主流海表风场资料在舟山群岛近海的性能评估     

刘紫薇  赵帅康  魏笑然  白晔斐 《海洋与湖沼》2022,53(3):528-537

再分析风场资料已广泛应用于我国舟山群岛海域可再生能源评估、海洋灾害预防决策以及港口运维和船舶运输等涉海发展领域,然而不同业务机构所提供的再分析数据在舟山近海的性能表现不一,严重阻碍了此类数据的有效应用。基于2018年全年单点浮标观测资料,综合评价了舟山群岛近海面(10 m)风场的长期变化趋势,并利用误差分析和风玫瑰图等统计工具对6种主流海表风场再分析资料,包括:ECMWF第五代全球大气再分析数据(the 5th generation ECMWF atmospheric reanalysis,ERA5)、NECP第二版全球高分辨率再分析数据(climate forecast system version 2,CFSv2)、美国宇航局物理海洋学分布存档中心的多卫星融合资料(cross-calibrated multi-platform,CCMP)、日本55年再分析数据(Japanese 55-year reanalysis,JRA-55)、第二版现代研究与应用回顾性分析数据(modern-era retrospective analysis for research and applications version 2,MERRA-2)和ECMWF哥白尼大气监测服务再分析数据(the Copernicus Atmosphere Monitoring Service,CAMS)在时间变化特征上进行了对比与评估。研究表明:在综合性能方面,ERA5对风场的再现能力最优,其次为JRA-55;在要素可信度方面,ERA5对风速的再现情况相对较优,而CFSv2的风向再现情况较好;风场产品在不同季节的模拟能力有所差异;不同风场产品在不同风速区间的重构能力也有所不同;在全年风向分布方面,各再分析资料都存在显著的东向偏差。研究结果为不同应用场景下风场资料的选取提供评估依据,并为进一步开发适用于舟山群岛近海的高精度长周期风场数据产品奠定基础。  相似文献   

FT-IR measurements of cold C₃H₈ cross sections at 7–15 μm for Titan atmosphere     

Keeyoon Sung  Geoffrey C. Toon  Arlan W. Mantz  Mary Ann H. Smith 《Icarus》2013

We present absorption cross sections of propane (C₃H₈) at temperatures from 145 K to 297 K in the 690–1550 cm⁻¹ region. Pure and N₂-broadened spectra were measured at pressures from 3 Torr to 742 Torr using a Bruker IFS125 FT-IR spectrometer at JPL. The gas absorption cell, developed at Connecticut College, was cooled by a closed-cycle helium refrigerator. The cross sections were measured and compiled for individual spectra recorded at various experimental conditions covering the planetary atmosphere and Titan. In addition to the cross sections, a propane pseudoline list with a frequency grid of 0.005 cm⁻¹, was fitted to the 34 laboratory spectra. Line intensities and lower state energies were retrieved for each line, assuming a constant width. Validation tests showed that the pseudoline list reproduces discrete absorption features and continuum, the latter contributed by numerous weak and hot band features, in most of the observed spectra within 3%. Based on the pseudoline list, the total intensity in the 690–1550 cm⁻¹ region was determined to be 52.93 (±3%) × 10⁻¹⁹ cm⁻¹/(molecule cm⁻²) at 296 K; this value is within 3% of the average from four earlier studies. Finally, the merit of the pseudoline approach is addressed for heavy polyatomic molecules in support of spectroscopic observation of atmospheres of Titan and other planets. The cold cross sections will be submitted to the HITRAN database (hitran.harvard.edu), and the list of C₃H₈ pseudolines will be available from a MK-IV website of JPL (http://mark4sun.jpl.nasa.gov/data/spec/Pseudo).  相似文献   

海气通量算法在海上蒸发波导诊断中的应用   总被引：1，自引：0，他引：1  

李云波  张永刚  唐海川  王华  焦林 《海洋技术学报》2008,27(1):106-110

利用TOGA COARE Bulk Air-Sea Flux Algorithm3.0,建立了基于通量算法的蒸发波导模型(Flux Evaporation duct Model),并进行了环境敏感性分析,而且与Paulus-Jeske模型对比,进行误差敏感性分析,并开展了雷达探测评估的海上试验,较全面的阐述了基于通量算法的蒸发波导模型的性能。  相似文献   

大气对地球自转参数（ERP）的高频激发   总被引：4，自引：0，他引：4  

谢伯全  郑大伟 《天文学报》1996,37(2):113-123

本文采用１９８３—１９９２年期间由空间大地测量技术观测和归算的地球自转参数（ＥＲＰ）序列，以及由全球气象资料归算的大气角动量（ＡＡＭ）序列，分析和研究了大气对地球自转参数的日长变化（ＬＯＤ）和极移（ｘ和ｙ）在一个月时间尺度以内的高频激发作用，得到的主要结果如下：１大气对ＬＯＤ分量高频潮汐的估计值存在着影响，但是，潮汐形变参数ｋ／ｃ随时间和频率的变化却是受非大气因素的扰动引起的．２．大气可以解释３０天以下ＬＯＤ非潮汐的大部分变化．３．极移分量３０天以内的高频变化也主要由大气激发．ｘ分量与大气的相关性要强于ｙ分量，而且更为稳定，主要表现为平均时间尺度约为２７天的波动，大气对这个波动的贡献可达７０％．  相似文献   

