Advances in Meteorology The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Identifying Vegetation Dynamics and Sensitivities in Response to Water Resources Management in the Heihe River Basin in China Wed, 30 Sep 2015 09:32:42 +0000 The Heihe River Basin, the second largest inland river basin in China, plays a vital role in the ecological sustainability of the Hexi Corridor. However, the requirements for regional economic development and ecological balance cannot be fully met due to water resource shortage and overexploitation induced by an extremely dry climate and population growth, especially in the middle and lower basins. Thus, environmental conservation projects that reallocate water resources have been planned and implemented step by step since 2001. The aim of this study is to evaluate ecosystem restoration benefits by identifying vegetation dynamics and sensitivities. The MODIS Normalized Difference Vegetation Index (NDVI) and its derivative indices, coupled with Geographic Information System (GIS), are introduced to explore ecosystem evolution at the pixel level, based on the hydrological and meteorological data in the whole region at varying temporal and spatial scales. Results indicate there are slight vegetation restoration trends in the upper, middle, and lower basin; the results of correlation analyses between vegetation and runoff into the lower basin suggest that the impact of a water supplement lasts at most three years, and engineering or nonengineering measures should be maintained for permanent ecosystem recovery. Dongqin Yin, Xiang Li, Yuefei Huang, Yuan Si, and Rui Bai Copyright © 2015 Dongqin Yin et al. All rights reserved. Research on Nonpoint Source Pollution Assessment Method in Data Sparse Regions: A Case Study of Xichong River Basin, China Tue, 29 Sep 2015 09:02:14 +0000 The NPS pollution is difficult to manage and control due to its complicated generation and formation mechanism, especially in the data sparse area. Thus the ECM and BTOPMC were, respectively, adopted to develop an easy and practical assessment method, and a comparison between the outputs of them is then conducted in this paper. The literature survey and field data were acquired to confirm the export coefficients of the ECM, and the loads of TN and TP were statistically analyzed in the study area. Based on hydrological similarity, runoff data from nearby gauged sites were pooled to compensate for the lack of at-site data and the water quality submodel of BTOPMC was then applied to simulate the monthly pollutant fluxes in the two sections from 2010 to 2012. The results showed agricultural fertilizer, rural sewage, and livestock and poultry sewage were the main pollution sources, and under the consideration of self-purification capacity of river, the outputs of the two models were almost identical. The proposed method with a main thought of combining and comparing an empirical model and a mechanistic model can assess the water quality conditions in the study area scientifically, which indicated it has a good potential for popularization in other regions. Xing Liu, Donglong Li, Hongbo Zhang, Shixiang Cai, Xiaodong Li, and Tianqi Ao Copyright © 2015 Xing Liu et al. All rights reserved. Satellite Observation of Atmospheric Compositions for Air Quality and Climate Study Sun, 27 Sep 2015 08:00:15 +0000 Xiaozhen Xiong, Liangfu Chen, Yang Liu, Ugo Cortesi, and Pawan Gupta Copyright © 2015 Xiaozhen Xiong et al. All rights reserved. Investigation of Precipitation Variations over Wet and Dry Areas from Observation and Model Sun, 27 Sep 2015 06:48:26 +0000 Our observational study revealed that the precipitation increased over the wet area and decreased over the dry area during the past two decades. Here, we further investigate whether the current atmospheric models can quantitatively capture the characteristics of precipitation from the observation. The NASA Goddard Institute for Space Studies (GISS) model is used to examine the historic simulation of the precipitation, in which the historic greenhouse gases and aerosols are included in the radiative forcing. The consistency between the historic GISS simulation and the Global Precipitation Climatology Project (GPCP) precipitation suggests that the model can qualitatively capture the temporal trends of precipitation over the wet and dry areas. However, the precipitation trends are weaker in the model than in the observation. The observed trends of precipitation do not appear in the control simulation with the fixed concentrations of greenhouse gases and aerosols, which suggests that the global warming due to anthropogenic forcing can influence the temporal variations of precipitation over the wet and dry areas. Diagnostic studies of other variables from the model further suggest that enhanced rising air can increase the precipitation over the wet area. James H. Trammell, Xun Jiang, Liming Li, Maochang Liang, Mao Li, Jing Zhou, Eric Fetzer, and Yuk Yung Copyright © 2015 James H. Trammell et al. All rights reserved. Tropospheric NO2 Trends over South Asia during the Last Decade (2004–2014) Using OMI Data Sun, 20 Sep 2015 12:41:43 +0000 The focus of