我国近海和陆地巨型盐核的分布特点和变化规律

本文介绍了1978年9、10月分别在我国海洋岛、大连和北京的盐核观测结果以及盐核浓度的日变化和日际变化规律等。得出盐核的浓度与湿度、风向风速、低层湿度场以及天气系统等有一定的关系。     

DJM10型新湿度检定设备的使用经验

新疆气象技术装备中心计量检定所于1997年2月开始使用“DJM10型”新湿度检定设备,在安装调试和8年多的实际使用中,发现存在一些问题,同时也总结出一些实践经验。1 DJM10工作原理1.1气路原理需要升湿时,稳定阀、降湿阀关闭,加湿阀打开,加湿器工作,湿气经过加湿阀直接进入恒湿箱体;需要降湿时,加湿器、稳定阀、加湿阀关闭,降湿阀打开,湿气(相对而言)从恒湿箱内两边的气路下行,经干燥箱干燥后通过降湿阀由搅拌风扇吹入恒湿箱内;需要稳定时,加湿阀、降湿阀关闭,稳定阀打开,恒湿箱内空气从边气路下行,经稳定阀由风扇吹入箱内形成自循环,达到稳…     

PC—1500计算机轻便风速表检定记录整理程序

一、概述:轻便风速表的检定实际上是在特制的小风洞内测定人工制成的风速值与作用在轻便风速表上的感应值之差值。所以轻便风速表检定对各种气象条件的要求是比较严格的,即气压变化平稳,空气温度和湿度要稳定少变。但大范围的恒温恒湿、和稳定的气压一     

气泡内水汽平衡研究与气泡法饱和盐湿度发生器的原理

气泡具有密封性好、其内部水汽平均扩散距离小的特点, 因此, 其内部很容易达到水汽平衡, 利用这个特点的气泡法饱和盐湿度发生器, 与通常饱和盐湿度发生器比较具有效率高的突出优点。该文重点定量分析了气泡内水汽平衡条件; 定性分析了在发生湿度过程中其他重要物理效应。利用General Eastern公司M4型露点仪作为标准器, 实测试验装置输出湿度与试验装置标称湿度之间差值的绝对值不大于1.0%。     

加热式电解湿度传感器的研制总结

美国人Foxboro于1944年发表用氯化锂盐做吸湿性物质的电解式湿度传感器专利之后,不少国家开始进一步研制这种湿度传感器,在原专利基本结构特点基础上所做的改进和完善工作取得了不小进展,一批专利相继出现。氯化锂电解湿度传感器在苏联、法国、民主德国、联邦德国、美国和日本等一些国家的气象部门也被采用。这种湿度传感器所以得到广泛应用是与它有如下几个优点分不开的:     

一种新型的耐水性高分子湿度传感器

我们研制了一种新型的耐水性高分子薄膜湿度传感器,其湿敏材料是由一种基质聚合物和碱金属盐形成的配合物. 测定了这种传感器在不同湿度下的复数阻抗,为测量线路设计中的参数选择提供了必要的依据.用一个RC振荡电路测量了传感器的振荡频率与相对湿度的关系.结果表明,传感器除了具有响应快、滞后小、灵敏度高等优点外,在它遇水汽结露后,返回各相对湿度时其电参量仍几乎不变,即具有极好的耐水性;在20％—90％RH范围内,传感器的振荡频率与相对湿度的关系几乎是线性的.     

自动气象站与人工站湿度测量结果的对比分析

为进一步提高湿度测量的准确性,通过对宁津2004年、2005年自动站和人工站湿度数据的对比分析,根据湿度差值的变化波动情况,来研究自动站和人工站湿度观测数据器的差异及其变化规律。     

双套站湿度传感器现场校准前后的期间核查

取2018年9月上旬逐日和部分分钟湿度,用现用湿度传感器去核查未校准的备用湿度传感器;取2018年9月下旬逐日和部分小时、分钟湿度,用2018年9月18日刚校准的备用湿度传感器去核查现用湿度传感器,采用现用与备用传感器湿度差是否在最大允许误差范围内的评判方法。结果发现:①在日湿度的核查中,双套湿度传感器均保持在校准状态或出厂合格状态;②在分湿度的核查中,备用湿度传感器在上升中,升不到高湿或慢了,未保持在出厂合格状态;②在时、分湿度的核查中,现用湿度传感器在高湿往下降时,慢了,未保持在校准状态。自动气象站各传感器的期间核查,根据需要做日、时和分钟等各时段的统计分析;现用与备用湿度传感器都是卡在"高湿","一个下不来"、"一个上不去",要考虑传感器的灵敏度。     

