用红外云图估测小区域雨强及其在短时预报中的应用   总被引：6，自引：0，他引：6  

兰红平  张儒林  江崟 《热带气象学报》2000,16(4):366-373

在吸收国内外对卫星估测降水的经验和方法的基础上,利用深圳自动气象站网观测资料,对卫星云图资料进行分析、对比、反演,得到小区域红外云图对流云云顶亮温与降水强度的统计关系,建立了一个利用红外云图云顶亮温,结合空气水汽含量,云顶亮温的变化进行自动短量估测小区域对流云团降雨强度的方法;利用这种方法对深圳本地的短时强降雨的估测取得较好的效果。并在此基础上,运用云团移动外推的办法预测未来小区域云顶亮温的变化,  相似文献   

Pressure dependence of hydroxyl solubility in coesite     

J. L. Mosenfelder 《Physics and Chemistry of Minerals》2000,27(9):610-617

 The solubility of hydroxyl in coesite was investigated in multianvil experiments performed at 1200 °C over the nominal pressure range 5–10 GPa, at an f _O2 close to the Ni-NiO buffer. The starting material for each experiment was a cylinder of pure silica glass plus talc, which dehydrates at high P and T to provide a source of water and hydrogen (plus enstatite and excess SiO₂). Fourier-transform infrared (FTIR) spectra of the recovered coesite crystals show five sharp bands at 3606, 3573, 3523, 3459, and 3299 cm⁻¹, indicative of structurally bonded hydrogen (hydroxyl). The concentration of hydrogen increases with pressure from 285 H/10⁶ Si (at 5 GPa) to 1415 H/10⁶ Si (at 10 GPa). Assuming a model of incorporation by (4H)_Si defects, the data are fit well by the equation C _OH=Af ² _H2<\INF>Oexp(−PΔV/RT), with A=4.38 H/10⁶ Si/GPa, and ΔV=20.6 × 10⁻⁶ m³ mol⁻¹. An alternative model entailing association of hydrogen with cation substitution can also be used to fit the data. These results show that the solubility of hydroxyl in coesite is approximately an order of magnitude lower than in olivines and pyroxenes, but comparable to that in pyropic garnet. However, FTIR investigations on a variety of ultrahigh pressure metamorphic rocks have failed in all cases to detect the presence of water or hydrogen in coesite, indicating either that it grew in dry environments or lost its hydrogen during partial transformation to quartz. On the other hand, micro-FTIR investigations of quartz crystals replacing coesite show that they contain varying amounts of H₂O. These results support the hypothesis that preservation of coesite is not necessarily linked to fast exhumation rates but is crucially dependent on limited fluid infiltration during exhumation. Received: 23 August 1999 / Accepted: 10 April 2000  相似文献   

中国江南—华南地区一次强飑线天气过程位涡诊断分析     

李文娟  俞小鼎  滕代高  彭霞云  刘汉华 《气象与环境学报》2021,37(6):1-10

应用FY-4A卫星红外和水汽云图资料,结合NCEP分析场资料以及地面自动气象站变压、变温、大风及降水资料,计算等熵面位涡,分析2018年3月4日中国江南—华南地区强飑线过程的发生发展机制及持续性大风产生的主要原因。结果表明：对流单体触发于低层辐合系统,由于雷暴下沉气流与其前方的低层暖湿西南气流形成地面辐合线,并且移入地区的水汽、静力不稳定及垂直风切变条件对强对流风暴的发展均十分有利,使得导致极端对流大风的强对流风暴持续发展。极端大风主要分布在飑线中弓形结构的顶端,落区与亮温梯度和变压梯度相对应,导致变压风增大;飑线的移动与引导气流方向一致,系统走向和低层西南急流接近于垂直,系统移速加快,动量下传效应增强,均是导致极端地面大风的成因。位涡分布表明高位涡的侵入和呈弓形分布的低位涡区的形成具有一定关联,干侵入区与等熵面上高位涡区有着较好的对应,飑线后部的暗区正是干侵入的前沿,高层高位涡的下传是飑线系统持续发展的成因。  相似文献   

红外云图的参数化及其与局地降雨的关系探讨   总被引：2，自引：0，他引：2  

王越  肖稳安 《气象科学》1999,19(4):366-374

本文从大气探测原理和大气物理的基本概念出发,将地面气象观测资料与红外卫星云图相结合进行参数化估计,得到一些参数化估计结果。初步分析表明,这些参数化估计值与局地降雨有较好的相关关系。  相似文献   

Temperature-induced changes in the NIR spectra of hydrous albitic and rhyolitic glasses between 300 and 100 K     

