<div dir="ltr"><div><br clear="all"></div><div>After bullying GeorgeIV for a couple hours, I got this superb answer out of him. <br></div><div><br></div><div>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Summary:<span></span></b></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">In <b>pseudo-adiabatic calculations</b>, we disregard:<span></span></p>
<ul style="margin-top:0in;margin-bottom:0in" type="disc"><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Condensed
water retained in the parcel</b> (assuming it falls out as precipitation),<span></span></li><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Precipitation
drag</b> (the downward resistance of falling precipitation),<span></span></li><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Heat
transfer between the parcel and the environment</b> (except latent heat
release).<span></span></li></ul>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">These variables are considered <b>trivial</b> relative to
the dominant forces in convective storms, especially the <b>latent heat release</b>
from condensation, which drives strong updrafts and is the primary factor
determining the parcel’s buoyancy.<span></span></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">Does this clarify the role of simplifications in
pseudo-adiabatic processes? Would you like to go deeper into any specific part
of this?<span></span></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>You said:<span></span></b></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">Ok. Now this all makes sense. But compare your most recent
answer to ones you made earlier which seemed to suggest that the latent heat
released by condensation (in addition to the condensed water) is lost to the
parcel. No heat is lost to the parcel, only mass, and that mass is trivial by
comparision with the total mass of the parcel since even most air contains
relatively little mass of water.<span></span></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>ChatGPT said:<span></span></b></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">ChatGPT<span></span></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">You're absolutely right, and I can see how my earlier
answers might have created some confusion. Let's clear that up, focusing on the
distinction between <b>latent heat</b> and <b>condensate (water)</b> in
pseudo-adiabatic processes.<span></span></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Correct Understanding: No Heat is Lost from the Parcel,
Only Mass<span></span></b></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">In a <b>pseudo-adiabatic process</b>, the <b>latent heat
released by condensation</b> is <b>not lost</b> from the air parcel. It remains
in the parcel and directly contributes to:<span></span></p>
<ul style="margin-top:0in;margin-bottom:0in" type="disc"><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Warming
the parcel</b>: The <b>latent heat</b> released when water vapor condenses
into liquid (or ice) <b>warms</b> the parcel, slowing the rate at which it
cools as it rises. This additional warmth keeps the parcel <b>more buoyant</b>
compared to its surroundings.<span></span></li></ul>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">What <b>is lost</b>, however, is the <b>condensate</b>:<span></span></p>
<ul style="margin-top:0in;margin-bottom:0in" type="disc"><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Mass
loss</b>: The condensed water (in liquid or ice form) is assumed to <b>precipitate
out</b> of the parcel. This <b>reduces the total mass</b> of the parcel
but has a relatively small impact on the overall mass, since even in moist
air, the water vapor content is small compared to the air’s mass. As a
result, the <b>mass loss from precipitation</b> is considered <b>trivial</b>
relative to the total parcel mass, but it is a simplification made for the
sake of easier calculation.<span></span></li></ul>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Earlier Miscommunication: What Happens to Latent Heat?<span></span></b></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">In my earlier explanation, I might have implied that both
the <b>condensate</b> and the <b>latent heat</b> are somehow lost from the
parcel in the pseudo-adiabatic process. That’s not the case. The <b>latent heat</b>
stays with the parcel—it’s only the <b>water droplets (or ice crystals)</b>
that are assumed to fall out.<span></span></p>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Why This Matters:<span></span></b></p>
<ol style="margin-top:0in;margin-bottom:0in" start="1" type="1"><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Buoyancy</b>:
The <b>latent heat</b> remains inside the parcel, increasing its <b>temperature</b>
and <b>buoyancy</b> as it rises. This helps the parcel remain <b>warmer</b>
than the surrounding air, driving the upward motion.<span></span></li><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Mass
Loss is Small</b>: As you correctly pointed out, the <b>mass of water
vapor</b> in a parcel is generally small relative to the <b>total mass</b>
of the air parcel (which consists mostly of nitrogen and oxygen). Even in
very humid conditions, water vapor usually makes up only a few percent of
the total mass of the air. So, the <b>mass lost to precipitation</b> is <b>trivial</b>
when compared to the overall mass of the parcel.<span></span></li></ol>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Summary of Correct Picture:<span></span></b></p>
<ul style="margin-top:0in;margin-bottom:0in" type="disc"><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Latent
heat</b>: <b>Remains within the parcel</b>, keeping it warm and buoyant.<span></span></li><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Condensate</b>:
Assumed to fall out of the parcel, leading to <b>mass loss</b>.<span></span></li><li class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif"><b>Mass
loss is small</b>: Even though the mass of the parcel decreases due to
precipitation, it is considered <b>trivial</b> relative to the total mass
of the parcel.<span></span></li></ul>
<p class="MsoNormal" style="margin:0in 0in 8pt;line-height:115%;font-size:12pt;font-family:"Aptos",sans-serif">In the <b>pseudo-adiabatic process</b>, the <b>main focus is
on the latent heat</b> retained by the parcel, as this is what maintains
buoyancy. The loss of mass due to precipitation is simplified for ease of
calculation but is relatively minor in the big picture of atmospheric
processes.<span></span></p>
</div><div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Nicholas S. Thompson</div><div>Emeritus Professor of Psychology and Ethology</div><div>Clark University</div><div><a href="mailto:nthompson@clarku.edu" target="_blank">nthompson@clarku.edu</a></div><a href="https://wordpress.clarku.edu/nthompson" target="_blank">https://wordpress.clarku.edu/nthompson</a></div></div></div></div>