A new study by the Hebrew University in collaboration with the University of Maryland reveals that air pollution can exacerbate precipitation
A new study by Prof. Daniel Rosenfeld from the Institute of Earth Sciences at the Hebrew University in collaboration with researchers from the University of Maryland in the USA proves that air pollution can have opposite effects, depending on the weather conditions. According to the research findings, in dry and cool countries, such as Israel in the winter season, pollution particles in the atmosphere can cause a reduction in the intensity and amount of precipitation, while in hot and humid areas, such as the eastern United States in the summer season, air pollution actually contributes to an increase in the intensity of rainfall and storms.
The study explains how pollution particles present in the atmosphere, soot, dust, sulfur and more, can affect the weather and climate. The research has important implications for the availability of water reservoirs, their management and their use in different climate zones.
The researchers used data collected for ten consecutive years at a research site in Oklahoma and discovered the long-term effect of pollution particles on cloud height and thickness, and these affect changes in the frequency of precipitation. The study confirmed the theory developed by Prof. Rosenfeld in his previous studies.
The research findings have important implications regarding the policies of sustainable development and water resources, especially in developing regions that are more sensitive to extreme events such as droughts and floods.
The pollution particles, apart from being dangerous to human health and the environment, affect the cloud particles due to their being nuclei around which water and ice droplets form, a process that affects the properties of the cloud and its operation.
"As the air rises, the water vapor condenses around air particles to form droplets. In clean air, the drops are larger and their quantity is less. In polluted air the droplets are smaller and more numerous. They float in the air and the process of their crystallization into raindrops is slower," says Prof. Rosenfeld. According to him, "In a cold atmosphere capable of containing a little moisture, most of the droplets in a polluted cloud do not grow to dimensions that allow precipitation, especially if the cloud does not develop to a high altitude. On the other hand, in a warm atmosphere, the creation of rain is delayed until the clouds reach a high altitude, where the drops already reach a size that allows them to quickly freeze into hailstones. The energy released during the freezing process causes the clouds to grow to an additional height and thus encourages an even greater increase in the intensity of the precipitation - the rain and hail. This is why air pollution can lead to floods just as it leads to drought."
The research was published in the prestigious journal Nature Geoscience and was supported by: the US Department of Energy, NASA, the US National Science Foundation and the Chinese Ministry of Science and Technology.
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Cloud seeding increased the amount of precipitation in Israel by about 15%, which is probably the amount that air pollution reduced. Therefore the amount of precipitation remains similar. They also sow in the south of the country, although less and with ovens and not by flying due to a variety of reasons. In any case, cloud seeding is based on adding stasis nuclei and not condensation. For your information, my father.
I thought these were really well-known things that they discovered as part of the "cloud seeding" attempts here in Israel. That's how they decided that sowing is more beneficial in the humid and less dusty north (meaning it's better to add condensation nuclei to the atmosphere there) and actually harms the precipitation in the dry and dusty south. (Too many nuclei = too small drops)
Father, do you see that I claimed that there was no warming?
I read the report and it says that Israel has warmed in the last 90 years (slightly less than the world average).
Like I said don't panic.. you are reading things that are not written.
This also appears in the same report:
However, it should be noted that from a nationwide perspective, the sequence of the last 8 years, in which the amount of precipitation did not exceed the average even once, is unusual.
Strange... I did a "copy paste" and the 90 became a 91. my life!!!
Here, my father, especially for you, is the last sentence in the report: "In conclusion, we can say that no substantial change has been observed in the amount of precipitation and its seasonal distribution over the past 91 years."
Why does all the derogatory names help science? censorship? The thought police? The witch/troll hunt?
You have already solved all the problems, so are you bored?
But no one cited the report correctly either, after he posted the link I checked, and there is explicitly a reference to warming there at the beginning. It could be that there was a warm year here and there even 90 years ago, that's why I emphasized that the correct figure is groups of 15 years. And there is no disputing that the last 15 years have been the hottest in history.
The fact that I used your quote is because I remembered it easily and I'm sure you didn't make it up but heard it from someone interested in dwarfing the achievements of the solar energy field. I could search and I'm sure I'll find all kinds of Republicans making these kinds of claims in the current election race.
Abby, a friendly remark.
Don't make your site a neighborhood, you jump every time with nicknames and scores for other commenters (deniers, etc.). "Ish" backed up his words with data from an independent body. You took a statement of mine that was made during the study of the data... and took it out of context.
Indeed, at the beginning they contradict your claim that there was no warming:
Averages calculated for a period of 29 years show that the average temperature of the 15 years 1996-2010 is the highest, compared to the average of periods of the same length, since 1951. This finding is true even if the year 2010, which was unusually warm, is not included in the analysis.
This way you get a more accurate picture than comparing a normal hot year today to a random hot year 90 years ago.
Father, don't panic...:-)
I suggest you take a look at the website of the Israeli Meteorological Service.
http://www.ims.gov.il/ims/odot/news/climatechangeisrael.htm
Really interesting, all climate deniers have embraced science fiction. Just yesterday it was being talked about that this is the seventh year of drought in a row. Apparently the correctness of the ninety year figure is like the figure that the prices of photovoltaic solar collectors have not changed for 13 years. Why not, the keyboard tolerates everything.
In Israel, the air is probably relatively clean or the humidity is in a range that is not affected by pollution,
Because according to the meteorological service, the amount of rainfall in Israel has not changed almost (on average) in the last 90 years.