Periodic variations in light-diurnal and seasonal, Biology

Periodic Variations in Light-Diurnal and Seasonal

We know that rotation of the earth on its axis accounts for day-to-night variations in the amount of radiations falling at a given place and seasonal variations occur due to the orbiting of the earth around the sun. Since the earth's equatorial plane is inclined to its orbit at an angle of 23o.27'. the rays of the sun do not fall vertically on all parts of the earth. From March 22nd to Sept. 22nd (AutumnaTequinox), the northpole is inclined towards the sun. So the most intense solar beam is focused on the northern hemisphere. We in the northern hemisphere, have summer season and on the northpole the sun shines for 24 hours of the day. While on South pole it is dark for six months and the southern hemisphere has winter season. The opposite situation exists on the poles from September 24 to March 20 (spring equinox) when the northern hemisphere has winter season and southern hemisphere has
summer season (Figure shown below).

1739_periodic varaitions.jpg

There is also horizontal variation in the distribution of radiation on the earth. Because the earth is nearly spherical in shape, parallel beam of incoming sunlight does not fall vertically on all parts of the earth. It strikes lower latitudes more directly than higher latitudes. Therefore, at higher latitudes the incident radiation falls obliquely on the surface, travels more through the atmosphere, and spreads over a greater area and thus is less intense than the vertical beam falling on or near the equator.

 

Posted Date: 12/10/2012 6:10:49 AM | Location : United States







Related Discussions:- Periodic variations in light-diurnal and seasonal, Assignment Help, Ask Question on Periodic variations in light-diurnal and seasonal, Get Answer, Expert's Help, Periodic variations in light-diurnal and seasonal Discussions

Write discussion on Periodic variations in light-diurnal and seasonal
Your posts are moderated
Related Questions
A person has swelling on the front of his neck. Name the disease he is suffering from and the cause of it.

You are interested in using formic acid (pKa = 3.75) as a buffer for your biochemical Experiment. a) Would it be most useful for creating a buffered solution at pH 2, 4 or 6? Ex

How does the metachronal waves form in the ciliary row of protozoa ? Explain the cilia beating mechanism associates with it.

Conduct a test of hypothesis to verify whether a difference exists among the average numbers of ant species found at sites in the two regions of Mongolia. Use  .  You will require

Chemical Methods of Estimating Available Nutrients  Water soluble forms of nutrients are available to plants but forms other than water soluble may also become available to pla

Haemoglobin Among the respiratory pigments we shall consider haemoglobin in some detail as this is the most familiar, widespread as well as the most efficient respiratory pigm

Explain the Methodology for seliwanoff test? Take 5 ml of seliwanoff's reagent in a test tube. Add 5-6 drops of the glucose solution and heat the mixture to boiling for about 3

Q. What is the difference between sperm and spermatids cells? What is the name of the transformation of spermatids into sperm cells? Sperm cells (the male gametes) are matured

Q. What is the DNA vaccine? The DNA vaccination or is a vaccination technology based on genetic engineering. In DNA vaccine a recombinant plasmid (vector) containing the gene o

Endodontics principles and practice According to American association of endodontic, retreatment defined as:A procedure to remove root canal filling materials from the tooth vi