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1.
The correction, validation and homogenisation of the long temperature series of Padova (1725–1998) are discussed. After a careful historical investigation made in order to discover the metadata concerning the series, i.e., instrument features, calibrating methodologies, operational procedures (i.e., exposure, timing and number of daily observations), instrument maintenance, relocations and instrument replacements, the series has been corrected for all the systematic errors derived from any change in the instruments or the operative methodology. Above all, correction focused on instrumental drift, scale expansion, building influence, relationship between indoor-outdoor measurements, minima and maxima evaluation from observations performed at different times, homogenisation for difference of level and change of site. Statistical tests applied to the data and the comparison with other known series has clarified some uncertainties about exposure and operational procedures that the historical analysis of metadata was unable to solve. Moreover, gaps have been filled after the comparison of the series with others of neighbouring sites. The critical work of debugging, correcting, validating and homogenising the series is essential for a correct interpretation of data, as in some cases the errors that have been corrected have been found to be greater than the climate signal. Especially in the early period, the algebraic sum of the corrections of the mean daily temperature exceeds 8 ° C, where monthly corrections can reach 6 ° C. After correction, validation and homogenisation, the linear trend of the Padova series is positive, +0.31 ° C/100 yr over the period1774–today. Looking at post-industrial warming, the temperature rise is+0.44 ° C in the last 130 years, which means +0.34 ° C/100 yr, not farfrom the above bulk average. 相似文献
2.
Dario Camuffo Antonio della Valle Chiara Bertolin Elena Santorelli 《Climatic change》2017,142(1-2):7-22
The observations taken in Bologna, Italy, from 1715 to 1815, three times a day, with a number of thermometers (i.e., Stancari air thermometers, Little Florentine thermometer, Florentine stick thermometer and a number of Réaumur spirit and mercury thermometers) some of them operating in parallel, have been recovered and analysed. The early thermometers had unknown scales and temperature units, with deviations due to the bulb shape or the thermometric liquid, but it is possible to interpret them after comparison between parallel readings. Historical sources and the analysis of the data fingerprints and their variability permit recognition of where instruments were located and who the observers were. It is also possible to relate the indoor climate of historical buildings to the outdoor one, and transform indoor readings as they were taken outdoors, expressed in Celsius. The Bologna series has been compared with the contemporary observations in Padua, Venice and Milano. The climate analysis shows that the temperature fluctuated but with an increasing trend. The 1730–1770 decades constituted the coldest period and 1980—today the warmest one. The eighteenth century was generally cold and had an impressive frequency of extremely severe winters that exceeded the rest of the series. The whole dataset (i.e. 1715–2015) of daily temperatures has been included to allow further use for scientific purposes. Finally, the paper provides a methodological example of procedures to recover and analyse early instrumental series. 相似文献
3.
This paper presents the earliest temperature observations, scheduled every 3–4 h in the 1654–1670 period, which have been
recovered and analysed for the first time. The observations belong to the Medici Network, the first international network
of meteorological observations, based on eleven stations, the two main ones being Florence and Vallombrosa, Italy. All observations
were made with identical thermometers and operational methodology, including outdoor exposure in the shade and in the sunshine
to evaluate solar heating, state of the sky, wind direction and precipitation frequency. This paper will consider only the
regular temperature series taken in the shade. The observations were made with the newly invented spirit-in-glass thermometer,
also known as Little Florentine Thermometer (LFT). The readings have been transformed into modern units of temperature (°C)
and time (TMEC). The LFT has been analysed in detail: how it was made, its linearity, calibration and performances. Since
the middle of the LIA, the climate in Florence has shown less than 0.18°C warming. However, although the yearly average showed
little change, the seasonal departures are greater, i.e. warmer summers, colder winters and unstable mid seasons. The temperature
in the Vallombrosa mountain station, 1,000 m a.m.s.l, apparently rose more, i.e. 1.41°C. A discussion is made on the interpretation
of this finding: how much it is affected by climate change or bias. A continuous swinging of the temperature was observed
in the Mediterranean area, as documented by the long instrumental observations over the 1654–2009 period. However, changes
in vegetation, or exposure bias might have contributed to reduce the homogeneity of the series over the centuries. 相似文献
4.
