摘要:

AbstractWithin the context of a 500 mb synoptic climatology, relationships between synoptic types and Pacific north‐west coast climatological regimes are investigated. Distinct fluctuations in thermal and moisture trends are identified for the winters of 1948‐1949 to 1977‐1978. Within any one of these climatological regimes, interannual variability in temperature and precipitation is related to the frequency of occurrence of synoptic types associated with warm and wet conditions, respectively. However, the analysis suggests that mixing of data from differing regimes may contribute to within‐type variation, often identified as a major methodological problem in synoptic climatological r

ISSN:0196-1748    

DOI:10.1002/joc.3370050302

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe dynamic climatology of the Asiatic and North American sectors of the Polar Basin is examined for the winter season using NMC grid data for 1975 and 1976. The relative contributions to the total vertical circulation field by the mechanisms of differential vorticity and thickness advection, the diabatic effects of latent heat release and surface heating, and the surface effects of friction and orography are evaluated for the major synoptic patterns of the region. From this analysis, the relative significance of advective versus local affects on synoptic development is determined. The results are compared with those from a similar study for the summer period.

ISSN:0196-1748    

DOI:10.1002/joc.3370050303

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractUpper‐air data for a network of tropical stations have been used to create seasonal and annual time‐series of 850‐500 mb and 500‐200 mb thickness for the zone 20°N–20°S for 1950‐1983.Linear regressions of thickness in each layer against a Southern Oscillation index show that in the northern winter about half the interannual variance of thickness is predicted by the Southern Oscillation index two seasons earlier. Similar but weaker results hold for the other seasons. Low Southern Oscillation index, implying low pressure in the southern tropical mid‐Pacific, is followed by a warm tropical troposphere.The residuals of thickness after the regressions against the Southern Oscillation index were examined for evidence of the effects of major volcanic eruptions. The cooling in 1964‐1965 cannot be ascribed unambiguously to the March 1963 eruption of Agung, and there has been no significant cooling in the two years following the April 1982 erupt

ISSN:0196-1748    

DOI:10.1002/joc.3370050304

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractIn this study spatial and temporal relationships involving Southern Hemisphere (SH) sea level pressure (SLP) were examined using a 25‐year data set assembled for this purpose, with special emphasis on discovering inter‐hemispheric teleconnections in the seasonal SLP field. Principal component and correlation analysis was employed. The most important findings include:1Season‐to‐season autocorrelation of SLP is at least as large in the SH as in the Northern Hemisphere (NH), though the amount of area of significant autocorrelation is not great in either hemisphere (i.e. a total global area of 17‐24 per cent).2Principal component (PC) analysis performed on SH SLP in conjunction with Monte Carlo tests of significance showed that three or four PCs, explaining 40 to 58 per cent of the variance, represent the climatic signal in the data set.3Field significance tests applied to each teleconnection map, produced for each grid point in the SH, implied that there is a strong likelihood of real inter‐hemispheric relationships in NH winter. There was much less certainty in the other seasons. Examination of significant teleconnection maps suggested SH links to the Southern Oscillation, the North Atlantic Oscillation, Siberian High strength, and the ‘West Pacific pattern’ described by Wallace and

ISSN:0196-1748    

DOI:10.1002/joc.3370050305

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe monthly mean outgoing long‐wave radiation data from June 1974 o May 1981 were analysed for dominant eigenvector patterns. The first three eigenvector patterns explain nearly 93 per cent of the total variance. The first eigenvector pattern exhibits an annual cycle with a pronounced variation in the outgoing long‐wave radiation over the tropical belt between 10 and 20°N. This is largely indicative of strong seasonal shift of the major area of cloudiness associated with the Intertropical Convergence Zone. The second eigenvector pattern shows an out‐of‐phase relationship between north India and the equatorial region, having a pronounced semi‐annual oscillation. The third eigenvector pattern exhibits the characteristic features of the north‐east monsoon over south‐east peninsular India. The first and second harmonics, corresponding to annual and semi‐annual oscillations, exhibit the major characteristic features of the first two eigenvectors, respectively.The interannual variation of the outgoing long‐wave radiation for the summer monsoon period shows a close association with the large‐scale monsoon rainfall over India.It is concluded that the satellite‐derived outgoing long‐wave radiation can be used to monitor more comprehensively the large‐scale monsoon circulation and its year‐to‐year variability in view of its spati

ISSN:0196-1748    

DOI:10.1002/joc.3370050306

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractTwo computer programs were executed on the available climatic data of fifty stations dispersed throughout Saudia Arabia. The first was a program for calculating the variables that represent potential evapotranspiration, soil moisture content and actual evapotranspiration. The aim of this step was to broaden the base of analysis whereby the processing of twenty‐four climatic variables becomes possible. The second was a principal component analysis program. The application of this program was carried out in two stages. First, on the twenty‐four climatic variables. This has led to the identification of five climatic components as being the principal factors that control the spatial variations of the climate in Saudi Arabia. Secondly, on the scaled distance matrix that was originally calculated using the station scores of the five components. This resulted in grouping the fifty climatic stations into six categories each of which represents a distinct spatial climatic subdivision of the coun

ISSN:0196-1748    

DOI:10.1002/joc.3370050307

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractThis paper describes a simple but efficient method, based on classical techniques, which enables one lo estimate missing data and to extrapolate short instrumental climate series from other instrumental or proxy ones. By mutually exclusive digital filters, the variations of the data are decomposed into a rough spectrum. A canonical analysis is performed on each of these parts, providing relationships for each principal time‐scale. A global equation is then computed by inverse transformation. Generally, the predictands are better fitted by this method than by a standard regression. The improvement is shown for both instrumental and proxy data. The method can easily be applied in many topics where relationships between two groups of variables have to be estimated: agroclimatology, ecology and geophysics in general. It can run on a microcomputer with a BASIC program available from the author.By this method, a reconstruction of June‐July temperature at Marseille (France) is proposed showing a period of weak variability of the temperature during 1400‐1850, that is to say a period of rare warm summers with very cold summers only in the early 16th and late 17th centuries. An extrapolation of the instrumental series at Nice from corresponding series of Marseille and Gap is also deve

ISSN:0196-1748    

DOI:10.1002/joc.3370050308

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0196-1748    

DOI:10.1002/joc.3370050309

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0196-1748    

DOI:10.1002/joc.3370050310

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0196-1748    

DOI:10.1002/joc.3370050311

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY