Analysis of the Relationship between the Cloud Water Path and Precipitation Intensity of Mature Typhoons in the Northwest Pacific Ocean     

Shuang LUO  Yunfei FU  Shengnan ZHOU  Xiaofeng WANG  Dongyong WANG 《大气科学进展》2020,37(4):359-376

The relationship between precipitation intensity and cloud water in typhoon systems remains unclear.This study combined time-and space-synchronized precipitation and spectral data obtained by the Precipitation Radar(PR)as well as the Visible and Infrared Scanner(VIRS)onboard the TRMM satellite,to overcome the limitations of precipitation properties and cloud parameters not being synchronized in previous studies.A merged dataset of near-surface rain rate(RR)and corresponding cloud water path(CWP)was established and used to analyze the potential correlation between cloud microphysical properties and precipitation,to deepen our understanding of the evolution of cloud to rain.In addition,25 collocated satellite overpasses of mature typhoon cases in the Northwest Pacific Ocean from 1998 to 2012 were obtained,and the relationships between the CWP and RR of 144515 pixels were analyzed in detail.The results show that the CWP and RR of mature typhoon systems with different precipitation types,precipitation cloud phases,and vertical depths of precipitation can be fitted by a notable sigmoid function,which may be useful for estimating CWP and parameterizing precipitation in models.Furthermore,the relationship was applied and tested with an independent sample to show that RR is a significant indicator of CWP.  相似文献   

三维点云室内平面要素提取与优化     

宋锦阳  钱建国  汤圣君  王伟玺  李晓明 《测绘通报》2021,(9):15-20,27

室内平面要素的准确提取与关系恢复是室内模型自动化语义重建的重要基础,本文提出了一种面向复杂三维点云的室内平面要素提取与优化方法。该方法首先利用区域增长和RANSAC平面混合分割方法分割室内点云数据;其次利用室内语义部件的空间位置信息及包围盒和法向量信息,对分割后的平面进行平面要素的精确提取;然后对提取的墙面进行优化,实现共享墙面的合并,解决室内墙面冗余的问题;最后利用门与墙的空间位置信息,恢复门墙关联关系。试验部分采用了两组试验数据：一组是深圳大学某层教学楼的激光点云数据,另一组是国际摄影测量与遥感学会（ISPRS）的标准数据,通过对试验结果进行评估,验证了本文方法的有效性和可靠性。  相似文献   

一种基于倾斜摄影测量点云密度自适应分割的建筑物边界提取方法     

刘禹麒  陈广亮  蔡岳臻  李名豪  陈定安  胡小中 《测绘通报》2022,(9):52-57

针对倾斜摄影场景中建筑物单体化问题,本文提出了基于倾斜摄影测量点云数据的建筑物识别和边界提取自动化算法。首先,对点云进行预处理,去除地面点和噪声点;然后,对点云进行二维栅格化处理,按间隔距离预分割;最后,结合改进的大津算法和区域增长算法,从预分割点云识别其中的建筑物,并提取建筑物边界点。从广东省江门市和湛江市选取两处试验区域对算法进行测试,结果表明:区域内建筑物点云均能准确被分割识别,建筑物边界提取准确度分别为87.8%与92.3%,说明本文提出的方法对于倾斜摄影测量建筑物识别和边界提取的适用性较强。  相似文献   

层状云微物理属性垂直分布的季节变化——以新疆地区为例     

光莹  邓军英  陈勇航  辛渝  孙冉  王旭  杨莲梅  刘岩  张瑞 《干旱区地理》2017,40(4):754-761

利用CloudSat卫星资料2B-CLDCLASS和2B-CWC-RVOD数据集,分别揭示了层云与层积云的云粒子等效半径、数浓度及含水量等微物理属性的垂直分布特征及其季节变化规律。结果表明：层云所在的云层高度比层积云高,特别是春季,层云可以延伸到11.0 km处,而层积云云层所在高度最高出现在夏季,最高延伸到8.5 km处。层云中的冰水分布在1.0~11.0 km,液态水分布在0~9.0 km,而层积云的冰水和液态水均分布在0~9.0 km。层云与层积云的冰粒子等效半径、水云粒子数浓度、液态水含量呈现随云层高度的增加而减小的趋势,冰粒子数浓度随云层高度增加呈增大趋势,冰水含量呈峰值分布,峰值出现在6~10 km范围内。各季节层积云粒子等效半径、粒子数浓度及水含量的最大值均大于层云的对应值,从这方面看,层积云更适合作人工增水对象。  相似文献   

A burst of outflows from the Serpens cloud core: wide-field submillimetre continuum, CO J=2–1 and optical observations     