通过对CTL713C数字化天气雷达回波标定原理和方法的阐述,从雷达参数的测量、A/D变换及视频积分处理、测试仪器的稳定性及精确度等几方面因素对造成雷达回波强度标定误差进行了分析,分别得出几种情况下可能出现的误差值,对测试环境与人为可能造成的回波强度标定误差进行了说明。给出雷达回波强度标定结果准确性的检验方法,并对雷达回波强度标定工作中的关键问题进行了总结。 相似文献
5.
为进一步评估地基微波辐射计红外传感器的观云性能,收集了2017、2018两年5—7月布设在广州野外雷电实验基地的一台MWP967KV型地基微波辐射计红外传感器与一台K/LLX502B型激光测云仪观测的云底高度数据,并利用人工观测的天空状况、云状数据进行分类,在不同云类、天空状况下对地基微波辐射计红外传感器云识别和观测云底高度的性能进行分析。结果表明:①地基微波辐射计红外传感器具有良好的云识别能力,准确率达80.4%,由于观测视角的原因,未能识别出有云存在主要发生在"多云"情况下。②地基微波辐射计红外传感器与激光测云仪所测云底高度相关系数为0.63,有着较好的一致性。③因为观测原理不同,地基微波辐射计红外传感器所测云底高度总是高于激光测云仪,且两部仪器在低云阴天时所测的云底高度一致性要优于中、高云多云。综上所述,地基微波辐射计红外传感器用来识别云、观测云底高度具有一定的可行性,尤其是在低云、"阴天"条件下,有着较好的观云性能。 相似文献
6.
Silvia Comani 《Climatic change》1987,11(3):375-390
The Bologna meteorological record is one of the oldest and most complete among the series already collected for Europe. Data from the regions south of the Alps being extremely sparse, this station is of great importance for all climatic reconstructions dating as far back as the beginning of the 18th century. The focus here is on the temperature series, because it presents some a priori problems with respect to the series analysis itself. These problems relate to the homogeneity of the temperature record, which is affected by the use of different thermometers within the record, the statistical reconstruction of the thermometric scales, and the drift in calibration of one of these instruments. After correcting for these heterogeneities, the temperature series indicate a thermal behaviour in agreement with other historical European sources. The Bologna series is characterised by a warm period during the first decades of the 18th century, with large decreases in temperature in 1740 and 1742, and a positive trend from 1742 to the end of the record. The behaviour of the Bologna temperature series is in good agreement with the series for Central England, De Bilt (Netherlands) and Padua (Italy). 相似文献
7.
Some of the problems associated with measurements of the small-scale characteristics of dynamic and thermal fully developed turbulence are considered in the context of a study of the tendency-towards-isotropy assumption, Taylor’s hypothesis, and internal intermittency, taking advantage of the possibilities offered by the I.M.S.T. Air—Sea Interaction Simulation Tunnel. The paper reviews and discusses the choices of probes and operating parameters for hot-wire anemometers and cold-wire thermometers. A detailed study of the most important characteristic, the spectral signal-to-noise ratio, is presented. Problems specific to measurements with several wires are studied, especially the true resolution of one-point multi-wire probes and the errors due to calibration uncertainties for two-point measurements. Serious doubts are raised on the validity of ‘gradient-probe’ data. 相似文献
8.
自动气象站是由各要素的传感器和数据采集器组成的。随着时间的推移, 各传感器和数据采集器的测量误差将会发生漂移。为确保各要素观测数据的准确、可靠并具有可比性, 定期开展自动气象站的检定和校准是非常重要的。通过检定将各要素系统误差控制在允许范围内, 并对检定结果进行不确定度分析, 是考察检定结果可信程度的重要步骤。本文依据自动气象站检定规程及JJF1059-1999《测量不确定度评定与表示》的要求, 并根据检定数据, 进行自动气象站的各要素检定结果的不确定度分析, 对自动气象站检定结果可信度评估具有指导意义。 相似文献
9.
Covadonga Palencia Claude Berthet Marta Massot Amaya Castro Jean Dessens Roberto Fraile 《Atmospheric Research》2007,83(2-4):493-504
This paper is a comparative study between the two most common hailpad calibration systems: one annual calibration of a whole consignment of material, and the individual calibration of each plate after a hailfall. Individual calibration attempts to minimize errors due to differences in sensitivity to the impact of hailstones between plates from the same consignment, or due to differences in the inking process before the actual measurement.The comparison was carried out using calibration data from the past few years in the hailpad network in south-western France, and data from an individual calibration process on material provided by the hailpad network in Lleida (Spain). The same type of material was used in the two cases.The results confirm that the error in measuring hailstone sizes is smaller in the case of an individual calibration of hailpads than when one single calibration process was carried out for a whole consignment. The former is approximately 80% of the latter. However, this error could have been higher if it had not been the same person carrying out the single calibration process and the measuring of the dents: it has been found that differences in the inking process may account for up to 20% of the error in the case of small hailstones. Calibration errors affecting other variables, e.g. energy or parameter λ of the exponential size distribution are generally higher (5% and 18%, respectively) than errors due to the spatial variability of the hailstones. However, the calibration method does not influence the maximum size, since the relative error attributed to the spatial variability is about 8 times the calibration error.In conclusion, if errors in determining energy or parameter λ are to be reduced to a minimum, it is highly advisable to be consistent in applying the measuring procedure (if possible with the same person carrying out the measurements all the time), and even to use individual calibration on each plate, always bearing in mind that technicians have to be trained appropriately in order to achieve the highest possible degree of uniformity. 相似文献
10.
H. K. Roscoe P. V. Johnston M. Van Roozendael A. Richter A. Sarkissian J. Roscoe K. E. Preston J-C. Lambert C. Hermans W. DeCuyper S. Dzienus T. Winterrath J. Burrows F. Goutail J-P. Pommereau E. D'Almeida J. Hottier C. Coureul R. Didier I. Pundt L. M. Bartlett C. T. McElroy J. E. Kerr A. Elokhov G. Giovanelli F. Ravegnani M. Premuda I. Kostadinov F. Erle T. Wagner K. Pfeilsticker M. Kenntner L. C. Marquard M. Gil O. Puentedura M. Yela D. W. Arlander B. A. Kastad Hoiskar C. W. Tellefsen K. Karlsen Tornkvist B. Heese R. L. Jones S. R. Aliwell R. A. Freshwater 《Journal of Atmospheric Chemistry》1999,32(2):281-314
In June 1996, 16 UV-visible sensors from 11 institutes measured spectra of the zenith sky for more than 10 days. Spectra were analysed in real-time to determine slant column amounts of O3 and NO2. Spectra of Hg lamps and lasers were measured, and the amount of NO2 in a cell was determined by each spectrometer. Some spectra were re-analysed after obvious errors were found. Slant columns were compared in two ways: by examining regression analyses against comparison instruments over the whole range of solar zenith angles; and by taking fractional differences from a comparison instrument at solar zenith angles between 85° and 91°. Regression identified which pairs of instruments were most consistent, and so which could be used as universal comparison instruments. For O3, regression slopes for the whole campaign agreed within 5% for most instruments despite the use of different cross-sections and wavelength intervals, whereas similar agreement was only achieved for NO2 when the same cross-sections and wavelength intervals were used and only one half-day's data was analysed. Mean fractional differences in NO2 from a comparison instrument fall within ±7% (1-sigma) for most instruments, with standard deviations of the mean differences averaging 4.5%. Mean differences in O3 fall within ±2.5% (1- sigma) for most instruments, with standard deviations of the mean differences averaging 2%. Measurements of NO2 in the cell had similar agreement to measurements of NO2 in the atmosphere, but for some instruments measurements with cell and atmosphere relative to a comparison instrument disagreed by more than the error bars. 相似文献
11.
