By reading the website of islandnet .com., the discussions about raindrops were still common in the weather literature or introductory meteorology texts. In this website stated that the two persons, German Philipp Lenard and American Wilson A. Bentley published their results about the raindrop size and shape in 1898. They did not know each other. They used their own methods to carry out the investigations.
From the points of view of the meteorologists, both methods were not good enough. Philipp Lenard collected ten field samples and did not relate raindrop size distribution to weather condition. Bentley kept detailed records of the weather conditions under which he carried out the tests. In several years’ time, Bentley collected a total of 344 separate size distributions sampled from 70 individual storms including 25 thunderstorms. In order to understand the distributed of various sizes of raindrops, he divided the raindrop fossils from the 344 collections into 5 size categories: very small, small, medium, large and very large. Bentley collected raindrops in a pan of wheat flour. He reported the results in Monthly Weather Review in October 1904. He concluded that the sizes of the raindrops from these categories were nearly the same. The smaller drops outnumbered larger ones. Low clouds produced few large drops. He found the maximum raindrop size to be around 6 to 8 mm in diameter. Lenard got the similar result that the raindrops that larger than 6 mm would break apart.
In 1943, researchers from the US Soil Conservation Service used the flour pellet technique to measure raindrop size as a function of rainfall intensity. Canadian scientists Marshall and Palmer found the relationship between raindrop size distribution and rain intensity was similar to the result of the experiment of US Soil Conservation Service. They used the advance technology liked radar as a tool to observe precipitation.
Rain would not fall without some degree of impurity in the air to act as a seed. Raindrops fell as they combined with other particles from the air as they passed through. Acid rain was the good example.
Today, with the help of radar and the advance technology, the information on the time variability of drop size distributions as seen by a disdrometer was used to estimate the size of raindrops and it's location. How to generate the space-time variability of the distributions of the size of raindrops was developed.
Your design about the raindrop was simple. The background was coloured in pink. I looked like the cloud with raindrops moved in curved shaped. The explanation was also very simple. It showed you had made an effect by using Flash to display your information.
yiuLibrary 提到... More about the improved FLASH "raindrop":
Group members: Lidia Ho and Candy Yiu
- We use the water cycle picture as the raindrop's background and its colour is light.
- We use four pictures to introduce the water cycle process. So when the mouse is near different picture, it will show you different numbers, e.g. 1, 2, 3, 4. Then you will know the first process is "Evaporation", and the second process is "Condensation"...
- We use the flash to introduce the size and shape of raindrop from 1mm to 8mm. We also mentioned that the size of raindrop will be affected by air pressure.
4 則留言:
Title: The size of a raindrop
By reading the website of islandnet .com., the discussions about raindrops were still common in the weather literature or introductory meteorology texts. In this website stated that the two persons, German Philipp Lenard and American Wilson A. Bentley published their results about the raindrop size and shape in 1898. They did not know each other. They used their own methods to carry out the investigations.
From the points of view of the meteorologists, both methods were not good enough. Philipp Lenard collected ten field samples and did not relate raindrop size distribution to weather condition. Bentley kept detailed records of the weather conditions under which he carried out the tests. In several years’ time, Bentley collected a total of 344 separate size distributions sampled from 70 individual storms including 25 thunderstorms. In order to understand the distributed of various sizes of raindrops, he divided the raindrop fossils from the 344 collections into 5 size categories: very small, small, medium, large and very large. Bentley collected raindrops in a pan of wheat flour. He reported the results in Monthly Weather Review in October 1904. He concluded that the sizes of the raindrops from these categories were nearly the same. The smaller drops outnumbered larger ones. Low clouds produced few large drops. He found the maximum raindrop size to be around 6 to 8 mm in diameter.
Lenard got the similar result that the raindrops that larger than 6 mm would break apart.
In 1943, researchers from the US Soil Conservation Service used the flour pellet technique to measure raindrop size as a function of rainfall intensity. Canadian scientists Marshall and Palmer found the relationship between raindrop size distribution and rain intensity was similar to the result of the experiment of US Soil Conservation Service. They used the advance technology liked radar as a tool to observe precipitation.
Rain would not fall without some degree of impurity in the air to act as a seed.
Raindrops fell as they combined with other particles from the air as they passed through. Acid rain was the good example.
Today, with the help of radar and the advance technology, the information on the time variability of drop size distributions as seen by a disdrometer was used to estimate the size of raindrops and it's location. How to generate the space-time variability of the distributions of the size of raindrops was developed.
Reference: http://www.agu.org/cig-bin/SFgate?&listenv=tables
http://www.isuite101.com/article.cfm/science-sky/9123/2
http://www.eng.vt.edu/fluids/msc/my-pages/raindrops/raindrop.htm
http://www.fluidmech.net/tutorials/raindrops/drop-flow.htm
With the help of Emily Cheung, I obtained the names of these websites.
2007年3月16日 下午 8:49
Hi, Ronda,
Your design about the raindrop was simple. The background was coloured in pink. I looked like the cloud with raindrops moved in curved shaped. The explanation was also very simple. It showed you had made an effect by using Flash to display your information.
2007年3月26日 下午 8:17
yiuLibrary 提到...
Group Members: Lidia Ho, Candy Yiu
We make use of this Saturday to improve the Flash design of "Raindrop", we hope it is much better and now we have more confidence in using Flash.
The "Play (red square)" and "Stop (green triangle)" buttons are useful. The different shape and size of raindrops are described.
We look forward to receiving more comments about our improved flash "Raindrop". Thank you for your comments!
2007年3月31日 上午 3:05
yiuLibrary 提到...
More about the improved FLASH "raindrop":
Group members: Lidia Ho and Candy Yiu
- We use the water cycle picture as the raindrop's background and its colour is light.
- We use four pictures to introduce the water cycle process. So when the mouse is near different picture, it will show you different numbers, e.g. 1, 2, 3, 4. Then you will know the first process is "Evaporation", and the second process is "Condensation"...
- We use the flash to introduce the size and shape of raindrop from 1mm to 8mm. We also mentioned that the size of raindrop will be affected by air pressure.
Thank you for your (visitors') comments.
2007年4月1日 上午 12:22
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