Advances in Meteorology The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. The Evolution of Temporal and Spatial Patterns of Carbon Monoxide Concentrations in the Metropolitan Area of Sao Paulo, Brazil Wed, 21 Sep 2016 14:22:11 +0000 The Environmental Agency of Sao Paulo has a large dataset of carbon monoxide measurements: 20 years of records in 18 automatic stations inside the metropolitan area. However, a thorough investigation on the time evolution of CO concentration tendency and cycles also considering spatial variability is lacking. The investigation consists of a trend line analysis, a periodogram analysis, a correlation between CO concentration and meteorological variables, and spatial distribution of CO concentration. Local and federal policies helped in decreasing CO concentrations and the highest decreasing rate was 0.7% per month. This tendency is lately stabilizing, since the vehicles fleet is increasing. CO most relevant cycles are annual and diurnal and a few series indicate a weekly cycle. Diurnal cycle shows two peaks, morning and evening rush hours, 1.2 and 1.1 ppm, respectively, in 2012. However, lately there is an extended evening peak (20 h to 23 h), related to changes in emission patterns. The spatial analysis showed that CO concentration has high spatial variability and is influenced by proximity to heavy traffic and vegetated areas. The present work indicates that several processes affect CO concentration and these results form a valuable basis for other studies involving air quality modeling, mitigation, and urban planning. Flavia Noronha Dutra Ribeiro, Delhi Teresa Paiva Salinas, Jacyra Soares, Amauri Pereira de Oliveira, Regina Maura de Miranda, and Luana Antunes Tolentino Souza Copyright © 2016 Flavia Noronha Dutra Ribeiro et al. All rights reserved. Recent Changes and Variation in Precipitation over Asia-Pacific Region in relation to Long-Term Temperature and MSLP Tue, 20 Sep 2016 16:47:53 +0000 The years 2014 and 2015 turned out to be quite catastrophic for the Asia-Pacific region which took a major toll on the socioeconomic stature of all the entities of the region. The agricultural sector which is one of the most contributing factors to the economy of the region has been highly sensitive to the global climatic changes. Hence this endeavor shall greatly help in an efficient prediction of monsoon cycles, thus enabling the hapless farmers to be better informed and avoid major losses of any kind. The paper focuses on the climatology of air temperature and MSLP with the variation pattern in precipitation over the Asia-Pacific region. The NCEP-NCAR reanalysis data is used for air temperature and MSLP along with high-resolution precipitation dataset for Asia-Pacific monsoon region obtained from GPCP. The temperature datasets are analyzed up to the level 500 hPa. Monte Carlo method of correlation and Bootstrapping method of confidence interval are used to analyze the relation of GPCP with MSLP and temperature at all defined levels. So, in this paper authors attempt to assess the nature and relationship of temperature and MSLP to precipitation over the Asia-Pacific region with the recent 10-year changes which are quantified in detail. Gargi Akhoury, Kirti Avishek, and Moushumi Hazra Copyright © 2016 Gargi Akhoury et al. All rights reserved. Observation of Clouds Using the CSIR Transportable LIDAR: A Case Study over Durban, South Africa Tue, 20 Sep 2016 08:22:35 +0000 The Council for Scientific and Industrial Research (CSIR) transportable Light Detection And Ranging (LIDAR) was used to collect data over Durban (29.9°S, 30.9°E) during 20–23 November 2012. Aerosol measurements have been carried out in the past over Durban; however, no cloud measurements using LIDAR have ever been performed. Therefore, this study further motivates the continuation of LIDAR for atmospheric research over Durban. Low level clouds were observed on 20–22 November 2012 and high level clouds were observed on 23 November 2012. The low level cloud could be classified as stratocumulus clouds, whereas the high level clouds could be classified as cirrus clouds. Low level cloud layers showed high extinction coefficients values ranging between 0.0009 and 0.0044 m−1, whereas low extinction coefficients for high level clouds were observed at values ranging between 0.000001 and 0.000002 m−1. Optical depth showed a high variability for 20 and 21 November 2012. This indicates a change in the composition and/or thickness of the cloud. For 22 and 23 November 2012, almost similar values of optical depth were observed. Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observations (CALIPSO) revealed high level clouds while the CSIR LIDAR could not. However, the two instruments complement each other well to describe the cloudy condition. Lerato Shikwambana and Venkataraman Sivakumar Copyright © 2016 Lerato Shikwambana and Venkataraman Sivakumar. All rights reserved. Assessment of Seasonal and Annual Rainfall Trends and Variability in Sharjah City, UAE Mon, 19 Sep 2016 09:24:15 +0000 Although a few studies on rainfall spatial and temporal variability in the UAE have been carried out, evidence of the impact of climate change on rainfall trends has not been reported. This study aims at assessing the significance of long-term rainfall trends and temporal variability at Sharjah City, UAE. Annual rainfall and seasonal rainfall extending over a period of 81 years (1934–2014) recorded at Sharjah International Airport have been analyzed. To this end, several parametric and nonparametric statistical measures have been applied following systematic data quality assessment. The analyses revealed that the annual rainfall trend decreased from −3 mm to −9.4 mm per decade over the study periods. The decreasing annual rainfall trend is mainly driven by the significant drop in winter rainfall, particularly during the period from 1977 to 2014. The results also indicate that high probability extreme events have shifted toward low frequency (12.7 years) with significant variations in monthly rainfall patterns and periodicity. The findings of the present study suggest reevaluating the derivation of design rainfall for infrastructure of Sharjah City and urge developing an integrated framework for its water resources planning and risk under climate change impacts scenarios. Tarek Merabtene, Mohsin Siddique, and Abdallah Shanableh Copyright © 2016 Tarek Merabtene et al. All rights reserved. Hydrological Response of East China to the Variation of East Asian Summer Monsoon Thu, 15 Sep 2016 14:30:56 +0000 The sensitivity of hydrologic variables in East China, that is, runoff, precipitation, evapotranspiration, and soil moisture to the fluctuation of East Asian summer monsoon (EASM), is evaluated by the Mann-Kendall correlation analysis on a spatial resolution of 1/4° in the period of 1952–2012. The results indicate remarkable spatial disparities in the correlation between the hydrologic variables and EASM. The regions in East China susceptible to hydrological change due to EASM fluctuation are identified. When the standardized anomaly of intensity index of EASM (EASMI) is above 1.00, the runoff of Haihe basin has increased by 49% on average, especially in the suburb of Beijing and Hebei province where the runoff has increased up to 105%. In contrast, the runoff in the basins of Haihe and Yellow River has decreased by about 27% and 17%, respectively, when the standardized anomaly of EASMI is below −1.00, which has brought severe drought to the areas since mid-1970s. The study can be beneficial for national or watershed agencies developing adaptive water management strategies in the face of global climate change. Fuxing Li, Dong Chen, Qiuhong Tang, Wenhong Li, and Xuejun Zhang Copyright © 2016 Fuxing Li et al. All rights reserved. A Hybrid Model Based on Ensemble Empirical Mode Decomposition and Fruit Fly Optimization Algorithm for Wind Speed Forecasting Thu, 08 Sep 2016 17:38:33 +0000 As a type of clean and renewable energy, the superiority of wind power has increasingly captured the world’s attention. Reliable and precise wind speed prediction is vital for wind power generation systems. Thus, a more effective and precise prediction model is essentially needed in the field of wind speed forecasting. Most previous forecasting models could adapt to various wind speed series data; however, these models ignored the importance of the data preprocessing and model parameter optimization. In view of its importance, a novel hybrid ensemble learning paradigm is proposed. In this model, the original wind speed data is firstly divided into a finite set of signal components by ensemble empirical mode decomposition, and then each signal is predicted by several artificial intelligence models with optimized parameters by using the fruit fly optimization algorithm and the final prediction values were obtained by reconstructing the refined series. To estimate the forecasting ability of the proposed model, 15 min wind speed data for wind farms in the coastal areas of China was performed to forecast as a case study. The empirical results show that the proposed hybrid model is superior to some existing traditional forecasting models regarding forecast performance. Zongxi Qu, Kequan Zhang, Jianzhou Wang, Wenyu Zhang, and Wennan Leng Copyright © 2016 Zongxi Qu et al. All rights reserved. The Study of Frost Occurrence in Free State Province of South Africa Mon, 05 Sep 2016 16:24:10 +0000 The study investigated the cessation, onset, and duration of light, medium, and heavy frost in Free State province of South Africa using minimum temperatures from 1960 to 2015. Trends in the frost indices were assessed using the Man-Kendall test. Onset of frost varied spatially with earlier onset over the northern, eastern, and southeastern parts. Areas of early onset also experience late cessation of frost resulting in shorter growing period of less than 240 days. The western parts have longer growing period exceeding 240 days due to earlier cessation of frost and relatively late onset of frost. Trends for the frost-free period (growing period) show contrasting negative and positive trends with isolated significant trends. Mokhele Edmond Moeletsi, Mphethe