联合降水微物理特征测量仪、激光雨滴谱仪和雨量计的降水对比观测分析

为了对降水微物理特征测量仪(PMCS)的测量性能进行评估,利用PMCS、激光雨滴谱仪(OTT)和雨量计(Gauge)在南京地区进行了降水对比观测实验,通过分析各仪器所测得的降水强度和累计降水量,研究了PMCS和OTT在不同降水强度条件下的尺度谱及其谱参数测量的差异性。结果表明:PMCS所测得的降水强度和累计降水量较OTT小,但更接近于Gauge所测得标准降水强度和累计降水量,3种仪器降水强度结果的相关性均在0.96以上。PMCS测得的谱均值、谱方差、雷达回波强度均小于OTT所测得结果,数密度均大于OTT所测得结果,两者所测得谱参数的变化趋势具有较好的一致性。在相同降水强度范围内,PMCS和OTT所测得的雨滴尺度谱分布趋势具有较好的一致性,在雨滴大尺度段,PMCS测得的雨滴数较OTT偏少,PMCS和OTT对于雨滴的捕获性能随着降水强度增加而增强,并在达到峰值后逐渐减弱。     

二级生化出水化学法深度除磷实验

以二级生化出水为对象,采用4种常规除磷剂开展了化学法深度除磷和投药量经验系数法研究.研究结果表明,FeCl₃在pH为7.5、投加量为6.5 mg/L条件下,Al₂(SO₄)₃在pH为6、投加量为3.75 mg/L条件下,可使出水总磷小于0.5 mg/L,且处理费用低廉,是生化出水深度除磷的适宜药剂.FeCl₃在除磷的同时,对COD也具有较好的去除效果,可作为总磷和COD均超标的二级生化出水深度处理的有效途径.投药量经验系数法可根据原水和出水的磷质量浓度,估算出除磷剂投加量,在工程实践中具有较大的参考价值.     

Accuracy validation of TRMM Multisatellite Precipitation Analysis daily precipitation products in the Lancang River Basin of China

Using statistical methods and contingency table method, this paper evaluates the accuracy of 12 years (1998–2009) Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis (TMPA) daily-accumulated precipitation products within a year, the dry season, and rain season for each of the five subbasins and for each grid point (0.25?×?0.25°) in the Lancang River basin by comparing the results with data from the 35 rain gauges. The results indicate that TMPA daily precipitation estimates tend to show an underestimation comparing to the rain gauge daily precipitations under any scenarios, especially for the middle stream in the dry season. The accuracy of TMPA-averaged precipitation deteriorates with the increase of elevation at both basin and grid scale, with upstream and downstream having the worst and best accuracy, respectively. A fair capability was shown when using daily TMPA accumulations to detect rain events at drizzle rain and this capability improves with the increase of elevation. However, the capability deteriorates when it is used to detect moderate rain and heavy rain events. The accuracy of TMPA precipitation estimate products is better in the rain season than in the dry season at all scenarios. Time difference and elevation are the main factors that have impact on the accuracy of TMPA daily-accumulated precipitation products.     

Improved reliability of ENSO hindcasts with multi-ocean analyses ensemble initialization

Currently, ensemble seasonal forecasts using a single model with multiple perturbed initial conditions generally suffer from an “overconfidence” problem, i.e., the ensemble evolves such that the spread among members is small, compared to the magnitude of the mean error. This has motivated the use of a multi-model ensemble (MME), a technique that aims at sampling the structural uncertainty in the forecasting system. Here we investigate how the structural uncertainty in the ocean initial conditions impacts the reliability in seasonal forecasts, by using a new ensemble generation method to be referred to as the multiple-ocean analysis ensemble (MAE) initialization. In the MAE method, multiple ocean analyses are used to build an ensemble of ocean initial states, thus sampling structural uncertainties in oceanic initial conditions (OIC) originating from errors in the ocean model, the forcing flux, and the measurements, especially in areas and times of insufficient observations, as well as from the dependence on data assimilation methods. The merit of MAE initialization is demonstrated by the improved El Niño and the Southern Oscillation (ENSO) forecasting reliability. In particular, compared with the atmospheric perturbation or lagged ensemble approaches, the MAE initialization more effectively enhances ensemble dispersion in ENSO forecasting. A quantitative probabilistic measure of reliability also indicates that the MAE method performs better in forecasting all three (warm, neutral and cold) categories of ENSO events. In addition to improving seasonal forecasts, the MAE strategy may be used to identify the characteristics of the current structural uncertainty and as guidance for improving the observational network and assimilation strategy. Moreover, although the MAE method is not expected to totally correct the overconfidence of seasonal forecasts, our results demonstrate that OIC uncertainty is one of the major sources of forecast overconfidence, and suggest that the MAE is an essential component of an MME system.     

