<p>My answer is no. The reclassification of clouds is not affected by climate change. It is more of our understanding of how they work, formation mechanisms, etc. Cloud classification can generally be broken down into altitude and shape (cirrus-type, cumulus-type, and stratus-type). The subtypes of those describe the behavior, and may be combinations of types (such as cirrostratus, pyrocumulus and cumulonimbus). There are other types, such as the new asperitas cloud (formed by gravity waves), the Kelvin-Helmholtz instability cloud (formed by the Kelvin-Helmholtz instability), contrails (formed by jet exhaust), fog (formed by either advection or radiation), etc.</p>

<p>That is not to say that clouds don't affect climate. For example, cirrus clouds, and other high clouds, are optically thick, preventing the low temperature from dropping. It has been debated what the net effect clouds have on the environment, newer research seems to indicate net warming (see latest IPCC report), despite the traditional thought being cooling. Being that water vapor is a greenhouse gas with generally greater concentrations than the famed CO$_2$, it is extremely important to consider in climate discussion.</p>

CC BY-SA 3.0
2017-03-24T18:48:15.707Z
They were discovered, and many were even named. They just were recognized as a byproduct of a certain phenomenon. Consider the Kelvin-Helmholtz wave clouds described above. The now official name is "fluctus clouds" with the dynamical phenomenon called Kelvin-Helmholtz instability. Phenomenon like wall clouds are now "murus." Consider it to be like a known species of an animal given a Latin name- the animal has been recognized, but the Latin name has recently been given.
BarocliniCplusplus
CC BY-SA 3.0
2017-03-24T13:31:44.420Z
2017-03-24T13:31:44.420Z
BarocliniCplusplus
<p>This question was originally posted on Physics SE, (now deleted) but I think this community is a better fit. </p>

<p>This article <a href="http://www.bbc.com/news/science-environment-39351843" rel="noreferrer">"New" type of Clouds</a>, reports that a revision to the  <a href="https://en.wikipedia.org/wiki/International_Cloud_Atlas" rel="noreferrer">International Cloud Atlas</a> will include 12 extra examples of cloud shapes. </p>

<p><a href="https://i.sstatic.net/6WdzB.jpg" rel="noreferrer"><img src="https://i.sstatic.net/6WdzB.jpg" alt="enter image description here"></a></p>

<blockquote>
  <p>This time around 12 new terms have been added. The best known of these is asperitas, meaning rough-like in Latin, as the clouds can look like the tossing of the waves at sea when viewed from below.</p>
</blockquote>

<p>I am aware that these are <strong>not</strong> new cloud types per se, rather the article is referring to a reclassification system. </p>

<p>These cloud types in all probability have been in existence for a long time, and it is due to the increasing use of cameras on smartphones that has contributed to their new prominence in the Atlas. The article I cite above includes references to the well known jet contrails, but does not ascribe any more significance to these cloud classifications than that.</p>

<p><a href="https://i.sstatic.net/gsEYv.jpg" rel="noreferrer"><img src="https://i.sstatic.net/gsEYv.jpg" alt="enter image description here"></a></p>

<blockquote>
  <p>In terms of the way the WMO classifies clouds, they have also added one new "species" - the volutus, or roll-cloud, a low horizontal tube-shaped cloud mass that appears to roll about a horizontal axis. </p>
</blockquote>

<p>My question, promoted by this reclassification of <strong>existing</strong> cloud types,  is: could new cloud types be associated with human activity and, (a  tenuous connection I admit), could we use the amount of these putative new cloud types to act as a crude marker of our impact on the current atmospheric environment?</p>

<p>I would stress that the website of the <a href="https://public.wmo.int/en/media/news/international-cloud-atlas" rel="noreferrer">International Cloud Atlas</a> makes no obvious, at least on initial reading, link to my question above.</p>

<p>I am aware of the  <a href="http://news.psu.edu/story/361041/2015/06/18/research/jet-contrails-affect-surface-temperatures" rel="noreferrer">Penn State Jet Trail Research</a> regarding jet trails, in particular their absence from the atmosphere following the 9/11 attacks and subsequent temporary flight ban.</p>

