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	Comments for RealClimate	</title>
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	<description>Climate science from climate scientists...</description>
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		Comment on Unforced Variations: Aug 2026 by John Pollack		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850405</link>

		<dc:creator><![CDATA[John Pollack]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 16:37:56 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850405</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850361&quot;&gt;Chuck&lt;/a&gt;.

I&#039;ll stick to the fire situation.  

My understanding is that part of the overall problem is fire suppression practices in the 20th century that resulted in a large buildup of potential fuel to the point that fires could no longer be contained.  Count that as a contributing factor.

The phrase &quot;a meteorological nuclear bomb&quot; is apt.  WWII warfare, including both firebombing and nuclear bombing, was informed by the 1923 Tokyo earthquake and subsequent firestorm.  It burned a substantial portion of Tokyo and killed over 100,000 people.  There have been other very large fires following earthquakes, and also under extreme fire weather conditions, such as the Chicago Fire and concurrent Peshtigo, Wisconsin forest fire fueled by sloppy logging practices.

Climate change is undoubtedly making things worse.  The combination of drought and other formerly unusual weather events results in more dead trees, so there is more fuel available.  One of the changes that I find noteworthy is the increasing incidence of strong mid latitude excursions of the subtropical anticyclones (&quot;heat domes.&quot;)  These create both drought and unusually high temperatures.  As they reach higher latitudes, they also occur in closer proximity to the subpolar jet stream to their north.  The interaction frequently results in strong surface winds and intensely hot and dry weather as cyclones pass to the north of the hot area.  While this sort of weather pattern wasn&#039;t unknown in the past, it is clearly becoming stronger and more frequent in both Europe and the U.S.  I haven&#039;t seen any research yet, but it is my impression that there has been a fairly abrupt uptick since around 2020 in interior western North America.  This is clearly visible in numerous heat records that exceed previous norms.  I don&#039;t know if the same is true for Europe or the NH as a whole.  Since this has happened relatively abruptly, I would attribute it to atmospheric adjustment to an underlying warming trend, combined with some sort of &quot;regime change&quot; that makes the subtropical anticyclone excursions stronger and more lasting.  These occur somewhat irregularly, and then go away for a while, possibly to reappear later.  The U.S. 1930s Dust Bowl would be an example.  Heat waves were observed in multiple years, but that particular pattern simply disappeared after 1940.]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850361">Chuck</a>.</p>
<p>I&#8217;ll stick to the fire situation.  </p>
<p>My understanding is that part of the overall problem is fire suppression practices in the 20th century that resulted in a large buildup of potential fuel to the point that fires could no longer be contained.  Count that as a contributing factor.</p>
<p>The phrase &#8220;a meteorological nuclear bomb&#8221; is apt.  WWII warfare, including both firebombing and nuclear bombing, was informed by the 1923 Tokyo earthquake and subsequent firestorm.  It burned a substantial portion of Tokyo and killed over 100,000 people.  There have been other very large fires following earthquakes, and also under extreme fire weather conditions, such as the Chicago Fire and concurrent Peshtigo, Wisconsin forest fire fueled by sloppy logging practices.</p>
<p>Climate change is undoubtedly making things worse.  The combination of drought and other formerly unusual weather events results in more dead trees, so there is more fuel available.  One of the changes that I find noteworthy is the increasing incidence of strong mid latitude excursions of the subtropical anticyclones (&#8220;heat domes.&#8221;)  These create both drought and unusually high temperatures.  As they reach higher latitudes, they also occur in closer proximity to the subpolar jet stream to their north.  The interaction frequently results in strong surface winds and intensely hot and dry weather as cyclones pass to the north of the hot area.  While this sort of weather pattern wasn&#8217;t unknown in the past, it is clearly becoming stronger and more frequent in both Europe and the U.S.  I haven&#8217;t seen any research yet, but it is my impression that there has been a fairly abrupt uptick since around 2020 in interior western North America.  This is clearly visible in numerous heat records that exceed previous norms.  I don&#8217;t know if the same is true for Europe or the NH as a whole.  Since this has happened relatively abruptly, I would attribute it to atmospheric adjustment to an underlying warming trend, combined with some sort of &#8220;regime change&#8221; that makes the subtropical anticyclone excursions stronger and more lasting.  These occur somewhat irregularly, and then go away for a while, possibly to reappear later.  The U.S. 1930s Dust Bowl would be an example.  Heat waves were observed in multiple years, but that particular pattern simply disappeared after 1940.</p>
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		Comment on Unforced Variations: Aug 2026 by MA Rodger		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850404</link>