this study is to assess spatiotemporal variability of tropospheric NO2 over South Asia using data from spaceborne OMI during the past decade (2004–2015). We find an average value of NO2 1.0 ± 0.05 × 1015 molec/cm2 and a significant decadal increase of 14%. The elevating NO2 pollution over the region is linked to rise in motor vehicles and industrial and agricultural activities and increase in biomass fuel usage. The observed seasonality of NO2 is associated with change in meteorological conditions and seasonal cycles of anthropogenic emissions. OMI data reveal a seasonal peak in spring followed by winter largely linked to metrological conditions and anthropogenic emissions from crop residue and biomass burning for heating purpose, and low concentration in summer is mostly attributed to meteorological conditions. Significant increase, up to 42%, in NO2 concentrations over northwestern IGB, is observed connected to large scale postmonsoon crop residue events of 2010 and 2012. It is seen that NO2 is mounting over all the hotspot locations and most of the cities. Dhaka shows the highest increase of 77% followed by Islamabad (69%), Kabul (68%), Korba (64%), Bardhaman (47%), and Lahore (40%). On the contrary, DG Khan has shown negative trend of −11%. Zia ul-Haq, Salman Tariq, and Muhammad Ali Copyright © 2015 Zia ul-Haq et al. All rights reserved. Analysis of Long-Range Transport of Carbon Dioxide and Its High Concentration Events over East Asian Region Using GOSAT Data and GEOS-Chem Modeling Sun, 20 Sep 2015 11:20:19 +0000 This study aims to evaluate the long-range transport of CO2 in East Asian region, using concentration data in a surface measurement site (Gosan Station), column averaged concentration data of satellite-borne instrument (GOSAT), and GEOS-Chem modeling results for the period of June 2009 to May 2011. We perform a validation of the data from GOSAT and GEOS-Chem with total column observations (TCCON). The analysis of the long-range transport and high concentration (HC) events using surface/satellite observations and modeling results is conducted. During the HC events, the concentrations in CO2 and other air pollutants such as SO2 and CO are higher than that of all episodes. It means that CO2, known as a globally well-mixed gas, may also act as a fingerprint of human activity with unique regional characteristics like other air pollutants. This comprehensive analysis, in particular with GOSAT CO2 observation data, shows that CO2 plume with high concentration can be long-range transported with 1-2 days’ duration with regional scale. We can find out with GEOS-Chem tagging simulation that more than 45% of the elevated CO2 concentration over central/eastern China, Korea, and Japan on high concentration days can be explained by emission sources of East Asia mainland. Seung-Yeon Kim, Sang-Deok Lee, Jae-Bum Lee, Deok-Rae Kim, Jin-Seok Han, Kwang-Ho Choi, and Chang-Keun Song Copyright © 2015 Seung-Yeon Kim et al. All rights reserved. Preliminary Assessment of Methane Concentration Variation Observed by GOSAT in China Sun, 20 Sep 2015 11:15:47 +0000 Atmospheric column-averaged methane (XCH4) observations from GOSAT are analyzed to study the spatiotemporal variation of XCH4 in China. Furthermore, we investigate the driving mechanism of XCH4 spatiotemporal variations, especially for high XCH4 values shown over Sichuan Basin, by analyzing both the emission mechanism of rice planting process and the regional atmosphere dynamic transportation. The results indicate that spatially the Sichuan Basin presents a higher XCH4 concentration than other regions in China and is 17 ppb higher than the paddy area in the same latitude zone. Seasonally, XCH4 in Sichuan Basin during rice harvest season is generally higher than that in early cultivation period. However, comparing to paddy area in the same latitude zone, Sichuan Basin shows a relatively higher XCH4 value during the winter of noncultivation period when the emissions from rice paddies are weak and surface air temperature is low. To further investigate the high XCH4 concentration during this low-emission period, we use the HYSPLIT model to simulate the atmosphere dynamic transport process, and the result suggests that the typical closed topography of Sichuan Basin, which may lead to CH4 accumulation and keep it from diffusion, is one possible reason for the high XCH4 value in winter. Xiuchun Qin, Liping Lei, Zhonghua He, Zhao-Cheng Zeng, Masahiro Kawasaki, Masafumi Ohashi, and Yutaka Matsumi Copyright © 2015 Xiuchun Qin et al. All rights reserved. Analysis of Changes in Precipitation and Drought in Aksu River Basin, Northwest China Sun, 20 Sep 2015 09:00:11 +0000 The analysis of the spatiotemporal trends of precipitation and drought is relevant for the future development and sustainable management of water resources in a given region. In this study, precipitation and Standardized Precipitation Index (SPI) trends were analyzed through applying linear regression, Mann–Kendall, and Spearman’s Rho tests at the 5% significance level. For this goal, meteorological data from 9 meteorological stations in and around Aksu Basin during the period 1960–2010 was used, and two main annual drought periods were detected (1978-1979 and 1983–1986), while the extremely dry years were recorded in 1975 and 1985 at almost all of the stations. The monthly analysis of precipitation series indicates that all stations had increasing trend in July, October, and December, while both increasing and decreasing trends were found in other months. For the seasonal scale, precipitation series had increasing trends in summer and winter. 