Its the last day of march, and as promised the April-showers that bring much relief to heat stricken bangaloreans are here, a day earlier...
And after the rain last night, rain water has collected up all over the city (Gosh its the first rain, and the drains are already choked???? what will happen when the monsoon arrives...? shudder... double shudder). With all the rain forming little lakes all along the road (and some even in the middle of the road.. hehehehe) a peculiar foam has suddenly appeared over all the rain water which has collected up on the road, all over the city. Its bizzare... the entire city (well most of it, that I saw when I traveled across city to get to work) has this soap-sud layer on the streets. These were bubbly, but not the kind there are caused cos of wheels driving though water (they disappear quickly). These bubbles are persistent (cos the rain stopped long back, more than 3 hours earlier), and these bubbles are not very "airy" either. they are small and tiny, and look like the someones tried real hard to foam up hard water. (i don't have any pics to show ...)
Initially, I was a bit wonder struck. It kinda looked novel and the streets looked kinda pretty (all street road in dull white, unseen) but as the kms increased, it got uglier, and even puzzling to the point of annoying and irritation. I don't know what this foamy thing in Bangalore is, but its getting on my nerves (especially when there is talk of compulsory rain water harvesting in all homes (which is a good thing)).
From some googling and some general sense I gather this :
Foams are often seen on pools and lakes. Most of the times, this happens because of existence of surface active agents (surfactants) in water (natural and synthetic) which reduce the surface tension of water. Foam, created in air, enters water through turbulences in streams or waves. Foaming is also observed on trees when it rains. I read that its because of the stem flow collects impurities over the barks and other surfaces and mixes with atmospheric nitrogen, sulfur or potassium. These, act as condensation nuclei, reduce the surface tension of water and cause a foamy production on the bark or foot of trees. I also know that foams are a common on rainwater puddles, especially when there is a detergent spill or oil-coolant spill. Foaming due to detergents is, after all, not problem unheard of.
What surprises me bout this is
1. It suddenly shows up : Its never happened before. I don't think i have seen such large scale foaming event before. Most foams are seen near edges of lakes and water bodies, or near the source of the pollutant.
2. Its so widespread: Initially i thought it was a truck spill or something and didn't think much. after traveling for more than 3 kms away from the current rain water streams, to parallel streams, the foam persisted. it was everywhere. I mean, it couldn't have been a spillage, the foam was too wide spread for it.
3. A friend of mine at office suggested its cause of natural detergents in some seeds like रीठा (Reetha, soap nut tree). But soap nut trees are not very widespread in Bangalore. and unless there was a forest of soap nuts, I don't think a soap-sud type layer of this size could be worked up.
I just saw this article posted nearly 3 years back. it talks bout the same problem in Michigan, US. although no solution has been posted. there are a lot of similarities. common line of though (as i read this article, i thought to myself... " Hey!! i thought the same thing!!" ... not very relevant, but sometime what instinct guides us to is perhaps more important ). It during the spring time. it happened after the first rainfall event(s).not due to any spillage. it was wide spread. Maybe it was something in the air. Some kind of pollution sign. maybe it had something to do with the seasonal pollen (although am pretty sure flora and fauna of Bangalore and Detroit are quite different). (also, I don't think it has anything to do with volcanic ash... :) )
Intriguing. Any clues? if anyone knows.. tell me!
(this post does not have any rambling... phew!)









