Advances in Meteorology http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Long-Term Precipitation Analysis and Estimation of Precipitation Concentration Index Using Three Support Vector Machine Methods Sat, 30 Apr 2016 11:30:47 +0000 http://www.hindawi.com/journals/amete/2016/7912357/ The monthly precipitation data from 29 stations in Serbia during the period of 1946–2012 were considered. Precipitation trends were calculated using linear regression method. Three CLINO periods (1961–1990, 1971–2000, and 1981–2010) in three subregions were analysed. The CLINO 1981–2010 period had a significant increasing trend. Spatial pattern of the precipitation concentration index (PCI) was presented. For the purpose of PCI prediction, three Support Vector Machine (SVM) models, namely, SVM coupled with the discrete wavelet transform (SVM-Wavelet), the firefly algorithm (SVM-FFA), and using the radial basis function (SVM-RBF), were developed and used. The estimation and prediction results of these models were compared with each other using three statistical indicators, that is, root mean square error, coefficient of determination, and coefficient of efficiency. The experimental results showed that an improvement in predictive accuracy and capability of generalization can be achieved by the SVM-Wavelet approach. Moreover, the results indicated the proposed SVM-Wavelet model can adequately predict the PCI. Milan Gocic, Shahaboddin Shamshirband, Zaidi Razak, Dalibor Petković, Sudheer Ch, and Slavisa Trajkovic Copyright © 2016 Milan Gocic et al. All rights reserved. Implementation of the WSM5 and WSM6 Single Moment Microphysics Scheme into the RAMS Model: Verification for the HyMeX-SOP1 Wed, 27 Apr 2016 12:34:47 +0000 http://www.hindawi.com/journals/amete/2016/5094126/ This paper shows the results of the implementation of two widely used bulk microphysics parameterizations (BMP) into the Regional Atmospheric Modeling System to improve the Quantitative Precipitation Forecast (QPF). The schemes are the WSM5 and WSM6 (WRF-single-moment-microphysics classes 5 and 6). The RAMS is run at high horizontal resolution (4 km) over the whole Italian territory and, to mimic the operational context, it is initialized by the analysis/forecast cycle issued at 12 UTC by the European Centre for Medium Weather Range Forecast (ECMWF). The performance of the BMP is analysed for the period of September 11 to October 31, 2012, which span most of the Special Observing Period 1 (SOP1) of the hydrological cycle in the Mediterranean experiment (HyMeX). For this period a database of daily precipitation of thousands of rain gauges over the Italian territory is available. In SOP1 few hazardous events occurred over Italy and, for one of them, the model performance is shown in detail. The potential improvement gained by combining the model outputs with different BMP in a single forecast is finally explored. Stefano Federico Copyright © 2016 Stefano Federico. All rights reserved. Evapotranspiration Partitioning and Response to Abnormally Low Water Levels in a Floodplain Wetland in China Tue, 19 Apr 2016 14:39:22 +0000 http://www.hindawi.com/journals/amete/2016/3695427/ Evapotranspiration (ET) is an important component of the wetland water budget. Water level declines in Poyang Lake, the largest freshwater lake in China, have caused concerns, especially during low water levels. However, how wetland ET and its partitioning respond to abnormally low water levels is unclear. In this study, wetland ET was estimated with MODIS data and meteorological data. The wetland ET partitioning and its relationship with abnormally low water levels were analyzed for 2000–2013. The results showed that the water evaporation rate () was larger than the land ET rate (); the / ranged from 0.77 to 0.99. When the water level was below 12.8 m, the ET partition ratio was larger than 1, which indicates that wetland ET comes from land surface ET more than water evaporation. The negative standardized water level index (SWI) was used to represent an abnormally low water level in the wetland. Although the monthly wetland ET decreased as the negative SWI decreased, was higher than the average under negative SWI conditions from September to December, when the water level decreased. The abnormally low water level induced more water loss from the land surface, especially when the water level decreased, which reduced the available water resources along the wetland shore. Xiaosong Zhao and Yuanbo Liu Copyright © 2016 Xiaosong Zhao and Yuanbo Liu. All rights reserved. The Relationship between the Heat Disorder Incidence Rate and Heat Stress Indices at Yamanashi Prefecture in Japan Mon, 18 Apr 2016 10:00:48 +0000 http://www.hindawi.com/journals/amete/2016/9492815/ In recent years, the risk of heat disorder in daily life has increased dramatically because the thermal environment has been deteriorating. The main objective of this study was to examine regional differences in the relationship between heat disorder incidence rate and heat stress indices at Yamanashi Prefecture, Japan. Daily maximum air temperature and daily maximum WBGT were used as heat stress indices in each region. Nonlinear regression analysis was used to examine the regional difference in the relationship between the heat disorder incidence rate and heat stress indices in each region. The heat disorder incidence rate was correlated with both indices of heat stress in all regions. However, the more appropriate heat stress index for heat disorder prevention differed among regions. The