		<dc:creator><![CDATA[MA Rodger]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 15:54:08 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850404</guid>

					<description><![CDATA[Both &lt;a href=&quot;https://data.giss.nasa.gov/gistemp/&quot; rel=&quot;nofollow ugc&quot;&gt;GISTEMP&lt;/a&gt; and &lt;a href=&quot;https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/global/time-series/globe/land_ocean/tavg/1/0/2020-2026&quot; rel=&quot;nofollow ugc&quot;&gt;NOAA&lt;/a&gt; have reported for July, with the GISS global July anomaly the warmest-July-on-record but not by any great margin. (GISS July26 = +1.23ºC topping July24 +1.20ºC. NOAA&#039;s July26 only manage an =1st spot with July24.)

The July26 anomaly shows an increase from June26 although year-to-date July&#039;s anomaly only makes 3rd-highest-month (2nd-highest in NOAA while actual-highest in ERA5 SAT) for the year-to-date. (GISS 2026 Jan-July runs +1.08ºC, +1.24ºC, +1.32ºC, +1.17ºC, +1.13ºC, +1.18ºC, +1.23ºC.)

With GISS/NOAA records a combined SAT/SST measure, I had expected a larger increase for July given the 60N-60S SST in the ERA5 re-analysis have been running at record levels since mid-June.
In all (GISS, NOAA &#038; ERA5), the June→July anomaly-increase is mainly a NH thing with smaller SH increases.

The &lt;a href=&quot;https://climate.copernicus.eu/surface-air-temperature-july-2026&quot; rel=&quot;nofollow ugc&quot;&gt;Copernicus report for July&lt;/a&gt; mentioned their 60N-60S SST which has been hottest-on-record-for-the-day since mid-June was  &lt;i&gt;“rapidly approaching”&lt;/i&gt; the all-day absolute record of +21.09ºC set back in March 2024. This &lt;i&gt;&quot;approach&quot;&lt;/i&gt; has a bit of a shelf-life as the global absolute-temperature cycle sees cooling set in mid-August. &lt;b&gt;An update&lt;/b&gt; - as of 10th Aug the 60-60SST anomaly remains stuck +21.05º.]]></description>
			<content:encoded><![CDATA[<p>Both <a href="https://data.giss.nasa.gov/gistemp/" rel="nofollow ugc">GISTEMP</a> and <a href="https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/global/time-series/globe/land_ocean/tavg/1/0/2020-2026" rel="nofollow ugc">NOAA</a> have reported for July, with the GISS global July anomaly the warmest-July-on-record but not by any great margin. (GISS July26 = +1.23ºC topping July24 +1.20ºC. NOAA&#8217;s July26 only manage an =1st spot with July24.)</p>
<p>The July26 anomaly shows an increase from June26 although year-to-date July&#8217;s anomaly only makes 3rd-highest-month (2nd-highest in NOAA while actual-highest in ERA5 SAT) for the year-to-date. (GISS 2026 Jan-July runs +1.08ºC, +1.24ºC, +1.32ºC, +1.17ºC, +1.13ºC, +1.18ºC, +1.23ºC.)</p>
<p>With GISS/NOAA records a combined SAT/SST measure, I had expected a larger increase for July given the 60N-60S SST in the ERA5 re-analysis have been running at record levels since mid-June.<br />
In all (GISS, NOAA &amp; ERA5), the June→July anomaly-increase is mainly a NH thing with smaller SH increases.</p>
<p>The <a href="https://climate.copernicus.eu/surface-air-temperature-july-2026" rel="nofollow ugc">Copernicus report for July</a> mentioned their 60N-60S SST which has been hottest-on-record-for-the-day since mid-June was  <i>“rapidly approaching”</i> the all-day absolute record of +21.09ºC set back in March 2024. This <i>&#8220;approach&#8221;</i> has a bit of a shelf-life as the global absolute-temperature cycle sees cooling set in mid-August. <b>An update</b> &#8211; as of 10th Aug the 60-60SST anomaly remains stuck +21.05º.</p>
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		<title>
		Comment on This new El Niño is different by Tomáš Kalisz		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850403</link>

