气候标准序列变率

首先,综论已有气候序列变率的各种量数,提出气候标准序列变率和推导其与他种序列变率间的关系,以资比较。然后,推导了气候标准序列变率抽样分布的参数(平均数与方差),并证明了在正态假设下这些参数的简化结果和气候标准序列变率抽样分布函数中的参数是一致的。这些是本文的重点。最后,应用气候标准序列变率的一些统计理论说明其在资料统计方面的实用价值,指出其优越性。气候标准序列变率不仅可以分析气候特征,它可以用于研究气候变迁与旱涝规律,以及用于气候统计予报。     

Spectral analysis of climatological series in Duero Basin

Summary General harmonic analysis (FFT) and maximum entropy spectral analysis (MEM) are used in order to study annual and monthly values of air temperature, precipitation and insolation in a number of weather stations in Duero Hydrographic Basin. The corresponding spectra estimates were prepared and compared. MEM estimates show better power resolution and a better spectral definition than FFT estimates. Based on the similarity behavior of the spectra, four main climatic zones were clearly defined. Finally, physical interpretation of the main features of the most representative spectra for the four regions was attempted.With 9 Figures     

Spectral analysis of unevenly spaced climatological time series

Spectral analysis is often based on the periodogram and on fitting a first-order autoregressive [AR(1)] process to data as climatological time series generally exhibit red noise spectra that can be well approximated by AR(1) models. When the periodogram exceeds some threshold at a frequency, the spectrum is said to differ from the AR(1) spectrum, and the frequency is generally taken as a member of the discrete spectrum. This traditional technique, however, must not be used without modifications for unevenly spaced data. Our purpose is to provide an AR(1) modeling tool that is more accurate than the TAUEST procedure commonly used for unevenly spaced paleoclimatical records. A periodogram based on an entire least square fit to unevenly spaced data is also introduced instead of the well-known Lomb–Scargle periodogram. The methodology is applied to two paleoclimatological records. Our results compared to those of a frequently used procedure (consisting of TAUEST and Lomb–Scargle periodogram) show some interesting differences.     

A climatological analysis of Saharan cyclones

In this study, the climatology of Saharan cyclones is presented in order to understand the Saharan climate, its variability and its changes. This climatology includes an analysis of seasonal and interannual variations, the identification and classification of cyclone tracks, and a presentation of their chief characteristics. The data used are drawn from the 1980–2009, 2.5° × 2.5°, NCEP/NCAR reanalysis (NNRP I) dataset. It is found that cyclone numbers increase in September–October–November (SON) at 4.9 cyclones per decade, while they decrease in June–July–August at 12.3 cyclones per decade. The identification algorithm constructed 562 tracks, which are categorized into 12 distinct clusters. Around 75 % of the Saharan cyclones originate south of the Atlas Mountains. The percentage of tracks that move over the Sahara is around 48 %. The eastern Mediterranean receives 27 % of the Saharan tracks, while the western basin receives only 17 and 8 % of all the Saharan cyclones decay over the Arabian Peninsula. The maximum cyclonic activity occurs in April. There is a general decrease in the number of tracks in all categories between 1993 and 2009, compared with the period between 1980 and 1992. About 72 % of the Saharan cyclones do not live more than 3 days, and about 80 % of the cyclones in the tracks never reach central pressures 1,000 hPa during their lifetimes. The maximum deepening in the tracks occurs over the western Mediterranean and over northern Algeria.     

广东气候变暖若干特征及其对气候带变化的影响

气候变化对区域经济的发展有重大影响。粤港澳大湾区是中国经济活力最强的区域之一,认识大湾区的气候变化规律是科学应对气候变化的基础。利用1961-2018年大湾区26个气象观测站的气温、降水量和日照时数资料,采用趋势分析、Mann-Kendall突变分析等方法分析了大湾区的气候变化特征。结果表明：1961-2018年,大湾区观测站气温、降水量和日照时数的一致性变化是其最主要的特征,近58 a来大湾区年平均气温以0.22℃·（10 a）^-1的升温速率显著上升,高于广东省同期升温速率0.18℃·（10 a）^-1,低于中国、亚洲同期升温速率。顺德、番禺、斗门、深圳、广州、南海是大湾区年平均气温上升最明显的地区,而惠东、澳门、增城相对升温最低。近58 a大湾区年降水量变化趋势不明显,年日照时数以60.1 h·（10 a）^-1的速率显著减少,减少速率远高于同期广东省平均和中国平均。1961-2018年广州年降水量增加明显,而香港、澳门变化不明显。

     

A climatological study of the nocturnal planetary boundary layer

Seventy-five nights of fast-response wind and temperature data taken from a 300 m tower near Augusta, GA, were analyzed to determine the time-height structure of the nocturnal planetary boundary layer. The nights were selected from all four seasons over a wide range of synoptic conditions. Statistical summaries of Pasquill-Gifford stability, boundary-layer depth, nocturnal jet height, directional shear, gravity wave occurrence, and azimuthal meandering were obtained. The diversity of nocturnal conditions for the 75 cases resulted in histograms with broad peaks and slowly-varying distributions.To reduce the overall variance, we grouped the nights into two classes: steady nights and unsteady nights. Nights classified as steady maintained relatively uniform wind conditions. The data base was large enough to permit a further breakdown of the steady nights into three subclasses based on the height and strength of the wind maximum. Unsteady nights were more disturbed, showing time-dependent features in the wind field and were also divided into three subclasses, depending on the predominant features observed: microfrontal passage, trend, or variable conditions. Although the subclasses were based mainly on wind structure, they correlated well with other NPBL properties, such as mixed-layer depth and inversion strength. Thus, the classification procedure tended to group together nights with similar dispersion characteristics.     