distributions of heat stress indices, such as the slope of regression curve and the temperature threshold, differed in each region, irrespective of the index used. Therefore, the criteria for thermal conditions for heat disorder prevention need to be determined for each region, considering the regional characteristics of the relationship between the heat disorder incidence rate and heat stress indices. Shin Akatsuka, Tadashi Uno, and Masahiro Horiuchi Copyright © 2016 Shin Akatsuka et al. All rights reserved. Prediction of Frost Occurrences Using Statistical Modeling Approaches Sun, 17 Apr 2016 10:55:04 +0000 http://www.hindawi.com/journals/amete/2016/2075186/ We developed the frost prediction models in spring in Korea using logistic regression and decision tree techniques. Hit Rate (HR), Probability of Detection (POD), and False Alarm Rate (FAR) from both models were calculated and compared. Threshold values for the logistic regression models were selected to maximize HR and POD and minimize FAR for each station, and the split for the decision tree models was stopped when change in entropy was relatively small. Average HR values were 0.92 and 0.91 for logistic regression and decision tree techniques, respectively, average POD values were 0.78 and 0.80 for logistic regression and decision tree techniques, respectively, and average FAR values were 0.22 and 0.28 for logistic regression and decision tree techniques, respectively. The average numbers of selected explanatory variables were 5.7 and 2.3 for logistic regression and decision tree techniques, respectively. Fewer explanatory variables can be more appropriate for operational activities to provide a timely warning for the prevention of the frost damages to agricultural crops. We concluded that the decision tree model can be more useful for the timely warning system. It is recommended that the models should be improved to reflect local topological features. Hyojin Lee, Jong A. Chun, Hyun-Hee Han, and Sung Kim Copyright © 2016 Hyojin Lee et al. All rights reserved. A Modeling Study of Impact of Emission Control Strategies on PM2.5 Reductions in Zhongshan, China, Using WRF-CMAQ Thu, 14 Apr 2016 15:31:18 +0000 http://www.hindawi.com/journals/amete/2016/5836070/ A WRF-CMAQ modeling system is used to assess the impact of emission control strategies and weather conditions on haze pollution in Zhongshan, Guangdong Province, China. One-month simulations for January 2014 are completed and evaluated with the observational data. The simulations show reasonable agreement with the observations. Several sensitivity studies are completed to quantify the percentage contributions of local emissions versus regional emissions to the PM2.5 concentrations under different weather conditions. The results indicate that the contributions from local emission is higher than those of the emissions from regional transport when there is no intrusion of cold front (i.e., 58% contribution from local emission versus 42% contribution from the regional transport). The contribution of regional transport is increased to 76% when a strong cold front appears. Furthermore, the sensitivity study demonstrates that PM2.5 concentrations on the first, second, and third days are reduced by 47%, 52%, and 58%, respectively, after the local emissions are turned off when there is no intrusion of cold front. Finally, a case study shows that industrial, residential, and mobile emissions account for 24%, 22%, and 15% of the change of PM2.5, respectively, during a heavy haze pollution event in Zhongshan. Jianhua Mai, Tao Deng, Lingling Yu, Xuejiao Deng, Haobo Tan, Shiqiang Wang, and Xiantong Liu Copyright © 2016 Jianhua Mai et al. All rights reserved. Compositional Variation of PCBs, PAHs, and OCPs at Gas Phase and Size Segregated Particle Phase during Dust Incursion from the Saharan Desert in the Northwestern Anatolian Peninsula Mon, 11 Apr 2016 12:59:54 +0000 http://www.hindawi.com/journals/amete/2016/7153286/ A dust incursion occurred in Istanbul on 1 February 2015 from the Saharan Desert. During this episode, 938 μg·m−3 of TSP concentration was observed. TSP concentration was 64 μg·m−3 and 78 μg·m−3 on the following two days. Particles of 3 μm were dominant during the episode; however, particles < 0.49 μm were dominant after the episode. The averages of total (gas + particle) PCB, PAH, and OCP concentrations were 279 pg·m−3, 175 ng·m−3, and 589 pg·m−3, respectively. Tri-CBs were dominant in most of the samples. Flt and Phe had the highest contribution to PAH species. β-HCH and heptachlor had the highest share in terms of OCPs. Particle phase PCBs exhibited monomodal size distribution, whereas OCPs had bimodal size distribution. PAHs exhibited either monomodal or bimodal size distribution on different days. The mass median diameter of PAHs did not change significantly during different atmospheric conditions due to their local sources. Gas/particle partitioning of each pollutant was evaluated by plotting their subcooled vapor pressure against the partitioning coefficient. From 1 to 3 February, the slope of the regression line shifted close to −1, indicating that the least favorable conditions were present during dust incursion for an equilibrium state. S. Levent Kuzu Copyright © 2016 S. Levent Kuzu. All rights reserved. Characteristics of Atmospheric Compositions in the Background Area of Yangtze River Delta during Heavy Air Pollution Episode Mon, 11 Apr 2016 09:46:16 +0000 http://www.hindawi.com/journals/amete/2016/7240486/ In order to understand the formation and evolution of recurrent severe haze pollution episodes in Yangtze River Delta, China, a short comparative sampling campaign was conducted at the Lin’an background monitoring station from 25 November 2013 to 14 December 2013. The characteristic concentrations of PM2.5, black carbon, CO2, CO, and CH4 have been systematically recorded at the abovementioned site. Coupled with detailed analysis of air backward trajectories, fire spot distribution surrounding the studied site and meteorological impacts, temporal trend, diurnal variation, and intercorrelation of the aforementioned species have also been comprehensively investigated throughout prehaze, haze, and posthaze periods. Hong-Hui Xu, Jing-Jiao Pu, Jun He, Jie Liu, Bing Qi, and Rong-Guang Du Copyright © 2016 Hong-Hui Xu et al. All rights reserved. National Environmental Meteorological Services in China Wed, 06 Apr 2016 14:17:15 +0000 http://www.hindawi.com/journals/amete/2016/1985207/ The environmental meteorological services in China are concerned with atmospheric environmental quality, which is directly related to human activities and affects human health. In recent years, air pollution and other environmental problems have attracted nationwide attention in China, so the environmental meteorological services have been developed rapidly. To provide better meteorological monitoring and forecasting services, the Environmental Meteorological Centre of China Meteorological Administration was established in March 2014 by integrating the resources of various national service units. We review the development of China’s national environmental meteorological services and highlight their current status including major technological capabilities. We also explore future trends of the national environmental meteorological services by analysing deficiencies, gaps in supply and demand, and capabilities of the current environmental meteorological services. Zhiming Kang, Hailin Gui, Cong Hua, Bihui Zhang, Hengde Zhang, Mengyao Lv, and Jikang Wang Copyright © 2016 Zhiming Kang et al. All rights reserved. Accelerating the SCE-UA Global Optimization Method Based on Multi-Core CPU and Many-Core GPU Wed, 06 Apr 2016 06:57:16 +0000 http://www.hindawi.com/journals/amete/2016/8483728/ The famous global optimization SCE-UA method, which has been widely used in the field of environmental model parameter calibration, is an effective and robust method. However, the SCE-UA method has a high computational load which prohibits the application of SCE-UA to high dimensional and complex problems. In recent years, the hardware of computer, such as multi-core CPUs and many-core GPUs, improves significantly. These much more powerful new hardware and their software ecosystems provide an opportunity to accelerate the SCE-UA method. In this paper, we proposed two parallel SCE-UA methods and implemented them on Intel multi-core CPU and NVIDIA many-core GPU by OpenMP and CUDA Fortran, respectively. The Griewank benchmark function was adopted in this paper to test and compare the performances of the serial and parallel SCE-UA methods. According to the results of the comparison, some useful advises were given to direct how to properly use the parallel SCE-UA methods. Guangyuan Kan, Ke Liang, Jiren Li, Liuqian Ding, Xiaoyan He, Youbing Hu, and Mark Amo-Boateng Copyright © 2016 Guangyuan Kan et al. All rights reserved. Are GRACE-era Terrestrial Water Trends Driven by Anthropogenic Climate Change? Sun, 03 Apr 2016 11:29:50 +0000 http://www.hindawi.com/journals/amete/2016/4830603/ To provide context for observed trends in terrestrial water storage (TWS) during GRACE (2003–2014), trends and variability in the CESM1-CAM5 Large Ensemble (LE) are examined. Motivated in part by the anomalous nature of climate variability during GRACE, the characteristics of both forced change and internal modes are quantified and their influences on observations are estimated. Trends during the GRACE era in the LE are dominated by internal variability rather than by the forced response, with TWS anomalies in much of the Americas, eastern Australia, Africa, and southwestern Eurasia largely attributable to the negative phases of the Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO). While similarities between observed trends and the model-inferred forced response also exist, it is inappropriate to attribute such trends mainly to anthropogenic forcing. For several key river basins, trends in the mean state and interannual variability and the time at which the forced response exceeds background variability are also estimated while aspects of global mean TWS, including changes in its annual amplitude and decadal trends, are quantified. The findings highlight the challenge of detecting anthropogenic climate change in temporally finite satellite datasets and underscore the benefit of utilizing models in the interpretation of the observed record. J. T. Fasullo, D. M. Lawrence, and S. C. Swenson Copyright © 2016 J. T. Fasullo et al. All rights reserved. A Study on the Determination of Korea Affecting Tropical Cyclone Center for Best Tracking Tue, 29 Mar 2016 14:21:50 +0000 http://www.hindawi.com/journals/amete/2016/5946342/ The establishment of an independent tropical cyclone (TC) position is suggested for the purpose of constructing TC best track data of the Korea Meteorological Administration. The best track process was designed with five basic stages: database, potential interval (PI), optimization, smoothing, and metadata. The PI was newly devised as a tool for