A Comparison Study Between Spring and Summer Fogs in the Yellow Sea-Observations and Mechanisms

New observations from buoys and soundings reveal the discrepancies in air–sea interface and in vertical structures between spring (April to May) and summer (July) fogs in the Yellow Sea. Spring fogs are shallow with a robust temperature inversion, dry layer and cold phase (surface air temperature or SAT is lower than sea surface temperature or SST); summer fogs are deep with weaker stability, indistinct fog top and warm phase (SAT?>?SST). Along with numerical simulations, conceptual models for the mechanisms of temperature inversion are suggested. The land–sea contrast is responsible for the robust temperature inversion in spring, and the deep southerlies derived from the east Asian summer monsoon and the adiabatic sinking from the western Pacific subtropical high contributes to the weaker inversion in summer. The dry layer above the sea fog top intensifies the longwave radiative cooling effect to lead to the cold phase in spring fogs. The radiative cooling is weaker in summer fogs resulting in SAT?>?SST.     

New fossil eccoptarthrids (Coleoptera: Curculionoidea) from the Yixian Formation of western Liaoning, China

One new genus and three new species of the weevil family Eccoptarthridae (Curculionoidea), Leptocar polychaetus gen. et sp. nov., Abrocar macilentus sp. nov., Cretonanophyes punctatus sp. nov., are described and illustrated. They pertain to the Upper Jurassic or Lower Cretaceous Yixian Formation of western Liaoning Province, China. The host plants to the living eccoptarthrids and the floras in Yixian Formation indicate that those archaic eccoptarthrids possibly lived on conifers with a phylogenetic closeness to Cupressaceae. Besides, the early diversification of eccoptarthrids is discussed: origi- nated in Central or East Asia in the Late Jurassic, spread into Western Europe and South America during the Early Cretaceous, underwent a dramatic decline after the Early Cretaceous which likely was caused by competitive pressure and the displacement of their host plants.     

Megacrysts in the Cenozoic basalt of the Tuoyun Basin,Southwest Tianshan

Abundant megacrysts of clinopyroxene, amphibole, anorthoclase, and phlogopite are found together with deep-seated xenoliths in the Cenozoic basalt of the Tuoyun Basin, Southwest Tianshan. The megacrysts are mainly in the cone sheet formed at the early stage of the volcanic activity. Clinopyrox-ene megacrysts are located in the lower part of the profile, with amphibole and phlogopite megacrysts in the middle part and anorthoclase megacrysts in the upper part. The crystal integrity, absence of de-formation fabric and their relation to the host basalt suggest that they were crystallized from the host magma and quickly transported to the surface. The mineralogical studies imply that the clinopyroxene megacrysts are of Al-augite with higher Al2O3 (>9%). Amphibole megacrysts are kaersutite rich in TiO2 (>4.5%). Sulfide inclusions such as pyrrhotite occur in some clinopyroxene and amphibole megacrysts. Thermodynamic calculations reveal that pyroxene megacrysts formed under the temperature of 1185.85―1199.85℃ and the pressure between 1.53 and 1.64 GPa comparable to the crust-mantle boundary and amphibole megacrysts crystallized under the pressure of around 0.85 GPa, temperature about 1000℃ comparable to the depth of 30 km. Anorthoclase megacrysts crystallized under the pressure between 0.8―1 GPa,temperature about 900℃.The absence of Ti-rich inclusions such as rutile can be considered as an evidence of quick magma ascending. The P-T conditions estimated via py-roxene megacrysts and phenocrysts compose a P-T path with a steep slope. It can be considered as another evidence of quick magma ascending. However, the estimated temperatures for amphibole megacrysts are markedly lower than those for pyroxene megacrysts given the same pressure. It probably shows that the amphiboles have crystallized at the vanguard of magma and under the vola-tile-rich condition. Thus, we can conclude that the Cenozoic basalts are produced in an extensional tectonic setting and the processes governing crystallization and ascending of the megacrysts are very complex.     