东北冷涡气候研究进展及展望

本文主要从东北冷涡气候研究角度,回顾和总结了东北冷涡在定义、主客观识别方法、气候特征、分类研究、影响因子、气候效应等方面的研究进展,并探讨了东北冷涡研究现状中存在的问题及未来可能的研究方向和发展趋势。识别与量化是东北冷涡气候研究的基础,客观识别结果的对比分析及其技术的完善是未来冷涡识别研究的重点。今后有针对性地开展不同类别东北冷涡的气候特征、异常成因及气候影响等,深入探究东北冷涡与影响因子相互作用的物理机制,科学客观的定量化预测,可为东北区域气候异常成因诊断和预测提供更精细、准确的科学依据。     

A climatological analysis of four-day back trajectories from aliartos,Greece

Summary This study presents a flow climatology for Greece based on a survey of climate and synoptic weather types, and a five-year trajectory climatology. Isobaric back trajectories at the 850 and 700 hPa levels were calculated daily at 0 and 12 Z for the years 1983–1987 for the Aliartos, Greece EMEP station, using the Air Resources Laboratory (ARL) trajectory model. Trajectories were classified by direction and speed to examine monthly, seasonal and annual variability in flow characteristics. The main features of the flow are similar from year to year. Dominant transport sectors are NW and W, followed by N, SW and NE. Four-day back trajectories from NW and W usually originate from beyond 2,400 km, while those from other directions tend to originate closer to Greece. Cases of most rapid transport occur in January and December. Potential pollutant source regions are identified corresponding to preferred trajectory directions and distance ranges.With 6 Figures     

宝鸡市气候服务系统

为满足气象服务的要求 ,采用 VB6.0和 VC 等语言和统计预报等方法开发研制了宝鸡市气候服务系统。系统由数据库、灾害性天气、预测方法、产品制作等部分组成 ,能够及时、准确地向各级政府和有关部门提供各类气象情报 ,决策咨询意见和优质的气象服务。系统客观化、自动化程度较高 ,具有较强的实用性     

新旧南京国家基准气候站观测数据差异

南京国家基准气候站2008年1月1日完成迁站。虽然新旧站址直线距离只有7 km,但两地地形、环境都存在较大差异,找出资料序列的差异性对气象资料的连续性、代表性、均一化分析具有重要意义。我们利用2006—2007年的观测资料,分析两站点资料的差异,研究外部环境对资料差异产生的可能影响,依据气候学原理、气候统计方法及气候资料审核规范,结合南京的气候特点,对一些重要天气条件(高温、低温、大风、暴雨等)下两个观测点各气象要素进行分析,研究各气象要素对环境的敏感性。通过两个观测站点资料的对比分析,为今后南京站气象资料的应用提供科学依据。     

Trend and homogeneity analysis in temperature and rainfall series in western Black Sea region,Turkey

Theoretical and Applied Climatology - This paper includes a study which applied homogeneity and trend tests on time series of monthly mean temperature and monthly total rainfall recorded in the...     

A 28-Year Climatological Analysis of Size Parameters for Northwestern Pacific Tropical Cyclones

A 28-year best track dataset containing size parameters that include the radii of the 15.4 m s^-1 winds （R15） and the 25.7 m s^-1 winds （R26） of tropical cyclones （TCs） in the Northwestern Pacific, the NCEP/ NCAR reanalysis dataset and the Extended Reconstructed Sea Surface Temperature （ERSST） dataset are employed in this study. The climatology of size parameters for the tropical cyclones in the Northwestern Pacific from 1977 to 2004 is investigated in terms of the spatial and temporal distributions. The results show that the major activity of TCs in the Northwestern Pacific is from July to October. A majority of TCs lie over the ocean west of 150°E, and a few TCs can intensify to the Saffir-Simpson （S-S） categories 4, 5. Both R15 and R26 tend to increase as the tropical cyclones intensify. The values of R15 and R26 are larger for intense TCs in the Northwestern Pacific than in the North Atlantic generally. Both R15 and R26 peak in October, and before and after October, R15 and R26 decrease, which is different from the case in the North Atlantic. The smaller R15s and R26s occur in a large range over the Northwestern Pacific, while the larger R15s and R26s mainly lie in the eastern ocean from Taiwan Island to the Philippine Islands where many tropical cyclones develop in intense systems. The tropical cyclones with size parameters of R15 or R26 on average take a longer time to intensify than to weaken, and the weak tropical cyclones have faster weakening rates than intensification rates. From 1977 to 2004, the annual mean values of R15 increase basically with year; during the 28-year period, the value of R15 increases by 52.7 kin, but R26 does not change with year obviously.     

Excel中的回归分析在气候统计中的应用

介绍了用Excel进行回归分析的3种方法(散点图、工作表函数和回归分析工具)，及其在气候统计中应用的方法和回归分析结果的解释。