expressing the uncertainty in the location of the center of the TC. This PI determined the minimum range at which the center of the TC can be adjusted and based on the analysis manual for each dataset used in the TC best tracking. Furthermore, the PI can be optimized by the differential application of the range depending on the reliability of the data. By smoothing all TC centers within the optimized PI, a best track can be produced more stably. Therefore, the analysis can be less subjective even when the determination of the TC center is difficult. For three typhoon cases that had affected Korea in 2013 (LEEPI, KONG-REY, and DANAS), best tracks were obtained based on the suggested analysis stages and verified. The results showed that the PI was relatively large in the early development and weakening stage of the TC or when the estimation of the TC center was difficult because of interactions with the land. And the best tracking was performed well with reasonable applicability. Yumi Cha, Jinyeon Kim, Kiryong Kang, Nam-Young Kang, and Won-Tae Yun Copyright © 2016 Yumi Cha et al. All rights reserved. Spatial Estimation of Losses Attributable to Meteorological Disasters in a Specific Area (105.0°E–115.0°E, 25°N–35°N) Using Bayesian Maximum Entropy and Partial Least Squares Regression Thu, 24 Mar 2016 11:36:09 +0000 http://www.hindawi.com/journals/amete/2016/1547526/ The spatial mapping of losses attributable to such disasters is now well established as a means of describing the spatial patterns of disaster risk, and it has been shown to be suitable for many types of major meteorological disasters. However, few studies have been carried out by developing a regression model to estimate the effects of the spatial distribution of meteorological factors on losses associated with meteorological disasters. In this study, the proposed approach is capable of the following: (a) estimating the spatial distributions of seven meteorological factors using Bayesian maximum entropy, (b) identifying the four mapping methods used in this research with the best performance based on the cross validation, and (c) establishing a fitted model between the PLS components and disaster losses information using partial least squares regression within a specific research area. The results showed the following: (a) best mapping results were produced by multivariate Bayesian maximum entropy with probabilistic soft data; (b) the regression model using three PLS components, extracted from seven meteorological factors by PLS method, was the most predictive by means of PRESS/SS test; (c) northern Hunan Province sustains the most damage, and southeastern Gansu Province and western Guizhou Province sustained the least. F. S. Zhang, S. B. Zhong, Z. T. Yang, C. Sun, C. L. Wang, and Q. Y. Huang Copyright © 2016 F. S. Zhang et al. All rights reserved. Propagation of Drought: From Meteorological Drought to Agricultural and Hydrological Drought Wed, 23 Mar 2016 13:00:09 +0000 http://www.hindawi.com/journals/amete/2016/6547209/ Wen Wang, Maurits W. Ertsen, Mark D. Svoboda, and Mohsin Hafeez Copyright © 2016 Wen Wang et al. All rights reserved. Searching for an Added Value of Precipitation in Downscaled Seasonal Hindcasts over East Africa: COSMO-CLM Forced by MPI-ESM Wed, 16 Mar 2016 14:33:15 +0000 http://www.hindawi.com/journals/amete/2016/4348285/ Downscaling of seasonal hindcasts over East Africa with the regional climate model (RCM) COSMO-CLM (CCLM), forced by the global climate model (GCM) and MPI-ESM, is evaluated. The simulations are done for five months (May to September) for a ten-year period (2000–2009), with the evaluation performed only for June to September. The dry years, 2002 and 2009, and the wet years, 2006 and 2007, are well captured by the models. By using ground based and satellite gridded observation data for evaluation it is found that both COSMO-CLM and MPI-ESM overestimate June to September precipitation over the Ethiopian highlands and in parts of the lowland with respect to all reference datasets. In addition we investigated the potential and real added value for both the RCM and the GCM hindcasts by upscaling (arithmetic mean) the precipitation resolution both in temporal and in spatial scales, over North Ethiopia (EN), South Ethiopia (ES), South Sudan (SS), and Sudan (S). Results inferred that using the RCM for seasonal forecast adds value in capturing extreme precipitation years, especially in the Ethiopian highlands. It is also found that the potential and relative potential added value decrease with decreasing the temporal resolution. Bedassa R. Cheneka, Susanne Brienen, Kristina Fröhlich, Shakeel Asharaf, and Barbara Früh Copyright © 2016 Bedassa R. Cheneka et al. All rights reserved. Assessing the Effects of Spatial Resolution on Regional Climate Model Simulated Summer Temperature and Precipitation in China: A Case Study Wed, 16 Mar 2016 12:56:39 +0000 http://www.hindawi.com/journals/amete/2016/7639567/ The regional climate model, RegCM3, is used to simulate the 2004 summer surface air temperature (SAT) and precipitation at different horizontal (i.e., 30, 60, and 90 km) and vertical resolutions (i.e., 14, 18, and 23 layers). Results showed that increasing resolution evidently changes simulated SATs with regional characteristics. For example, simulated SATs are apparently better produced when horizontal resolution increases from 60 to 30 km under the 23 layers. Meanwhile, the SATs over the entire area are more sensitive to vertical resolution than horizontal resolution. The subareas