The rhythm in the atmosphere and oceans in application to long-range weather forecasting

The most effective technique in long-range weather forecasting in China is teleconnection. Summer rainfall and temperatures are closely correlated to the preceding winter 500 mb heights over the Northern Hemisphere and sea surface temperatures over the North Pacific, so the former can be predicted from the latter. This kind of connection is called rhythm. In this paper, four examples of rhythm are outlined. The manifestation of rhythm and its universal significance is demonstrated. The mechanism of rhythm is discussed.     

裂隙岩石介质中核素迁移的模型及其算子分裂、迎风、均衡格式

建立了放射性核素在裂隙岩石介质中迁移的双重介质模型,对模型的求解提出了一种新的数值方法—Galerkin有限元法与算子分裂、迎风、均衡格式相结合的新方法,给出了水质模型算子分裂、迎风、均衡格式的稳定性条件,且所得到的计算格式是非负的。最后通过对核素90Sr 100年、99Tc 1000年的预测计算,验证了本文所提方法的有效性和稳定性,并得出了一些有重要意义的结论。     

Three-dimensional analysis of ozone and PM<Subscript>2.5</Subscript> distributions obtained by observations of tethered balloon and unmanned aerial vehicle in Shanghai,China

A lightweight unmanned aerial vehicle (UAV) and a tethered balloon platform were jointly used to investigate three-dimensional distributions of ozone and PM_2.5 concentrations within the lower troposphere (1000 m) at a localized coastal area in Shanghai, China. Eight tethered balloon soundings and three UAV flights were conducted on May 25, 2016. Generalized additive models (GAMs) were used to quantitatively describe the relationships between air pollutants and other obtained parameters. Field observations showed that large variations were captured both in the vertical and horizontal distributions of ozone and PM_2.5 concentrations. Significant stratified layers of ozone and PM_2.5 concentrations as well as wind directions were observed throughout the day. Estimated bulk Richardson numbers indicate that the vertical mixing of air masses within the lower troposphere were heavily suppressed throughout the day, leading to much higher concentrations of ozone and PM_2.5 in the planetary boundary layer (PBL). The NO and NO₂ concentrations in the experimental field were much lower than that in the urban area of Shanghai and demonstrated totally different vertical distribution patterns from that of ozone and PM_2.5. This indicates that aged air masses of different sources were transported to the experimental field at different heights. Results derived from the GAMs showed that the aggregate impact of the selected variables for the vertical variations can explain 94.3% of the variance in ozone and 94.5% in PM_2.5. Air temperature, relative humidity and atmospheric pressure had the strongest effects on the variations of ozone and PM_2.5. As for the horizontal variations, the GAMs can explain 56.3% of the variance in ozone and 57.6% in PM_2.5. The strongest effect on ozone was related to air temperature, while PM_2.5 was related to relative humidity. The output of GAMs also implied that fine aerosol particles were in the stage of growth in the experimental field, which is different from ozone (aged air parcels of ozone). Geographical parameters influenced the horizontal variations of ozone and PM_2.5 concentrations by changing underlying surface types. The differences of thermodynamic properties between land and sea resulted in quick changes of PBL height, air temperature and dew point over the coastal area, which was linked to the extent of vertical mixing at different locations. The results of GAMs can be used to analyze the sources and formation mechanisms of ozone and PM_2.5 pollutions at a localized area.     

Comparison of the LEW88516 and ALHA77005 martian meteorites: Similar but distinct

Abstract By mineral and bulk compositions, the Lewis Cliff (LEW) 88516 meteorite is quite similar to the ALHA77005 martian meteorite. These two meteorites are not paired because their mineral compositions are distinct, they were found 500 km apart in ice fields with different sources for meteorites, and their terrestrial residence ages are different. Minerals in LEW88516 include: olivine, pyroxenes (low- and high-Ca), and maskelynite (after plagioclase); and the minor minerals chromite, whitlockite, ilmenite, and pyrrhotite. Mineral grains in LEW88516 range up to a few mm. Texturally, the meteorite is complex, with regions of olivine and chromite poikilitically enclosed in pyroxene, regions of interstitial basaltic texture, and glass-rich (shock) veinlets. Olivine compositions range from Fo₆₄ to Fo₇₀, (avg. Fo₆₇), more ferroan and with more variation than in ALHA77005 (Fo₆₉ to Fo₇₃). Pyroxene compositions fall between En₇₇Wo₄ and En₆₅Wo₁₅ and in clusters near En₆₃Wo₉ and En₅₃Wo₃₃, on average more magnesian and with more variation than in ALHA77005. Shock features in LEW88516 range from weak deformation through complete melting. Bulk chemical analyses by modal recombination of electron microprobe analyses, instrumental neutron activation, and radiochemical neutron activation confirm that LEW88516 is more closely related to ALHA77005 than to other known martian meteorites. Key element abundance ratios are typical of martian meteorites, as is its non-chondritic rare earth pattern. Differences between the chemical compositions of LEW88516 and ALHA77005 are consistent with slight differences in the proportions of their constituent minerals and not from fundamental petrogenetic differences. Noble gas abundances in LEW88516, like those in ALHA77005, show modest excesses of ⁴⁰Ar and ¹²⁹Xe from trapped (shock-implanted) gas. As with other ALHA77005 and the shergottite martian meteorites (except EETA79001), noble gas isotope abundances in LEW88516 are consistent with exposure to cosmic rays for 2.5–3 Ma. The absence of substantial effects of shielding from cosmic rays suggest LEW88516 spent this time as an object no larger than a few cm in diameter.     