Some of the problems associated with measurements of the small-scale characteristics of dynamic and thermal fully developed turbulence are considered in the context of a study of the tendency-towards-isotropy assumption, Taylor's hypothesis, and internal intermittency, taking advantage of the possibilities offered by the I.M.S.T. Air-Sea Interaction Simulation Tunnel. The paper reviews and discusses the choices of probes and operating parameters for hot-wire anemometers and cold-wire thermometers. A detailed study of the most important characteristic, the spectral signal-to-noise ratio, is presented. Problems specific to measurements with several wires are studied, especially the true resolution of one-point multi-wire probes and the errors due to calibration uncertainties for two-point measurements. Serious doubts are raised on the validity of gradient-probe data. 相似文献
12.
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14.
Revision and necessary correction of the long-term temperature series of Hohenpeissenberg, 1781–2006
P. Winkler 《Theoretical and Applied Climatology》2009,98(3-4):259-268
Having been in use at Hohenpeissenberg from 1781–1841, the Palatina thermometer was found to suffer from a positive bias of 0.5°R (or 0.63°C) as discovered by Lamont following a re-calibration made in 1842. The main reason was due to the composition of the glass used during the early instrumental period. Glass of this period tended to contract over many years due to thermal aftereffects, resulting in a gradual rise of the freezing point position in consequence of the shrinking bulb forming the mercury reservoir. While the problem of the gradually rising zero point was recognised relatively early, the reason was attributed to wrong causes. Around 1880, scientists recognised that the chemical composition of glass might be responsible for the drift of the zero point. New glass types were developed which were free from such effects. Although these facts became known, no correction was applied to the Hohenpeissenberg temperature series when in 1981, the complete 200-year series was published. Most probably this bias is also relevant for other stations, at least those of the network of the Societas Meteorologica Palatina that were supplied with thermometers manufactured in Mannheim. Another problem originates from the different observing times for the period 1879–1900, which were set to 0800, 1400 and 2000 hours instead of 0700, 1400 and 2100 hours before and afterwards. In addition, a new formula to calculate the daily mean was established resulting in the temperature being too low by 0.5°C in that period. The overall trend changes after application of the two necessary corrections. There remain two biases that cannot be quantified without a major detailed study being made: (1) At the start of the observations, the window of the observation room was always kept “open during dry weather”. It is not known how long this practice was remained in use. (2) Lamont also employed an easily melting glass to construct his thermometers which in use between 1841 and 1878. An analysis of the glass composition seems to be necessary to find out whether it also suffered from a rising freezing point. Lamont replaced the Hohenpeissenberg thermometer in 1842 by a new instrument produced in his own workshop. One still existing Lamont thermometer, but not that one of Hohenpeissenberg, was re-calibrated and the zero point found to have lowered by ?1.4°C. Since the opposite drift had been expected and the original Lamont-type Hohenpeissenberg thermometer is no longer available, no correction is justified for the period in which this thermometer was in use. 相似文献
15.
Reconstruction of Nineteenth Century Summer Temperatures in Norway by Proxy Data from Farmers'Diaries 总被引：2，自引：0，他引：2
P.Ø. Nordli 《Climatic change》2001,48(1):201-218
Proxy data from five farmers; diaries in the Møre, Dovre and Trøndelag regions in central Norway were used for climatic reconstruction purposes. The method chosen was "simple linear regression analysis" with the start of the grain harvest (barley or oats) as predictor and summer temperature (May – August) as predictand. Overlapping periods with modern instrumental observations (starting 1858 or later) were used for calibration of the model. The model was tested on independent data by establishing the regression on one half of the overlapping period and applying the regression on the other half. The standard deviation in the residuals varied from 0.3°C to 0.7°C and the biases of the mean values from –0.3°C to +0.3°C. Climatic reconstructions were established for the early- and mid-nineteenth century summer temperature, i.e. during the last part of what has come to be regarded as the "Little Ice Age", in this article considered to end around 1880.By use of the proxy data model, huge inhomogeneities of the "classical" Trondheim series were detected, the early nineteenth century part of the series evidently being too warm. The inhomogeneity was removed by use of adjustment terms. The adjusted series indicates that in the Trondheim region the summer temperature during the last part of the "Little Ice Age" phase was about 1°C lower than the latest 60 years. This is in serious contradiction to the classical Trondheim series. 相似文献
16.
