scholarly journals Directional observations of atmospheric disturbances, 1920-21

1923 ◽  
Vol 102 (717) ◽  
pp. 460-478
Keyword(s):  
Seasonal Variations ◽  
Atmospheric Electricity ◽  
Direction Of Arrival ◽  
Close Correlation ◽  
Quantitative Relation ◽  
Solar Altitude ◽  
General Law ◽  
Apparent Direction ◽  
Atmospheric Disturbances ◽  
Modal Values

The paper analyses 12 months' observations of the intensity and apparent direction of arrival of atmospheric disturbances, carried out for the Radio Research Board at a station in S. E. England. Observations were made at 7 h., 13 h., and 16 h. daily, the average number of such disturbances heard being 80 per minute. The apparent direction of arrival is well marked, with unexpectedly simple diurnal and seasonal variations, following a general law of counter-clockwise swing in direction accompanying increase in solar altitude. The mean direction of greatest disturbance for the year is 153°, with a diurnal variation of 60° range, a seasonal of 100°. The numbers heard per unit-time have also comparatively simple diurnal and seasonal variations, March being the quietest, June the most disturbed month, with a disturbance twice that of March. Fourier coefficients for the monthly mean and modal values are tabulated. Close correlation between apparent direction of arrival and solar altitude is found, no local topographical effect is traced, and no quantitative relation with terrestrial magnetism, atmospheric electricity, or any of the surface meteorological elements (except temperature) has yet been established. Special observations during a solar eclipse are reported.

scholarly journals The magnitude of variation in temperature within a year has an effect on the seasonal variations of chickenpox incidence in Japan

2001 ◽  
Vol 126 (2) ◽  
pp. 269-277 ◽  
Author(s):  
A. KOKAZE ◽  
M. YOSHIDA ◽  
Y. SEKINE ◽  
M. ISHIKAWA ◽  
T. KUROKOCHI ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Close Correlation ◽  
Daily Temperature ◽  
Size And Shape ◽  
Different Types ◽  
Close Relationship ◽  
The Difference ◽  
Two Peaks ◽  
Second Peak

We investigated the epidemic pattern of chickenpox incidence among 47 prefectures in Japan. There were two peaks in chickenpox incidence in all prefectures. The first peaks appear at almost the same time in a year, while the second peaks occur at different times with relatively different types of size and shape. The feature of the second peak might characterize the epidemic pattern of chickenpox. We first introduced the second peak index, that is, the ratio of the difference between the incidence at the point of the second peak and the minimum incidence between the first and second peaks to the difference between the incidence at the point of the second peak and the minimum incidence in the year. There was a close correlation between the second peak index and the magnitude of variation in temperature within a year corresponding to the difference between the maximum and the minimum of the monthly mean of the highest daily temperature. This is the first article focusing on the close relationship between the second peak of epidemic pattern of chickenpox incidence and the variation of temperature within a year.

Measurements of the direction of arrival of short radio waves reflected at the ionosphere

1951 ◽  
Vol 207 (1089) ◽  
pp. 251-267 ◽  
Keyword(s):  
Large Scale ◽  
Wave Length ◽  
Direction Of Arrival ◽  
Close Correlation ◽  
Comparison Method ◽  
Radio Waves ◽  
Frequency Range ◽  
Compressional Waves ◽  
First Order ◽  
Random Direction

Using a phase-comparison method described in another paper, measurements have been made of the direction of arrival of waves reflected at the ionosphere during normal daytime conditions, both over an oblique path corresponding to a range of 700 km. and at nearly vertical incidence. The frequency range covered was 4 to 15 Mc./see., and using pulsed signals the direction of arrival of discrete rays could be studied. The work so far carried out has been confined principally to first-order F -layer reflexions, but a few observations of second-order reflexions and of reflexions from the E region have also been made. The results show that a typical first-order F echo exhibits both rapid (second to second) fluctuations in direction and slow changes of a quasi-period of many minutes (ranging from a few up to more than 30 min.). These results confirm earlier deductions from direction-finding studies and are interpreted as indicating that large-scale and apparently random tilts occur in the ionosphere. The F layer at any point is to be regarded as usually tilted in a random direction, the r. m. s. magnitude of the tilt being of the order of 1·5 to 2° and the tilt changing at a rate corresponding to the slow directional changes observed. Some indication as to the extent of these tilts is given by experiments using two direction-measuring stations separated by 27 km. These two stations, operated simultaneously, exhibit extremely close correlation so far as the slowly changing directional deviations are concerned, both for oblique paths and at nearly vertical incidence. The results are consistent with others obtained in Australia by different methods which suggest that there are compressional waves in the atmosphere at the height of the F layer, and that these waves have a wave-length of several hundred kilometres and a velocity of some 5 to 10 km./min.

