Sunday, August 9, 2009

Earth Cloudiness 1969 and 2009

What a difference four decades makes! Below is a August 2009 photo of the Earth from space, showing almost no clouds. Below that is a famous photo from July 1969 taken from the Apollo 11 spacecraft, showing the Earth almost covered in clouds.

View of Earth from Apollo 11, July 1969, showing clouds covering much of the surface. Such cloudiness increases the Earth's albedo and leads to reduced air temperatures.

1 comment:

Ellie in Belfast said...

Hello Roger,

These are two lovely photos. I'm sure you've thought of this. It is just that satelite technology has moved on - there seem to be so many different filters that can be used with satellite imaging to detect different types of clouds. There seem to be faint low level clouds in the 2009 one that could in a different imaging system show up as bright white.

Regardless, I am convinced there is a difference.

Interestingly, in Ireland long term cloudiness is associated with milder Winter temperatures; in summer wind direction affects temperature more than cloud/sun. Summer sun gives warm days and cool nights; summer cloud gives cooler days but less of a drop at night and overall about the same, so I guess it depends on latitude.