昆明高空大气活动与天文视宁度关系初探     

李晓明  赵本忠 《天文研究与技术》1995,(4)

本文初步对比分析了昆明大气探空资料与大气视宁度观测资料之间的相关关系。结果表明，它们之间有着明显的关系和规律，但关系式的确立还需更多的资料分析才能确定。  相似文献   

Wavelet imaging cleaning method for atmospheric Cherenkov telescopes     

R. W. Lessard  L. Cayn  G. H. Sembroski  J. A. Gaidos 《Astroparticle Physics》2002,17(4):427-440

We present a new method of image cleaning for imaging atmospheric Cherenkov telescopes. The method is based on the utilization of wavelets to identify noise pixels in images of gamma-ray and hadronic induced air showers. This method selects more signal pixels with Cherenkov photons than traditional image processing techniques. In addition, the method is equally efficient at rejecting pixels with noise alone. The inclusion of more signal pixels in an image of an air shower allows for a more accurate reconstruction, especially at lower gamma-ray energies that produce low levels of light. We present the results of Monte Carlo simulations of gamma-ray and hadronic air showers which show improved angular resolution using this cleaning procedure. Data from the Whipple Observatory's 10-m telescope are utilized to show the efficacy of the method for extracting a gamma-ray signal from the background of hadronic generated images.  相似文献   

Spectral analysis of the background in ground-based, long-slit spectroscopy     

Frédéric Zagury 《Journal of Astrophysics and Astronomy》2005,26(4):377-394

This paper examines the variations, because of atmospheric extinction, of broad-band visible spectra, obtained from long-slit spectroscopy, in the vicinity of some stars, nebulae, and one faint galaxy.  相似文献   

Aeronomy of extra-solar giant planets at small orbital distances     

Roger V. Yelle 《Icarus》2004,170(1):167-179

One-dimensional aeronomical calculations of the atmospheric structure of extra-solar giant planets in orbits with semi-major axes from 0.01 to 0.1 AU show that the thermospheres are heated to over 10,000 K by the EUV flux from the central star. The high temperatures cause the atmosphere to escape rapidly, implying that the upper thermosphere is cooled primarily by adiabatic expansion. The lower thermosphere is cooled primarily by radiative emissions from H⁺₃, created by photoionization of H₂ and subsequent ion chemistry. Thermal decomposition of H₂ causes an abrupt change in the composition, from molecular to atomic, near the base of the thermosphere. The composition of the upper thermosphere is determined by the balance between photoionization, advection, and H⁺ recombination. Molecular diffusion and thermal conduction are of minor importance, in part because of large atmospheric scale heights. The energy-limited atmospheric escape rate is approximately proportional to the stellar EUV flux. Although escape rates are large, the atmospheres are stable over time scales of billions of years.  相似文献   

四川盆地大气边界层气象资料数据系统     

刘建西  但尚铭  刘兴华  彭虎  魏袁立 《成都信息工程学院学报》1992,(4)

本文介绍在IBM-PC微机(或兼容机)上利用DBASEⅡ、BASIC和FOR-TRAN语言设计和研制的一套大气边界层气象资料数据库软件系统,给出它的主要结构和功能。该系统实现了大气边界层气象资料共享和信息化处理,不但操作简便、快速、准确、稳定性好,而且具有较强的通用性和较大的实用价值。  相似文献   

Distinct climate change synchronous with Heinrich event one, recorded by stable oxygen and carbon isotopic compositions in stalagmites from China   总被引：2，自引：0，他引：2  

Houyun Zhou  Jianxin Zhao  Michael K. Gagan  Jun Yan 《Quaternary Research》2008,69(2):306-315

Uranium-series dating of oxygen and carbon isotope records for stalagmite SJ3 collected in Songjia Cave, central China, shows significant variation in past climate and environment during the period 20-10 ka. Stalagmite SJ3 is located more than 1000 km inland of the coastal Hulu Cave in East China and more than 700 km north of the Dongge Cave in Southwest China and, despite minor differences, displays a clear first-order similarity with the Hulu and Dongge records. The coldest climatic phase since the Last Glacial Maximum, which is associated with the Heinrich Event 1 in the North Atlantic region, was clearly recorded in SJ3 between 17.6 and 14.5 ka, in good agreement in timing, duration and extent with the records from Hulu and Dongge caves and the Greenland ice core. The results indicate that there have been synchronous and significant climatic changes across monsoonal China and strong teleconnections between the North Atlantic and East Asia regions during the period 20-10 ka. This is much different from the Holocene Optimum which shows a time shift of more than several thousands years from southeast coastal to inland China. It is likely that temperature change at northern high latitudes during glacial periods exerts stronger influence on the Asian summer monsoon relative to insolation and appears to be capable of perturbing large-scale atmospheric/oceanic circulation patterns in the Northern Hemisphere and thus monsoonal rainfall and paleovegetation in East Asia. Climatic signals in the North Atlantic region propagate rapidly to East Asia during glacial periods by influencing the winter land-sea temperature contrast in the East Asian monsoon region.  相似文献