Tongwane, and Mitsuru Tsubo Copyright © 2016 Mokhele Edmond Moeletsi et al. All rights reserved. Hydrometeorological Hazards: Monitoring, Forecasting, Risk Assessment, and Socioeconomic Responses Mon, 05 Sep 2016 12:59:27 +0000 Huan Wu, Maoyi Huang, Qiuhong Tang, Dalia B. Kirschbaum, and Philip Ward Copyright © 2016 Huan Wu et al. All rights reserved. Evaluation of the Impacts of Assimilating the TAMDAR Data on 12/4 km Grid WRF-Based RTFDDA Simulations over the CONUS Mon, 05 Sep 2016 07:47:46 +0000 An analysis of the impacts of assimilating the Tropospheric Airborne Meteorological Data Report (TAMDAR) data with the Weather Research and Forecasting- (WRF-) real-time four-dimensional data assimilation (RTFDDA) and forecasting system over the Contiguous US (CONUS) is presented. The impacts of the horizontal resolution increase from 12 km to 4 km on the WRF-RTFDDA simulations are also examined in conjunction with the TAMDAR data impacts. The assimilation of the TAMDAR data reduces the root mean squared error of the moisture field predictions and increases the correlation between the predictions and the observations for both domains with 12 km and 4 km grid spacings. The TAMDAR data reduce the model dry biases in the middle and lower levels by adding moisture at those levels. Assimilating the TAMDAR data improves temperature predictions at middle to high levels and wind speed predictions at all levels especially for the 12 km domain. Increasing the horizontal resolution from 12 km to 4 km results in significantly larger impacts on surface variables than assimilating the TAMDAR data. Yongxin Zhang, Yubao Liu, and Thomas Nipen Copyright © 2016 Yongxin Zhang et al. All rights reserved. Regional Frequency Analysis of Extreme Dry Spells during Rainy Season in the Wei River Basin, China Mon, 05 Sep 2016 07:46:06 +0000 Our research analyzes the regional changes of extreme dry spell, represented by the annual maximum dry spell length (noted as AMDSL) during the rainy season in the Wei River Basin (WRB) of China for 1960–2014 using the L-moments method. The mean AMDSL values increase from the west to the east of the WRB, suggesting a high dry risk in the east compared to the west in the WRB. To investigate the regional frequency more reasonably, the WRB is clustered into four homogenous subregions via the K-means method and some subjective adjustments. The goodness-of-fit test shows that the GEV, PE3, and GLO distribution can be accepted as the “best-fit” model for subregions 1 and 4, subregion 2, and subregion 3, respectively. The quantiles of AMDSL under various return levels figure out a similar spatial distribution with mean AMDSL. We also find that the dry risk in subregion 2 and subregion 4 might be higher than that in subregion 1. The relationship between ENSO events and extreme dry spell events in the rainy season with cross wavelet analysis method proves that ENSO events play a critical role in triggering extreme dry events during rainy season in the WRB. Dunxian She, Jun Xia, Yanjun Zhang, and Lijie Shan Copyright © 2016 Dunxian She et al. All rights reserved. The Classification of Synoptic-Scale Eddies at 850 hPa over the North Pacific in Wintertime Tue, 30 Aug 2016 06:43:49 +0000 Empirical orthogonal function (EOF) is applied to the study of the synoptic-scale eddies at 850 hPa over the North Pacific in winter from 1948 to 2010. The western developing pattern synoptic-scale eddies (WSE) and the eastern developing pattern synoptic-scale eddies (ESE) are extracted from the first four leading modes of EOF analysis of high-pass filtered geopotential height. The results show the following: (1) The WSE and the ESE both take the form of a wave train propagating eastward. The WSE reach their largest amplitude around the dateline in the North Pacific, while the largest amplitude of ESE occurs in the northeast Pacific. (2) The WSE and ESE are the most important modes of the synoptic-scale eddies at 850 hPa over the North Pacific, which correspond to the two max value centers of the storm track. (3) In addition to geopotential height, the WSE and the ESE also leave their wave-like footprints in the temperature, meridional wind, and vertical velocity fields, which assume typical baroclinic wave features. (4) The WSE and the ESE have an intrinsic time scale of four days and experience a “midwinter suppression” corresponding to the midwinter suppression of storm tracks. Linlin Xia, Yanke Tan, Chongyin Li, and Cheng Cheng Copyright © 2016 Linlin Xia et al. All rights reserved. Investigating Incursion of Transboundary Pollution into the Atmosphere of Dhaka, Bangladesh Sun, 28 Aug 2016 12:32:07 +0000 Concentrations of particulate matter (PM) in Dhaka, Bangladesh, during November 2013 to April 2014 were found 7-8 times higher than the World Health Organization (WHO) guideline value. Probability of contribution of transboundary sources to this PM pollution was investigated through different approaches. Ninety-six-hour backward trajectories with every 3-hour interval were computed and clustered into 06 groups based on angle distance matrix. Probabilities