I. On the electrical resistance of carbon contacts

1883 ◽  
Vol 35 (224-226) ◽  
pp. 1-18 ◽  
Keyword(s):  
Electrical Resistance ◽  
Quantitative Relation ◽  
General Law ◽  
The Subject ◽  
Increased Pressure

1. Object of the Investigation . It is well known that the electrical resistance of carbon contacts diminishes with increased pressure, though, so far as I am aware, the phenomenon has never hitherto been systematically investigated. The experiments described in this paper were begun with the object of establishing a quantitative relation between pressure and resistance; but the subject grew considerably under treatment; fresh facts from time to time claimed attention, and several interesting details, not, I believe, previously observed, were eventually brought to light. Loose contacts are proverbial for the uncertainty of their action, and it was to be expected that the investigation would prove troublesome and the results obtained by no means uniform. By multiplying experiments, however, the element of uncertainty was to a great extent removed, and in most cases it was found possible to indicate a general law with tolerable certainty.

scholarly journals The Relation between Puerperal Septicaemia and certain Infectious Diseases

1928 ◽  
Vol 27 (2) ◽  
pp. 186-196 ◽  
Author(s):  
Peter L. McKinlay
Keyword(s):  
Infectious Diseases ◽  
Seasonal Variations ◽  
Scarlet Fever ◽  
Puerperal Fever ◽  
Inflammatory Diseases ◽  
Close Correlation ◽  
Secular Trends ◽  
Causal Organism ◽  
Contagious Nature ◽  
The One

The possibility that the prevalence of diseases in which there is no specific causal organism may be affected by the prevalence of other diseasses of a contagious nature is well recognised. Even in the early days of bactriology interrelationships between infectious diseases and puerperal septicaemia were suspected on purely statistical grounds. Longstaff (1891), for example, pointed out the remarkably close correlation between the seasonal variations and the secular trends of the mortalities of erysipelas and childbed fever—a relationship so close that he “found it difficult to avoid the conclusion that they were both due to the one poison.” A somewhat similar but less striking association was shown with other inflammatory diseases, such as pyaemia, scarlet fever, “rheumatism of the heart or pericardium” and diphtheria. Even more emphatic were the views of Minor (quoted by Longstaff) who, with reference to the association between erysipelas and puerperal fever, gave reasons for the belief that there existed an intimate connection between them, and that “in any place where erysipelas is found, there will be found puerperal fever.”

scholarly journals Quantitative relation between PMSE and ice mass density

2010 ◽  
Vol 28 (6) ◽  
pp. 1333-1343 ◽  
Author(s):  
S. Kirkwood ◽  
M. Hervig ◽  
E. Belova ◽  
A. Osepian
Keyword(s):  
Daily Variation ◽  
Mass Density ◽  
Geomagnetic Latitude ◽  
Close Correlation ◽  
Quantitative Relation ◽  
Mesopause Region ◽  
Quantitative Expression ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes ◽  
Mesospheric Clouds

Abstract. Radar reflectivities associated with Polar Mesosphere Summer Echoes (PMSE) are compared with measurements of ice mass density in the mesopause region. The 54.5 MHz radar Moveable Atmospheric Radar for Antarctica (MARA), located at the Wasa/Aboa station in Antarctica (73° S, 13° W) provided PMSE measurements in December 2007 and January 2008. Ice mass density was measured by the Solar Occultation for Ice Experiment (SOFIE). The radar operated continuously during this period but only measurements close to local midnight are used for comparison, to coincide with the local time of the measurements of ice mass density. The radar location is at high geographic latitude but low geomagnetic latitude (61°) and the measurements were made during a period of very low solar activity. As a result, background electron densities can be modelled based on solar illumination alone. We find a close correlation between the time and height variations of radar reflectivity and ice mass density, at all PMSE heights, from 80 km up to 95 km. A quantitative expression relating radar reflectivities to ice mass density is found, including an empirical dependence on background electron density. Using this relation, we can use PMSE reflectivities as a proxy for ice mass density, and estimate the daily variation of ice mass density from the daily variation of PMSE reflectivities. According to this proxy, ice mass density is maximum around 05:00–07:00 LT, with lower values around local noon, in the afternoon and in the evening. This is consistent with the small number of previously published measurements and model predictions of the daily variation of noctilucent (mesospheric) clouds and in contrast to the daily variation of PMSE, which has a broad daytime maximum, extending from 05:00 LT to 15:00 LT, and an evening-midnight minimum.

Seasonal variations in AADSAS applicants

1985 ◽  
Vol 49 (6) ◽  
pp. 445-447
Author(s):  
E Solomon ◽  
D Stoll
Keyword(s):  
Seasonal Variations
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