|Make a Smilebox slideshow|
The above slideshow is intended to show how cirrus cloud distribution changes each year. I am chieflyconcerned with the tropical regions.
Cirrus clouds have a yearly path Northwards and then Southwards. From January to March, cirrus clouds are maintained South. From April to June, they move North. From July to August, they are maintained North. And from September to December, they move South. This annual pattern has a significant impact on cirrus cloud-free zones in the Pacific, Indian, and Atlantic oceans. As the cirrus clouds move Northward, regions near the equator in the Pacific ocean become very cloud-free along with the coast of S. America just South of the equator. A cloud free zone forms slightly south of the equator in the Atlantic, by Africa. And from October through April, the strong cirrus cloud cover over the Northern Indian Ocean (stretching outwards into the Pacific) dissipates, becoming less intense and less organized.
With these annual trends in cirrus cloud distribution, we are led to a question concerning our postulation that decreases in cirrus cloud cause El Ninos. Does it matter that inter-annual fluctuations in cirrus cloud cover are larger than changes during El Ninos? But that is a question to be asked down the road. Right now, I am focussing on determining if changes in cirrus cloud cover accompany tropical warming events.