"Little drops of water... make the mighty ocean", wrote Julia Carney. We have a name for those "little drops of water". It is called rain or raindrops. The question that intrigued many great minds for ages is what is the size of the raindrop? And when it rains, how many drops are there in it?
In 1948, John Stewart Marshall and his doctoral student Walter Palmer performed a fundamental experiment to make the measurement of raindrops [1] for correlation with radar echoes. There wasn't any sophistication involved in their work. The duo collected raindrops on dyed filter papers which they then used to measure the size and get the number distribution of rain.
Marshall and Palmer published their findings as very short communication. The paper, which was only one and a quarter page in length, became a game-changer. More than 70 years have passed. We have developed many new and innovative technologies to measure the raindrop size more accurately. But the distribution developed by Marshall and Palmer in 1948 with only the basic tools from their time is still being used for the estimation of rainfall with remarkable accuracy!
[1] J.S. Marshall and W. McK. Palmer, 1948, The distribution of raindrops with size, Journal of Meteorology, Vol. 5, pp.165-166.
No comments:
Post a Comment