A comprehensive set of trace gas concentrations and meteorological parameters were measured simultaneously during a cruise of the research vessel Polarstern from Bremerhaven (54° N, 8° E) to Rio Grande (32° S, 52° W) during the period from 15 September to 9 October 1988. This paper describes the general features of the cruise and summarizes the measurements made, the techniques employed, and the placement of the instruments on board the ship. The synoptic data base is used to characterize the nature and possible origins of the air masses encountered during the cruise and to draw some general conclusions from the measurements. 相似文献
17.
湿度表(计)检定装置不确定度分析 总被引：3，自引：3，他引：0
湿度检定装置的不确定度,直接影响到湿度传感器和各种湿度测量仪器的检测结果。该文针对我国省级气象计量单位,现用的湿度表（计）检定装置,从检定装置的组成、主要误差来源及分类人手,借鉴国内外通用的不确定度分析方法,介绍整个湿度检定装置的不确定度测试与评估。 相似文献
18.
Bao Yang Dmitry M. Sonechkin Nina M. Datsenko Nadezda N. Ivashchenko Jingjing Liu Chun Qin 《Theoretical and Applied Climatology》2011,106(3-4):489-497
Based on a set of very long-living (2,000?years) Qilian junipers (Sabina przewalskii Kom.) from the north-eastern part of the Tibetan Plateau (the region of Dulan), we carefully consider the regional curve standardization (RCS) technique. For this goal, we correlate deviations of individual tree-ring width records from their regional mean age-dependent curve (RC). It turns out that these correlations keep their positivity for almost all shifts between ages compared (up to 500?years and even more) evidencing each Dulan juniper to be a unique ??thermometer??. Just the unification of these ??thermometers?? in the form RC creates a spurious positive trend in the Dulan chronology. We modify the RCS technique to closer attach RC to these ??thermometers?? in order to construct a new chronology in which the trend is absent. 相似文献
19.
Abstract Observations of sea‐surface temperatures and salinities, made by a variety of methods during August and September 1975 in the northeast Pacifie Ocean, are examined to evaluate the quality of surface data. The bucket method is capable of providing sea‐surface temperatures to an accuracy (standard deviation) of ±0.15°C. The thermograph/salinograph when corrected by applying a “field‐calibration” value, gives temperatures with a standard deviation one half that obtained by the bucket method. Expendable bathythermograph temperatures were, on the average, 0.3°C urate as the true values. Were it not for this offset they would have been as accurate as those obtained with bucket thermometers. Engine‐intake temperatures observed by the engine‐room crew were, on the average, 0.3°C larger than the true values, but were characterized by large inaccuracies, with a standard deviation about an order of magnitude greater than those found for other methods. These variations are believed to be due to reading errors. Sea‐surface salinities observed with the bucket could be, with reasonable care, accurate within the limitation of the salinometer method used aboard ships. The quality of data has been found to vary significantly between observers. Results obtained from this cruise and from weathership data (1956–1976) suggest that the surface temperatures and salinities observed during the past, 1956–1962, in the northeast Pacific Ocean have generally been overestimated. 相似文献
20.
A three-component sonic anemometer/thermometer system has been developed. It employs single switched transducer pairs and the inverse timed pulse method to yield an absolute calibration. Microprocessor control and use of newly developed transducers give a very small parts cost. The path length of the instrument can be varied from 10 to 15 cm; output is available in digital or analog form. Temperature sensing, via a 5 Μm tungsten resistance element, is integrated into the digital system. Wind tunnel and field results have confirmed the success of the prototype and a set of operational instruments has been constructed. 相似文献