THE IMPACT OF CUMULUS PARAMETERIZATIONS AND MICROPHYSICS SCHEMES UNDER DIFFERENT COMBINATIONS ON TYPHOON TRACK PREDICTION

This study examines the effects of cumulus parameterizations and microphysics schemes on the track forecast of typhoon Nabi using the Weather Research Forecast model. The study found that the effects of cumulus parameterizations on typhoon track forecast were comparatively strong and the typhoon track forecast of Kain-Fritsch (KF) was superior to that of Betts-Miller (BM). When KF was selected, the simulated results would be improved if microphysics schemes were selected than otherwise. The results from Ferrier, WSM6, and Lin were very close to those in the best track. KF performed well with the simulations of the western extension and eastern contraction changes of a North Pacific high as well as the distribution and strength of the typhoon wind field.

An Observational Study on Physical and Optical Properties of Atmospheric Aerosol in Autumn in Nanjing

Based on observing data of atmospheric aerosol in the north suburban area of Nanjing from September to November in 2007, the number concentration, mass concentration, size distribution and optical properties of atmospheric aerosol particles and the relation to meteorological factors were analyzed, and their concentration and optical properties during hazy and non-hazy days were compared. The results showed that aerosol pollution was serious in autumn in this region; the deterioration of visibility had close correlation to fine particles, that is, the average number concen- tration of aerosol was 17 044.2 cm^-3, in which ultra fine particles accounted for 64.3%; the daily average mass concentration of PM2.5 was 281 μg/m3, and the ratio of PM2.5 to PM10 was 0.74; the accumulation mode particles dominated in number and surface concentration distributions, while the volume concentration distribution presented a main peak at size of 1.0 -2.8 μm; fine particles increased during hazy days compared with non-hazy days; the scatter coefficient closely correlated to the particle size, concentration and atmospheric humidity. It was also indicated that meteorological conditions played a critical role in formation of hazy weather, that is, weak large-scale weather systems, low wind speed, high humidity and strong inversion were favorable conditions for hazy weather in autumn.

Comparison of isotope-based linear and Bayesian mixing models in determining moisture recycling ratio

Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,which affects the accuracy of local moisture recycling.In this study,a total of 18 stations from four typical areas in China were selected to compare the performance of isotope-based linear and Bayesian mixing models and to determine local moisture recycling ratio.Among the three vapor sources including advection,transpiration,and surface evaporation,the advection vapor usually played a dominant role,and the contribution of surface evaporation was less than that of transpiration.When the abnormal values were ignored,the arithmetic averages of differences between isotope-based linear and the Bayesian mixing models were 0.9%for transpiration,0.2%for surface evaporation,and–1.1%for advection,respectively,and the medians were 0.5%,0.2%,and–0.8%,respectively.The importance of transpiration was slightly less for most cases when the Bayesian mixing model was applied,and the contribution of advection was relatively larger.The Bayesian mixing model was found to perform better in determining an efficient solution since linear model sometimes resulted in negative contribution ratios.Sensitivity test with two isotope scenarios indicated that the Bayesian model had a relatively low sensitivity to the changes in isotope input,and it was important to accurately estimate the isotopes in precipitation vapor.Generally,the Bayesian mixing model should be recommended instead of a linear model.The findings are useful for understanding the performance of isotope-based linear and Bayesian mixing models under various climate backgrounds.

Using a Modified Soil-Plant-Atmosphere Scheme(MSPAS)to Simulate the Interaction between Land Surface Processes and Atmospheric Boundary Layer in Semi-Arid Regions

This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study.

Precipitation Chemistry and Corresponding Transport Patterns of Influencing Air Masses at Huangshan Mountain in East China

One hundred and ten samples of rainwater were collected for chemical analysis at the summit of Huangshan Mountain, a high-altitude site in East China, from July 2010 to June 2011. The volume-weighted-mean （VWM） pH for the whole sampling period was 5.03. SO2- and Ca2＋ were the most abundant anion and cation, respectively. The ionic concentrations varied monthly with the highest concentrations in winter/spring and the lowest in summer. Evident inter-correlations were found among most ions, indicating the common sources for some species and fully mixing characteristics of the alpine precipitation chemistry. The VWM ratio of [SO]-]/[NO3] was 2.54, suggesting the acidity of rainwater comes from both nitric and sulfuric acids. Compared with contemporary observations at other alpine continental sites in China, the precipitation at Huangshan Mountain was the least polluted, with the lowest ionic concentrations. Trajectories to Huangshan Mountain on rainy days could be classified into six groups. The rainwater with influencing air masses originating in Mongolia was the most polluted with limited effect. The emissions of Jiangxi, Anhui, Zhejiang and Jiangsu provinces had a strong influence on the overall rain chemistry at Huangshan Mountain. The rainwater with influencing air masses from Inner Mongolia was heavily polluted by anthropogenic pollutants.