		<dc:creator><![CDATA[Tomáš Kalisz]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 13:33:28 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26545#comment-850403</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850375&quot;&gt;Nabil Swedan&lt;/a&gt;.

in Re to Nigelj, 11 Aug 2026 at 4:10 PM,

https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850391

Hello Nigel,

I read the &quot;primary published paper outlining his alternative model&quot; and the sheer absurdity of its publication in a &quot;scientific&quot; journal inspired me to the following AI prompt:

&quot;Would you call extreme examples of junk science published in journals pretending seriousness, e.g. a relatively recent article 
 
https://pmc.ncbi.nlm.nih.gov/articles/PMC9857689/pdf/entropy-25-00072.pdf
 
treating Earth as a closed system in terms of classical thermodynamics (and on this basis deriving a &quot;scientific&quot; disproval of current climate science) that - despite of this fundamental flaw – was not recognized by referee(s) and editor(s) of the publishing journal “Entropy” as total bullshit, &quot;pataphysics&quot;?&quot;

Two checked AI engines admitted that this label might work as a satirical metaphor, however, they also add following warnings:

&quot;While the comparison is poetic, there is one major difference in intent:

- True Pataphysics requires self-awareness. Alfred Jarry and his followers knew they were engaging in a brilliant, satirical joke to mock human arrogance and scientific dogmatism.

- Junk science lacks irony. The authors of ideologically driven or fundamentally flawed climate papers usually take themselves entirely seriously. Their goal is not artistic satire, but to manufacture doubt or exploit cracks in the commercialized scientific publishing system.&quot;

&quot;Calling it &quot;&#039;pataphysics&quot; actually gives the author and journal too much credit—it implies a level of witty, self-aware artistic performance that simply isn&#039;t present.&quot;

I encourage you to run a similar prompt on any decent AI tool yourself and enjoy the provided analysis (or analyses) in its (their) entirety.