of individual cluster to be associated with different ranges of coarse and fine particles were studied. Gazipur station near Dhaka city was found to have 68% probability of receiving PM10 concentration higher than 150 μg/m3 when air masses followed the route of Middle East through the Himalayan valley to the station. This channel was identified as the main route of PM transport to Bangladesh during dry season. Transboundary source-regions were spotted by concentration weighted trajectory (CWT) method and also by the monthly average aerosol optical depths (AOD) over South Asia. North-western Indian regions, Nepal and its neighboring areas, and Indian state of West Bengal were identified as the most probable zones that might have contributed to PM pollution in Gazipur, Dhaka. November to January was the high time the station had experienced fine particles from those transboundary regions. Md. Masud Rana, Mastura Mahmud, Munjurul Hannan Khan, Bjarne Sivertsen, and Norela Sulaiman Copyright © 2016 Md. Masud Rana et al. All rights reserved. Climate Change Detection and Annual Extreme Temperature Analysis of the Amur River Basin Thu, 25 Aug 2016 08:56:14 +0000 This paper aims to detect climate change points and compare the extreme temperature changes with the average-value changes in the Amur River basin. The daily air temperatures of 44 stations in the Amur River basin were collected from April 1, 1954, to March 31, 2013. The change points for annual mean and extreme temperature in 44 individual stations and their average were detected by the Mann-Kendall test, respectively. The annual mean temperature changed during 1980s in terms of increased mean value and relative stable standard deviation. The annual maximum temperature from 31 stations mostly located in the central and northwest basin changed significantly, and their change points occurred mainly in 1990s. For the annual minimum temperature, 32 stations mainly located in the central basin had significant changes. The generalized extreme value distribution was fitted to the postchange point subseries of annual extreme temperature and the parameters were estimated by the maximum likelihood method. The 10/50/100-year return levels were estimated by the method of profile likelihood. For the areas in the central and Northwestern basin, the probability of occurrence of hot extremes increased, while the occurrence probability of cold extremes was decreased in the central basin under climate change. Bo Yan, Ziqiang Xia, Feng Huang, Lidan Guo, and Xiao Zhang Copyright © 2016 Bo Yan et al. All rights reserved. Long-Term Simulation of Daily Streamflow Using Radar Rainfall and the SWAT Model: A Case Study of the Gamcheon Basin of the Nakdong River, Korea Wed, 24 Aug 2016 14:20:53 +0000 In recent years, with the increasing need for improving the accuracy of hydrometeorological data, interests in rain-radar are also increasing. Accordingly, with high spatiotemporal resolution of rain-radar rainfall data and increasing accumulated data, the application scope of rain-radar rainfall data into hydrological fields is expanding. To evaluate the hydrological applicability of rain-radar rainfall data depending on the characteristics of hydrological model, this study applied and to a SWAT model in the Gamcheon stream basin of the Nakdong River and analyzed the effect of rainfall data on daily streamflow simulation. The daily rainfall data for , , and were utilized as input data for the SWAT model. As a result of the daily runoff simulation for analysis periods using and , the simulation which utilized reflected the rainfall-runoff characteristics better than the simulations which applied or . However, in the rainy or wet season, the simulations which utilized or were similar to or better than the simulation that applied . This study reveals that analysis results and degree of accuracy depend significantly on rainfall characteristics (rainy season and dry season) and QPE algorithms when conducting a runoff simulation with radar. Huiseong Noh, Jongso Lee, Narae Kang, Dongryul Lee, Hung Soo Kim, and Soojun Kim Copyright © 2016 Huiseong Noh et al. All rights reserved. Variation of Main Phenophases in Phenological Calendar in East China and Their Response to Climate Change Tue, 23 Aug 2016 17:09:47 +0000 Based on the phenological data from China Phenological Observation Network, we compiled the phenological calendars of 3 phenological observation stations (Shanghai, Nanjing, and Hefei) in East China for 1987–1996 and 2003–2012 according to the sequences of mean phenophases. We calculated the correlated coefficient and the root mean square error (RMSE) between phenophases and the beginning of meteorological seasons to determine the beginning date of phenological season. By comparing new phenological calendars with the old ones, we discussed the variation of phenophases and their responses to temperature. The conclusions are as follows. (1) The beginning dates of spring and summer advanced, while those of autumn and winter delayed. Thus, summers got longer and winters got shorter. (2) The beginning time of the four