Practice and Thinking on Current Planning Environmental Impact Assessment of Transmission and Transformation Power Grid in Jiangsu Province

The planning environmental impact assessment （EIA） of transmission and transformation power grid at levels of 500 and 220 kV had been finished completely in the 13 municipalities of Jiangsu Province by the end of 2012, which played important roles in guiding and planning the following transmission and transformation projects in environmental protection. In this paper, through the detail analysis on the objective and significance of the planning EIA of transmission and transformation power grid, legal basis and planning EIA practices, some suggestions and thinking about the planning EIA of transmission and transformation power grid were put forward.

Stable Isotope Signatures and Moisture Transport of a Typical Heavy Precipitation Case in the Southern Tianshan Mountains

Stable oxygen isotopes in precipitation contain meaningful environmental information on a synoptic scale and can be applied to diagnose hydrometeorological processes.A series of rainstorms occurred at the southern Tianshan Mountains during the period from May to June 2013,and the event-based precipitation was sampled along the mountain range from west to east.Based on δ18 O values in precipitation samples as well as the corresponding meteorological parameters,the moisture transport paths during the sampling period were identified.In late-May(stage 1),isotopes in precipitation collected generally showed a depleting trend.In mid-June(stage 2),there was no coherent trend of isotopes in precipitation for these stations,and only isotope values in Aksu showed a continually depleting trend.Checking other meteorological proxies during the sampling period,the event-based precipitation isotopes sensitively reflected the moisture process.In central Asia,both the westerly and monsoon moisture can be delivered to cause extreme precipitation events,and the isotopic information provides an alternative tool to investigate the atmospheric processes.

Water use characteristics of different pioneer shrubs at different ages in western Chinese Loess Plateau:Evidence from δ^(2)H offset correction

Caragana korshinskii Kom.and Tamarix ramosissima Ledeb.are pioneer shrubs for water and soil conservation,and for windbreak and sand fixation in arid and semi-arid areas.Understanding the water use characteristics of different pioneer shrubs at different ages is of great importance for their survival when extreme rainfall occurs.In recent years,the stable isotope tracing technique has been used in exploring the water use strategies of plants.However,the widespreadδ^(2)H offsets of stem water from its potential sources result in conflicting interpretations of water utilization of plants in arid and semi-arid areas.In this study,we used three sets of hydrogen and oxygen stable isotope data(δ^(2)H andδ^(18)O,correctedδ^(2)H_c1 based on SW-excess andδ^(18)O,and correctedδ^(2)H_c2 based on−8.1‰andδ^(18)O)as inputs for the MixSIAR model to explore the water use characteristics of C.korshinskii and T.ramosissima at different ages and in response to rainfall.The results showed thatδ^(2)H_c1 andδ^(18)O have the best performance,and the contribution rate of deep soil water was underestimated because ofδ^(2)H offset.During the dry periods,C.korshinskii and T.ramosissima at different ages both obtained mostly water from deeper soil layers.After rainfall,the proportions of surface(0-10 cm)and shallow(10-40 cm)soil water for C.korshinskii and T.ramosissima at different ages both increased.Nevertheless,there were different response mechanisms of these two plants for rainfall.In addition,C.korshinskii absorbed various potential water sources,while T.ramosissima only used deep water.These flexible water use characteristics of C.korshinskii and T.ramosissima might facilitate the coexistence of plants once extreme rainfall occurs.Thus,reasonable allocation of different plants may be a good vegetation restoration program in western Chinese Loess Plateau.

Rainfall Variability Patterns in West Africa： Case of Cote d＇lvoire and Ghana

This study is focused first on the rainfall variability in C6te d＇Ivoire and in Ghana; second, on the determination of the climatic zones of these areas. Monthly rainfall heights recorded in 43 weather stations from 1964 to 2000 is carried out. This study suggests a sudivision in three climatic zones which are： the littoral zone that borders the tropical Atlantic, the center zone that is located in the central region of both countries, and the northern zone whose seasonal cycle is close to that of the Sahel of West Africa. The study of the interannual variability of the rainfall shows some patterns which are differently influenced by sea surface temperature. Such work could be useful for agricultural activities and to better quantify the role of the vegetation dynamics.

