<p>In the field, in which I work, the term _ambient aerosol` is related to the water content of aerosol particles.</p>

<p>Commonly in the atmosphere, water is attached to particles. The amount of water attached to particles depends on the relative humidity (in ambient air). Increasing relative humidity means more water and, hence, larger particle/droplet diameter. When we provide a measured/modeled particle diameter, we need to note whether the diameter is given as <em>dry</em>, as <em>wet at XX% relative humidity</em> or as <em>wet at ambient relative humidity</em>.</p>

<p>Maybe it is also used in other contexts.</p>

CC BY-SA 4.0
2019-05-25T19:46:07.970Z
2019-05-25T19:46:07.970Z
daniel.heydebreck
<p>I see this term being used everywhere, but I have not been able to find a formal definition for "ambient aerosols".</p>

CC BY-SA 4.0
2019-05-21T04:11:31.670Z
This is a *really good question!* It's easy to guess that it refers to aerosols in ambient air, but then what's the definition of ambient? Does it mean places where people happen to breathe no matter where they are (Top of Mt. Everest? Space stations?, Deep coal mines?) Or 2 meters off the surface, anywhere on Earth?
uhoh
CC BY-SA 4.0
2019-05-21T15:23:39.327Z
When I talk about the water content of aerosol particles, I distinguish between dry aerosol particles (water evaporated that was present in ambient air) and ambient aerosol particles (_wet particles_ as in ambient air). Commonly in the atmosphere, water is attached to particles. The amount of water attached to particles depends on the relative humidity (in __ambient air__) and considerably increases  the particle/droplet diameter. Measured/model particle diameters might be given as dry, as wet at XX% rel. humidity or as wet at ambient relative humidity. Maybe it is also used in other contexts.
daniel.heydebreck
CC BY-SA 4.0
2019-05-24T21:38:18.220Z
@gansub I second your opinion.
Bhoutik Shastri
CC BY-SA 4.0
2019-05-25T19:46:35.690Z
@gansub : I posted it as wiki article. Then, it can be freely edited.
daniel.heydebreck
<meteorology><atmospheric-chemistry>
What exactly are "ambient aerosols"?
Bhoutik Shastri
# What exactly are "ambient aerosols"?

(Asked by: username_0 on 2019-05-20)

I see this term being used everywhere, but I have not been able to find a formal definition for "ambient aerosols".

**Tags:** meteorology, atmospheric-chemistry

> **Comments:**
> **username_1**: This is a *really good question!* It's easy to guess that it refers to aerosols in ambient air, but then what's the definition of ambient? Does it mean places where people happen to breathe no matter where they are (Top of Mt. Everest? Space stations?, Deep coal mines?) Or 2 meters off the surface, anywhere on Earth?  
> **username_2**: When I talk about the water content of aerosol particles, I distinguish between dry aerosol particles (water evaporated that was present in ambient air) and ambient aerosol particles (_wet particles_ as in ambient air). Commonly in the atmosphere, water is attached to particles. The amount of water attached to particles depends on the relative humidity (in __ambient air__) and considerably increases  the particle/droplet diameter. Measured/model particle diameters might be given as dry, as wet at XX% rel. humidity or as wet at ambient relative humidity. Maybe it is also used in other contexts.  
> **username_0**: @gansub I second your opinion.  
> **username_2**: @gansub : I posted it as wiki article. Then, it can be freely edited.  

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## 1 answers

### Answer by username_2 on 2019-05-25. Score: 2

In the field, in which I work, the term \_ambient aerosol` is related to the water content of aerosol particles.

Commonly in the atmosphere, water is attached to particles. The amount of water attached to particles depends on the relative humidity (in ambient air). Increasing relative humidity means more water and, hence, larger particle/droplet diameter. When we provide a measured/modeled particle diameter, we need to note whether the diameter is given as *dry*, as *wet at XX% relative humidity* or as *wet at ambient relative humidity*.

Maybe it is also used in other contexts.


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