phenological seasons was advancing during 1987–1996, while it was delaying during 2003–2012. (3) Most spring and summer phenophases occur earlier and most autumn and winter phenophases occur later in 2003–2012 than in 1987–1996. (4) The beginning time of phenological seasons was significantly correlated with temperature. The phenological sensitivities to temperature ranged from −6.49 to −6.55 days/°C in spring, −3.65 to −5.02 days/°C in summer, 8.13 to 10.27 days/°C in autumn, and 4.76 to 10.00 days/°C in winter. Fengyi Zheng, Zexing Tao, Yachen Liu, Yunjia Xu, Junhu Dai, and Quansheng Ge Copyright © 2016 Fengyi Zheng et al. All rights reserved. Soil Moisture Assimilation Using a Modified Ensemble Transform Kalman Filter Based on Station Observations in the Hai River Basin Thu, 18 Aug 2016 11:59:32 +0000 Assimilating observations to a land surface model can further improve soil moisture estimation accuracy. However, assimilation results largely rely on forecast error and generally cannot maintain a water budget balance. In this study, shallow soil moisture observations are assimilated into Common Land Model (CoLM) to estimate the soil moisture in different layers. A proposed forecast error inflation and water balance constraint are adopted in the Ensemble Transform Kalman Filter to reduce the analysis error and water budget residuals. The assimilation results indicate that the analysis error is reduced and the water imbalance is mitigated with this approach. Guocan Wu, Bo Dan, and Xiaogu Zheng Copyright © 2016 Guocan Wu et al. All rights reserved. Numerical Simulation of Urban Waterlogging Based on FloodArea Model Tue, 16 Aug 2016 07:06:09 +0000 Assessment of urban water logging risk depth is mainly based on extreme value of rainstorm and its occurrence frequency as disaster causing factor. Regional waterlogging disaster risk assessment can be determined through regional geographic spatial information coupling calculation; the fundamental reason lies in the lack of an effective method for numerical simulation of waterlogging risk depth. Based on the hydrodynamic principle, FloodArea model realizes the numerical simulation of regional waterlogging depth by hydrologic calculating of runoff generation and runoff concentration of waterlogging. Taking risk assessment in Nanchang city as an example, spatial distribution of urban waterlogging depth was simulated by using FloodArea model in return period of 5 years, 10 years, 50 years, and 100 years. Research results show that FloodArea model can simulate urban waterlogging forming process and spatial distribution qualitatively. Fengchang Xue, Minmin Huang, Wei Wang, and Lin Zou Copyright © 2016 Fengchang Xue et al. All rights reserved. Numerical Forecasting Experiment of the Wave Energy Resource in the China Sea Mon, 15 Aug 2016 08:21:59 +0000 The short-term forecasting of wave energy is important to provide guidance for the electric power operation and power transmission system and to enhance the efficiency of energy capture and conversion. This study produced a numerical forecasting experiment of the China Sea wave energy using WAVEWATCH-III (WW3, the latest version 4.18) wave model driven by T213 (WW3-T213) and T639 (WW3-T639) wind data separately. Then the WW3-T213 and WW3-T639 were verified and compared to build a short-term wave energy forecasting structure suited for the China Sea. Considering the value of wave power density (WPD), “wave energy rose,” daily and weekly total storage and effective storage of wave energy, this study also designed a series of short-term wave energy forecasting productions. Results show that both the WW3-T213 and WW3-T639 exhibit a good skill on the numerical forecasting of the China Sea WPD, while the result of WW3-T639 is much better. Judging from WPD and daily and weekly total storage and effective storage of wave energy, great wave energy caused by cold airs was found. As there are relatively frequent cold airs in winter, early spring, and later autumn in the China Sea and the surrounding waters, abundant wave energy ensues. Chong Wei Zheng, Chong Yin Li, Xuan Chen, and Jing Pan Copyright © 2016 Chong Wei Zheng et al. All rights reserved. Future Changes in Drought Characteristics under Extreme Climate Change over South Korea Thu, 11 Aug 2016 16:17:20 +0000 This study attempts to analyze several drought features in South Korea from various perspectives using a three-month standard precipitation index. In particular, this study aims to evaluate changes in spatial distribution in terms of frequency and severity of droughts in the future due to climate change, using IPCC (intergovernmental panel on climate change) GCM (general circulation model) simulations. First, the Mann-Kendall method was adopted to identify drought trends at the five major watersheds. The simulated temporal evolution of SPI (standardized precipitation index) during the winter showed significant drying trends in most parts of the watersheds, while the simulated SPI during the spring showed a somewhat different feature in the GCMs. Second, this study explored the low-frequency patterns