On the Causes of the Minor Dry Season over the Coastal Region of the Northern Gulf of Guinea

Along the littoral shelf of northern coast of the Gulf of Guinea (GG), a minor dry season of the rainfall regime is concomitantly observed with the occurrence of a major coastal upwelling in July-August-September (JAS). It was then supposed that this upwelling drives that minor dry season. But no previous studies have tried to understand this minor dry season and, this study is the first focusing on this question. The investigations undertaken to explain this dry season on the Ivorian littoral shelf with the ERA-Interim data from the European Centre for Medium Range Weather Forecasts over the 1980-2016 period have shown that the minor dry season is driven by the Northward migration of the Inter Tropical Convergence Zone (ITCZ) during this period and, enhanced by the occurrence of the major coastal upwelling of the northern GG at the same time. These two phenomena interact as follow: i) the ITCZ is located in JAS far in the north cutting off convective processes along the coast, ii) the air on the coastal region is poor in humidity, iii) the air temperature on the bordering region of the GG is cooled by the coastal upwelling to value less than 26°C and not favorable for providing convection.

Consistency in <i>Z</i>-<i>R</i>Relationship Variability Regardless Precipitating Systems, Climatic Zones Observed from Two Types of Disdrometer

Data from rain Drop Size Distributions gathered on five sites in Africa as well as those of the pilot site in Kourou (French Guyana, South America), located in different climatic zones, and collected by two types of disdrometer (the impact JW RD-69 disdrometer and the Optical Spectro-Pluviometer, OSP) are used to study the consistency of the reflectivity factor-rain rate at the ground (Z-R) relationship variability. The results clearly confirm that the relationship Z-R knows a large spatial variability, from a type of precipitation to another and within the same precipitation regardless the type of disdrometer used for DSD measurements. Base on the similarity of the relations reflectivity factor-rain rate and ratio median volume diameter over the total number of drops-rain rate, the variability of the Z-R coefficients (A, b) through the simultaneously implication of the size and number of drops which characterize the DSD was exhibited. It was shown that the relationships A-α and b-β designed to understand the involvement of parameters D0 and NT of DSD in the variability of the relationship Z-R are similar regardless the types of disdrometer used. However, the relations A-α in the Sahelian region appear to deviate from those of Guinean, equatorial and Soudanian zones. The plausible reasons were discussed.

Inventory Research of Greenhouse Gas about Energy Sector Activities in Jiangsu Province and Analysis on Relevant Problems

The emission of greenhouse gas generated by energy activity had the maximum influence on total emission. We introduced research content and method of inventory for greenhouse gas generated by energy activity in Jiangsu in 2005 and 2010, and obtained finial results. According to the sum of green gas emission from various parts, greenhouse gas emission of energy activity in Jiangsu occupied 76% -79% of total emission in 2005 and 2010. Meanwhile, the problems encountering in preparation process of inventory were summed and deeply analyzed, such as data ob- taining and processing, inconsistent statistical channel and actual measurement of emission factor. Finally, some suggestions about carrying out provincial greenhouse gas inventory work of energy activity in the future were put forward.

Physical Forcing Induced Coastal Vulnerability along the Gulf of Guinea

Coastal areas of the Gulf of Guinea experience accelerated degradation as a result of erosion and flooding associated with intensification of extreme marine-meteorological phenomena. The coastal erosion process, especially on the sandy or muddy littoral, constitutes one of the main factors of the degradation of the Gulf of the Guinean coast. These risks, which are still poorly studied, could increase over the coming decades because of climate change and the human activities that exacerbate them. Data related to ocean forcing (tide, wave, and sea level anomaly), to hydrologic parameter (rainfall) and to the state (geomorphology, coastal slope, and rate of coastal retreat) of the coast were analyzed by several statistical methods and a numerical vulnerability model to map the vulnerability of the different coastlines of this region. The results showed that the vulnerability of these coastal areas is influenced by geomorphology, tide, waves and rainfall intensity. 24.34% and 37% of the entire coast are of low and moderate vulnerability respectively. While 26.98% and 11.66% are of high and very high vulnerability respectively. This information could facilitate developing sustainable policies to effectively manage hazards in this coastal zone.

