Hi Craig, that's a very interesting point of view! But how sure are you that it's the trees (or rather, the bacteria) causing cloud formation and not the many, many other aerosols coming from polluted India?

Thanks for your reply.  When I first saw these monsoon cloud formations, that was my first thought, that somehow these long narrow cloud streams were originating from smoke stacks from industries, because their source was from such a narrow point, and with satellite images you could probably retrace the source within a few hundred meters. 

However after watching these unusual clouds develop for years during the monsoon in the lands of SE Asia and India, these clouds originated from tropical forests, never agricultural lands, never deserts, never cities.  The only other possibility would be smoke from the burning of the forests?

And you can confirm that these clouds are not caused by smoke from the burning of the tropical forest, by checking with the daily NAAPS images in Monterey at http://www.nrlmry.navy.mil/shared-bin/display_image.cgi?URL=/aerosol_web/globaer/ops_01/india/current.gif

And if you overlay the daily NAAPS smoke images from burning forests like in Indonesia or Eastern Africa, no Pseudomonas streaky cloud ever appear in those areas.  

For example, I believe that Australia once had plants that were hosts to a similar powerful strain of Pseudomonas, and it probably grew on some type of vegetation like an herbaceous plant that sheep liked to eat, and within the last couple of decades, the 100 million sheep ate it all up, so there is no more Pseudomonas on that continent compared to the amounts that existed before the European invasion.  So in 2014, no Pseudomonas, maybe no normal rains for the future?

If you watch the images from http://tropic.ssec.wisc.edu/real-time/indian/images/xxirmet5n.GIF on a daily basis, you can confirm when you see the long clouds--what I call the "Pseudomonas tropical forest clouds", and trace them back to their origin, and confirm that they are tropical forest in origin, and not industrial or any other kind of aerosols being produced in those spots.

Thanks for your vote up on my answer.  You can use the India coastal Pseudomonas cloud image shown above, and trace back their source of origins, or use the attached image of the 1,000 mile long Pseudomonas cloud coming from the forest preserves of Sri Lanka from July 20th this year, to confirm the connection.  I have been collecting those images all summer, because they are so distinctive and seem to be the best evidence of the potentially massive effect that Pseudomonas has on rain cloud formation in the monsoon zone. 

A close up view of the origins of the 1,000 mile long Pseudomonas cloud in Sri Lanka, show that it originated from the middle of the Wasgamuwa National Park from Lat. N 7.75, Long. E 80.92.

Today's 1,000 mile long Pseudomonas clouds are originating from the forests of Burma/Myanmar.

For initial cloud formation, adequate *moisture* supply is more important than the existence of cloud condensation aerosols - [because there are usually plenty of the latter available in some form]. Once clouds are available, whether or not they give substantial rain often depends on the existence of *freezing nuclei* or ice nuclei, whose fine *crystal structure* is critical to their success; i.e., these microscopic particles are completely different from condensation aerosols. At temperatures around -30C there are plenty of natural ice nuclei available in the atmosphere, whereas at (say) -10C or -15C there are fewer - so it is at these warmer temperatures that cloud-seeding can be relevant. There are recognised techniques for measuring the concentration of ice nuclei in the air. That is probably the best way to answer your question conclusively - i.e., to undertake freezing nuclei counts in [or downstream of] those forests.

The other possibility is that those trees are a source of *hygroscopic* nuclei - thereby producing "warm" rain. That would therefore be like seeding the clouds with sodium chloride. However, this latter technique is less well researched than the other one - i.e., using silver iodide to provide freezing nuclei. Have you any idea what the temperatures are inside your clouds?

Thanks for your reply.  Cloud images I have posted for this question are  from http://tropic.ssec.wisc.edu/real-time/indian/images/xxirmet5n.GIF and I have attached the color and temperature legend for those images

I got a clue about the Pseudomonas in the India-Pakistan area and the monsoon from Alexander Frater when he chased the India monsoon in his book “Chasing the Monsoon” in 1987 and wrote a diary of that year.

On June 2 he attended a meeting of Mrs. Das’ anti-deforestration committee, where he writes: …”India was once a sylvan country. When Alexander the Great invaded in 327 BC he encountered dense, close-canopied almost impenetrable forests. But peasants were already pursuing a slash-and-burn policy…Trees play a crucial role in the monsoon cycle. By SEEDING clouds they encourage the rain to fall; by trapping it they help recharge the aquifers and hold groundwater in store for the common good.”

I highlighted the word seeding, because the Pseudomonas living on the trees creating the monsoon rainfall was unknown by science in the 1980s, but the local people knew something like cloud seeding was going on, from their observations.