associated with drought by comparing global wavelet power, with significance test. Future spectra decreased in the fractional variance attributed to a reduction in the interannual band from 2 to 8 years. Finally, the changes in the frequency and the severity under climate change were evaluated through the drought spell analyses. Overall features of drought conditions in the future showed a tendency to increase (about 6%) in frequency and severity of droughts during the dry season (i.e., from October to May) under climate change. Joo-Heon Lee, Hyun-Han Kwon, Ho-Won Jang, and Tae-Woong Kim Copyright © 2016 Joo-Heon Lee et al. All rights reserved. Evaluation and Correction of Quantitative Precipitation Forecast by Storm-Scale NWP Model in Jiangsu, China Thu, 11 Aug 2016 14:24:56 +0000 With the development of high-performance computer systems and data assimilation techniques, storm-scale numerical weather prediction (NWP) models are gradually used for short-term deterministic forecasts. The primary objective of this study is to evaluate and correct precipitation forecasts of a storm-scale NWP model called the advanced regional prediction system (ARPS). The evaluation and correction consider five heavy precipitation events that occurred in the summer of 2015 in Jiangsu, China. The performances of the original and corrected ARPS precipitation forecasts are evaluated as a function of lead time using standard measurements and a spatial verification method called Structure-Amplitude-Location (SAL). In general, the ARPS could not produce optimal forecasts for very short lead times, and the forecast accuracy improves with increasing lead time. The ARPS overestimates precipitation for all lead times, which is confirmed by large bias in many forecasts in the first and second quadrant of the diagram of SAL, especially at the 1 h lead time. The amplitude correction is performed by matching percentile values of the ARPS precipitation forecasts and observations for each lead time. Amplitude correction significantly improved the ARPS precipitation forecasts in terms of the considered performance indices of standard measures and A-component and S-component of SAL. Gaili Wang, Dan Wang, Ji Yang, and Liping Liu Copyright © 2016 Gaili Wang et al. All rights reserved. On the Linkage between the Extreme Drought and Pluvial Patterns in China and the Large-Scale Atmospheric Circulation Tue, 09 Aug 2016 13:21:14 +0000 China is a nation that is affected by a multitude of natural disasters, including droughts and floods. In this paper, the variations of extreme drought and pluvial patterns and their relations to the large-scale atmospheric circulation have been analyzed based on monthly precipitation data from 483 stations during the period 1958–2010 in China. The results show the following: the extreme drought and pluvial events in China increase significantly during that period. During 1959–1966 timeframe, more droughts occur in South China and more pluvial events are found in North China (DSC-PNC pattern); as for the period 1997–2003 (PSC-DNC pattern), the situation is the opposite. There are good relationships among the extreme drought and pluvial events and the Western Pacific Subtropical High, meridional atmospheric moisture flux, atmospheric moisture content, and summer precipitation. A cyclone atmospheric circulation anomaly occurs in North China, followed by an obvious negative height anomaly and a southern wind anomaly at 850 hPa and 500 hPa for the DSC-PNC pattern during the summer, and a massive ascending airflow from South China extends to North China at ~50∘N. As for the PSC-DNC pattern, the situation contrasts sharply with the DSC-PNC pattern. Zengxin Zhang, Qiu Jin, Xi Chen, Chong-Yu Xu, and Shanshan Jiang Copyright © 2016 Zengxin Zhang et al. All rights reserved. West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic Sun, 31 Jul 2016 13:41:22 +0000 Based on daily precipitation from the Global Precipitation Climatology Project (GPCP) data during April–October of the 1997–2014 period, the daily extreme rainfall trends and variability over West Africa are characterized using 90th-percentile threshold at each grid point. The contribution of the extreme rainfall amount reaches ~50–90% in the northern region while it is ~30–50% in the south. The yearly cumulated extreme rainfall amount indicates significant and negative trends in the 6°N–12°N; 6°N–12°N; 17°W–10°W and 4°N–7°N; 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E domains, while the number of days exhibits nonsignificant trends over West Africa. The empirical orthogonal functions performed on the standardized anomalies show four variability modes that include all West Africa with a focus on the Sahelian region, the eastern region including the south of Nigeria, the western part including Guinea, Sierra Leone, Liberia, and Guinea-Bissau, and finally a small region at the coast of Ghana and Togo. These four modes are influenced differently by the large-scale ocean surface and atmospheric conditions in the tropical Atlantic. The results are applicable in planning the risks associated with