浅议新形势下的国土资源队伍形象塑造

树立良好的国土资源管理队伍形象,是当前国土资源管理体制改革的迫切需要,是充分发挥国土资源管理各项职能的客观要求。塑造新形势下的国土资源队伍形象是一项长期的、需要全体“国土卫士”持之以恒艰苦努力的工程。可总结为：塑“魂”、创“新”、建“制”、促“廉”、立“本”、树“形”6个方面。     

The first Surijokocixiidae (Insecta: Hemiptera: Fulgoromorpha) from the Triassic of China

A planthopper originally assigned to the genus Boreocixius in Surijokocixiidae (Surijokocixioidea, Fulgoromorpha) from the Ladinian (Middle Triassic) of Tongchuan in Shaanxi, northwestern China is described as Boreocixius tongchuanensis Zhang et al. sp. nov. As the third species ascribed to the genus, it differs from its congeners in having the much larger tegmen with postnodal veinlets and pigmented bands, providing new morphological information for Boreocixius. The establishment of the new species further increases the diversity of Boreocixius and Surijokocixiidae as well.     

Heterogeneous characteristics of streambed saturated hydraulic conductivity of the Touchet River,south eastern Washington,USA

Traditionally a streambed is treated as a layer of uniform thickness and low saturated hydraulic conductivity (K) in surface‐ and ground‐water studies. Recent findings have shown a high level of spatial heterogeneity within a streambed and such heterogeneity directly affects surface‐ and ground‐water exchange and can have ecological implications for biogeochemical transformations, nutrient cycling, organic matter decomposition, and reproduction of gravel spawning fish. In this study a detailed field investigation of K was conducted in two selected sites in Touchet River, a typical salmon spawning stream in arid south eastern Washington, USA. In‐stream slug tests were conducted to determine K following the Bouwer and Rice method. For the upper and lower sites, each 50 m long and 9 m wide and roughly 20 m apart, a sampling grid of 5 m longitudinally and 3 m transversely was used. The slug tests were performed for each horizontal coordinate at 0·3–0·45, 0·6–0·75, 0·9–1·05 and 1·2–1·35 m depth intervals unless a shallower impenetrable obstruction was encountered. Additionally, water levels were measured to obtain vertical hydraulic gradient (VHG) between each two adjacent depth intervals. Results indicated that K ranged over three orders of magnitude at both the upper and lower sites and differed between the two sites. At the upper site, K did not differ significantly among different depth intervals based on nonparametric statistical tests for mean, median, and empirical cumulative distribution, but the spatial pattern of K varied among different depth intervals. At the lower site, K for the 0·3–0·45 m depth interval differed statistically from those at other depth intervals, and no similar spatial pattern was found among different depth intervals. Zones of upward and downward water flow based on VHG also varied among different depth intervals, reflecting the complexities of the water flow regime. Detailed characterization of the streambed as attempted in this study should be helpful in providing information on spatial variations of streambed hydraulic properties as well as surface‐ and ground‐water interaction. Copyright © 2009 John Wiley & Sons, Ltd.     

Occurrence and characteristics of sporadic sodium layer observed by lidar at a mid-latitude location

Na lidar observations of SSL during the past 5 years at a mid-latitude location (Wuhan, China, 31°N, 114°E) are reported in this paper. From 26 SSL events detected in about 230 h of observation, an SSL occurrence rate of 1 event/9 h at our location was obtained. This result, combined with that reported by Nagasawa and Abo (Geophys. Res. Lett. 22 (1995) 263) at Tokyo, Japan, reveals that the SSL occurrence can be relatively frequent at some mid-latitude locations. The statistical analyses of main parameters for the 26 SSL events were made, and the results were compared with those previously reported. By examining the corresponding data from a nearby ionosonde, it was found that there was a fairly good correlation between SSL and Es. Of the 18 pairs of SSL and Es events checked, 15 of SSL were accompanied by Es, and 8 pairs of them were correlated within 1 h in time and within 5 km in altitude. From the analyses of observed perturbations during SSL development, the role of dynamic processes of atmosphere in the SSL formations were emphasized.     

Tests and applications of an approach to absorbing reflected waves towards incident boundary

If the upstream boundary conditions are prescribed based on the incident wave only, the time-dependent numerical models cannot effectively simulate the wave field when the physical or spurious reflected waves become significant. This paper describes carefully an approach to specifying the incident wave boundary conditions combined with a set sponge layer to absorb the reflected waves towards the incident boundary. Incorporated into a time-dependent numerical model, whose governing equations are the Boussinesq-type ones, the effectiveness of the approach is studied in detail. The general boundary conditions, describing the down-wave boundary conditions are also generalized to the case of random waves. The numerical model is in detail examined. The test cases include both the normal one-dimensional incident regular or random waves and the two-dimensional oblique incident regular waves. The calculated results show that the present approach is effective on damping the reflected waves towards the incident wave boundary.