1. Mick West

    Mick West Administrator Staff Member

    There are a variety of photos circulating on the internet that show some pipes lowered out of the back of a cargo plane, spraying a white substance, for example:


    These photos are of the Malaysian Air Force conducting cloud seeding. They date back as far as 2005, but the same photos get re-used whenever the Malaysian press writes about cloud seeding.

    What is being debunked here is the idea that these photos show something suspicious, unusual, harmful, or secret (like "chemtrails", or secret geoengineering projects). Cloud seeding has been done perfectly openly since the 1950s in many countries around the world. The Malaysian cloud seeding (done since 1979) is just another example of this. And it's a particularly innocuous example, as they are simply spraying salt water onto existing clouds (all cloud seeding is done on existing clouds) in order to make them rain in a particular place to help fight forest fires.

    Here's the 2005 article:

    And a more recent story explains how they think it works (although they seem to be a little confused, as this is a "warm cloud" method, and no ice is involved).

    This story shows the tank of salt water being loaded:

    Multiple tanks are used:

    This 2005 story shows the mixing of the Sodium Chloride (regular table salt) with water:

    And here's the tank in place:

    Here's another article with explanation:

    The cloud seeding is carried out by the Malaysian Meteorological Department since 1973
    And again, this is nothing new. Cloud seeding dates back to the 1950s. Here's a 1951 (publically published) paper that discusses cloud seeding with table salt (sodium chloride):

    The infographics above are somewhat vague and misleading about what is going. There are actually two main forms of cloud seeding techniques, "warm" and "cold" seeding. The cold seeding is more common in the US, and involves spraying Silver Iodide, which is an ice nuclei, and makes the supercooled water in the clouds form ice - this will then precipitate out as snow, hail, or rain (if it melts on the way down)

    "Warm" seeding is done at temperatures above freezing, and uses a "hygroscopic" (water attracting/absorbing) material to encourage the formation of larger droplets of water that will then then precipitate out (rain). This is explained by US cloud seeding company Weather Modification Inc:
    Last edited: May 13, 2014
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  2. deirdre

    deirdre Moderator Staff Member

    airhead questions that might be OT: how cold does it need to be for salt water to freeze? meaning can cloud seeding make what looks like a non persisting contrail?
    and how high do you need to be before you cant breathe with a mask?
  3. Mick West

    Mick West Administrator Staff Member

    -1.9°C/28.4°F is the freezing temp of normal salt water (i.e. sea water). The lowest possible freezing temp is for saturated salt water (which is essentially what they use here), where it's around -21°/-5.1F. Much colder than at 7,000 feet over Malaysia in the summer. You could in theory make a contrail with just water, but then your engines would likely also be leaving contrails anyway.

    You can "breath" all the way up to around 25,000 feet. But oxygen masks are required in an unpressurized cabin above 12,000 feet (or 10,000 feet if you are going to be up there more than 30 minutes).

    The cloud seeding seen here is under 7000 feet. Most US cloud seeding is done with small planes at similar altitudes.
    Last edited: May 13, 2014
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  4. derrick06

    derrick06 Active Member

    Great info Mick. Thought I would share a fitting picture for our amusement. :p

    Attached Files:

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  5. OldCrab

    OldCrab New Member

    Very well put