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Advances in Atmospheric Sciences 1997年第1期14卷 104-111页

作者： P. Ernest Raj and P.C.S. Devara Indian Institute of Tropical Meteorology, Pune-411008, India Indian Institute of Tropical Meteorology Pune India

Spatio-temporal variations of water vapor optical depth in the lower troposphere (450-3850 m) over Pune (18°32′N, 73°51′E, 559 m Above Mean Sea Level), India have been studied over a period of five years. The mean vertical structure showed that the moisture content is greatest at the lowest level and decreases with increasing altitude, except in the south-west monsoon season (June to September) where an increase upto 950 m has been found. optical depths are maximum in the monsoon season. The increase from pre-monsoon (March-May) to monsoon season in moisture content on an average is by about 58% in the above altitude range. The temporal variations in surface Relative Humidity and optical depth at 450 m show positive correlation. The amplitude of seasonal oscillation is the largest at 1465 m altitude. The time-height cross-sections of water vapor optical depths in the lower troposphere showed a contrast between years of good and bad monsoon.

关键词： optical depth Precipitable water

Calculation of the Effect of Opacity on the Solar Spectral Lines of CIV

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Plasma Science and Technology 2013年第8期15卷 760-763页

作者：郝希平宋志强贺健李秋泽闫海涛 School of Physics and Engineering Henan University of Science and Technology Henan Police College Luoyang Campus

In this paper, using the intensity ratio between two spectral lines arising from the common lower level, we determine the optical depth of the solar atmosphere of CIV emission lines. The optical depth at the line center of the （1/2-3/2） component is calculated to be 0.05 at the center of the solar disc. By introducing a measured abundance of carbon and the results of ionization balance calculations, we estimate the line-of-sight physical thickness of the regions emitting CIV lines as Heff = 27 km, and we estimate the population density of the lower level to be 1.8 × 106 cm-3 .

关键词： solar spectrum intensity ratio opacity escape factor optical depth

Implications of gamma-ray photon measurements at the LHAASO on Lorentz symmetry

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Chinese Physics C 2022年第5期46卷 165-170页

作者： Yi Ling Yuxuan Liu Sai Wang Meng-He Wu Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China School of Physics University of Chinese Academy of SciencesBeijing 100049China Kavli Institute for Theoretical Sciences(KITS) University of Chinese Academy of SciencesBeijing 100190China

The Large High Altitude Air Shower Observatory(LHAASO)has reported the measurement of photons with high energies of up to 1.42 PeV from twelve gamma-ray *** are concerned with the implications of the LHAASO data on the fate of Lorenz symmetry at such high energy levels;thus,we consider the interaction between gamma rays and photons in the cosmic microwave background(CMB)and compute the optical depth,mean free path,and survival probability of photons from these gamma-ray *** the threshold value predicted by standard special relativity,the lowest survival probability for observed gamma ray photons is found to be approximately 0.60,which is fairly high and implies that abundant photons with energies above the threshold may reach the Earth without Lorentz symmetry *** conclude that it is unreasonable to argue that Lorentz symmetry would be violated using current observations at the LHAASO.

关键词： ultra-high energy gamma ray Lorentz symmetry optical depth

Cirrus Cloud Macrophysical and optical Properties over North China from CALIOP Measurements

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Advances in Atmospheric Sciences 2011年第3期28卷 653-664页

作者：闵敏王普才 James R. Campbell 宗雪梅夏俊荣 Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of Sciences UCAR Visiting Scientist Programs Naval Research LaboratoryMontereyCaliforniaUSA

Two years of mid-latitude cirrus cloud macrophysical and optical properties over North China are described from Earth-orbiting Cloud-Aerosol Lidar with Orthogonal Polarization(CALIOP) satellite measurements. Global cloud climatological studies based on active remote sensing data sets benefit from more accurate resolution of vertical structure and more reliable detection of optically thin *** mean values for cirrus cases over North China are 0.19±0.18 for infrared emittance,0.41±0.68 for visible optical depth, 0.26±0.12 for integrated depolarization ratio,and 0.72±0.22 for integrated color *** studied using reasonable assumptions for the relationship between extinction and ice crystal backscatter coefficients,our results show that most of the cirrus clouds profiled using the 0.532μm channel data stream correspond with an optical depth of less than *** dependence of cirrus cloud properties on cirrus cloud mid-cloud temperature and geometry thickness are generally similar to the results derived from the ground-based lidar, which are mainly impacted by the adiabatic process on the ice cloud ***,the differences in macrophysical parameter variability indicate the limits of spaceborne-lidar and dissimilarities in regional climate variability and the nature and source of cloud nuclei in different geographical regions.