Observation and Analysis of Meteorological Conditions for Icing of Wires in Guizhou, China

Icing of wires is a product of rain, fog, and freezing rain, and is a common meteorological disaster in winter in Guizhou Province of China. It is extremely harmful to facilities such as power transmission and communication lines, and has caused huge economic loss up to 48.9566 billion dollars a year. Based on the meteorological records of Guizhou from 1967, we analyze the meteorological characteristics during the icing of wires, and obtain the temperature, wind speed and direction conditions of the ice accident. The icing of wires is carried out by supercooling raindrops, freezing of the clouds, freezing and spreading on the wires. Different types of supercooled raindrops and cloud freezing and freezing processes will form different types of ice accretion;wind direction and wind speed will affect the growth of ice accretion by changing the speed of sub-cooling raindrops and cloud falling. The weight of rain-type ice accretion is between 24 and 152 g, and the weight of smog-type ice is between 40 - 76 g. The average ice density of these two places can be calculated to be 0.2 - 0.5 g/cm3. The longer the icing of wires, the higher the ice disaster rate.

Analysis and Forecasting of the Impact of Climatic Parameters on the Yield of Rain-Fed Rice Cultivation in the Office Riz Mopti in Mali

During the period spanning the 1970s and1980s, countries in the West African Sahel experienced severe drought. Its impact on agriculture and ecosystems has highlighted the importance of monitoring the Sahelian rainy season. In Sahelian countries such as Mali, rainfall is the major determinant of crop production. Unfortunately, rainfall is highly variable in time and space. Therefore, this study is conducted to analyze and forecast the impact of climatic parameters on the rain-fed rice yield cultivation in the Office Riz Mopti region. The data were collected from satellite imagery, archived meteorology data, yield and rice characteristics. The study employed Hanning filter to highlight interannual fluctuation, a test of Pettitt and the standardized precipitation index (SPI) to analyze the rainfall variability. Climate change scenarios under the RCP 8.5 scenario (HadGEM-2 ES) and agroclimatic (Cropwat) model are carried out to simulate the future climate and its impact on rice yields. The results of satellite image classifications of 1986 and 2016 show an increase of rice fields with a noticeable decrease of bare soil. The analysis of the SPI reveals that over the 30 years considered, 56.67% of the rainy seasons were dry (1986-2006) and 43.33% were wet (2007-2015). The modelling approach is applied over 1986-2006 and 2007-2015 periods—considered as typical dry and rainy years—and applied over the future, with forecasts of climate change scenarios in 2034. The results show a decrease in potential yield during dry and slightly wet years. The yields of rain-fed rice will be generally low between 2016 and 2027. Deficits are observed over the entire study area, in comparison with the potential yield. Thus, this situation could expose the population to food insecurity.

Vertical Profile Comparison of Aerosol and Cloud Optical Properties in Dominated Dust and Smoke Regions over Africa Based on Space-Based Lidar

This study evaluates the vertical profiles of aerosol and cloud optical properties in 40 dominated dust and smoke regions in Western-Northern Africa (WNA) and Central-Southern Africa (CSA), respectively, from the surface to 10km and from 2008 to 2011 based on LIVAS (LIdar climatology of Vertical Aerosol Structure for space-based lidar simulation studies). Aerosol extinction (AE), aerosol backscatter (AB), and aerosol depolarization (AD) generally increase from the surface to 1.2 km and decrease from 1.2 km to the upper layers in both WNA and CSA. AE and AB in CSA (maximum of 0.13 km-1, 0.14 km-1, 0.0021 km-1‧sr-1, 0.0033 km-1‧sr-1) are higher than in WNA (maximum of 0.07 km-1, 0.08 km-1, 0.0017 km-1‧sr-1, 0.0015 km-1‧sr-1) at 532 and 1064 nm respectively. AD in WNA (maximum of 0.25) is significantly higher than in CSA (maximum of 0.05). There is a smooth change with the height of cloud extinction and backscatter in WNA and CSA, while there is a remarkable increase of cloud depolarization with height, whereby it is high in CSA and low in WNA due to high and low fraction of cirrus respectively. Altocumulus has the highest extinction in NA (0.0139 km-1), CA (0.058 km-1), WA (0.013 km-1), while low overcast transparent (0.76 km-1) below 1 km in SA. The major findings of this study may contribute to the improvement of our understanding of aerosol-cloud interaction studies in dominated dust and smoke aerosol regions.