33% of the stations had the decreasing trend on precipitation in the spring series, and it was 11% in the autumn. At the same time, the SPI-12 values of all stations had the increasing trend. The significant trends were detected at Aheqi, Baicheng, Keping, and Kuche stations. Yuhu Zhang, Wanyuan Cai, Qiuhua Chen, Yunjun Yao, and Kaili Liu Copyright © 2015 Yuhu Zhang et al. All rights reserved. Optical Properties of the Urban Aerosol Particles Obtained from Ground Based Measurements and Satellite-Based Modelling Studies Sun, 13 Sep 2015 11:22:36 +0000 Applications of satellite remote sensing data combined with ground measurements and model simulation were applied to study aerosol optical properties as well as aerosol long-range transport under the impact of large scale circulation in the urban environment in Lithuania (Vilnius). Measurements included the light scattering coefficients at 3 wavelengths (450, 550, and 700 nm) measured with an integrating nephelometer and aerosol particle size distribution (0.5–12 μm) and number concentration ( > 0.5 μm) registered by aerodynamic particle sizer. Particle number concentration and mean light scattering coefficient varied from relatively low values of 6.0 cm−3 and 12.8 Mm−1 associated with air masses passed over Atlantic Ocean to relatively high value of 119 cm−3 and 276 Mm−1 associated with South-Western air masses. Analysis shows such increase in the aerosol light scattering coefficient (276 Mm−1) during the 3rd of July 2012 was attributed to a major Sahara dust storm. Aerosol size distribution with pronounced coarse particles dominance was attributed to the presence of dust particles, while resuspended dust within the urban environment was not observed. Genrik Mordas, Nina Prokopciuk, Steigvilė Byčenkienė, Jelena Andriejauskienė, and Vidmantas Ulevicius Copyright © 2015 Genrik Mordas et al. All rights reserved. Satellite Observed Aerosol Optical Thickness and Trend around Megacities in the Coastal Zone Sun, 13 Sep 2015 08:50:20 +0000 Nearly 30-year aerosol optical thickness (AOT) climate data record (CDR) derived from the operational satellite observations of National Ocean and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) is used to study the AOT trends over seventeen megacities in the coast zone (MCCZ). Linear trends are derived from monthly and seasonal mean AOT in the past three decades and used in the analysis. The results indicate the following: (1) AOT around a MCCZ in fast developing countries has relatively high value and a positive trend with a confidence level generally above 95%; (2) AOT around a MCCZ in industrialized countries has relatively low value and a negative trend with a confidence level generally above 95%; (3) AOT values and their trends show distinct seasonal variations in MCCZ, which can be explained somewhat by the seasonal variations of meteorological conditions. AOT trend is an effective index for examining the efficacy of air pollution control policies implemented for these megacities. Xuepeng Zhao Copyright © 2015 Xuepeng Zhao. All rights reserved. Operational Monitoring of Trace Gases over the Mediterranean Sea Sun, 13 Sep 2015 08:48:52 +0000 This paper describes the operational implementation of the processor -IASI over the Mediterranean sea. The -IASI model implements two physically based inversion algorithms for the sequential retrieval of (a) the thermodynamic state of the atmosphere and (b) the tropospheric content of CO, CO2, CH4, and N2O from hyperspectral radiance observations of the Infrared Atmospheric Sounding Interferometer (IASI). The retrieval algorithm for trace gases exploits the concept of partially scanned interferogram technique, which is a tool mostly suited for Fourier transform spectrometers in the infrared. Minor and trace gases retrievals for July 2010 are presented and compared to in situ observations from five Mediterranean, permanent, stations of the Global Atmospheric Watch (GAW) network. The comparison evidences a good general consistency between satellite and in situ observations. IASI retrievals show a marked southeastern gradient, which is shown to be consistent with the general tropospheric circulation over the Mediterranean basin. These patterns are barely seen from in situ observations, a fact which stresses the importance of satellite (trace gases) data assimilation to improve the performance and quality of trace gases transport models. Giuseppe Grieco, Guido Masiello, and Carmine Serio Copyright © 2015 Giuseppe Grieco et al. All rights reserved. Dominant Modes of Tropospheric Ozone Variation over East Asia from GOME Observations Sun, 13 Sep 2015 08:15:55 +0000 The variation in tropospheric ozone over