摘要:

AbstractA field of average annual enhancement, defined as the mean rainfall rate al inland sites minus the mean rate over the coast, has been derived for England and Wales. Past cases of frontal rain associated with low‐level winds from the SW quadrant were analysed so as to determine the typical distribution and intensity of orographic enhancement. It is shown that these results are sensitive to wind speed and, in particular, direction. Comparison of these results suggest relationships between orographic enhancement and average annual enhancement which are used to produce estimates of the distribution of enhancement which may occur with low‐level winds from other directions. These enhancement fields can he combined with radar observations of rain over the sea to produce short‐period forecasts of rainfall intensity when it moves ove

ISSN:0196-1748    

DOI:10.1002/joc.3370030202

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe surplus or deficit of precipitation is of fundamental importance in hydrology. An analysis is presented which provides for the prediction of surplus or deficit conditions as far as six months ahead. Data from Yorkshire, together with thirteen years data from a station in Nottinghamshire, are used statistically to analyse problems in water supply, irrigation and drainage. This analysis is based upon a technique developed by Stol in which differences between evaporation and precipitation are analysed over different periods of time.

ISSN:0196-1748    

DOI:10.1002/joc.3370030203

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractSea surface temperature (SST) measurements from 1950 to 1969 are analysed for an extensive region of the Southern Hemisphere for six years of very high and very low areal extent of above normal Australian continental rainfall. Years of extensive drought are found to be associated with a predominantly low SST persisting throughout the year over the eastern Indian Ocean and the south west Pacific in the Australasian region particularly at low latitudes; very wet years over the continent are associated with a persistently warm SST extending from the equator to mid latitudes in the same region. Although the extreme years tend to be related to extremes of a Southern Oscillation index this is not always the case. Examination of SST over the eastern Pacific for the same years indicates some evidence that its thermal anomalies are in general opposite to those in the Australasian region though this is not so in all cases. Eastern South Pacific SST data sequences for years preceding and following individual extreme rainfall years over Australia show rapid and differing changes so that their forecasting potential is very limited.

ISSN:0196-1748    

DOI:10.1002/joc.3370030204

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractSeasonal and diurnal patterns produced by the interaction of synoptic scale winds and two thermo‐topographic systems, the land/sea breeze and mountain/plain winds, are investigated in a spatial context. Together with gradient winds and the shallow ‘lee trough’ north‐easterlies these local winds create a wind regime composed of several distinctive regional element, the boundaries of which are transitional in nature and dependent on time day and year and the strength of synoptic influences. The sea breeze maximum frequency by day in summer in coastal areas whereas katabatic flows are most frequent by night, in winter adjacent to the Alps. Banks Peninsula strongly influences the wind regime by funnelling north‐easterly airflow onto the plains and possibly creating a zone of sea breeze convergence extending inland. South of Banks Peninsula the interaction of onshore wind components with north‐easterly synoptic winds appears responsible for the diurnal rhythm in the synoptic wind, a phenomenon already observed north of Banks Peninsula in relation to south‐westerly gradient winds.Practical and theoretical implications of the regional study

ISSN:0196-1748    

DOI:10.1002/joc.3370030205

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractSpatial patterns of surface temperature and precipitation variability over the Great Lakes region and their changes during the past 78 years are examined using eigenvector analysis. The results show that the region is homogeneous in terms of temperature variations. The most important regional temperature trends have been very similar to the trends in the average annual temperature for the Northern Hemisphere. In the case of precipitation, however, an important boundary divides the region into a north‐western and south‐eastern portion. Positive precipitation anomalies occurred over the south‐east during the early part of this century and again after about 1960. The north‐western portion, on the other hand, experienced wet conditions during most of the intervenin

ISSN:0196-1748    

DOI:10.1002/joc.3370030206

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractSimple empirical relationships based on the hours of bright sunshine, the daily temperature range and relative humidity have been developed to estimate the daily global solar irradiation at Corvallis, Oregon (U.S.A.). It is observed that the greater part of the variability in the daily solar radiation income at the surface is explained by changes in the available solar energy at the top of the atmosphere in the course of the year. The relationship based on the hours of bright sunshine yields estimates of the daily global solar irradiation which compare favorably with the measured values (coefficient of determination>0‐90

ISSN:0196-1748    

DOI:10.1002/joc.3370030207

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractA decision‐analytic approach to the problem of assessing the value of climate information is presented and an application of this methodology to a decision‐making problem involving the use of climate information is described. First, decision analysis is discussed briefly with emphasis on its informational aspects. Then a decision‐making situation is considered in which a farmer must decide which of two crops to plant in the face of uncertainty as to whether growing season precipitation will be above or below average. It is assumed that information concerning growing season precipitation is embodied in a climate forecast provided by a meteorologist and that this information constitutes the basis for the farmer's decision. Several probabilistic models for the climate forecasts are considered, including symmetric and asymmetric discrete distributions and a normal model. These models can provide reasonable descriptions of currently available climate forecasts. The analysis reveals that relatively uncertain climate information may be of value in some decision‐making situations, although the value of climate forecasts with skill levels commensurate with existing seasonal forecasts does not approach the value of perfect forecasts. Nevertheless, in the situations considered, once a minimum level of skill is achieved, further improvements in the forecasts result in steadily increasing benefits. Finally, it is indicated that decision analysis is also applicable to more complex situations in which climate information may play an importa

ISSN:0196-1748    

DOI:10.1002/joc.3370030208

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

ISSN:0196-1748    

DOI:10.1002/joc.3370030209

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

ISSN:0196-1748    

DOI:10.1002/joc.3370030210

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

ISSN:0196-1748    

DOI:10.1002/joc.3370030212

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY