ISSN:0035-9009    

DOI:10.1002/qj.49708536502

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractThe annual variation of temperature in Antarctica has interesting properties: it is largest in the stratosphere (50° to 60°C), smaller at the surface (20° to 40°C) and smallest in the troposphere (10°C). During the winter night the troposphere temperature decreases only slightly while the stratosphere temperature drops steadily at about 1/4°C per day. This differential cooling, which weakens and at times wipes out the tropopause, is caused, on the one hand, by intense horizontal advection of maritime air into the Antarctic troposphere, and, on the other hand, by very little advection through the strong stratospheric jet stream encircling Antarctica.This ventilation of the Antarctic troposphere by warm marine air causes large portions of Antarctica to exhibit thekernlosewinter‐temperature curve instead of the sharp winter minimum usually found in polar continental climate. Anomalously high June temperatures in the lower troposphere at Little America are attributed to intense cyclones which form in the Ross Sea area and advect air from the lightly ice‐clad or open ocean located not too far north of the Ross Sea.Large deviations in average monthly temperatures are found in the Ross Sea area which are undoubtedly a reflection of large year‐to‐year circulation changes in that area.The Antarctic and Arctic stratospheres exhibit quite different temperature behaviours after the winter solstice. The Antarctic stratosphere continues to cool until the sun returns and then warms as much as 50°C in 1 month. On the other hand, the Arctic stratosphere exhibits a warming of 30° to 40°C, sometimes beginning 6 weeksbeforethe sun returns.A secular trend of temperature since 1912 of + 2·6°C at Little America (78° 12'S, 162° 15′W) compares with a + 6·2°C trend at Spitsbergen (78° 04′N, 13° 38′E).Finally, temperature and outgoing radiation observations made at the South Pole I.G.Y. Station during the cold period of 19‐24 April 1958 are presented to illustrate quantitatively the important effect of warm cloud radiation on surface air tempe

ISSN:0035-9009    

DOI:10.1002/qj.49708536503

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractThe mean meridional circulation in winter and summer is derived as a function of latitude and height from an analysis of observed winds in the area 160°W‐0‐40°E, 75°N‐15°N. The results confirm the classical idea of a direct circulation in low latitudes, but the indirect circulation in middle latitudes is stronger than expected. An investigation of the energy released by the meridional circulation implies that it is of comparable importance to large‐scale disturbances in the energy balance of the general

ISSN:0035-9009    

DOI:10.1002/qj.49708536504

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractIt is demonstrated theoretically that the ‘filtering’ effects exerted on a turbulence record by taking averages over an intervals, for a total sampling timet, may be reproduced by simple electrical filters as far as the variance is concerned. The smoothed rectified output of such a filter may be recorded on a slowly moving chart and, with the further assumption of Gaussian distribution in the amplitudes of the fluctuations, may be read directly as a statistical mean of the standard deviation.A description is given of an experimental system, and of direct tests of its performance in recording the standard deviation of wind‐direction fluctuations when averaged over 5 sec and sampled over 3 min. Proposed applications are briefly out

ISSN:0035-9009    

DOI:10.1002/qj.49708536505

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractA series of detailed measurements was made of the concentration of small ions near the ground. It was found that for values of the atmospheric potential gradient exceeding some ± 500 v m−1the electrode effect in the small ions was readily observable, and that when rain fell in a large electric field, there took place a large production of ions of sign opposite to that of the field. The latter effect was examined in some laboratory experiments which showed that the release of charge in the form of ions was associated with splashing. The mechanism by which the ions were produced was found and a determination made of the dependence of the charge released by individual drops on the field, drop mass and drop speed at impact.To determine the importance of the charge released by splashing at the ground, another series of observations was made including the measurement of space charge. It was found that in fine weather the field was sometimes controlled by clouds of charge near the ground. In disturbed weather natural point discharge gave rise to considerable values of the space charge, and in comparison with these, the charges produced by the splashing of rain only became important during heavy ra