关注您身边的空气湿度

所谓空气湿度,是指空气干湿的程度,气象上通常用相对湿度来表示,它的范围为0～100％,数值越大,空气越潮湿。它的大小取决于空气中含水量的多少。一般来说,秋冬季节空气湿度较小,春夏季节湿度较大,上午和早晚的空气湿度较大,下午湿度较小。下雨时和下雨前后,空气湿度大;而久晴不雨的时候,空气湿度较小。科学研究表明,空气湿度跟人体的健康关系极为密切。     

中国L波段探空湿度观测资料的质量评估及偏差订正

L波段探空观测资料无论在天气预报还是数值预报中均为最基本和最重要的一类数据,而其湿度观测资料的质量对同化分析及降水预报有直接影响。通过用L波段探空湿度观测资料与不同类型的其他观测反演的湿度资料互校及与NCEP、GRAPES、EC等不同模式分析场为背景的湿度场比较,评估中国L波段探空湿度观测资料的质量状况,对探空湿度资料的质量有了新的认识,为更好地使用该资料提供依据。研究发现中国L波段探空湿度观测资料存在偏干的现象,特别是当背景场湿度大于60%时,观测湿度偏低更加明显。通过分析其偏差特征,找出了适合中国L波段探空湿度观测资料偏差特点的分段函数订正方法。个例试验表明,对探空湿度观测资料的偏差订正后,观测偏差明显减小,订正效果非常显著;模式降水强度预报能力有一定的提高。从连续试验检验的降水预报评分(TS)和预报偏差(Bias)看,中雨和暴雨的预报在探空湿度观测偏差订正后都表现出正效果。     

Rainfall generator with spatial and temporal characteristics

The aim of this paper is to present a rainfall generator which takes both spatial and temporal characteristics into account. The statistical model behind the generator is based on long-time experience with statistical analyses of empirical rainfall data and represents, therefore, a genuine theoretical point for simulating series of precipitation values. The sites of the recording gauges and the actual time (day, month, year etc.) enter a statistical model as systematic components for the prediction of expected rainfall in a two-way analysis of variance design. Beyond these systematic components, spatial correlations among the observations are still present in nature, a feature which is modelled also by the rainfall generator.     

BS-1型机载碘化银发生器的维护与改进

介绍了ＢＳ－１型机载碘化银发生器的基本结构与原理。在实践经验的基础上总结出了各部件的维护方法，并对控制器电路进行了改进。     

BS－1型机载碘化银发生器的维护与改进

介绍了ＢＳ－１型机载碘化银发生器的基本结构与原理。在实践经验的基础上总结出了各部件的维护方法，并对控制器电路进行了改进。     

High-Frequency and Low-Frequency Variability in Stochastic Daily Weather Generator and Its Effect on Agricultural and Hydrologic Modelling

The high-frequency and low-frequency variabilities, which are often misreproduced by the daily weather generators, have a significant effect on modelling weather-dependent processes. Three modifications are suggested to improve the reproduction of the both variabilities in a four-variate daily weather generator Met&Roll: (i) inclusion of the annual cycle of lag-0 and lag-1 correlations among solar radiation, maximum temperature and minimum temperature, (ii) use of the 3rd order Markov chain to model precipitation occurrence, (iii) applying the monthly generator (based on a first-order autoregressive model) to fit the low-frequency variability. The tests are made to examine the effects of the three new features on (i) a stochastic structure of the synthetic series, and on (ii) outputs from CERES-Wheat crop model (crop yields) and SAC-SMA rainfall-runoff model (monthly streamflow characteristics, distribution of 5-day streamflow) fed by the synthetic weather series. The results are compared with those obtained with the observed weather series.Results: (i) The inclusion of the annual cycle of the correlations has rather ambiguous effect on the temporal structure of the weather characteristics simulated by the generator and only insignificant effect on the output from either simulation model. (ii) Increased order of the Markov chain improves modelling of precipitation occurrence series (especially long dry spells), and correspondingly improves reliability of the output from either simulation model. (iii) Conditioning the daily generator on monthly generator has the most positive effect, especially on the output from the hydrological model: Variability of the monthly streamflow characteristics and the frequency of extreme streamflows are better simulated. (iv) Of the two simulation models, the improvements related to the three modifications are more pronounced in the hydrological simulations. This may be also due to the fact that the crop growth simulations were less affected by the imperfections of the unmodified version of Met&Roll.     