Greetings
Tomáš]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850375">Nabil Swedan</a>.</p>
<p>in Re to Nigelj, 11 Aug 2026 at 4:10 PM,</p>
<p><a href="https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850391" rel="ugc">https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850391</a></p>
<p>Hello Nigel,</p>
<p>I read the &#8220;primary published paper outlining his alternative model&#8221; and the sheer absurdity of its publication in a &#8220;scientific&#8221; journal inspired me to the following AI prompt:</p>
<p>&#8220;Would you call extreme examples of junk science published in journals pretending seriousness, e.g. a relatively recent article<br />
 <br />
<a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9857689/pdf/entropy-25-00072.pdf" rel="nofollow ugc">https://pmc.ncbi.nlm.nih.gov/articles/PMC9857689/pdf/entropy-25-00072.pdf</a><br />
 <br />
treating Earth as a closed system in terms of classical thermodynamics (and on this basis deriving a &#8220;scientific&#8221; disproval of current climate science) that &#8211; despite of this fundamental flaw – was not recognized by referee(s) and editor(s) of the publishing journal “Entropy” as total bullshit, &#8220;pataphysics&#8221;?&#8221;</p>
<p>Two checked AI engines admitted that this label might work as a satirical metaphor, however, they also add following warnings:</p>
<p>&#8220;While the comparison is poetic, there is one major difference in intent:</p>
<p>&#8211; True Pataphysics requires self-awareness. Alfred Jarry and his followers knew they were engaging in a brilliant, satirical joke to mock human arrogance and scientific dogmatism.</p>
<p>&#8211; Junk science lacks irony. The authors of ideologically driven or fundamentally flawed climate papers usually take themselves entirely seriously. Their goal is not artistic satire, but to manufacture doubt or exploit cracks in the commercialized scientific publishing system.&#8221;</p>
<p>&#8220;Calling it &#8220;&#8216;pataphysics&#8221; actually gives the author and journal too much credit—it implies a level of witty, self-aware artistic performance that simply isn&#8217;t present.&#8221;</p>
<p>I encourage you to run a similar prompt on any decent AI tool yourself and enjoy the provided analysis (or analyses) in its (their) entirety.</p>
<p>Greetings<br />
Tomáš</p>
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		Comment on Unforced Variations: Aug 2026 by KM		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850402</link>

		<dc:creator><![CDATA[KM]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 07:10:26 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850402</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850379&quot;&gt;Barton Paul Levenson&lt;/a&gt;.

BPL: But you’re not anti-science…


KM: No, I&#039;m not anti-science I am very pro-science especially as a tool for ethical decision making. 

The same as Kevin Anderson is pro-science. 

You know, &lt;b&gt;the climate scientist doing the speaking you quoted:&lt;/b&gt; &lt;i&gt; &quot;And we’re sold all this — just look how dominant astrologers are in our government — Economists, whatever you call them — they’re the same thing in my view, they’re astrologers.&quot;&lt;/i&gt;]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850379">Barton Paul Levenson</a>.</p>
<p>BPL: But you’re not anti-science…</p>
<p>KM: No, I&#8217;m not anti-science I am very pro-science especially as a tool for ethical decision making. </p>
<p>The same as Kevin Anderson is pro-science. </p>
<p>You know, <b>the climate scientist doing the speaking you quoted:</b> <i> &#8220;And we’re sold all this — just look how dominant astrologers are in our government — Economists, whatever you call them — they’re the same thing in my view, they’re astrologers.&#8221;</i></p>
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		Comment on Unforced Variations: Aug 2026 by KM		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850401</link>

		<dc:creator><![CDATA[KM]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 06:58:41 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850401</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850378&quot;&gt;Barton Paul Levenson&lt;/a&gt;.

Barton Paul Levenson says 11 Aug 2026 at 6:58 AM

-

Predictable. Play the man. Ignore the content from the Climate Scientist speaking. 



Barton is saying: we don’t want those questions asked. They’re uncomfortable. We like the deep inequalities we have now. We like the elite structures we have today. We want them to continue.]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850378">Barton Paul Levenson</a>.</p>
<p>Barton Paul Levenson says 11 Aug 2026 at 6:58 AM</p>
<p>&#8211;</p>
<p>Predictable. Play the man. Ignore the content from the Climate Scientist speaking. </p>
<p>Barton is saying: we don’t want those questions asked. They’re uncomfortable. We like the deep inequalities we have now. We like the elite structures we have today. We want them to continue.</p>
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		Comment on Unforced Variations: Aug 2026 by KM		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850400</link>

		<dc:creator><![CDATA[KM]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 06:15:48 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850400</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850376&quot;&gt;Martin Smith&lt;/a&gt;.

MS: If you mean they represent you (plural) shifting away from a debate about the existence of climate change, etc,, then, yes, that IS happening. You (plural) ARE finally accepting what climate science has been showing all along, that: 1. Global warming is real; 2 Global warming is caused by burning fossil fuels and land use practices, and 3. Global warming will be/is bad for the human race.


