A Reflection on Monthly Shortwave Radiation

a. Using the legend, determine the value (number and unit) for the darkest blue-black /dark- blue-black /almost-black color.



The darkest blue-black color represents 0 watts per square meter.

b. Where is this color located in the image?

The darkest blue-black color is located in the Northern region of the globe, also known as the Arctic region.

c. Determine the value for the lightest yellow color. Where is this located in the image?

The lightest yellow-white color represents 425 watts per square meter. This color is located in the southern region of the globe. This is also known as the Antarctic Circle.

d. Can you think of a possible reason for this situation in January?

This is because of the tilt of the earth towards the sun makes the earth only get sun light towards the southern hemisphere in January. Every day the southern hemisphere will get 24 hours of sunlight. The sunlight can only reach the southern hemisphere. There will be no light reflecting of the top of the northern hemisphere because there is no sunlight (24 hours of no sunlight) even reaching there in January. Also, Ice and snow reflect lots of light because of the white surface.

e. What do you think the image would look like in July? Why?

The image will look opposite because the earth will be at an angle that is opposite (because of opposite seasons). This will reverse the part of the globe that will get the sunlight. The North Pole on the image will be very light and the Antarctic will be very dark because it will receive 0 sunlight to reflect.

f. Click on the image for July to check your answer and describe what you found below:

It is not entirely opposite because the southern hemisphere is darker but the northern hemisphere is merely green not white (except for Greenland).

g. In general, does water or land appear to have the higher reflectance?

In general, I think the land has a higher reflectance because all the maps show certain parts of the water with blue-black colors. Land however always has a certain a green color.

h. Explain why the poles seem to always show the extremes of reflectance.

I think the pole have extremes of reflectance because of the tilt of the sun. The tilt of the sun will allow one to get all sunlight and reflect most sunlight, while the other will get 0 sunlight because the other is in the way.

i. Earth’s energy balance is the difference between energy coming in (from the sun) and that leaving (through radiation to space). How does reflectance impact the energy balance?

Reflectance impacts energy balance because it makes sure that our Earth will not only take in the heat. Reflectance help maintain a cooler energy balance because without it Earth would only be taking in the heat making Earth a much hotter place. Reflectance is equally important in the role of energy balance as its counter (coming in). It definitely does impact the earth because the energy would overheat our Earth without it being removed.

j. How does reflectance and the energy balance impact the temperature of the planet?

If more sunlight was reflected away the Earth’s temperature would go down because there would be less heat being kept to warm the Earth. This can be proved by the polar ice caps because their surface is a white color that reflects sunlight the most. Without much sunlight being absorbed, there is almost no warmth near the earth. This is a cause for cold in high latitude regions with snow. If there was more sunlight being absorbed into the Earth and the Earth was reflecting less, than the earth would be much hotter. An example of this on a smaller scale is the black top in parking lots. The more sunlight the blacktop absorbs the hotter it gets. To restate, the Earth's temperature is dependent on the reflectance and other things. So, if reflectance changes so does the temperature.

The first diagram above shows what earth is normally like, with a balance of light coming in and being reflected, but the second and third show more and less light being reflected. However, these do not show what would happen to the land if more or less were to be reflected. The second shows a lighter Earth with more arrows coming from it. As one can analyze, this means that the land would be colder because less of the heat is staying on the surface. The third show a darker Earth with less arrows coming from it. The darkness represents the high absorption rate from the surface. Lots of absorption means that the Earth would be warmer.

My source for photos and information: http://neo.sci.gsfc.nasa.gov/view.php?datasetId=CERES_SWFLUX_M&year=2015