these climate hazards, particularly on water resource management and civil defense. S. Ta, K. Y. Kouadio, K. E. Ali, E. Toualy, A. Aman, and F. Yoroba Copyright © 2016 S. Ta et al. All rights reserved. Retrieval of Land Surface Model State Variables through Assimilating Screen Level Humidity and Temperature Measurements Sun, 31 Jul 2016 11:27:40 +0000 This study demonstrates successful variational retrieval of land surface states by assimilating screen level atmospheric measurements of specific humidity and air temperature. To this end, the land surface scheme is first validated against the Oklahoma Atmospheric Surface Layer Instrumentation System measurements with necessary refinements to the forward model implemented. The retrieval scheme involves a 1D land surface-atmosphere model, the corresponding adjoint codes, and a cost function that measures residuals between observed and modeled screen level atmospheric temperature and specific humidity. The retrieval scheme is robust when subjected to observational errors with magnitudes comparable to instrument accuracy and for initial guess errors larger than typical model forecast errors. Using varying assimilation window lengths centered on different periods of a day, the sampling strategy is assessed. The daytime observations are more informative compared to nocturnal observations. An assimilation window as narrow as four hours, if centered on local noon, contains comparable information to an expanded window covering the whole day. There exists an optimal assimilation window length resulting from the contest between degrading forecast accuracy and increasing information content. For an assimilation window less than two days, the “optimal” assimilation window length is inversely proportional to the data ingesting frequency. Diandong Ren and Ming Xue Copyright © 2016 Diandong Ren and Ming Xue. All rights reserved. Development and Application of Urban Landslide Vulnerability Assessment Methodology Reflecting Social and Economic Variables Sun, 31 Jul 2016 09:19:40 +0000 An urban landslide vulnerability assessment methodology is proposed with major focus on considering urban social and economic aspects. The proposed methodology was developed based on the landslide susceptibility maps that Korean Forest Service utilizes to identify landslide source areas. Frist, debris flows are propagated to urban areas from such source areas by Flow-R (flow path assessment of gravitational hazards at a regional scale), and then urban vulnerability is assessed by two categories: physical and socioeconomic aspect. The physical vulnerability is related to buildings that can be impacted by a landslide event. This study considered two popular building structure types, reinforced-concrete frame and nonreinforced-concrete frame, to assess the physical vulnerability. The socioeconomic vulnerability is considered a function of the resistant levels of the vulnerable people, trigger factor of secondary damage, and preparedness level of the local government. An index-based model is developed to evaluate the life and indirect damage under landslide as well as the resilience ability against disasters. To illustrate the validity of the proposed methodology, physical and socioeconomic vulnerability levels are analyzed for Seoul, Korea, using the suggested approach. The general trend found in this study indicates that the higher population density areas under a weaker fiscal condition that are located at the downstream of mountainous areas are more vulnerable than the areas in opposite conditions. Yoonkyung Park, Ananta Man Singh Pradhan, Ungtae Kim, Yun-Tae Kim, and Sangdan Kim Copyright © 2016 Yoonkyung Park et al. All rights reserved. Advances in Boundary-Layer/Air Pollution Meteorology Tue, 26 Jul 2016 07:45:40 +0000 Xiao-Ming Hu, Jianping Huang, Jose D. Fuentes, Renate Forkel, and Ning Zhang Copyright © 2016 Xiao-Ming Hu et al. All rights reserved. Improving the Predictability of Severe Convective Weather Processes by Using Wind Vectors and Potential Temperature Changes: A Case Study of a Severe Thunderstorm Tue, 19 Jul 2016 06:22:20 +0000 Strong, local convective weather events are capable of causing extensive damage, but weather observation systems with limited resolution and radar monitoring can typically provide only a few minutes to hours of prior warning time. This paper presents a comprehensive case study of the cumulative evolution of several characteristic quantities during one extremely severe convective weather process. The research results indicate that the main feature of strong convective weather is the uneven distribution of thermal energy in the atmosphere, and the structure of this heat distribution determines the level of instability in the atmosphere. A vertical “clockwise rolling current” occurs in the wind field structure at the beginning of the process, and this is accompanied by a rapid drop in temperature at the top of the troposphere. When these signs occurred in the case study, radar technology was used to refine the precipitation region and spatial characteristics of the approaching storm. The height and vertical evolution of radar echoes were indicative of the characteristics of the system’s movement through space. Such findings may be useful for improving the forecasting times for strong convective weather. Hao Wang, Gangyi Chen, Huanhuan Lei, Yongqian Wang, and Shunxian Tang Copyright © 2016 Hao Wang et al. All rights reserved. Evaluation of Air Quality Model Performance for Simulating Long-Range Transport and Local Pollution of PM2.5 in Japan Thu, 14 Jul 2016 06:21:57 +0000 The Community Multiscale Air Quality Model (CMAQ) v5.0.2 was applied to PM2.5 simulation in Japan, which is strongly affected by long-range transport (LRT) from anthropogenic sources in the Asian Continent, for one year from April 2010 to March 2011. The model performance for LRT and local pollution (LP) of PM2.5 was evaluated to identify the model processes that need to be improved. CMAQ well simulated temporal and spatial variation patterns of PM2.5 but underestimated the concentration level by 15% on average. The contribution of LRT was estimated from the difference between the baseline simulation case and a zero-emission case for anthropogenic emissions in the continent. The estimated LRT contribution to PM2.5 was 50% on average and generally higher in the western areas of Japan (closer to the continent). Days that were dominantly affected by LRT or LP were determined based on the contribution of LRT to sulfate, which was fairly well simulated and strongly affected by LRT among major PM2.5 components. The underestimation of PM2.5 was larger in LP days (by 26% on average) than LRT days (by 10% on average). Therefore, it is essential to improve local emissions, formation, and loss processes of precursors and PM2.5 in Japan. Hikari Shimadera, Tatsuya Kojima, and Akira Kondo Copyright © 2016 Hikari Shimadera et al. All rights reserved. Evaluation of Relations between Extreme Precipitation and Temperature in Observational Time Series from the Czech Republic Mon, 11 Jul 2016 14:12:10 +0000 The intensity of precipitation extremes is expected to increase as the climate warms and it may cause floods and increase erosion. From the Clausius-Clapeyron relation (CC) it follows that the maximum moisture content of the atmosphere increases by approximately 7% per degree as temperature rises. However, the increases in observed hourly precipitation extremes of approximately two times the CC relation were described recently. This super CC scaling is attributed to the increased prevalence of convective rainfall and decreased prevalence of stratiform rainfall as temperatures increase. We carried out the disaggregation of precipitation into prevailing stratiform and convective component on the observational data from the Czech Republic for 1966–2006. Then, we analyzed trends in characteristics of disaggregated events and assessed correlation of precipitation intensities with daily mean temperature. The results suggest the increasing trend of convective precipitation in summer. The scaling for total rain events is steeper than for the events with prevailing convective component and for the events with prevailing stratiform component. It is a result of mixing of the two storm types. At higher temperature the events with prevailing convective component prevail and vice versa. Marta Martinkova and Martin Hanel Copyright © 2016 Marta Martinkova and Martin Hanel. All rights reserved. A Three-Parameter S-Shaped Function of Flood Return Period and Damage Sun, 10 Jul 2016 12:42:06 +0000 With growing flood risk due to increased urbanization, flood damage assessment and flood risk management must be reconsidered. To demonstrate and assess the new features and trends of flood risk in urbanized areas, a novel S-shaped function of return period and damage is proposed. The function contains three parameters, which are defined as the maximum flood damage , critical return period , and integrated loss coefficient . A basic framework for flood damage assessment was established to evaluate flood damage in the Taihu Basin under various scenarios. The simulation results were used to construct the flood functions. The study results show that the flood model based on the Gompertz function agrees well with the mutability of flood damage in the highly urbanized basin when the flood scale exceeds the defense capability. The function can be utilized for timely and effective flood damage assessment and prediction. It can describe the impacts of socioeconomic development, urbanization degree, and flood control capability improvements well. The turning points of the function curve can be used as gradation criteria for rational strategy development associated with flood hazards. Chaochao Li, Xiaotao Cheng, Na Li, Zhongmin Liang, Yanyan Wang, and Song Han Copyright © 2016 Chaochao Li et al. All rights reserved. Hydrological Hazards in a Changing Environment: Early Warning, Forecasting, and Impact Assessment Sun, 10 Jul 2016 08:36:10 +0000 Slavisa Trajkovic, Ozgur Kisi, Momcilo Markus, Hossein Tabari, Milan Gocic, and Shahaboddin Shamshirband Copyright © 2016 Slavisa Trajkovic et al. All rights reserved.