关键词： cirrus cloud spaceborne-lidar optical depth

Aerosol optical properties derived from simultaneous sunphotometer and aureolemeter measurements in Lhasa

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Journal of Environmental Sciences 2000年第4期12卷 439-443页

作者： BAI Yu-bo SHI Guang-yu Koichi Tamura Takashi Shibata Yasunobu Iwasaka Kaneta Shin′ichi Takamura Tamio State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Inst itute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Solar Terrestrial Environment Laboratory Nagoya UniversityNagoyaJapan Center for Environmental Remote Sensing Chiba UniversityChibaJapan

In order to obtain some aerosol properties in Tibetan Plateau atmosphere, simultaneous measurements of aerosols by use of a sunphotometer and an aureolementer were performed in the summer of 1998 in Lhasa(29.65°N, 91.13°E). optical depth, volume size distribution and phase\|function of aerosols were obtained from the measurements. Religious activities can have an effect on optical depth in Lhasa. The daily average aerosol optical depth( λ =500 nm) is less than 0.2. The diurnal variations of aerosol optical depth are relatively small during the period of summer. The maximal value of the mode radius in the volume size distribution are about 0.4, 2.0 and 4.0μm.

关键词： sunphotometer aureolemeter optical depth aerosol volume spectrum phase function

Supersonic Propagation of Heat Waves in Low Density Heavy Material

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Plasma Science and Technology 2005年第4期7卷 2965-2967页

作者：江少恩许琰丁永坤赖东显郑志坚黄翼翔李敬宏孙可煦胡昕张文海易荣清崔延莉陈久森 National Key Laboratory of Laser Fusion Laser Fusion Research Center Mianyang 621900China Institute of Applied Physics and Computation Mathematics Beijing 100088 China

The propagation of a supersonic heat-wave through copper-doped foam with a density of 50 mg/cm^3 was experimentally investigated. The wave is driven by 140 eV Holhraum radiations generated in a cylindrical gold cavity heated by a 2 kJ, ins laser pulse （0.35 μm）. The delayed breakout time of the radiation waves from the rear side of the foam is measured by a three-chromatic streaked x-ray spectrometer （TCS） consisting of a set of three-imaging pinholes and an array of three transmission gratings coupled with an x-ray streak camera （XSC）. With one shot, simultaneous measurements of the delays of the drive source and the radiation with two different energies （210 eV, 840 eV） through the foam have been made for the first time. The experimental results indicate that the time delays vary with photon energies. The radiation with an energy of 210 eV propagates at a lower velocity. The radiating heat wave propagates with a velocity that is larger than the sound speed. Using TGS, the transmitting spectrum was measured, and then lower limit of the optical depth which is more than 1, was obtained. The experimental data were in agreement with numerical simulations.

关键词： supersonic propagation heat wave copper-doped foam optical depth

The Effects of Different HITRAN Versions on Calculated Long-Wave Radiation and Uncertainty Evaluation

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Acta meteorologica Sinica 2012年第3期26卷 389-398页

作者：卢鹏张华荆现文 Chinese Academy of Meteorological Sciences Nanjing University of Information Science & Technology Laboratory for Climate Studies China Meteorological Administration

Four editions of the High Resolution Transmission （HITRAN） databases （HITRAN96, HITRAN2K, HITRAN04, and HITRAN08） are compared by using a line-by-line （LBL） radiative model in the long-wave calculation for six typical atmospheres. The results show that differences in downward radiative fluxes between HITRAN96 and HITRAN08 at the surface can reach a maximum of 1.70 W m-2 for tropical atmospheres. The largest difference in heating rate between HITRAN96 and HITRAN08 can reach 0.1 K day-1 for midlatitude summer atmosphere. Uncertainties caused by line intensity and air-broadened half- widths are also evaluated in this work using the uncertainty codes given in HITRAN08. The uncertainty is found to be 1.92 W m-2 for upward fluxes at the top of the atmosphere （TOA） and 1.97 W m-2 for downward fluxes at the surface. The largest heating rate caused by the uncertainty of line intensity and air-broadened hMf-width can reach 0.5 K day-1. The differences in optical depths between 1300 and 1700 cm-1 caused by different HITRAN versions are larger than those caused by the uncertainties in intensity and air-broadened half-width. This paper suggests that there is inaccurate representation of line parameters over some spectral ranges in HITRAN and more attention should be paid to these ranges in fields such as remote sensing.