East Asia was analyzed using tropospheric column ozone data measured by the Global Ozone Monitoring Experiment (GOME) satellite. An empirical orthogonal function (EOF) analysis was carried out to derive the dominant modes of the variation in the tropospheric ozone volume-mixing ratio (TOVMR). The EOF1 mode, which explained 61.5% of the total variance, showed a same-sign distribution over all of East Asia, with a belt of enhanced ozone concentrations around 40°N. The principal component of EOF1 (PC1) suggested that photochemical ozone production together with Brewer-Dobson circulation and subtropical westerly jet plays important roles in modulating the seasonal variation of the TOVMR; ozone-rich air produced by photochemical processes was transported from the stratosphere to the troposphere by BD circulation and this ozone-rich air was then blocked by the subtropical westerly jet and accumulated north of the jet. The EOF2 mode explained 29.2% of the total variance with an opposite-sign pattern on the north and south side of 35°N. When anticyclonic circulation transported ozone-poor air from the upwelling area over the Bay of Bengal towards the Tibetan Plateau during the onset of the Asian summer monsoon, tropospheric ozone in this region decreased dramatically. Yi Liu, Yuli Zhang, Yong Wang, Chuanxi Liu, Zhaonan Cai, Paul Konopka, and Rolf Müller Copyright © 2015 Yi Liu et al. All rights reserved. How Well Do Gridded Datasets of Observed Daily Precipitation Compare over Australia? Thu, 10 Sep 2015 13:39:32 +0000 Daily gridded precipitation data are needed for investigating spatiotemporal variability of precipitation, including extremes; however, uncertainties related to daily precipitation products are large. Here, we compare a range of precipitation grids for Australia. These datasets include products derived solely from in situ observations (interpolated datasets) and two products that combine both remote sensed data and in situ observations. We find that all precipitation grids have similar climatologies for annual aggregated precipitation totals and annual maximum precipitation. The temporal correlations of daily precipitation values are higher between the interpolated datasets, but the correlations between the most widely used interpolated product (AWAP) and the two remotely sensed products (TRMM and GPCP) are still reasonable. Our results, however, point to distinct structural uncertainties between those datasets gridding in situ observations and those datasets deriving precipitation estimates primarily from satellite measurements. All datasets analysed agree well for low to moderate daily precipitation amounts up to about 20 mm but diverge at upper quantiles, indicating that substantial uncertainty exists in gridded precipitation extremes over Australia. Steefan Contractor, Lisa V. Alexander, Markus G. Donat, and Nicholas Herold Copyright © 2015 Steefan Contractor et al. All rights reserved. A Numerical Study on Impact of Taiwan Island Surface Heat Flux on Super Typhoon Haitang (2005) Thu, 10 Sep 2015 13:35:39 +0000 Three to four tropical cyclones (TCs) by average usually impact Taiwan every year. This study, using the Developmental Tested Center (DTC) version of the Hurricane WRF (HWRF) model, examines the effects of Taiwan’s island surface heat fluxes on typhoon structure, intensity, track, and its rainfall over the island. The numerical simulation successfully reproduced the structure and intensity of super Typhoon Haitang. The model, especially, reproduced the looped path and landfall at nearly the right position. Sensitive experiments indicated that Taiwan’s surface heat fluxes have significant influence on the super Typhoon Haitang. Compared to sensible heat (SH) fluxes, latent heat (LH) is the dominant factor affecting the intensity and rainfall, but they showed opposite effects on intensity and rainfall. LH (SH) flux of Taiwan Island intensified (weakened) Typhoon Haitang’s intensity and structure by transferring more energy from (to) surface. However, only LH played a major role in the looped path before the landfall of the Typhoon Haitang. Hongxiong Xu Copyright © 2015 Hongxiong Xu. All rights reserved. Possible Micrometeorological Anomalies Induced by Volcanic Activity Recorded at Stromboli Island (Aeolian Archipelago, Italy) Thu, 10 Sep 2015 09:59:32 +0000 Hourly values of atmospheric pressure and air temperature have been acquired at the top of two volcanic islands, Stromboli and Salina in the Aeolian Archipelago (Italy), very similar in height and morphology but completely different with regard to their volcanic activity state: the former is permanently active, whereas the latter is extinguished. During the last four years Stromboli experienced normal activity, volcanic unrests, and an effusive eruption (August–November 2014). The comparative analysis of the recorded data, both in the time and frequency domains, evidenced a peculiar micrometeorological regime at Stromboli, more turbulent during unrests with respect to the quieter periods, but showing an apparent paradox during eruptions, characterized by a lower atmospheric turbulence. These observations suggest