than the latitude of the specific location. This research will be helpful in designing building PV systems in different climate zones of China. Load matching analysis is helpful in designing building PV system in different climate zones of China. The results show that east and west facades of mid-rise buildings have an advantage over south façade in Kunming and Guangzhou. It is necessary to combine roof, south, east and west facades to meet the requirement of ZEBs for high-rise building. Image 1 • Load matching with PV system were analyzed for zero energy buildings. • PV potential were investigated based on self-sufficiency and self-consumption. • The optimal combinations of PV system were obtained in different climate zones. • East and west facades have advantages over south façade in Kunming and Guangzhou. [ABSTRACT FROM AUTHOR]