The Quarterly Journal of the Royal Meteorological Society

doi: 10.1002/qj.49709540501pmid: N/A

Mason, B. J.

doi: 10.1002/qj.49709540502pmid: N/A

Latham, J.; Stow, C. D.

doi: 10.1002/qj.49709540503pmid: N/A

Studies have been made using instrumented aircraft of the electrical and microphysical properties of cumulus and cumulonimbus clouds over Flagstaff, Arizona. Measurements were made throughout the life‐cycle of these clouds either by making horizontal penetrations through the cloud at intervals of 2 Centigrade degrees or by entering the cloud at the highest level attainable and spiralling down to cloud base. The aircraft could attain an altitude of around 32,000 ft (9·7 km), corresponding to a temperature ceiling of approximately −30°C. Continuous measurements were made of vertical electric field strength, F, the charge carried on larger hydrometeors, Q, the concentrations, types and dimensions of cloud particles, liquid‐water content, temperature and other meteorological parameters.

Kung, E. C.; Soong, S.

doi: 10.1002/qj.49709540504pmid: N/A

In an attempt to broaden the observational basis of the seasonal variation of the large‐scale atmospheric circulation, Fourier analysis was applied to time series of important kinetic energy variables which were computed for a 5‐year period over the North American Continent. The variance spectra of the direct Fourier analysis are also presented.

Ogawa, T.; Brook, M.

doi: 10.1002/qj.49709540505pmid: N/A

The negative charge involved in lightning flashes to ground is found to be distributed in a manner strongly dependent upon the direction of movement of the storm, and does not, in general, constitute a nearly vertical column as proposed by Malan and Schonland. Based on a study of electric field‐changes measured at two stations 10 km apart involving 539 return strokes from 84 flashes in 10 storms, we conclude that the horizontal component of the in‐cloud channel on the average exceeds the vertical component, and points in the direction of storm motion.

Paterson, M. P.; Spillane, K. T.

doi: 10.1002/qj.49709540506pmid: N/A

The number of condensation nuclei produced by the bursting of a single bubble in sea‐water, and detectable at a few per cent supersaturation, is shown to be markedly dependent on the film pressure of naturally occurring surface‐active material adsorbed on the surface.

Pick, D. R.; Houghton, J. T.

doi: 10.1002/qj.49709540507pmid: N/A

A radiometer sonde has been constructed to observe radiation from the atmosphere above the radiometer in the spectral region 5–7 μ with a spectral resolution of about 0·3 μ. The results from a flight of the instrument at night up to a height of 25 km are presented. Emission from water‐vapour indicates a dry stratosphere with a mass mixing ratio of about 3 × 10−6. An energy flux originating above 25 km amounting to about 2 μW cm−2 has been observed near 5·7 μ. Various possible sources for this additional radiation are discussed.

Atlas, D.; Tatehira, R.; Srivastava, R. C.; Marker, W.; Carbone, R. E.

doi: 10.1002/qj.49709540508pmid: N/A

Doppler radar observations during widespread frontal precipitation in England on 20 February 1967 show significant perturbations of the wind in and near the melting layer. The analysis suggests the following hypotheses: (i) Mesoscale oscillations of the wind near the melting layer are produced by pressure perturbations due to horizontal variations in cooling by melting snow associated with the precipitation pattern. A simple theoretical analysis of the effect is presented. In simple patterns, the perturbed wind has a maximum on the low pressure side of the rainfall. The perturbations propagate with the velocity of the precipitation generators and their magnitude increases with the precipitation rate. This hypothesis is in accord with the finding that the oscillation in the tangential wind across hurricane rain bands is generally a maximum on the low pressure side of the bands. (ii) Smaller scale wind perturbations were also observed in the melting layer with scale of a few kilometers comparable to those reported by Harrold and Browning (1967). However, unlike their observations, these perturbations did not appear to move with the melting layer winds. A tentative suggestion is made that these may represent wave motions.

Peterson, E. W.

doi: 10.1002/qj.49709540509pmid: N/A

A theory is developed which describes the adjustment of the flow of a hydrostatically neutral fluid in the lower portion of a fully‐turbulent boundary layer, after an abrupt change in surface roughness.

Craddock, J. M.; Flood, C. R.

doi: 10.1002/qj.49709540510pmid: N/A

A set of empirical orthogonal functions is produced which enable the large‐scale features of the 500 mb topography over the Northern Hemisphere to be represented with near optimal efficiency. The more important functions are described. Some of the properties of the coefficients of these functions which best represent the 500 mb charts for each day of the years 1965 to 1967 are summarized. The question of the number of functions required to obtain the most satisfactory representation of the 500 mb fields is discussed.