present higher sensitivities than the total area, with larger horizontal resolution effects than those of vertical resolution. For precipitation, increasing resolution shows higher impact compared to SAT, with higher sensitivity induced by vertical resolution than by horizontal resolution, especially in rainy South China. The best SAT/precipitation can be produced only when the horizontal and vertical resolutions are reasonably configured. This indicates that different resolutions lead to different atmospheric thermodynamic states. Because of the dry climate and low soil heat capacity in Northern China, resolution changes easily modify surface energy fluxes, hence the SAT; due to the rainy and humid climate in South China, resolution changes likely strongly influence grid-scale structure of clouds and therefore precipitation. Xin-Min Zeng, Ming Wang, Yujian Zhang, Yang Wang, and Yiqun Zheng Copyright © 2016 Xin-Min Zeng et al. All rights reserved. Recent Intensified Winter Coldness in the Mid-High Latitudes of Eurasia and Its Relationship with Daily Extreme Low Temperature Variability Tue, 15 Mar 2016 12:01:35 +0000 http://www.hindawi.com/journals/amete/2016/3679291/ Observational records in recent decades show a large-scale decrease in the cold-season temperature variance in the Northern Hemisphere midlatitudes under continuous global warming. However, severe low temperature events in winter frequently occurred in midlatitude Eurasia (MEA) in the last decade. Here, we define a new coldness intensity (CI) index for the near-surface based on the amplitude of daily anomalously cold temperatures in winter to demonstrate the CI of the variability of low temperature extremes. The results show that a sign-consistent mode dominates the CI variation in MEA, with a marked intensification during the last decade via empirical orthogonal function (EOF) analysis. This leading mode is significantly related to the frequency of winter extreme events. The associated circulations are characterized by a remarkable anomalous anticyclone in Northwest Eurasia, which induced substantial cold advection in MEA. The widespread intensified CI in MEA is closely linked with strong surface anticyclones and synoptic blocking in the mid-high latitudes (25°E–85°E). Coincidently, positive phase shifts of the first two leading modes of the extratropical circulation, which feature similar blocking-like anomalies in the northwestern Eurasian subarctic, jointly play an important role in the recent frequency of severe winters. Chuhan Lu, Shaoqing Xie, Yujing Qin, and Jiewen Zhou Copyright © 2016 Chuhan Lu et al. All rights reserved. The Temporal and Spatial Distribution of Hazy Days in Cities of Jiangsu Province China and an Analysis of Its Causes Tue, 15 Mar 2016 09:48:12 +0000 http://www.hindawi.com/journals/amete/2016/6761504/ Based on the surface meteorological data of Jiangsu Province during 1980–2012, the climatic characteristics and the trends of haze were analyzed. The results indicated that during 1980–2012 haze days increased; in particular, severe and moderate haze days significantly increased. In the northern and coastal cities of Jiangsu Province China, haze days showed a significant increase. Haze often appeared in fall and winter and rarely in summer in the study area. It also occurred more often inland, and less along the coast. Haze occurred more often in June due to straw burning in the harvest time. The haze day increased during the 1990s over southern and southwestern Jiangsu Province; in central and northern Jiangsu, haze day increased after 2000. The continuous, regional, and regional continuous haze days all showed increasing trends. As the urban area expanded each year, industrial emissions, coal consumption, and car ownership increased accordingly, resulting in regional temperature increase and relative humidity decrease, which formed the urban heat island and dry island effects. Hence, haze formation and maintenance conditions became more favorable for more haze days, which led to the increase of haze days, and the significant increases of continuous, regional, and regional continuous haze days. Jiansu Wei, Weijun Zhu, Duanyang Liu, and Xiao Han Copyright © 2016 Jiansu Wei et al. All rights reserved. Evaluation of High-Resolution Satellite-Based Real-Time and Post-Real-Time Precipitation Estimates during 2010 Extreme Flood Event in Swat River Basin, Hindukush Region Tue, 15 Mar 2016 09:38:45 +0000 http://www.hindawi.com/journals/amete/2016/2604980/ Satellite-based real-time and post-real-time precipitation estimates of Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA-3B42) were evaluated during an extreme heavy precipitation event (on 28–30 July 2010) over Swat River Basin and adjacent areas in Hindukush Region. Observations of 15 rain gauging stations were used for the evaluation of TMPA products. Results showed that the spatial pattern of precipitation in the event was generally captured by post-real-time product (3B42V7) but misplaced by real-time product (3B42RT), witnessed by a high spatial correlation coefficient for 3B42V7 (CC = 0.87) and low spatial correlation coefficient for 3B42RT (CC = 0.20). The temporal variation of the storm precipitation was not well captured by both TMPA products. 