Cancun Meteorological Station
CANCUN METEOROLOGICAL STATION
 
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Evapotranspiration Index
SOLAR RADIATION
 

The solar sensor of our weather station measures the global solar irradiance levels. This is the sun's strength in units of watts/square metre and the best objective is to measure of the sunshine's power. The values are used to calculate the sunshine hours per day.
 
Why Measure Solar Radiation?
Atmospheric circulation is driven by solar radiation.  Determining the solar radiation and its interaction with the atmosphere and the Earth's surface is important, since solar radiation accounts for almost all of the energy available to the Earth.  There are two ways solar radiation reaches the Earth's surface.  The first is direct solar radiation where the solar radiation is directly transmitted throug the atmosphere.  The second is diffuse solar radiation where the incoming solar radiation is scattered or reflected to the Earth's surface.  Almost 50% of shortwave solar radiation is absorbed by the Earth's surface and changed into thermal infrared radiation. 
 

Sunlight, an essential prerequisite for life, may be extremely dangerous to human health. Excessive exposure to the sun is known to be associated with increased risks of various skin cancers, cataracts and other eye diseases, as well as accelerated skin ageing. It may also adversely affect people's ability to resist infectious diseases, and compromise the effectiveness of vaccination programmes. Sunlight is electromagnetic energy, which is propagated by electromagnetic waves. Healthwise, the most important parts of the sunlight electromagnetic spectrum are:ultraviolet radiation (UV), invisible to the eye; visible light that allows us to see; and infrared radiation, which is our main source of heat but is also invisible. Excessive exposures to them poses particular risks to health. Skin: Excessive UV exposure results in a number of chronic skin changes. These include various skin cancers of which melanoma is the most life-threatening; an increased number of moles (benign abnormalities of melanocytes) and a range of other alterations arising from UV damage to keratinocytes and blood vessels. UV damage to fibrous tissue is often described as "photoageing". Photoageing makes people look older because their skin loses its tightness and so sags or wrinkles.