A. C. Withers  H. Behrens 《Physics and Chemistry of Minerals》1999,27(2):119-132

Near-infrared (NIR) absorption bands related to total water (4000 and 7050 cm⁻¹), OH groups (4500 cm⁻¹) and molecular H₂O (5200 cm⁻¹) were studied in two polymerised glasses, a synthetic albitic composition and a natural obsidian. The water contents of the glasses were determined using Karl Fischer titration. Molar absorption coefficients were calculated for each of the bands using albitic glasses containing between 0.54 and 9.16 wt.% H₂O and rhyolitic glasses containing between 0.97 and 9.20 wt.% H₂O. Different combinations of baseline type and intensity measure (peak height/area) for the combination bands at 4500 and 5200 cm⁻¹ were used to investigate the effect of evaluation procedure on calculated hydrous species concentrations. Total water contents calculated using each of the baseline/molar absorption coefficient combinations agree to within 5.8% relative for rhyolitic and 6.5% relative for albitic glasses (maximum absolute differences of 0.08 and 0.15 wt.% H₂O, respectively). In glasses with water contents >1 wt.%, calculated hydrous species concentrations vary by up to 17% relative for OH and 11% relative for H₂O (maximum absolute differences of 0.33 and 0.43 wt.% H₂O, respectively). This variation in calculated species concentrations is typically greater in rhyolitic glasses than albitic. In situ, micro-FTIR analysis at 300 and 100 K was used to investigate the effect of varying temperature on the NIR spectra of the glasses. The linear and integral molar absorption coefficients for each of the bands were recalculated from the 100 K spectra, and were found to vary systematically from the 300 K values. Linear molar absorption coefficients for the 4000 and 7050 cm⁻¹ bands decrease by 16–20% and integral molar absorption coefficients by up to 30%. Depending on glass composition and baseline type, the integral molar absorption coefficients for the absorption bands related to OH groups and molecular H₂O change by up to −5.8 and +7.4%, respectively, while linear molar absorption coefficients show less variation, with a maximum change of ∼4%. Using the new molar absorption coefficients for the combination bands to calculate species concentrations at 100 K, the maximum change in species concentration is 0.08 wt.% H₂O, compared with 0.39 wt.% which would be calculated if constant values were assumed for the combination band molar absorption coefficients. Almost all the changes in the spectra can therefore be interpreted in terms of changing molar absorption coefficient, rather than interconversion between hydrous species. Received: 17 December 1998 / Revised, accepted 8 July 1999  相似文献   

坡缕石的红外光谱研究   总被引：14，自引：0，他引：14  

宋功保  刘福生 《岩石学报》1999,15(3):469-474

在仔细分析坡缕石结构特点的基础上,对坡缕石结构的组成离子进行了详细划分。利用晶体化学和分子轨道理论,深入研究了热液型和沉积型坡缕石的红外光谱谱图特点, 对坡缕石结构中的水以及 Ｓｉ— Ｏ 区红外吸收带进行了归属研究。其中, 约 ３６９４ ｃｍ － １ 、３６１１ｃｍ － １ 吸收带分别归属为 ν Ｍ ｇ— Ｏ Ｈ 、ν Ａｌ— Ｏ Ｈ , 约 ３５４０ ｃｍ － １ 吸收带归属为 ν Ｏ Ｈ ２ , 约 ３３９４ ｃｍ － １ 、３２９４ｃｍ － １ 吸收带归属为ν Ｈ２ Ｏ , 约 １６５５ ｃｍ － １、１４００ ｃｍ － １ 吸收带归属为δ Ｏ Ｈ ２ 、δ Ｈ ２ Ｏ ; Ｓｉ— Ｏ 振动区,连接坡缕石倒转结构单元间的直线型 Ｓｉ— Ｏ桥倒— Ｓｉ的红外振动吸收频率最高, 与活性氧结合的 Ｓｉ— Ｏ活红外振动吸收频率居次, 其中 Ｓｉ— Ｏ活边 高于 Ｓｉ— Ｏ活内, 而连接辉石式单链的 Ｓｉ— Ｏ桥非— Ｓｉ较低, 且 Ｓｉ— Ｏ桥非间— Ｓｉ比 Ｓｉ— Ｏ桥非内 — Ｓｉ低。  相似文献   

红外热象仪在岩石力学遥感基础实验中的应用   总被引：1，自引：0，他引：1  

支毅乔  崔承禹  张晋开  邓明德  耿乃光 《遥感学报》1996,(3)