我国风力机潜力的估计

本文给出一个计算风能的方法，并计算了全国各地风能密度和利用小时数分析了气候变化规律。在此基础上又利用Justus给出的风力机输出潜力的方法，计算了全国三种不同类型风力机的容量系数并绘制成图。     

A new daily weather generator to preserve extremes and low-frequency variability

This paper addresses deficiencies of stochastic Weather Generators (WGs) in terms of reproduction of low-frequency variability and extremes, as well as the unanticipated effects of changes to precipitation occurrence under climate change scenarios on secondary variables. A new weather generator (named IWG) is developed in order to resolve such deficiencies and improve WGs performance. The proposed WG is composed of three major components, including a stochastic rainfall model able to reproduce realistic rainfall series containing extremes and inter-annual monthly variability, a multivariate daily temperature model conditioned to the rainfall occurrence, and a suitable multi-variate monthly generator to fit the low-frequency variability of daily maximum and minimum temperature series. The performance of IWG was tested by comparing statistical characteristics of the simulated and observed weather data, and by comparing statistical characteristics of the simulated runoff outputs by a daily rainfall-runoff model fed by the generated and observed weather data. Furthermore, IWG outputs are compared with those of the well-known LARS-WG weather generator. The tested characteristics are a variety of different daily statistics, low-frequency variability, and distribution of extremes. It is concluded that the performance of the IWG is acceptable, better than LARS-WG in the majority of tests, especially in reproduction of extremes and low-frequency variability of weather and runoff series.     

A study on the water vapor transport trend and water vapor source of the Tibetan Plateau

This study presents results of the pilot experiments made with new parametric multi-site multi-variable stochastic daily weather generator (WG) SPAGETTA. The experiments are performed for eight European regions and we focus on spatial characteristics of temperature. The WG is calibrated using the gridded weather data E-OBS. In evaluating the generator, the spatial and temporal temperature autocorrelations derived from the synthetic series were found to perfectly fit the values derived from the calibration data. Next, the WG is validated in terms of the frequency of “spatial hot days” and the annual maximum length of “spatial hot spells”. The results indicate a very good correspondence between characteristics derived from synthetic and calibration data. As part of the validation tests, the performance of the WG is compared with a regional climate model (RCM), which shows a similar performance as the generator. In a final experiment, the use of the WG for the future climate is demonstrated, the WG parameters (including the temperature autocorrelations) calibrated with the observed data are modified according to the RCM-based changes in these parameters. While analyzing synthetic series produced with the modified generator, we discuss partial impacts due to changes in individual WG parameters on the spatial hot days and spells. We show that the impacts are mainly (but not only) due to changes in temperature averages. The projected changes in temperature autocorrelations have also some impacts, larger for the spatial hot spells than for the spatial hot days. Climate change impacts on spatial hot days/spells based on the WG are compared with impacts based on the RCM, and we conclude that the differences are mainly due to simplifying assumptions adopted in our pilot experiment.     

碘化银地面发生器增雨（雪）作业可行性及作业时机选择

设置于高山迎风坡的碘化银发行器增雨(雪)作业，其关键是上升气流时段的选择，上升气流关系着有效核入云效率。文章分析了碘化银地面发生器增雨(雪)作业的可行性和利用天气图、卫星云图、雷达和物理量计算等方法确定作业时机的可能与技术。     

A new framework for multi-site weather generator: a two-stage model combining a parametric method with a distribution-free shuffle procedure

Keeping the spatial correlation of synthetic precipitation data is of utmost importance for hydrological modeling; however, most present weather generators are single-site models and ignore the spatial dependence in daily weather data. Multi-site weather generator is an effective method to solve this problem. This study proposes a new framework for multi-site weather generator denoted as two-stage weather generator (TSWG), in which the first stage generates the single-site precipitation occurrence and amount with a parametric chain-dependent process, and the second stage rebuilds the spatial correlation of the synthetic data using a post-processing, distribution-free shuffle procedure. Results show that TSWG reproduces the statistical parameters of the parametric stage quite well, such as wet days and precipitation amount, and it almost perfectly preserves the inter-station correlations of precipitation occurrence and amount as well as their dependences. Most important, it matches the input requirement of hydrological model and gives satisfactory hydrological simulations. There are several advantages for this new framework: (1) only one correlation matrix and two simple steps, no more input variables or iterative optimizations, are needed to rebuild the spatial correlation; (2) the statistical parameters of the observed data can be easily preserved; (3) the inter-station correlations can be satisfactorily rebuilt. As a post-processing method, the shuffle procedure used to reconstruct the spatial correlation has some potential extensions, such as turning current single-site weather generator into multi-site models and generating future multi-site climate scenarios.     

手机短信遥控人工增雨地面焰条播撒系统

针对我国目前高山人工增雪(雨)的需要,研制成功一种采用手机短信进行遥控的地面焰条播撒系统。该系统采用手机短信作为点火信号,可远距离遥控点火,实现了人工影响天气作业的自动化。系统由播撒装置、焰条、控制系统、控制软件4部分组成,播撒装置一次可装填焰条36支,每支焰条装BR-91-Y焰剂500 g,含AgI7.5 g。控制系统在手机信号覆盖的地方都可以实现遥控,而且对焰条的点火采用计算机软件控制,操作简单。应用该装置2006年4、5月在云南玉龙雪山进行了人工增雪试验,试验表明该系统性能稳定,具有应用推广价值。针对系统在试验中出现的问题,提出了改进方案。