<p>Yes. Since the later term doesn't change during dry adiabatic processes and the former neither, the equivalent potential temperature <span class="math-container">$\theta_e$</span> does also stay constant for dry adiabatic processes.
Whether it makes sense to &quot;assign&quot; (maybe you meant &quot;measure&quot;) it to unsaturated air parcels depends on the application.</p>

CC BY-SA 4.0
2023-05-10T07:19:20.620Z
2023-05-10T07:19:20.620Z
hschoell
<p>Equivalent Potential Temperature, defined as</p>
<p><span class="math-container">$$\theta_e = \theta \cdot e^{qL/c_pT}$$</span></p>
<p>with <span class="math-container">$\theta$</span> denoting potential temperature and q the specific moisture of water remains constant for wet adiabatic processes. Does it make sense to assign it also to unsaturated air parcels? Lets say, an an unsaturated parcel is lifted to LCL, where condensation starts. Is <span class="math-container">$\theta_e$</span> constant during this dry adiabatic process too? I'm not sure, but I would say, that T must be replaced by the T', at which condensation occur - otherwise it makes no sense.</p>

<meteorology><atmosphere><temperature><atmosphere-modelling><thermodynamics>
Is equivalent potential temperature constant also for dry adiabatic processes?
MichaelW
# Is equivalent potential temperature constant also for dry adiabatic processes?

(Asked by: username_0 on 2023-05-07)

Equivalent Potential Temperature, defined as

$$\theta\_e = \theta \cdot e^{qL/c\_pT}$$

with $\theta$ denoting potential temperature and q the specific moisture of water remains constant for wet adiabatic processes. Does it make sense to assign it also to unsaturated air parcels? Lets say, an an unsaturated parcel is lifted to LCL, where condensation starts. Is $\theta\_e$ constant during this dry adiabatic process too? I'm not sure, but I would say, that T must be replaced by the T', at which condensation occur - otherwise it makes no sense.

**Tags:** meteorology, atmosphere, temperature, atmosphere-modelling, thermodynamics


---

## 1 answers

### Answer by username_1 on 2023-05-10. Score: 2 | Accepted answer

Yes. Since the later term doesn't change during dry adiabatic processes and the former neither, the equivalent potential temperature $\theta\_e$ does also stay constant for dry adiabatic processes.
Whether it makes sense to "assign" (maybe you meant "measure") it to unsaturated air parcels depends on the application.


---