Paleomagnetic study on the Early Triassic red beds from Jiaocheng,Shanxi Province

Paleomagnetic and rock magnetic study has been conducted on the Early Triassic red beds of Liujiagou Formation from Jiaocheng, Shanxi Province. Hematite was shown as the main magnetic mineral. After eradicating an initial viscous component at room temperature to ~100°C–200°C, thermal demagnetization shows that most samples contain two remanence components, intermediate-temperature remanence component at 250°C–500°C and high-temperature component at 500°C–680°C. The intermediate-temperature component has a negative fold test at the 95% confidence level. And the pole position of the intermediate-temperature component in geographic coordinates is correlated with the Middle Jurassic reference pole of the North China Block (NCB) within the 95% confidence, suggesting that it might be a remagnetization component acquired during the Yanshanian period. The high-temperature component contains both reversal and normal polarities with positive fold test and C-level positive reversal test at the 95% confidence level, which suggests that this high-temperature component can be regarded as primary magnetization. Comparison of this newly obtained Early Triassic paleopole with the coeval mean pole of the Ordos Basin suggests that a locally relative rotation may have happened between the Ordos and the Jiaocheng area of Shanxi Province. This rotation may be related with two faults: one is Lishi big fault separating Ordos from Shanxi and the other is Jiaocheng big fault, which is situated in the southeast of sampling locality and was still in motion during the Cenozoic.     

Simulating nonequilibrium transport of atrazine through saturated soil

Atrazine, an herbicide widely used for selective control of grassy weeds in the fields where maize is grown, is a potential ground water contaminant in China and, consequently, there is interest in predicting its mobility in agricultural soils. In this study, we determined the nonequilibrium transport characteristics of atrazine in Shahe soil (Beijing sandy loam) using the advection-dispersion equation, and using a sensitivity analysis, we evaluated the contribution of the uncertainty in a given input parameter to the overall uncertainty in model results. The asymmetrical shape and tailing of the atrazine breakthrough curve (BTC) showed that atrazine was subject to nonequilibrium transport. The observed atrazine BTC was best fitted by the chemical nonequilibrium model with a nonlinear least-squares optimization approach. Results from the sensitivity analysis indicated that the retardation factor was the most sensitive parameter. Considering the reliability of the estimated parameters, the best fit to the atrazine BTC was obtained by fixing the retardation factor based on the linear distribution coefficient, and by calculating the dispersion coefficient from the bromide BTC and the average pore water velocity from the measured data; nonequilibrium parameters were the only unknown parameters that were optimized. Model verification procedures were based on best-fit parameters optimized from one soil column experiment and applied to simulate the transport of atrazine in the duplicate experiment. The results showed there was good agreement between measured and simulated concentrations for atrazine leaching in the soil column.     

Distribution and controlling factors of selenium in weathered soil in Kaiyang County,Southwest China

Selenium is one of the life-related elements. Survey reveals that selenium enrichment in the studied strata from Kaiyang County is considered to be closely related to the following factors： regional black shale series in Ni- utitang Formation of Early Cambrian, strong adsorption of organic matter （OM）, magmatic hydrothermal migrate along the deep fault, mixing and migration of hydrothermal brine, regional uranium mineralization and presence of a great deal sulfides. For selenium enrichment in its weathered soil and crops, the reason responsible is sele- nium-enriched bedrock, which provides material sources for weathering profile and is considered as the main con- trolling factor of selenium content in the soil profile. After leaching and migrates downwards, organic carbon （OC） adsorption, iron-manganese layer adsorption, geochemical barrier role, selenium content in different profiles, there are mainly three types of distribution features： bottom enrichment type, top enrichment type and no significant en- richment type. Comprehensive analyses find that selenium enrichment area is mainly distributed in the Machang, Gaoyun-Fengsan-Guanpo, Baimadong, Chuandong-Hefeng-Shaoshang and Longgang-Gaozhai region, etc. Besides, around the east part of the county, in Huali and Yongxing selenium are relatively scarce.     

黑龙江张家湾岩体锆石U-Pb年龄与地球化学及其地质意义

通过对兴蒙造山带东段小兴安岭-张广才岭地区张家湾岩体石英闪长岩、正长花岗岩进行的锆石LA-ICP-MS U-Pb年龄分析测试、岩石地球化学的各项分析测试,综合分析研究表明,石英闪长岩形成于早侏罗世(176.2±1.8Ma),具浆混花岗岩特点,属壳幔混合成因;正长花岗岩形成于中侏罗世(166±2.2Ma),具"S"型花岗岩的地球化学属性,属壳源熔融成因。结合该区大地构造背景,认为张家湾岩体很可能是环太平洋增生地体的佳木斯板块与西侧的张广才岭地块碰撞造山作用形成。     

A modified Richards equation, its adjoint, and a new perspective on land data assimilation