在岩石力学性质实验中，使用ＡＧＡ红外热象仪观测到随岩石应力的增加，岩石表面红外辐射温度升高；由岩石破裂处观测到岩石内部增温一般在２—４℃。也观测到随应力变化，岩石红外辐射温度场的变化过程，即随岩石应力增加，在弹性形变期其表面红外辐射温度呈上升趋势，在塑性形变期呈下降趋势，之后岩石破裂。这是很有重要意义的一种物理现象。热象仪的观测结果为红外遥感观测地应力变化提供了理论依据。  相似文献   

Palaeodiet of Miocene Producers and Depositional Environments: Inferences from the First Evidence of Microcoprolites from India     

Vivesh V. KAPUR  Kamlesh KUMAR  P. MORTHEKAI  Amritpal Singh CHADDHA 《《地质学报》英文版》2020,94(5):1574-1590

This paper reviews research on coprolites from India, providing the first evidence of microcoprolites from the early Miocene (Aquitanian) Khari Nadi Formation sedimentary succession, exposed about 1.5 km northeast of the village of Kotada, Kachchh (Kutch) District, Gujarat State, western India. Morphometric and size comparisons (in a statistical framework) with known coprolites from the Mesozoic-Cenozoic successions of India (including those recorded herein) and globally suggest that fishes were the likely producers of the Kotada coprolites. Scanning electron microscopy confirms the presence of fish dental remains within the coprolites, while both Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) reveal the phosphatic nature of the microscopic coprolite specimens (recorded herein) hinting that the producer(s) were predominantly carnivorous (ichthyophagous) in their diet. Furthermore, X-Ray Fluorescence (XRF) analysis of the host and associated lithologies allows us to deduce that the Kotada coprolites were deposited in a shallow marine environment, with possible aerial exposure of the host lithology occurring at some point after deposition. To the best of our knowledge, the present report is the first record of microscopic fish coprolites from India, as well as being the first from the Aquitanian of India and the oldest Neogene record from India.  相似文献   

冬奥赛场卫星和地基微波辐射计气温廓线观测对比和验证          下载免费PDF全文

张鹏  咸迪  孙雪琪  王银钢  尹佳莉 《气象科技》2022,50(4):485-493

利用探空站数据对北京和张家口冬奥赛场周边地区的地基微波辐射计和FY 4A大气垂直探测仪资料进行验证分析。选取2020年全年FY 4A大气垂直探测仪资料以及2020年12月至2021年3月期间对冬奥赛事有重要影响的寒潮前后、雾霾和沙尘暴这3种不同天气现象下探测得到的气温廓线数据进行个例分析。结果表明：在晴空条件下，地基微波辐射计和FY 4A大气垂直探测仪探测大气垂直气温的精度较高，平均相关系数达到0.97，低层大气（500 hPa以下）较高层大气探测结果的一致性较好；大气污染对探测精度产生一定影响，其中PM2.5产生的影响较小，PM10的提高对FY 4A大气垂直探测仪的探测产生较大影响，尤其是发生沙尘暴时，星载探测仪无法对低层大气进行探测。经过对比和验证，卫星探测作为补充探测手段，可以与地基微波辐射计互相补充，尤其是在空间覆盖和时间分辨率上具备一定优势，但在有云和沙尘暴的天气条件下无法对低层大气开展探测；地基微波辐射计可以对一个地点的大气垂直参数开展不间断的探测，与探空站数据的一致性较高。卫星探测和地基微波辐射计均可以为冬奥赛事提供高时间分辨率的探测数据，为数值天气预报提供有力的数据支撑。  相似文献   

基于FY-4A卫星遥感数据分析2021年3次沙尘暴特征          下载免费PDF全文

高泽田  胡秀清  张小曳  王亚强 《气象科技》2022,50(4):536-544

FY 4A上搭载的多通道扫描成像辐射计（AGRI）无论是时间分辨率还是空间分辨率与我国第一代静止气象卫星风云二号上搭载的扫描辐射计（VISSR）相比都有了明显的改进。本文基于FY 4A AGRI成像仪IDDI(红外差值沙尘指数)和新的昼夜沙尘遥感改进算法开展2021年中国北方沙尘过程连续遥感监测处理，并系统分析了2021年3个典型个例的沙尘暴特征和影响区域。结果表明：① 3次典型沙尘过程对我国北方各省份的影响面积总计最低达到260万km2以上，最高达到300万km2以上，4月14—17日的沙尘暴影响面积最大。②2021年沙尘高发区在新疆南部、甘肃河西走廊以北以及内蒙古西部。与2019、2020年同期相比，2021年我国北方沙尘发生频次更高、影响范围更大。③新一代FY 4A静止卫星对我国沙尘过程年际变化具备更加完整的监测能力。  相似文献