Search results
Results From The WOW.Com Content Network
The intensity of albedo temperature effects depends on the amount of albedo and the level of local insolation (solar irradiance); high albedo areas in the Arctic and Antarctic regions are cold due to low insolation, whereas areas such as the Sahara Desert, which also have a relatively high albedo, will be hotter due to high insolation.
This integrated solar irradiance is called solar irradiation, solar radiation, solar exposure, solar insolation, or insolation. Irradiance may be measured in space or at the Earth's surface after atmospheric absorption and scattering. Irradiance in space is a function of distance from the Sun, the solar cycle, and cross-cycle changes. [2]
Direct insolation is equal to the solar irradiance above the atmosphere minus the atmospheric losses due to absorption and scattering. While the solar irradiance above the atmosphere varies with the Earth–Sun distance and solar cycles , the losses depend on the time of day (length of light's path through the atmosphere depending on the solar ...
For example, with an axial tilt is 23°, and at a latitude of 45°, then the summer's peak sun angle is 68° (giving sin(68°) = 93% insolation at the surface), while winter's least sun angle is 22° (giving sin(22°) = 37% insolation at the surface). Thus, the greater the axial tilt, the stronger the seasons' variations at a given latitude.
The amount of Sun energy reaching a location on Earth ("insolation", shown in blue) varies through the seasons.As it takes time for the seas and lands to heat or cool, the surface temperatures will lag the primary cycle by roughly a month, although this will vary from location to location, and the lag is not necessarily symmetric between summer and winter.
To describe some of the internal flows within the budget, let the insolation received at the top of the atmosphere be 100 units (= 340 W/m 2), as shown in the accompanying Sankey diagram. Called the albedo of Earth, around 35 units in this example are directly reflected back to space: 27 from the top of clouds, 2 from snow and ice-covered areas ...
Idealised depiction (at equinox) of large-scale atmospheric circulation on Earth Long-term mean precipitation by month. Atmospheric circulation is the large-scale movement of air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth.
As the orbital eccentricity changes, the average distance from the Sun (the semimajor axis does not significantly vary, and so the total insolation over a year remains almost constant due to Kepler's second law, =, where is the "areal velocity" invariant. That is, the integration over the orbital period (also invariant) is a constant.