- ALBEDO?
- ALBEDO
- WHAT IS ALBEDO?
ALBEDO - whiteness (latin)
ALBEDO - ability of a surface to reflect light
ALBEDO - is another name for reflectivity
- The term ALBEDO is commonly used to applied to the overall average reflection coefficient of an object
- What object?
- Earth, maybe
ALBEDO OF THE EARTH
ALBEDO OF THE EARTH is a measure of how much of the Sun's energy is reflected back into space by a surface
A high albedo means the surface reflects the majority of the radiation that hits it and absorbs the rest. A low albedo means a surface reflects a small amount of the incoming radiation and absorbs the rest.
Fresh snow reflects up to 95% of the incoming radiation. Therefore, fresh snow has a high albedo of 95.
By contrast, water reflects about 10% of the incoming radiation, resulting in a low albedo of 10.
Since 30% of the sun’s energy is reflected by the entire earth, the earth has an average albedo of 30 (maybe 31)
The type of surface that sunlight first encounters is the most important factor that affects the warming or cooling of the planet.
Overall, the Earth's albedo has a cooling effect.
Surface Forests, lakes, oceans, glaciers, deserts, and cities all absorb, reflect, and radiate heat differently
Albedo highly variable depending on the surface type and intervening atmosphere (clouds) Type of a surface Relief of a surface Color of a surface etc
White - reflect
Black - absorb
Generally, dark surfaces have a low albedo and light surfaces have a high albedo. For example, in summer the black asphalt road is scorching hot
Albedo also changes due to human interaction. Forests have lower albedo than topsoil; deforestation increases albedo. Burning wood and fossil fuels adds black carbon to the atmosphere. Some black carbon settles on the surface of the ice, which reduces albedo.
Urban heat island Highly developed areas such as urban cities can experience higher average temperatures than surrounding suburban or rural areas, a phenomenon known as the UHI
Albedo and Global Warming
Climate Myth It is Albedo
since the albedo levels of earth's surface has risen, thus global warming should be a myth
Measuring Albedo Because of the lack of reliable data, traditionally the Earth's albedo has been considered to be roughly constant, or studied theoretically as a feedback mechanism in response to a change in climate
The Earthshine (ashen light) a phenomenon where light reflected by Earth illuminates the dark side of the moon. By measuring the brightness, the amount of albedo - reflectivity - could be estimated.
The Earthshine (ashen light) a phenomenon where light reflected by Earth illuminates the dark side of the moon. By measuring the brightness, the amount of albedo - reflectivity - could be estimated.
Earthshine dome in BBSO to the right of the NST dome Big Bear Solar Observatory
Earthshine dome in Tenerife, Canary Islands
Earth albedo anomalies as measured by earthshine. In black are the albedo anomalies published in 2004. In blue are the updated albedo anomalies after improved data analysis, which also include more years of data
satellite remote sensing data
There are contradictory assessments of current trends in global albedo, possibly because the changes and effects are small. Research is being conducted into the role of clouds, both as forcings and feedbacks, and the role of albedo in cloud formation.
Conclusion Albedo is a subject needing a lot more research. It’s an important feature of our climate, and a complex one. It is not yet possible to make definitive statements
WHY AM I CHOOSING THIS TOPIC
Research Steven E. Koonin https://www.youtube.com/watch?v=O0B8Yi7AZvQ Earth's radiation budget
Earth's radiation budget