NanoSIMS analysis of organic carbon from the Tissint Martian meteorite: Evidence for the past existence of subsurface organic‐bearing fluids on Mars

Two petrographic settings of carbonaceous components, mainly filling open fractures and occasionally enclosed in shock‐melt veins, were found in the recently fallen Tissint Martian meteorite. The presence in shock‐melt veins and the deuterium enrichments (δD up to +1183‰) of these components clearly indicate a pristine Martian origin. The carbonaceous components are kerogen‐like, based on micro‐Raman spectra and multielemental ratios, and were probably deposited from fluids in shock‐induced fractures in the parent rock of Tissint. After precipitation of the organic matter, the rock experienced another severe shock event, producing the melt veins that encapsulated a part of the organic matter. The C isotopic compositions of the organic matter (δ¹³C = ?12.8 to ?33.1‰) are significantly lighter than Martian atmospheric CO₂ and carbonate, providing a tantalizing hint for a possible biotic process. Alternatively, the organic matter could be derived from carbonaceous chondrites, as insoluble organic matter from the latter has similar chemical and isotopic compositions. The presence of organic‐rich fluids that infiltrated rocks near the surface of Mars has significant implications for the study of Martian paleoenvironment and perhaps to search for possible ancient biological activities on Mars.     

东昆仑三维重力异常解释方法研究

小波变换是一种广泛应用的信号处理技术,它具有良好的时—频局部化特性。本文探讨了小波变换在分解重力异常中的应用。同时,利用计算机对重力资料的三维定量解释,进行了初步试算。通过东昆仑地区实际资料处理,认为这二种方法在重力资料处理解释中,具有快速、简捷的特点。     

NUMERICAL SIMULATION OF INTERANNUAL AND INTERDECADAL VARIABILITY OF SURFACE WIND OVER THE TROPICAL PACIFIC

A global atmospheric general circulation model (L9R15 AGCMs) forced by COADS SST was integrated from 1945 to 1993. Interannual and interdecadal variability of the simulated surface wind over the tropical Pacific was analyzed and shown to agree vey well with observation. Simulation of surface wind over the central-western equatorial Pacific was more successful than that over the eastern Pacific. Zonal propagating feature of interannual variability of the tropical Pacific wind anomalies and its decadal difference were also simulated successfully. The close agreement between simulation and observation on the existence of obvious interdecadal variability of tropical Pacific surface wind attested to the high simulation capability of AGCM.     

实时相关跟踪图像处理系统

文章介绍了怀柔太阳观测基地最近完成的一套实时高分辨太阳磁场观测系统。系统采用局部相关跟踪算法来提高磁场观测数据的空间分辨率，同时对相关跟踪算法的实现程序进行了优化以满足常规太阳磁场观测的要求。通过对试观测和常规观测数据的分析，我们发现：1）该系统能够大大提高单色像、磁场数据的对比度和空间分辨率；2）对相关跟踪算法的优化大大提高了系统的时间分辨率，系统可以投入常规观测使用。     

AN ACCURATE MODEL FOR CALCULATING CORRECTION OF PATH FLEXURE OF SATELLITE SIGNALS

1　IntroductionTherefractionoflight electronicsignalpropa gatinginatmospherehasbeenstudiedbymanysci entistsandsomemodelofatmosphericrefractioncorreetionhaveheenestablished ,includingHopfieldSaastamoinen,DavisandMarinimodels[1 ] .Butthesemodelscanbeusedonlytocalculatethecorrec tionfortherefractionduetoatmosphericdensityvariation ,whilethecorrectionfortherefractionduetothesignalpathflexurecannotbecalculated .Hop fieldhasestimatedsignalpathflexureerrorbythemethodofraytracing[2 ] ,butastrictcorr…     

井中地震用于陆相储层分析的几项技术

中国陆相储层分布广泛，类型复杂，横向变化大，勘探开发成本高，进行储层分析要求采用高新技术和综合利用多种方法。本文总结了在我国几个油区进行陆相储层分析的几项地震技术即：垂直地震剖面（ＶＳＰ）技术，多偏移距和井间层析成象技术以及多参数分析和综合解释技术，在适应我国经济发展的水平和现状的条件下，用以解决我国复杂的陆相油气储层分析的问题。