that the studied volcanic-micrometeorological system is chaotic, due to contemporary opposite transients generated in the atmosphere by volcanic activity changes, and that micrometeorological conditions in volcanic areas are controlled both by exogenous processes and volcanic activity. Paolo Madonia, Marianna Cangemi, and Salvatore Inguaggiato Copyright © 2015 Paolo Madonia et al. All rights reserved. Quality of the Governing Temperature Variables in WRF in relation to Simulation of Primary Biological Aerosols Thu, 10 Sep 2015 09:52:13 +0000 We have evaluated three prognostic variables in Weather Research and Forecasting (WRF) model, mean daily temperature, daily maximum temperature, and daily minimum temperature using 9 months of model simulations at 36 and 12 km resolution, and compared the results with 1182 observational sites in north and central Europe. The quality of the results is then determined in the context of the governing variables used in crop science, forestry, and aerobiological models. We use the results to simulate the peak of the birch pollen season (aerobiology), growth of barley (crop science), and development of the invasive plant pathogen Hymenoscyphus pseudoalbidus (the cause of ash-dieback). The results show that the crop and aerobiological models are particularly sensitive to grid resolution and much higher quality is obtained from the 12 km simulations compared to 36 km. The results also show that the summer months have a bias, in particular for maximum and minimum temperatures, and that the low/high bias is clustered in two areas: continental and coastal influenced areas. It is suggested that the use of results from meteorological models as an input into biological models needs particular attention in the quality of the modelled surface data as well as the applied land surface modules. C. A. Skjøth, M. Werner, M. Kryza, B. Adams-Groom, A. Wakeham, M. Lewis, and R. Kennedy Copyright © 2015 C. A. Skjøth et al. All rights reserved. Wavelet Filter Approach and - Relationship in Meteorological Forecasting Mon, 31 Aug 2015 13:22:06 +0000 The purpose of this study is to investigate the - relationship for computing rainfall using conventional and wavelet filters technique. Wavelet filter technique was applied to data filtration process. The proposed model was applied to determine the rainfall of five rain gauge meteorological stations in Thailand. The three-hourly rainfall and radar reflectivity data were used in this study. The results indicated that the accumulative rainfall of wavelet filters technique was close to the observed rainfall data more than the results of conventional practice for both calibration and validation processes. Consequently, we are confident that a wavelet filters technique is a useful tool for estimating the rainfall. Wallop Jiwlong and Anongrit Kangrang Copyright © 2015 Wallop Jiwlong and Anongrit Kangrang. All rights reserved. Vertical Raindrop Size Distribution in Central Spain: A Case Study Sun, 30 Aug 2015 12:15:55 +0000 A precipitation event that took place on 12 October 2008 in Madrid, Spain, is analyzed in detail. Three different devices were used to characterize the precipitation: a disdrometer, a rain gauge, and a Micro Rain Radar (MRR). These instruments determine precipitation intensity indirectly, based on measuring different parameters in different sampling points in the atmosphere. A comparative study was carried out based on the data provided by each of these devices, revealing that the disdrometer and the rain gauge measure similar precipitation intensity values, whereas the MRR measures different rain fall volumes. The distributions of drop sizes show that the mean diameter of the particles varied considerably depending on the altitude considered. The level at which saturation occurs in the atmosphere is decisive in the distribution of drop sizes between 2,700 m and 3,000 m. As time passes, the maximum precipitation intensities are registered at a lower height and are less intense. The maximum precipitation intensities occurred at altitudes above 1,000 m, while the maximum fall speeds are typically found at altitudes below 700 m. Roberto Fraile, Amaya Castro, Miguel González-Colino, Elisabeth Alonso-Blanco, María Fernández-Raga, Covadonga Palencia, and Ana I. Calvo Copyright © 2015 Roberto Fraile et al. All rights reserved. Weather and Climate in Monsoon Regions Wed, 26 Aug 2015 09:49:38 +0000 Lin Wang, June-Yi Lee, Haishan Chen, Fred Kucharski, Xiaolong Jia, Xiaojing Jia, and Jieshun Zhu Copyright © 2015 Lin Wang et al. All rights reserved. Recent Trends in Temperature and Precipitation in the Langat River Basin, Malaysia Wed, 26 Aug 2015 07:25:14 +0000 A study was undertaken to detect long-term trends in the annual and seasonal series of maximum and minimum temperatures. Measurements were taken at 11 meteorological stations located in the Langat River Basin in Malaysia. The rainfall and maximum and minimum temperature data were obtained from the Malaysia Meteorological Department (MMD) and the Department of Irrigation and Drainage (DID) Malaysia. The procedures used included the Mann-Kendall test, the Mann-Kendall rank