3B42V7 product underestimated the storm accumulated precipitation by 32.15%, while underestimation by 3B42RT was 66.73%. Based on the findings of this study, we suggest that the latest TMPA-based precipitation products, 3B42RT and 3B42V7, might not be able to perform well during extreme precipitation events, particularly in complex terrain regions like Hindukush Mountains. Therefore, cautions should be considered while using 3B42RT and 3B42V7 as input data source for the modelling, forecasting, and monitoring of floods and potential landslides in Hindukush Region. Muhammad Naveed Anjum, Yongjian Ding, Donghui Shangguan, Muhammad Wajid Ijaz, and Shiqiang Zhang Copyright © 2016 Muhammad Naveed Anjum et al. All rights reserved. A Bayesian Network-Based Probabilistic Framework for Drought Forecasting and Outlook Thu, 10 Mar 2016 13:20:05 +0000 http://www.hindawi.com/journals/amete/2016/9472605/ Reliable drought forecasting is necessary to develop mitigation plans to cope with severe drought. This study developed a probabilistic scheme for drought forecasting and outlook combined with quantification of the prediction uncertainties. The Bayesian network was mainly employed as a statistical scheme for probabilistic forecasting that can represent the cause-effect relationships between the variables. The structure of the Bayesian network-based drought forecasting (BNDF) model was designed using the past, current, and forecasted drought condition. In this study, the drought conditions were represented by the standardized precipitation index (SPI). The accuracy of forecasted SPIs was assessed by comparing the observed SPIs and confidence intervals (CIs), exhibiting the associated uncertainty. Then, this study suggested the drought outlook framework based on probabilistic drought forecasting results. The overall results provided sufficient agreement between the observed and forecasted drought conditions in the outlook framework. Ji Yae Shin, Muhammad Ajmal, Jiyoung Yoo, and Tae-Woong Kim Copyright © 2016 Ji Yae Shin et al. All rights reserved. Significant Atmospheric Boundary Layer Change Observed above an Agulhas Current Warm Cored Eddy Mon, 07 Mar 2016 06:45:31 +0000 http://www.hindawi.com/journals/amete/2016/3659657/ The air-sea impact of a warm cored eddy ejected from the Agulhas Retroflection region south of Africa was assessed through both ocean and atmospheric profiling measurements during the austral summer. The presence of the eddy causes dramatic atmospheric boundary layer deepening, exceeding what was measured previously over such a feature in the region. This deepening seems mainly due to the turbulent heat flux anomaly above the warm eddy inducing extensive deep and persistent changes in the atmospheric boundary layer thermodynamics. The loss of heat by turbulent processes suggests that this kind of oceanic feature is an important and persistent source of heat for the atmosphere. C. Messager and S. Swart Copyright © 2016 C. Messager and S. Swart. All rights reserved. Suitability of Water Harvesting in the Upper Blue Nile Basin, Ethiopia: A First Step towards a Mesoscale Hydrological Modeling Framework Sun, 28 Feb 2016 17:33:18 +0000 http://www.hindawi.com/journals/amete/2016/5935430/ Extreme rainfall variability has been one of the major factors to famine and environmental degradation in Ethiopia. The potential for water harvesting in the Upper Blue Nile Basin was assessed using two GIS-based Multicriteria Evaluation methods: (1) a Boolean approach to locate suitable areas for in situ and ex situ systems and (2) a weighted overlay analysis to classify suitable areas into different water harvesting suitability levels. The sensitivity of the results was analyzed to the influence given to different constraining factors. A large part of the basin was suitable for water harvesting: the Boolean analysis showed that 36% of the basin was suitable for in situ and ex situ systems, while the weighted overlay analysis showed that 6–24% of the basin was highly suitable. Rainfall has the highest influence on suitability for water harvesting. Implementing water harvesting in nonagricultural land use types may further increase the benefit. Assessing water harvesting suitability at the larger catchment scale lays the foundation for modeling of water harvesting at mesoscale, which enables analysis of the potential and implications of upscaling of water harvesting practices for building resilience against climatic shocks. A complete water harvesting suitability study requires socioeconomic analysis and stakeholder consultation. Yihun T. Dile, Johan Rockström, and Louise Karlberg Copyright © 2016 Yihun T. Dile et al. All rights reserved. An MCV Nonhydrostatic Atmospheric Model with Height-Based Terrain following Coordinate: Tests of Waves over Steep Mountains Sun, 28 Feb 2016 16:19:06 +0000 http://www.hindawi.com/journals/amete/2016/4513823/ A nonhydrostatic atmospheric model was tested with the mountain waves over various bell-shaped mountains. The model is recently proposed by using the MCV (multimoment constrained finite volume) schemes with the height-based terrain following coordinate representing the topography. As discussed in our previous work, the model has some appealing features for atmospheric modeling and can be expected as a practical framework of the dynamic cores, which well balances the numerical accuracy and algorithmic complexity. The flows over the mountains of various half widths and heights were simulated with the model. The semianalytic solutions to the mountain waves through the linear theory are used to check the performance of the MCV model. It is revealed that the present model can accurately reproduce various mountain waves including those generated by the mountains with very steep inclination and is very promising