DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.20140#0068
IV. THE DAILY PERIOD OF TEMPERATURE.
Principal Dependency upon the Position of the Sun. General sources of terrestrial heat: Proper heat of the
globe; Temperature of Space; heat derived from the Sun.
Insolation and Radiation. Instruments for experimental Observations, readings of Thermometers in the Sun's
Rays. The Sun's heating power greater along the sea-shore than in the interior. Influence of moisture upon
accumulation of heat in the different provinces. Tyndall's Experiments on Heat.
Heat transmitted from the Moon. Melloni's direct proof of heating power. Analysis of very long meteorological
Series.
Numerical Data and descriptive Remarks to illustrate the daily Variation. Hourly observations at Bombay;
Madras; Calcutta; Ambala. Types varying with season and locality. Hot Winds. Sea-breezes. Second
Depression after the principal minimum.
(Daily variation is deduced from hourly observations or means; annual variation from monthly means.)
PEINCIPAL DEPENDENCY UPON THE POSITION OF THE SUN.
The periodical variation of temperature—its daily and yearly range—may best be
introduced by some considerations about the modifying causes.
The rays of the sun would produce an increase of temperature in direct con-
formity to the changes of his position above the horizon, did not time exercise so great an
influence upon the effects of insolation and radiation. Now we see that the maximum is
not reached with the greatest height of the sun, but only 2 to 3 hours later, in the
tropics as well as in higher latitudes; and even the disappeai-ance of the sun below
the horizon does not cause a sudden change in the form of the daily curve, but the
cooling by radiation continues with nearly uniform progress till the moment of the
re-appearance of the sun the following morning. Littoral climates, the rainy season
with its clouded sky, when the direct action of the sun and the loss of heat is most
limited, show the smallest variation; but they also approach most a daily change
proportional to the curve of the sun, and particularly a great uniformity during the
night. Continental regions with an unclouded sky, and great heights, where the variety
Principal Dependency upon the Position of the Sun. General sources of terrestrial heat: Proper heat of the
globe; Temperature of Space; heat derived from the Sun.
Insolation and Radiation. Instruments for experimental Observations, readings of Thermometers in the Sun's
Rays. The Sun's heating power greater along the sea-shore than in the interior. Influence of moisture upon
accumulation of heat in the different provinces. Tyndall's Experiments on Heat.
Heat transmitted from the Moon. Melloni's direct proof of heating power. Analysis of very long meteorological
Series.
Numerical Data and descriptive Remarks to illustrate the daily Variation. Hourly observations at Bombay;
Madras; Calcutta; Ambala. Types varying with season and locality. Hot Winds. Sea-breezes. Second
Depression after the principal minimum.
(Daily variation is deduced from hourly observations or means; annual variation from monthly means.)
PEINCIPAL DEPENDENCY UPON THE POSITION OF THE SUN.
The periodical variation of temperature—its daily and yearly range—may best be
introduced by some considerations about the modifying causes.
The rays of the sun would produce an increase of temperature in direct con-
formity to the changes of his position above the horizon, did not time exercise so great an
influence upon the effects of insolation and radiation. Now we see that the maximum is
not reached with the greatest height of the sun, but only 2 to 3 hours later, in the
tropics as well as in higher latitudes; and even the disappeai-ance of the sun below
the horizon does not cause a sudden change in the form of the daily curve, but the
cooling by radiation continues with nearly uniform progress till the moment of the
re-appearance of the sun the following morning. Littoral climates, the rainy season
with its clouded sky, when the direct action of the sun and the loss of heat is most
limited, show the smallest variation; but they also approach most a daily change
proportional to the curve of the sun, and particularly a great uniformity during the
night. Continental regions with an unclouded sky, and great heights, where the variety