statistic test, and the Theil-Sen’s slope method. The analytical results indicated that when there were increasing and decreasing trends in the annual and seasonal precipitation and temperature, only the increasing trends were significant at the 95% confidence level. The Theil-Sen’s slope method showed that the rate of increment in the annual precipitation is greater than the seasonal precipitation. A bootstrap technique was applied to explore uncertainty about significant slope values for rainfall, as well as the maximum and minimum temperatures. The Mann-Kendall rank statistics test indicated that most of the trends in the annual and seasonal time series started in the year 2000. All of the annual and seasonal significant trends were obtained at the stations located in the north, east, and northeast portions of the Langat River Basin. Mahdi Amirabadizadeh, Yuk Feng Huang, and Teang Shui Lee Copyright © 2015 Mahdi Amirabadizadeh et al. All rights reserved. Spatiotemporal Variability and Change of the South China Spring Precipitation during 1961–2012 Wed, 26 Aug 2015 07:05:03 +0000 We analyze precipitation data from 47 meteorological stations spanning between 1961 and 2012 and NCEP/NCAR reanalysis to understand spatiotemporal variability and change of spring precipitation of South China and their relations to atmospheric circulations. Empirical orthogonal function (EOF) analysis and rotated EOF (REOF) are used to reveal dominant spatial structures of precipitation anomaly and Mann-Kendall testing method to determine the temporal locations of abrupt changes during the analyzed time span. We find that the first spatial mode of the spring precipitation of the South China has a domain uniform structure; the second is dominated by a spatial dipole; and the third contains six variability centers. 1980s was the decade of the largest amount of precipitation while 1960s the decade of the smallest amount of precipitation. The spring precipitation also appeared to have a decreasing trend since 2000. We also find that spring precipitation of the South China has experienced a few abrupt changes: sudden increment at 1964, sudden decrement at 2002, and sudden increment at 1995. In addition to these abrupt changes, the precipitation could also be characterized by variability of multiple temporal scales, with dominant periodicities of 4 years, 8 years, and 14 years. The South China spring precipitation is also closely tied to the atmospheric circulations: when Aleutian Low strengthens, westerly weakens, and the center of the Western Pacific subtropical high shifts southeastward in the early spring; and the South China precipitation tends to be abundant (positive anomaly). In contrast, when Ural ridge strengthens, the southern branch of the East Asian trough weakens and the Western Pacific subtropical high shifts northwestward in the early spring, the South China precipitation tends to be reduced (negative anomaly). Hong-Lan Liu, Qiang Zhang, Jun-Qin Guo, Jun-Guo Zhang, and Sheng Wang Copyright © 2015 Hong-Lan Liu et al. All rights reserved. Dominant Large-Scale Atmospheric Circulation Systems for the Extreme Precipitation over the Western Sichuan Basin in Summer 2013 Tue, 25 Aug 2015 14:14:09 +0000 The western Sichuan Basin (WSB) is a rainstorm center influenced by complicated factors such as topography and circulation. Based on multivariable empirical orthogonal function technique for extreme precipitation processes (EPP) in WSB in 2013, this study reveals the dominant circulation patterns. Results indicate that the leading modes are characterized by “Saddle” and “Sandwich” structures, respectively. In one mode, a TC from the South China Sea (SCS) converts into the inverted trough and steers warm moist airflow northward into the WSB. At the same time, WPSH extends westward over the Yangtze River and conveys a southeasterly warm humid flow. In the other case, WPSH is pushed westward by TC in the Western Pacific and then merges with an anomalous anticyclone over SCS. The anomalous anticyclone and WPSH form a conjunction belt and convey the warm moist southwesterly airflow to meet with the cold flow over the WSB. The configurations of WPSH and TC in the tropic and the blocking and trough in the midhigh latitudes play important roles during the EPPs over the WSB. The persistence of EPPs depends on the long-lived large-scale circulation configuration steady over the suitable positions. Yamin Hu, Panmao Zhai, Lihong Liu, Yang Chen, and Yanju Liu Copyright © 2015 Yamin Hu et al. All rights reserved. Fuzzy Clustering-Based Ensemble Approach to Predicting Indian Monsoon Tue, 25 Aug 2015 13:42:43 +0000 Indian monsoon is an important climatic phenomenon and a global climatic marker. Both statistical and numerical prediction schemes for Indian monsoon have been widely studied in literature. Statistical schemes are mainly based on regression or neural networks. However, the variability of monsoon is significant over the years and a single model is often inadequate. Meteorologists revise their models on different years based on prevailing global climatic incidents like El-Niño. These indices often have degree