C. J. Davis  H. E. Matthews  T. P. Ray  W. R. F. Dent  J. S. Richer 《Monthly notices of the Royal Astronomical Society》1999,309(1):141-152

Wide-field mapping of Serpens in submillimetre continuum emission and CO J =2–1 line emission is here complemented by optical imaging in [S  ii ] λλ 6716, 6731 line emission. Analysis of the 450- and 850-μm continuum data shows at least 10 separate sources, along with fainter diffuse background emission and filaments extending to the south and east of the core. These filaments describe 'cavity-like' structures that may have been shaped by the numerous outflows in the region. The dust opacity index, β , derived for the identifiable compact sources is of the order of 1.0±0.2, with dust temperatures in excess of 20 K. This value of β is somewhat lower than for typical class I YSOs; we suggest that the Serpens sources may be 'warm', late class 0 or early class I objects.
With the combined CO and optical data we also examine, on large scales, the outflows driven by the embedded sources in Serpens. In addition to a number of new Herbig–Haro flows (here denoted HH 455–460), a number of high-velocity CO lobes are observed; these extend radially outwards from the cluster of submillimetre sources in the core. A close association between the optical and molecular flows is also identified. The data suggest that many of the submillimetre sources power outflows. Collectively, the outflows traced in CO support the widely recognized correlation between source bolometric luminosity and outflow power, and imply a dynamical age for the whole protostellar cluster of ∼3×10⁴ yr. Notably, this is roughly equal to the proposed duration of the 'class 0' stage in protostellar evolution.  相似文献   

Metal-containing molecules: some new candidates for interstellar detection     

Simon Petrie 《Monthly notices of the Royal Astronomical Society》1999,302(3):482-490

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Fluorescent molecular hydrogen in the Eagle nebula     

L. E. Allen  M. G. Burton  S. D. Ryder  M. C. B. Ashley  J. W. V. Storey 《Monthly notices of the Royal Astronomical Society》1999,304(1):98-108

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High-resolution stellar and interstellar spectra of HD 100340     

R. S. I. Ryans  F. P. Keenan  W. R. J. Rolleston  K. R. Sembach  R. D. Davies 《Monthly notices of the Royal Astronomical Society》1999,304(4):947-950

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Measurements of the 44-μm band of H₂O ice deposited on amorphous carbon and amorphous silicate substrates     

Marco M. Maldoni  Garry Robinson  R. G. Smith  W. W. Duley  A. Scott 《Monthly notices of the Royal Astronomical Society》1999,309(2):325-331

We present 20–110 µm absorbance spectra of H₂O ice, deposited on amorphous carbon and silicate substrates, obtained over the 10–140 K temperature range. The measurements have been carried out in a manner that simulates the deposition, warming and cooling of H₂O ice mantles on interstellar and circumstellar grains. For H₂O ice films deposited on these substrates we find (i) similar 44-µm-band peak wavelength temperature dependences, (ii) no bandshape differences in the respective spectra, and (iii) a structural phase transition occurring between 120 and 130 K. In comparison with published data obtained using a polyethylene substrate, the 52-µm feature (the longitudinal optical mode) observed in our spectra is less prominent. This suggests the presence of material-dependent substrate effects that can alter the appearance of the H₂O far-infrared spectrum. The crystallization temperature of H₂O ice films deposited on our amorphous silicate substrate is significantly different from that reported by Moore et al. (1994) , who found crystallization temperatures down to < 20 K for ice also deposited on an amorphous silicate substrate. This is attributed to differences in the surface structures of the respective substrates. This may indicate that, at least in the context of laboratory measurements, substrate material composition is not as significant as substrate surface structure.  相似文献   

有地形存在时对流云发展的数值模拟研究   总被引：13，自引：0，他引：13  

谷国军  王昂生  许焕斌 《气象学报》1994,52(1):90-98

本文通过应用地形转换坐标，建立了一个能够模拟复杂地形上对流云发展的二维非静力的弹性模式，并对以下几个方面进行了模拟实验：首先对初始环境场的调整适应过程进行了模拟研究，得到：在有对流云发展的情况下，只要调整适应时间大于一个浮力振荡周期（即２π／Ｎ），则此时间尺度的大小只对对流云的发展强度产生影响，而对其发展的趋势影响不大。然后我们对下述过程进行了模拟：①地形抬升对积云的触发作用；②上坡环流对已发展对流云的加强；③下坡环流对已发展对流云的减弱。模拟结果表明，模式是稳定的、可靠的。上述模拟研究为我们今后深入开展强对流云数值模拟工作打下了基础。  相似文献