CC BY-SA 3.0
2017-03-23T19:23:18.070Z
With the fundamental physics of how clouds form not changing, and the (relatively) small shift to temperature and even moisture (in the grand scheme of things... even 10 Kelvin would only 3% change in overall temp), I'd think there's no reason there'd be entirely new types of clouds.  Alternatively you could see the majority of global warming as just a slight equatorward shift of the polar jet.  A global warming would generally provide the same weather, just adjusted by a few weeks.
JeopardyTempest
CC BY-SA 3.0
2017-03-23T19:25:10.810Z
If you could bring about new storm types (like hypercanes) or see different phases for some types of matter, maybe.  But any changes being talked about would probably be insignificant in terms of cloud dynamics.
JeopardyTempest
CC BY-SA 3.0
2017-03-23T19:27:13.187Z
And likewise, I don't believe that such changes would cause a large increase in any rarer cloud forms, such that they need whole new classes.  No, I'll suggest that this shift in cloud types is just an obsessive desire to classify things and bring new attention to something they're interested in.
JeopardyTempest
CC BY-SA 3.0
2017-03-23T19:29:19.663Z
Though it would take a true cloud physicist, particularly one who has worked with other planets/environments, to give a real quality idea of whether there are other theoretical cloud types that aren't realized but could be.  I'm not sure whether you're going to get more than good opinions from meteorologist, who although knowledgeable and wise, can't give an absolute definitive answer or any solid reasoning to back their thoughts.
JeopardyTempest
CC BY-SA 3.0
2017-03-23T22:56:41.910Z
@JeopardyTempest  thank you very much  for your  time  in writing your comments. If you want to collate them as an answer, I would be happy to accept it, as I can't think of a better summary of the issues involved.
StudyStudy
CC BY-SA 3.0
2017-03-24T00:36:56.220Z
@JeopardyTempest  That 3% change in temperature corresponds to about a 15% increase in absolute humidity saturation.   That would be enough to make new clouds possible.   Also, the tropopause is rising creating a larger troposphere and potentially higher clouds.   Now, I'm still skeptical that these really are new clouds, but I think it's possible.
userLTK
CC BY-SA 3.0
2017-03-24T01:18:03.940Z
@userLTK, good point on the tropopause, though I'm not convinced a few degree temperature change would equate to a large tropopause change, nor that there'd be interesting formations in/due to those extra meters... but you definitely bring up an interesting avenue to consider.
JeopardyTempest
CC BY-SA 3.0
2017-03-24T01:22:07.773Z
@userLTK, indeed I sidestepped the further details of the moisture... yes, a 5C change would be a 10-25% change in "amount of moisture that can be held"... but was just playing with (this calculator)[http://apps.acpa.org/applibrary/EvaporationRate/] last night, and perhaps not as much evaporation.  But you may well be up on such details and research better than I!  But regardless, you've definitely got me there, such a change might be a more reasonable direction for such possible real changes.  Maybe you're well versed to give a more complete answer?
JeopardyTempest
CC BY-SA 3.0
2017-03-24T01:27:57.700Z
@JeopardyTempest I'm no where near educated enough to give this an answer.   I only wanted to say it was possible because water vapor saturation increases significantly with temperature.   I'm still skeptical that it's truly new clouds or just a new distinction or perhaps a bit of both, but I'm only guessing.
userLTK
CC BY-SA 3.0
2017-03-24T15:48:00.370Z
@userLTK. I regret using the word new , which the BBC site used, albeit in quotes.  I  don't believe these clouds are new,  and I am not asking that question here. It's the classification scheme alone that's new.  It's simply that the publicity surrounding the reclassification scheme prompted my question, that is : **could** climate change create distinctive **really** new cloud formations.  So you are absolutely correct to be  skeptical :) thanks for your interest in my question.
StudyStudy
<climate-change><clouds>
"New" cloud types: Can they be used as markers for climate change observations?
StudyStudy
# "New" cloud types: Can they be used as markers for climate change observations?

(Asked by: username_0 on 2017-03-23)

This question was originally posted on Physics SE, (now deleted) but I think this community is a better fit.

This article ["New" type of Clouds](http://www.bbc.com/news/science-environment-39351843), reports that a revision to the [International Cloud Atlas](https://en.wikipedia.org/wiki/International_Cloud_Atlas) will include 12 extra examples of cloud shapes.

[![enter image description here](https://i.sstatic.net/6WdzB.jpg)](https://i.sstatic.net/6WdzB.jpg)

> This time around 12 new terms have been added. The best known of these is asperitas, meaning rough-like in Latin, as the clouds can look like the tossing of the waves at sea when viewed from below.

I am aware that these are **not** new cloud types per se, rather the article is referring to a reclassification system.

These cloud types in all probability have been in existence for a long time, and it is due to the increasing use of cameras on smartphones that has contributed to their new prominence in the Atlas. The article I cite above includes references to the well known jet contrails, but does not ascribe any more significance to these cloud classifications than that.

[![enter image description here](https://i.sstatic.net/gsEYv.jpg)](https://i.sstatic.net/gsEYv.jpg)

> In terms of the way the WMO classifies clouds, they have also added one new "species" - the volutus, or roll-cloud, a low horizontal tube-shaped cloud mass that appears to roll about a horizontal axis.

My question, promoted by this reclassification of **existing** cloud types, is: could new cloud types be associated with human activity and, (a tenuous connection I admit), could we use the amount of these putative new cloud types to act as a crude marker of our impact on the current atmospheric environment?

I would stress that the website of the [International Cloud Atlas](https://public.wmo.int/en/media/news/international-cloud-atlas) makes no obvious, at least on initial reading, link to my question above.