of severity associated with them. In this paper, we cluster the monsoon years based on their fuzzy degree of associativity to these climatic event patterns. Next, we develop individual prediction models for the year clusters. A weighted ensemble of these individual models is used to obtain the final forecast. The proposed method performs competitively with existing forecast models. Moumita Saha, Pabitra Mitra, and Arun Chakraborty Copyright © 2015 Moumita Saha et al. All rights reserved. Analysis on the Extreme Heat Wave over China around Yangtze River Region in the Summer of 2013 and Its Main Contributing Factors Tue, 25 Aug 2015 13:24:35 +0000 In the summer of 2013, a rare extreme heat wave occurred in the middle and lower reaches of the Yangtze River in China. Based on high resolution reanalysis data from ECMWF, comprehensive analyses on the associated atmospheric circulation and the sea surface temperature anomaly (SSTA) were provided. The stable and strong West Pacific Subtropical High (WPSH) was the direct cause for the heat wave. The WPSH had four westward extensions, which brought about four hot spells in southern China. The South Asia High (SAH) at 150 hPa was more eastward and more northward than normal. The strong Hadley circulation in the central and western Pacific and the anomalous easterlies at 500 hPa and 250 hPa in the middle and high latitudes were favorable for more hot days (HDs). The total HDs in the middle and lower reaches of the Yangtze River had close relationships with the zonal wind anomalies in the middle and high latitudes, the SSTA in the Indian Ocean and Pacific, and the dry soil conditions of the Yangtze River Valley in spring and summer. The anomalies of the tropical, subtropical, and polar circulation and the underlying surfaces could be responsible for this extreme heat wave. Jin Li, Ting Ding, Xiaolong Jia, and Xianchan Zhao Copyright © 2015 Jin Li et al. All rights reserved. Spatiotemporal Characteristics of Evapotranspiration Paradox and Impact Factors in China in the Period of 1960–2013 Tue, 25 Aug 2015 13:06:00 +0000 Downward trend of potential evaporation accompanied with upward of air temperature which is denoted as evaporation paradox has been reported in many regions over the past several decades in the world. In this paper, evaporation paradox and key factors attributed to ET0 changes are systematically analyzed based on data from 599 meteorological stations during 1960–2013. Results show that (1) Evaporation paradox exists in all regions in1960–2013 and 1960–1999 except SWRB in 1960–2013 but no evaporation paradox in 2000–2013. (2) Evaporation paradox exists in large areas in spring and summer, the extent and range fall in autumn, and there is no evaporation paradox in winter. (3) The evaporation paradox area accounts for 73.7% of China in 1960–2013 and 91.2% in 1969–1999. (4) Sunshine hours, humidity, wind speed, and maximum temperature appear to be the most important variables which contributed to ET0 change in China. Huiping Huang, Yuping Han, Mingming Cao, Jinxi Song, Heng Xiao, and Weili Cheng Copyright © 2015 Huiping Huang et al. All rights reserved. Impact of Stratospheric Sudden Warming on East Asian Winter Monsoons Tue, 25 Aug 2015 12:43:59 +0000 Fifty-two Stratospheric sudden warming (SSW) events that occurred from 1957 to 2002 were analyzed based on the 40-year European Centre for Medium-Range Weather Forecasts Reanalysis dataset. Those that could descent to the troposphere were composited to investigate their impacts on the East Asian winter monsoon (EAWM). It reveals that when the SSW occurs, the Arctic Oscillation (AO) and the North Pacific Oscillation (NPO) are both in the negative phase and that the tropospheric circulation is quite wave-like. The Siberian high and the Aleutian low are both strengthened, leading to an increased gradient between the Asian continent and the North Pacific. Hence, a strong EAWM is observed with widespread cooling over inland and coastal East Asia. After the peak of the SSW, in contrast, the tropospheric circulation is quite zonally symmetric with negative phases of AO and NPO. The mid-tropospheric East Asian trough deepens and shifts eastward. This configuration facilitates warming over the East Asian inland and cooling over the coastal East Asia centered over Japan. The activities of planetary waves during the lifecycle of the SSW were analyzed. The anomalous propagation and the attendant altered amplitude of the planetary waves can well explain the observed circulation and the EAWM. Quanliang Chen, Luyang Xu, and Hongke Cai Copyright © 2015 Quanliang Chen et al. All rights reserved. The Okhotsk-Japan Circulation Pattern and the Heavy Rainfall in Beijing in 2012 Summer Mon, 24 Aug 2015 06:14:33 +0000 Using station precipitation and reanalysis data, we examined the evolution of the large-scale circulations associated with the heavy rainfall event that occurred around July 21, 2012 (721 heavy rainfall). This study focuses on a role that the large-scale circulations named “the Okhotsk-Japan (OKJ) circulation pattern” played in causing the heavy rainfall case. We found that the 721 heavy rainfall