Summary Richards equation, which is the key relationship for addressing basic soil hydrological processes within the rhizosphere and constitutes the basis for multiple-layer soil hydrology models for meteorological studies, is modified to include two vegetation processes: the transpiration (daytime) and hydraulic lift (nighttime). The analytical form of the adjoint system is derived and can serve as the guideline for discrete forms, as implemented in a variety of multiple layer land surface models. The modified equation and its adjoint model may be used to address at least two types of inverse problems: estimation of the initial soil moisture contents from sparse observations of related quantities; and retrieval of critical soil/vegetation parameters with observations of soil moisture contents (or other related quantities) distributed over a certain period of time. The former may be of more interest for numerical weather prediction studies, whereas the latter may be more valuable for longer time integration of climate models.     

Identification Standard for ENSO Events and Its Application to Climate Monitoring and Prediction in China

The El Niño–Southern Oscillation (ENSO) reflects anomalous variations in the sea surface temperature (SST) and atmospheric circulation over the tropical central–eastern Pacific. It remarkably impacts on weather and climate worldwide, so monitoring and prediction of ENSO draw intensive research. However, there is not yet a unique standard internationally for identifying the timing, intensity, and type of ENSO events. The National Climate Center of China Meteorological Administration (NCC/CMA) has led the effort to establish a national identification standard of ENSO events, which was officially endorsed by the National Standardization Administration of China and implemented operationally in NCC/CMA in 2017. In this paper, two key aspects of this standard are introduced. First, the Niño3.4 SST anomaly index, which is well-recognized in the international ENSO research community and used operationally in the US, has replaced the previous Niño Z index and been used to identify the start, end, and peak times, and intensity of ENSO events. Second, two new indices—the eastern Pacific ENSO (EP) index and the central Pacific ENSO (CP) index, based on the SST conditions in Niño3 and Niño4 region respectively, are calculated to first determine the ENSO type before monitoring and assessing the impacts of ENSO on China’s climate. With this standard, all historical ENSO events since 1950 are consistently re-identified; their distinct properties are diagnosed and presented; and the impacts of ENSO events under different types on China’s climate are re-assessed. This standard is also employed to validate the intensity, grade, and type of the ENSO events predicted by the NCC/CMA operational ENSO prediction system. The new standard and the thus derived unified set of re-analyzed historical ENSO events and associated information provide a good reference for better monitoring and prediction of future ENSO events.     

Single Particle Characterisation of the Aerosol in the Marine Boundary Layer and Free Troposphere over Tenerife, NE Atlantic, during ACE-2

In the framework of the 2nd Aerosol Characterization Experiment (ACE-2), in June and July 1997, size segregated samples were collected for single particle analysis on the island of Tenerife, in both the marine boundary layer (MBL) and the free troposphere (FT), to study the characteristics of the North Atlantic aerosol. A systematic assessment was made of the aerosol under background conditions and when the environment was perturbed by European emissions and/or Saharan dust. The aerosol particles were analysed by automated and manual SEM-EDX, followed by cluster analysis to identify the different particle types and their abundance. Basing on back trajectory calculations, particle numbers and volume concentrations, different periods can be identified regarding the origin of the sampled air masses. In the FT, the air masses were classified as clean Atlantic, Saharan dust from Africa or pollution from Europe. In the MBL, air masses were classified as clean, polluted or perturbed by emissions from Europe. For both the FT and MBL samples, the main changes in chemical composition were observed between the fine and coarse mode aerosol. The FT fine mode aerosol is dominated by S-poor aluminosilicates (62%) in the event of the dust samples or sulphates, carbonaceous particles (20%) and S-rich aluminosilicates (46%) in the polluted samples. For the larger fractions, a strong decreasing trend was observed for the sulphates (less than 20%) and carbonaceous particles (10%) in the polluted samples. The MBL fine mode was completely dominated by S-rich particles (polluted 55% and perturbed 59%), and to a lesser extent, carbonaceous and aged sea salt particles. In the coarse mode, the polluted air mass is dominated by sea salt particles (62%). Contrary to the fine fraction, the polluted air mass in the coarse fraction contained 5.3% of S-rich particles. The combined interpretation of the data from the analysis of size-fractioned particles and the calculated backward trajectories for air masses coming from Europe, Africa and the Atlantic, results in better insights on aerosol chemistry, especially for the comparison of the particle composition in the FT and the MBL.