I am aware of the [Penn State Jet Trail Research](http://news.psu.edu/story/361041/2015/06/18/research/jet-contrails-affect-surface-temperatures) regarding jet trails, in particular their absence from the atmosphere following the 9/11 attacks and subsequent temporary flight ban.

**Tags:** climate-change, clouds

> **Comments:**
> **username_1**: With the fundamental physics of how clouds form not changing, and the (relatively) small shift to temperature and even moisture (in the grand scheme of things... even 10 Kelvin would only 3% change in overall temp), I'd think there's no reason there'd be entirely new types of clouds.  Alternatively you could see the majority of global warming as just a slight equatorward shift of the polar jet.  A global warming would generally provide the same weather, just adjusted by a few weeks.  
> **username_1**: If you could bring about new storm types (like hypercanes) or see different phases for some types of matter, maybe.  But any changes being talked about would probably be insignificant in terms of cloud dynamics.  
> **username_1**: And likewise, I don't believe that such changes would cause a large increase in any rarer cloud forms, such that they need whole new classes.  No, I'll suggest that this shift in cloud types is just an obsessive desire to classify things and bring new attention to something they're interested in.  
> **username_1**: Though it would take a true cloud physicist, particularly one who has worked with other planets/environments, to give a real quality idea of whether there are other theoretical cloud types that aren't realized but could be.  I'm not sure whether you're going to get more than good opinions from meteorologist, who although knowledgeable and wise, can't give an absolute definitive answer or any solid reasoning to back their thoughts.  
> **username_0**: @username_1  thank you very much  for your  time  in writing your comments. If you want to collate them as an answer, I would be happy to accept it, as I can't think of a better summary of the issues involved.  
> **username_2**: @username_1  That 3% change in temperature corresponds to about a 15% increase in absolute humidity saturation.   That would be enough to make new clouds possible.   Also, the tropopause is rising creating a larger troposphere and potentially higher clouds.   Now, I'm still skeptical that these really are new clouds, but I think it's possible.  
> **username_1**: @username_2, good point on the tropopause, though I'm not convinced a few degree temperature change would equate to a large tropopause change, nor that there'd be interesting formations in/due to those extra meters... but you definitely bring up an interesting avenue to consider.  
> **username_1**: @username_2, indeed I sidestepped the further details of the moisture... yes, a 5C change would be a 10-25% change in "amount of moisture that can be held"... but was just playing with (this calculator)[http://apps.acpa.org/applibrary/EvaporationRate/] last night, and perhaps not as much evaporation.  But you may well be up on such details and research better than I!  But regardless, you've definitely got me there, such a change might be a more reasonable direction for such possible real changes.  Maybe you're well versed to give a more complete answer?  
> **username_2**: @username_1 I'm no where near educated enough to give this an answer.   I only wanted to say it was possible because water vapor saturation increases significantly with temperature.   I'm still skeptical that it's truly new clouds or just a new distinction or perhaps a bit of both, but I'm only guessing.  
> **username_0**: @username_2. I regret using the word new , which the BBC site used, albeit in quotes.  I  don't believe these clouds are new,  and I am not asking that question here. It's the classification scheme alone that's new.  It's simply that the publicity surrounding the reclassification scheme prompted my question, that is : **could** climate change create distinctive **really** new cloud formations.  So you are absolutely correct to be  skeptical :) thanks for your interest in my question.  

---

## 1 answers

### Answer by username_3 on 2017-03-24. Score: 2 | Accepted answer

My answer is no. The reclassification of clouds is not affected by climate change. It is more of our understanding of how they work, formation mechanisms, etc. Cloud classification can generally be broken down into altitude and shape (cirrus-type, cumulus-type, and stratus-type). The subtypes of those describe the behavior, and may be combinations of types (such as cirrostratus, pyrocumulus and cumulonimbus). There are other types, such as the new asperitas cloud (formed by gravity waves), the Kelvin-Helmholtz instability cloud (formed by the Kelvin-Helmholtz instability), contrails (formed by jet exhaust), fog (formed by either advection or radiation), etc.

That is not to say that clouds don't affect climate. For example, cirrus clouds, and other high clouds, are optically thick, preventing the low temperature from dropping. It has been debated what the net effect clouds have on the environment, newer research seems to indicate net warming (see latest IPCC report), despite the traditional thought being cooling. Being that water vapor is a greenhouse gas with generally greater concentrations than the famed CO$\_2$, it is extremely important to consider in climate discussion.

> **Comments:**
> **username_3**: They were discovered, and many were even named. They just were recognized as a byproduct of a certain phenomenon. Consider the Kelvin-Helmholtz wave clouds described above. The now official name is "fluctus clouds" with the dynamical phenomenon called Kelvin-Helmholtz instability. Phenomenon like wall clouds are now "murus." Consider it to be like a known species of an animal given a Latin name- the animal has been recognized, but the Latin name has recently been given.  

---