occurred under a background of the OKJ circulation that persisted for about 10 days. However, the pattern was different from the normal OKJ circulation, for this circulation pattern accompanied a blocking high between the Ural Mountains and the Baikal Lake. This difference resulted from the seasonal change of the basic flow. The related Rossby wave propagated eastward during the persisting period of the dominated OKJ pattern. This caused the development of a low-pressure system around the Baikal Lake and the weakening of a ridge around the Okhotsk Sea. The slow evolution of the OKJ circulation created a favorable environment for the moisture transport to northern China, assisting in the generation of the 721 heavy rainfall. Yafei Wang, Jianzhao Qin, and Lijuan Zhu Copyright © 2015 Yafei Wang et al. All rights reserved. Numerical Simulations of the 1 May 2012 Deep Convection Event over Cuba: Sensitivity to Cumulus and Microphysical Schemes in a High-Resolution Model Tue, 18 Aug 2015 06:32:40 +0000 This paper evaluates the sensitivity to cumulus and microphysics schemes, as represented in numerical simulations of the Weather Research and Forecasting model, in characterizing a deep convection event over the Cuban island on 1 May 2012. To this end, 30 experiments combining five cumulus and six microphysics schemes, in addition to two experiments in which the cumulus parameterization was turned off, are tested in order to choose the combination that represents the event precipitation more accurately. ERA Interim is used as lateral boundary condition data for the downscaling procedure. Results show that convective schemes are more important than microphysics schemes for determining the precipitation areas within a high-resolution domain simulation. Also, while one cumulus scheme captures the overall spatial convective structure of the event more accurately than others, it fails to capture the precipitation intensity. This apparent discrepancy leads to sensitivity related to the verification method used to rank the scheme combinations. This sensitivity is also observed in a comparison between parameterized and explicit cumulus formation when the Kain-Fritsch scheme was used. A loss of added value is also found when the Grell-Freitas cumulus scheme was activated at 1 km grid spacing. Yandy G. Mayor and Michel D. S. Mesquita Copyright © 2015 Yandy G. Mayor and Michel D. S. Mesquita. All rights reserved. Trend Change Study of Climate Variables in Xin’anjiang-Fuchunjiang Watershed, China Thu, 13 Aug 2015 14:06:57 +0000 This study emphasizes the precipitation and the maximum and minimum temperature trend and presents the results of study in temporal and spatial scales, after performing statistical analysis of the Xin’anjiang-Fuchunjiang watershed. Statistical Mann Kendall and Theil Sen techniques were used to determine the trend and its magnitude, respectively, and for determining the start and abrupt change in the trend, Sequential Mann Kendall test has been performed. Furthermore, statistical tests were performed to determine the overall trend in the area at a regional basis. For the removal of the serial effect of the data, prewhitening technique is applied. In this study, statistical tests were performed at 1901–2013 precipitation and temperature series and then after detection of the change year precipitation data were divided into two different scenarios of 1901–1960 period and 1961–2013 period. The results showed that precipitation trend is insignificant while maximum and minimum temperature have increased during 1901–2013 period except for some stations of autumn and summer seasons. Muhammad Zaman, Guohua Fang, Kashif Mehmood, and Muhammad Saifullah Copyright © 2015 Muhammad Zaman et al. All rights reserved. Land Use Zoning for Conserving Ecosystem Services under the Impact of Climate Change: A Case Study in the Middle Reaches of the Heihe River Basin Sun, 09 Aug 2015 06:51:21 +0000 Ecosystem services are the benefit human populations derive directly and indirectly from the natural environment. They suffer from both the human intervention, like land use zoning change, and natural intervention, like the climate change. Under the background of climate change, regulation services of ecosystem could be strengthened under proper land use zoning policy to mitigate the climate change. In this paper, a case study was conducted in the middle reaches of the Heihe River Basin to assess the ecosystem services conservation zoning under the change of land use associated with climate variations. The research results show the spatial impact of land use zoning on ecosystem services in the study area which are significant reference for the spatial optimization of land use zoning in preserving the key ecosystem services to mitigate the climate change. The research contributes to the growing literature in finely characterizing the ecosystem services zones altered by land use change to alleviate the impact of climate change, as there is no such systematic ecosystem zoning method before. Chenchen Shi, Jinyan Zhan, Yongwei Yuan, Feng Wu, and Zhihui Li Copyright © 2015 Chenchen Shi et al. All rights reserved.