关键词： High Resolution Transmission (HITRAN) long-wave radiation optical depth radiative flux,heating rate

Characterization of Stratospheric Aerosol Distributions during the Volcanically Quiescent Period of 1998–2004

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Atmospheric and Oceanic Science Letters 2014年第4期7卷 291-296页

作者： YANG Jing-Mei ZONG Xue-Mei WANG Pu-Cai Key Laboratory of Middle Atmosphere and Global Environment Observation (LAGEO) Institute of Atmospheric Physics Chinese Academy of Sciences

The Stratospheric Aerosol and Gas Experiment （SAGE） II aerosol extinction profiles at 1020 nm were used to study the distribution characteristics of stratospheric aerosols during the volcanically quiescent period of 1998-2004. The stratospheric aerosol distributions exhibited hemispheric asymmetry between the Northern Hemisphere （NH） and the Southern Hemisphere （SH）. In the lower stratosphere below 20 km, the zonal averaged aerosol optical depths in the NH were higher than those of the corresponding SH; whereas at higher altitudes above 20 km, the optical depths in the SH-- except the equatorial region--were higher than those of the NH. At 0-10°N and 10-20°N, the stratospheric aerosol optical depth （SAOD） exhibited larger values in boreal winter and lower values in the spring and summer; at 0-10°S and 10-20°S, the SAOD presented small seasonal variations. At 30-40°N, the SAOD presented larger values in the boreal fall and winter and lower values in the spring and summer; while at 30-40°S, the SAOD exhibited larger values in the austral winter and early spring and lower values in the summer and fall. These characteristics can mainly be attributed to the seasonal cycle of the dynamic transport, and the effects of the buildup and breakdown of the polar vortex. At 50-60°S, the SAOD exhibited extremely high values during austral winter associated with the Antarctic polar vortex boundary; at 50-60°N, the SAOD also exhibited larger values during the boreal winter, but it was much less obvious than that of its southern counterpart.

关键词： aerosol stratosphere distribution optical depth

OBSERVATIONAL STUDIES ON SAND-DUST STORM IN HELAN MOUNTAINOUS AREA

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Acta meteorologica Sinica 2001年第4期15卷 485-497页

作者：牛生杰章澄昌孙继明樊曙先 Nanjing Institute of Meteorology Beijing Institute of Meteorology Ningxia Key Laboratory of Meteorological Disaster Prevention and Mitigation Ningxia University

According to the observation of the number and mass concentration spectra of atmospheric aerosols,the total suspended particulates (TSP) and their size distribution,micrometeorology, and the solar spectroscopic radiation,even neutron activation treatment of sand dust samples in Helan Mountainous *** formation law of floating dust,blowing sand and sandstorm weather and the characteristics of climatic variation in this area and the influence of the Helan Mountain are counted and *** addition,the spectrum characteristics,optical depth and chemical composition of sand aerosol particles are also analyzed and discussed.

关键词： sand-dust storm particle size distribution optical depth chemical composition

PARAMETERIZATION OF SOLAR RADIATIVE FLUX CALCULATION IN THE ATMOSPHERE

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Acta meteorologica Sinica 1994年第1期8卷 79-88页

作者：赵高祥汪宏七 Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029

Based on the two-stream approximation a broad-band parameterization scheme for solar radiative flux calculation is *** whole solar spectral region from 0.2 to 3.58 μm is divided into three broad spectral *** effec- tive broad-band optical depths and single scattering albedos in the atmosphere in each spectral interval can be obtained using parameterized formulae from known atmospheric *** overlapping scattering and/or absorption ef- fects of two atmospheric constituents are considered *** the consideration of radiative effect of clouds in the atmosphere the single scattering albedos and backscattering parameters of clouds in each broad spectral interval are giv- en preliminarily and the cloud optical depths are determined according to the cloud liquid water content.

关键词： two-stream approximation single scattering albedo optical depth parameterization solar radiation