Boosting the Performance of Solar Cells with Intermediate Band Absorbers--The Case of ZnTe：O

Abstract： This work reports on modeling IB （intermediate band） solar cells based on ZnTe：O semiconductor and determination of their photovoltaic parameters using SCAPS （solar cell capacitance simulator） software. A comparative study between photovoltaic performance of ZnTe and ZnTe：O based solar cells has been carried out. It has been found that the energy conversion efficiency r/, short-circuit current density Jsc, EQE （external quantum efficiency） and FF （fill factor） increased with increasing oxygen doping concentration Nt up to the shallow acceptor density NA and decreased when Nt was higher than NA. The open circuit-voltage Voc remained constant for N lower than the acceptor doping concentration NA and decreased for Nt higher than NA. The increase of , Jsc and FF is due to the fact that IB is fully empted, so sub-bandgap photons can be absorbed by hole photoemission process from the VB （valence band） to the IB. The decrease of r/, J, EQE and FF is attributed to overcompensation for the base doping NA making electron photoemission process from IB to the CB （conduction band） maximized. This indicates that there is a competition between oxygen doping and intrinsic acceptor defects. The optimal concentrations of oxygen and shallow acceptor carriers were found to be Nr 1015 cm-3 and NA 1014 cm3, The corresponding photovoltaic parameters were r/= 41.5%, J = 31.2 mA/cm2, Voc = 1.80 V and FF = 75.1%. Finally, the EQE spectra showed a blue shift of absorption edge indicating that the absorption process is extended to the sub-bandgap photons through lB.

Development of an Integrated Coastal Vulnerability Index for the Ivorian Coast in West Africa

This study assesses the vulnerable state of the 566-km Ivorian coastal area using the physical (geomorphology, coastal slope, coastal retreat rate, relative sea level rise and wave/Tide energy) and socio-economic (coastal population density, harbor, airport, road, land use and protected area) factors as indicators. This enabled an Integrated Coastal Vulnerability Index to be determined for the Ivorian coastal zone. This Index could be defined as the weighted average of indexes based on physical and socio-economic factors. The study revealed that vulnerability of the western and the eastern coastlines of Cote d’Ivoire are strongly influenced by human activities, while physical forcing affects significantly the vulnerability of the central section. The relative vulnerability of the different sections depends also strongly on the geomorphology, wave energy, coastal population density and land use factors. The west and central sections of the coastline are more resilient than the eastern section when integrating physical and socio-economic factors. The Integrated Coastal Vulnerability Index, based on physical and socio-economic factors, appears to be more appropriate for coastal vulnerability assessment. These results could be useful in the development of adaptation strategies to increase the resilience of this coastal area and then extended for West Africa Coastal Areas Management.

Study of Formic and Acetic Acids in the Air of Humid Savannah Case of Lamto (Côte d’Ivoire)

From January 1995 to December 2004, 860 rainwater samples were collected in the humid savannah of Lamto. Using the Henry’s law, we determined the content of formic and acetic acids in the air based on their concentrations in rainwater. The annual partial pressure of both formic and acetic acids over the decade is variable. It covers a range of 0.003 (1998) to 0.21 ppbv (1996) and 0.27 (1999) to 0.47 ppbv (1996) for formic and acetic acids respectively. Also, the partial pressure in the dry season is higher than that in the wet season. This difference is related to the enrichment of the organic acid content in the air by the various sources that produce these acids. One of the main sources of increment in organic acid is biomass burning. This biomass burning contributes between 21% and 51% to the formation of the two acids in the humid savannah of Lamto. Ultimately the average annual organic acidity varies from 40% to 60% over the ten years period.

Surface Roughness Around a 325-m Meteorological Tower and Its Effect on Urban Turbulence

Based on slow- and fast-response measurements under neutral stratification conditions from a 325-m meteorological tower located in a built-up area of north-central Beijing as well as a descriptive survey of surface roughness elements (i.e., buildings and trees) around the tower site, urban roughness lengths, zo, with zero-plane displacement height are estimated using logarithmic wind profile and morphometric methods in eight 45° directional sectors. When comparing their results with each other, the slow-response method tends to give smaller zo values. At a given location, considerable directional variations in values are observed. The effect of surface roughness on urban turbulence characteristics in terms of non-dimensional standard deviations of three-component velocity, σi/u*1 (where i = u, v, w and u*1 is local friction velocity), is investigated.