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To improve the ensemble prediction system of the tropical regional atmosphere model for the South China Sea (TREPS) in predicting landfalling tropical cyclones (TCs), the impacts of three new implementing strategies for surface and model physics perturbations in TREPS were evaluated for 19 TCs making landfall in China during 2014–16. For sea surface temperature (SST) perturbations, spatially uncorrelated random perturbations were replaced with spatially correlated ones. The multiplier f, which is used to form perturbed tendency in the Stochastically Perturbed Parameterization Tendency (SPPT) scheme, was inflated in regions with evident convective activity (f-inflated SPPT). Lastly, the Stochastically Perturbed Parameterization (SPP) scheme with 14 perturbed parameters selected from the planetary boundary layer, surface layer, microphysics, and cumulus convection parameterizations was added. Overall, all these methods improved forecasts more significantly for non-intensifying than intensifying TCs. Compared with f-inflated SPPT, the spatially correlated SST perturbations generally showed comparable performance but were more (less) skillful for intensifying (non-intensifying) TCs. The advantages of the spatially correlated SST perturbations and f-inflated SPPT were mainly present in the deterministic guidance for both TC track and wind and in the probabilistic guidance for reliability of wind. For intensifying TCs, adding SPP led to mixed impacts with significant improvements in probability-matched mean of modest winds and in probabilistic forecasts of rainfall; while for non-intensifying TCs, adding SPP frequently led to positive impacts on the deterministic guidance for track, intensity, strong winds, and moderate rainfall and on the probabilistic guidance for wind and discrimination of rainfall. [ABSTRACT FROM AUTHOR]

A comprehensive observational study on a warm sector torrential rain(WSTR) on 20 May 2016 over south China is presented with a pioneering examination of simulation capabilities based on the Global/Regional Assimilation and Prediction System for Tropical Mesoscale Model(GRAPES_TMM). The results show that the meso-scale convective boundary formed between north wind from mountainous areas and the south wind from plain regions as well as the cold outflows boundary both contribute to the convections over Xinyi, and the convections were blocked and stayed stagnant in the trumpet-shaped topography for about 8 hours which eventually caused the torrential rains.Comparative verifications of the observational studies by simulations showed that GRAPES_TMM had better estimations of large-scale frontal precipitation than the local warm-sector torrential rains. The simulations of local torrential rains in the warm sector showed strong biases in precipitation location and amount. GRAPES_TMM also showed overestimated surface winds and a faster moving speed bias, as well as an overall underestimation of the nocturnal surface temperature during the WSTR. This work may lead to several prospective researches of its model improvements on model physics such as land surface process and PBL parameterization. [ABSTRACT FROM AUTHOR]

Purpose – Research on workplace loneliness has thus far been dominated by perceptions of followers; hence, few researchers have considered the perspective of leader-follower congruence. The purpose of this paper is to examine how the leader-follower relationship mediates the relationship between leader-follower congruence/incongruence in workplace loneliness and turnover intentions. Design/methodology/approach – Data were collected from 232 leader-follower dyads from ten companies in China. Polynomial regression combined with the response surface methodology was used to test the hypotheses. Findings – Four conclusions were drawn. First, leader-member exchange (LMX) was higher when leaders and followers were aligned in terms of workplace loneliness than otherwise. Second, in the case of leader-follower congruence, LMX rose as their workplace loneliness fell. Third, in the case of incongruence, followers had lower LMX when they were lonelier than their leaders. Finally, LMX partially mediated the leader-follower congruence/incongruence effect of workplace loneliness on followers’ turnover intention. Originality/value – This study emphasized the importance of leaders’ congruence with followers in workplace loneliness. Additionally, it extended research on leader-follower congruence from a positive perspective to a negative one. [ABSTRACT FROM AUTHOR]

The Variational Doppler Radar Analysis System (VDRAS) was implemented in Beijing, China, and contributed to the Beijing 2008 Forecast Demonstration Project (B08FDP) in support of the Beijing Summer Olympics. VDRAS is a four-dimensional variational data assimilation system that produces frequently updated analyses using Doppler radar radial velocities and reflectivities, surface observations, and mesoscale model data. The system was tested in real time during the B08FDP pretrials in the summers of 2006 and 2007 and run during the Olympics to assist the 0--6-h convective weather nowcasting. This paper provides a description of the upgraded system and its Beijing implementation, an evaluation of the system performance using data collected during the pretrials, and its utility on convective weather nowcasting through two case studies. Verification of VDRAS wind against a wind profiler shows that the analyzed wind is reasonably accurate with a smaller RMS difference for 2006 than for 2007 due to better radar data coverage in 2006. The analyzed cold pools in three convective episodes are compared with surface observations at selected stations. The result shows good agreement between the analysis and the observations. The two case studies demonstrate the role that VDRAS could play in nowcasting convective initiation. [ABSTRACT FROM AUTHOR]

Twelve-hour real-time and synchronous measurements of the three-dimensional components of the near-surface turbulence at four heights (8, 16, 32 and 47 m) during a dust storm are obtained by sonic anemometers for the first time. The experimental results show that (1) the mean vertical velocities at all four heights have considerably positive values during the dust storm, illustrating a strong upward flow near the surface; (2) during the dust storm, the mean vertical velocity is higher at 8 m than at 16 and 32 m, implying that the convection is stronger at 8 m than at the other two heights; and (3) when the longitudinal velocity is a maximum, the mean of the vertical components of wind velocities at 8 m is a minimum and the standard deviation is a maximum, which reveals weaker vertical convection during the period of greatest dust storm intensity, while the turbulence intensity contrarily increases, which may result in more entrainment of surface dust. The analysis results also show that the standard deviations of the longitudinal and vertical velocities increase as the mean inflow velocity increases, but the standard deviation of the lateral velocity is hardly affected by the mean inflow velocity. Based on the calculated skewness and kurtosis of the longitudinal, vertical and lateral velocities every 20 min at different heights, it is seen that all three components obviously fluctuate with height, which further indicates the importance of performing real-time and synchronous measurements at different heights near the surface during a dust storm so as to reveal the three-dimensional turbulence structure accurately. [ABSTRACT FROM AUTHOR]

Abstract: Organic films, collected from indoor and outdoor window surfaces in Guangzhou and Hong Kong of South China, were analyzed to quantify their organic carbon (OC), elemental carbon (EC), and polybrominated diphenyl ethers (PBDEs) content. The highest concentrations of OC, EC, and BDE-209 were found in Guangzhou with values of 10 000 μg m−2, 2200 μg m−2, and 4000 ng m−2, respectively, and the highest concentration of Σ7PBDE (sum of BDE-28, -47, -99, -100, -153, -154 and -183) was found in Hong Kong with a value of 25 ng m−2. In most cases, the concentrations of PBDEs were higher in the exterior films than those in the interior films with BDE-209 as the predominant congener in both cities, suggesting that PBDEs mainly come from ambient environment, and deca-BDE accounts for major PBDE consumption. The growth rates of organic film on window surfaces were fast at the beginning, and reached a consistent level afterwards. The evolution rates ranged from 2.6 to 11 nm day−1 for “bulk film”, while from 0.06 to 0.92 nm day−1 for “pure film”. The concentrations of PBDEs on the window surfaces did not increase with the growth time, suggesting that the window surface may provide a good place for photo-degradation of PBDEs. [Copyright &y& Elsevier]