for numerically simulating atmospheric flows over complex terrains. Xingliang Li, Xueshun Shen, Feng Xiao, and Chungang Chen Copyright © 2016 Xingliang Li et al. All rights reserved. Exploitation of Documented Historical Floods for Achieving Better Flood Defense Sun, 28 Feb 2016 16:17:36 +0000 http://www.hindawi.com/journals/amete/2016/2317252/ Establishing Base Flood Elevation for a stream network corresponding to a big catchment is feasible by interdisciplinary approach, involving stochastic hydrology, river hydraulics, and computer aided simulations. A numerical model calibrated by historical floods has been exploited in this study. The short presentation of the catchment of the Tisza River in this paper is followed by the overview of historical floods which hit the region in the documented period of 130 years. Several well documented historical floods provided opportunity for the calibration of the chosen numerical model. Once established, the model could be used for investigation of different extreme flood scenarios and to establish the Base Flood Elevation. The calibration has shown that the coefficient of friction in case of the Tisza River is dependent both on the actual water level and on the preceding flood events. The effect of flood plain maintenance as well as the activation of six potential detention ponds on flood mitigation has been examined. Furthermore, the expected maximum water levels have also been determined for the case if the ever observed biggest 1888 flood hit the region again. The investigated cases of flood superposition highlighted the impact of tributary Maros on flood mitigation along the Tisza River. Slobodan Kolaković, Julius Fabian, Sándor Kovács, Ljubomir Budinski, and Matija Stipić Copyright © 2016 Slobodan Kolaković et al. All rights reserved. Observation and Numerical Simulation of Terrain-Induced Windshear at the Hong Kong International Airport in a Planetary Boundary Layer without Temperature Inversions Thu, 25 Feb 2016 12:35:41 +0000 http://www.hindawi.com/journals/amete/2016/1454513/ Terrain-induced windshear at Hong Kong International Airport (HKIA) could be hazardous to the landing and departing aircraft. Such windshear occurring in a planetary boundary layer without temperature inversions is studied in this paper by using the data from the Terminal Doppler Weather Radar and Light Detection and Ranging systems. A high resolution numerical model, called aviation model (AVM), is also employed to find out its capability to forecast the occurrence of such windshear. The model is found to have skills in capturing the terrain-induced windshear, including the terrain-induced microburst due to the mountains of Lantau Island. Moreover, the windshear detection algorithm as applied to the AVM output, called AVM-GLYGA, is able to give advance alert for the occurrence of low-level windshear. The model also offers new dataset, such as vertical velocity and vertical cross sections across the windshear feature, to study the terrain-induced windshear phenomena with new insights. The AVM is found to have good skills in depicting the terrain-disrupted airflow at the airport area, and more comprehensive study would be conducted to study the skills of AVM-GLYGA as compared with pilot windshear report as sky truth. P. W. Chan and K. K. Hon Copyright © 2016 P. W. Chan and K. K. Hon. All rights reserved. Evaluating Spatiotemporal Variation of Groundwater Depth/Level in Beijing Plain, a Groundwater-Fed Area from 2001 to 2010 Tue, 23 Feb 2016 11:08:53 +0000 http://www.hindawi.com/journals/amete/2016/8714209/ Groundwater has always been a valuable resource in Beijing, facing a great decline of groundwater level during the past decades. However, few previous researches have revealed the spatial variation of groundwater level within Beijing Plain. In this study, spatiotemporal variation of groundwater level from 2001 to 2010 in Beijing Plain has been investigated. Factor analysis has been conducted to identify the primary influencing factor. Results showed that the groundwater level decreased by 8.41 m from 2001 to 2010, with a linear decreasing rate of 0.954 m per year averagely. Significant spatial variation characteristics have been detected. The north area suffered more groundwater depletion than the south part in general. The lowest groundwater level has been identified downstream Miyun Reservoir, central part of the Plain. Nevertheless, the most of the south part witnessed a slight revival between 2001 and 2010. This may be due to the differences of socioeconomic circumstances in the Plain. Three influencing factors, that is, “demand factor,” “supply factor,” and “loss factor,” have been identified in the water balance model. Eigenvalues of these factors are 3.563, 2.910, and 1.632, respectively, indicating that these factors influenced the groundwater system to various extents, with the demand factor being the primary one. Yuyan Zhou, Weihua Xiao, Jianhua Wang, Yong Zhao, Ya Huang, Jiyang Tian, and Yan Chen Copyright © 2016 Yuyan Zhou et al. All rights reserved. Information Analysis of Catchment Hydrologic Patterns across Temporal Scales Sun, 21 Feb 2016 14:37:08 +0000 http://www.hindawi.com/journals/amete/2016/1891465/ Catchment hydrologic cycle takes on different patterns across temporal scales. The interim between event-scale hydrologic process and mean annual water-energy correlation pattern requires further examination to justify self-consistent understanding. In this paper, the temporal scale transition revealed by observation and simulation was evaluated in an information theoretical framework named Aleatory Epistemic Uncertainty Estimation. The Aleatory Uncertainty refers to posterior uncertainty of runoff given the input variables’ observations. The Epistemic Uncertainty refers to the posterior uncertainty increase due to the imperfect observation decoding in models. Daily hydrometeorological observations in 24 catchments were aggregated from 10 days to 1 year before implementing the information analysis. Estimations of information contents and flows of hydrologic terms across temporal scales were related with the catchments’ seasonality type. It also showed that information distilled by the monthly and annual water balance models applied here did not correspond to that provided by observations around temporal scale from two months to half a year. This calls for a better understanding of seasonal hydrologic mechanism. Baoxiang Pan and Zhentao Cong Copyright © 2016 Baoxiang Pan and Zhentao Cong. All rights reserved. Terrestrial Water Storage Changes of Permafrost in the Three-River Source Region of the Tibetan Plateau, China Thu, 18 Feb 2016 11:26:05 +0000 http://www.hindawi.com/journals/amete/2016/4364738/ Changes in permafrost influence water balance exchanges in watersheds of cryosphere. Water storage change (WSC) is an important factor in water cycle. We used Gravity Recovery and Climate Experiment (GRACE) satellite data to retrieve WSC in the Three-River Source Region and subregions. WSC in four types of permafrost (continuous, seasonal, island, and patchy permafrost) was analyzed during 2003–2010. The result showed that WSC had significant change; it increased by  mm/a () over the Three-River Source Region during the study period. The most significant changes of WSC were in continuous permafrost zone, with a total amount of about . The spatial distribution of WSC was in state of gain in the continuous permafrost zone, whereas it was in a state of loss in the other permafrost zones. Little changes of precipitation and runoff occurred in study area, but the WSC increased significantly, according to water balance equation, the changes of runoff and water storage were subtracted from changes of precipitation, and the result showed that changes of evaporation is minus which means the evaporation decreased in the Three-River Source Region during 2003–2010. Min Xu, Shichang Kang, Qiudong Zhao, and Jiazhen Li Copyright © 2016 Min Xu et al. All rights reserved. Chemical Characteristics of High PM Episodes Occurring in Spring 2014, Seoul, Korea Mon, 15 Feb 2016 07:28:32 +0000 http://www.hindawi.com/journals/amete/2016/2424875/ This study was conducted for understanding of characteristics of two different high PM episodes occurred during the spring of 2014 in Seoul, Korea. Case 1 was the phenomenon by complex of long range transport and following domestic stagnation. Case 2 was caused by the Asian dust event. During high PM episodes, atmospheric condition became more acidic. The equivalent concentration ratio of nitrate to sulfate decreased to 0.75 and 0.95 in Case 1 and Case 2, respectively, implying that sulfate concentration increase was greater than nitrate concentration increase in high PM episode possibly caused by long range transport. In high PM episodes, SOR and NOR increased with steeper rate for NOR. Considering correlation between temperature and SOR, it was suggested that the homogeneous formation of sulfate was not active in the Korean Peninsula, especially in high PM episodic periods. On the other hand, heterogeneous sulfate formation reaction was dominant for high PM episodes. Considering NOR and its correlation with temperature and humidity, it was suggested that NO2 oxidation was mainly caused by homogeneous oxidation in Case 1. For Case 2, heterogeneous oxidation mainly contributed to forming the nitrate due to the extremely high particle concentrations in Asian dust. Hye Jung Shin, Seung-Myung Park, Jong Sung Park, In Ho Song, and You Deog Hong Copyright © 2016 Hye Jung Shin et al. All rights reserved. Trends in Extreme Precipitation Indices in Iran: 1951–2007 Sun, 14 Feb 2016 11:41:34 +0000 http://www.hindawi.com/journals/amete/2016/2456809/ We investigate trends in extreme precipitation in Iran for 1951–2007 using the recently released APHRODITE daily rainfall time series. We find that seven different indices of extreme precipitation all show an upward trend through the study period. The seven different precipitation indices include annual precipitation total, number of days above a certain threshold, maximum precipitation received over a certain period of time, maximum one-day precipitation, and number of days with precipitation above the 90th percentile. A principal components analysis reveals one eigenvector explaining much of the variance in the seven indices and reveals that this component exhibits a strong upward trend for the whole of Iran. On a regional level, we find that the upward trend in extreme precipitation has a strong southwest-to-northeast gradient across the country for all the indices. We repeated all the analyses for 42 stations across the country to compare with the results from the gridded data; trends in extreme rainfall generated from the station data compare favorably with the results from the APHRODITE daily rainfall time series thereby reinforcing the robustness of our conclusions. Robert C. Balling Jr., Mohammad Sadegh Keikhosravi Kiany, Shouraseni Sen Roy, and Javad Khoshhal Copyright © 2016 Robert C. Balling Jr. et al. All rights reserved.