ISSN:0035-9009    

DOI:10.1002/qj.49708536506

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractA distillation instrument for the integration of radiation, described by Bellani in 1836, rebuilt in modern materials by Gunn, Kirk and Waterhouse (1945), has a thermal efficiency of over 75 per cent. The improved instrument, mounted at ground level in East Africa, with the condenser underground in constant cool conditions, had a performance that justified manufacture. Comparisons of the manufactured instruments with a Kipp solarimeter gave high linear correlations. These results show the distillation instruments, when so calibrated, to be useful for field estimations of solar radiation. Their cost is low and the daily estimate of total radiation is quickly obtained from a simple burette reading.Ten years' data for these Gunn‐Bellani integrators are compared with those from 4 ft diameter open water pans. A mounting is described for these pans in shallow revetted pits where their sides are shielded from the sun and are insulated from the soil by an air space. A linear correlation based on 164 ten‐day means accounts for 85 per cent of the variability. It appears that in the high‐altitude tropics this radiation integrator by itself can give the basic data for adequate estimate of water use by vegetation, and for control of irrig

ISSN:0035-9009    

DOI:10.1002/qj.49708536507

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractRecent work at the Tidal Institute has provided means of predicting storm surges at the River Tyne entrance, Immingham, King's Lynn, Lowestoft and Southend in the North Sea and Newhaven in the English Channel, from meteorological forecasts.An investigation of surges at Aberdeen has not resulted in a completely satisfactory method of predicting external surges, which are generated outside the North Sea, so that their effects at ports further south have been allowed for by observing their magnitude at Aberdeen and applying an empirical rule which governs their amplification and rate of travel, after Corkan (1948). The disturbances generated inside the North Sea proper, at all the other North Sea ports except King's Lynn, have been correlated at intervals of 6 hr with quantities representing the tractive force of the gradient winds at chosen points in the sea, assuming a quadratic law of friction. The success of the formulae so produced is fully illustrated. For King's Lynn, tide and surge have been treated as an entity, and high‐ and low‐water heights have been expressed as functions of the corresponding heights at the River Tyne and the local wind strength and direction.The propagation of North Sea surges through the Straits of Dover has been studied using Newhaven observations, and it is shown that they travel from Lowestoft as free progressive waves, being attenuated by half. Depressions in the western approaches to the English Channel are also shown to be responsible for disturbances at Newha

ISSN:0035-9009    

DOI:10.1002/qj.49708536508

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractOn 2 September 1958, a tropical storm moved near the centre of the network of upper‐air observations in the Atlantic and Caribbean SE of Florida. This made possible determination of the structure of the storm at a radius of 4·5° latitude from the centre through the entire troposphere and computation of surface integrals concerning the exchange of heat moisture and momentum between the storm and its surroundings. It was found that a net heat export occurred, indicating a net tropospheric drying and cooling after inclusion of the effect of radiation. The inward transport of relative angular momentum was insufficient to balance the flux of angular momentum to the ground as estimated from calculations for the mean hurricane. These computations then suggest weakening of the disturbance with time, and this actually occur

ISSN:0035-9009    

DOI:10.1002/qj.49708536509

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractThis paper compares empirical values of the vector stretch correlation coefficient, and the total vector correlation as fundamentally defined. The former is apparently sufficiently accurate when applied to temporal stretch alone, up to three days, but when applied to space stretch it may have little meteorological meaning unless it exceeds about 0·3 in large data samples (about 450 daily observations)

ISSN:0035-9009    

DOI:10.1002/qj.49708536510

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY

摘要:

AbstractExpressing the coefficientq, of the rate‐of‐ascent formula of the balloon (e.g.V=q F1/2/(W + F)1/3, whereVis the rate of ascent of the balloon,Wthe weight of the balloon andFthe free‐lift) in terms of the coefficient of aerodynamic resistance κ of the balloon, a curve ofqas a function of the Reynolds numberNis worked out. Introducing aκN2– N curve, the value ofq, appropriate to a balloon flight is

ISSN:0035-9009    

DOI:10.1002/qj.49708536511

出版商:John Wiley&Sons, Ltd    

年代:1959

数据来源: WILEY