KM: Me, singular, accepted the climate science in the 1990s and ever since. So you are not talking to nor about me Martin. Sharpen your pencil.  Did you run my comment through your AIs to check if you understood what I was saying?   Because from your response here I can easily tell to do not understand it at all. 

I&#039;ve no interest in fighting strawmen that cover your comment. Nothing you say applies to me personally.]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850376">Martin Smith</a>.</p>
<p>MS: If you mean they represent you (plural) shifting away from a debate about the existence of climate change, etc,, then, yes, that IS happening. You (plural) ARE finally accepting what climate science has been showing all along, that: 1. Global warming is real; 2 Global warming is caused by burning fossil fuels and land use practices, and 3. Global warming will be/is bad for the human race.</p>
<p>KM: Me, singular, accepted the climate science in the 1990s and ever since. So you are not talking to nor about me Martin. Sharpen your pencil.  Did you run my comment through your AIs to check if you understood what I was saying?   Because from your response here I can easily tell to do not understand it at all. </p>
<p>I&#8217;ve no interest in fighting strawmen that cover your comment. Nothing you say applies to me personally.</p>
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		Comment on This new El Niño is different by KM		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850399</link>

		<dc:creator><![CDATA[KM]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 05:53:28 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26545#comment-850399</guid>

					<description><![CDATA[RELOCATING my reply to Nabil Swedan 8 Aug 2026 at 10:40 PM
https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850340 

... away from the noise. 



Nabil, thank you for your reply. I want to make sure I understand the &#039;low spot&#039; correctly in regards to your Pt 3.

Reading your paper, my understanding was that the &quot;low spot&quot; is a north-south phenomenon: the Southern Hemisphere warms faster, expands more, and the tropical Pacific becomes a relative depression between the two bulging hemispheres. This was the primary forcing in the ENSO cycle your paper alluded to.

Hemispheric warming asymmetry affects these gradients—warming changes the baseline sea-level difference from north to south. The low spot creates a sea-level gradient (predominantly in the South Pacific region) that increases with warming, affecting ocean heat content and movements.

The warm water piles up in the western Pacific (Indonesia) due to trade winds. This is the standard ENSO setup—when winds weaken, the warm water sloshes eastward and piles up against Central/South America (the barrier). This is the typical piling up of an El Niño event that&#039;s well documented.

But in your reply, you mention the Pacific-Atlantic sea-level difference (~20 cm at Panama Canal) and how hemispheric asymmetry might have decreased it by ~0.5 cm. That seems like an east-west hemisphere gradient, not north-south.

So my question is: Are these two different phenomena? Or is the &quot;low spot&quot; a combination of both? I want to make sure I&#039;m following the physics correctly.

And to be clear, my original question 3) was: Is the “low spot” mechanism testable with current observational data (e.g., sea level anomalies)?

I&#039;m interested in knowing whether the data exists that records the actual sea levels within the ENSO equatorial region of the South Pacific—showing that the sea-level &quot;low spot&quot; exists and follows the asymmetrical pattern you describe in your paper, and that it mirrors the arrival of an El Niño event.

Maybe I have that wrong—please clarify. My assumption from your paper was that one could predict the imminent arrival of an ENSO event based on shifts in sea level asymmetry, and potentially also predict the extent of a coming El Niño based on how &quot;extreme&quot; the &quot;low point&quot; was likely to be.

Thanks—looking forward to your reply.]]></description>
			<content:encoded><![CDATA[<p>RELOCATING my reply to Nabil Swedan 8 Aug 2026 at 10:40 PM<br />
<a href="https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850340" rel="ugc">https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850340</a> </p>
<p>&#8230; away from the noise. </p>
<p>Nabil, thank you for your reply. I want to make sure I understand the &#8216;low spot&#8217; correctly in regards to your Pt 3.</p>
<p>Reading your paper, my understanding was that the &#8220;low spot&#8221; is a north-south phenomenon: the Southern Hemisphere warms faster, expands more, and the tropical Pacific becomes a relative depression between the two bulging hemispheres. This was the primary forcing in the ENSO cycle your paper alluded to.</p>
<p>Hemispheric warming asymmetry affects these gradients—warming changes the baseline sea-level difference from north to south. The low spot creates a sea-level gradient (predominantly in the South Pacific region) that increases with warming, affecting ocean heat content and movements.</p>
<p>The warm water piles up in the western Pacific (Indonesia) due to trade winds. This is the standard ENSO setup—when winds weaken, the warm water sloshes eastward and piles up against Central/South America (the barrier). This is the typical piling up of an El Niño event that&#8217;s well documented.</p>
<p>But in your reply, you mention the Pacific-Atlantic sea-level difference (~20 cm at Panama Canal) and how hemispheric asymmetry might have decreased it by ~0.5 cm. That seems like an east-west hemisphere gradient, not north-south.</p>
<p>So my question is: Are these two different phenomena? Or is the &#8220;low spot&#8221; a combination of both? I want to make sure I&#8217;m following the physics correctly.</p>
<p>And to be clear, my original question 3) was: Is the “low spot” mechanism testable with current observational data (e.g., sea level anomalies)?</p>
<p>I&#8217;m interested in knowing whether the data exists that records the actual sea levels within the ENSO equatorial region of the South Pacific—showing that the sea-level &#8220;low spot&#8221; exists and follows the asymmetrical pattern you describe in your paper, and that it mirrors the arrival of an El Niño event.</p>
<p>Maybe I have that wrong—please clarify. My assumption from your paper was that one could predict the imminent arrival of an ENSO event based on shifts in sea level asymmetry, and potentially also predict the extent of a coming El Niño based on how &#8220;extreme&#8221; the &#8220;low point&#8221; was likely to be.</p>
<p>Thanks—looking forward to your reply.</p>
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		Comment on This new El Niño is different by KM		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850398</link>

		<dc:creator><![CDATA[KM]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 04:46:58 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26545#comment-850398</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850375&quot;&gt;Nabil Swedan&lt;/a&gt;.

Nigelj says 11 Aug 2026 at 4:10 PM


Paul Pukite says: “This is Nabiil Swedan’s work from circa 2013 onwards:
“This is a nonsense. There is no greenhouse gas effect; it is a fiction.”



Nigel: ”&quot; —his theories place him entirely outside the mainstream scientific consensus. &quot; 



KM : An apostate is a person who has completely given up or rejected their religious faith, a political party, or a specific cause they once believed in and supported.

Nigel Jones is an admitted climate science denying Apostate. Nigel Jones changed his mind and beliefs about the topic long ago. 

Should I deploy my own AI to track down his public comments which were anti-global warming, his disbelief in climate science formerly held by Nigel Jones before 2013 and re-post them here too? 

Do people change their opinions about things Nigel Jones? 

And will Nigel Jones and Paul Pukite and Piotr xxxxxx CA  retract their ad hominem attacks, their gratuitous innuendos and admit the topic being discussed here was Nabil Swedan&#039;s peer reviewed paper published in 2026 ? 

Of course they will not. Performative tribal anti-denier drama is what maintains this forum now. 

&lt;b&gt;It should be obvious to anyone professional enough to read Nabil&#039;s paper that it contains nothing contrary to the basic science of AGW and it&#039;s impacts. &lt;/b&gt; There is no evidence in the paper&#039;s abstract or description that suggests he rejects established climate science norms or the reality of anthropogenic global warming

What the Paper Actually Argues

The paper&#039;s central argument seems to be a proposal of a new physical mechanism for ENSO, rather than a denial of climate change:

    Challenging Established Theory: It critiques the traditional view of ENSO as a &quot;self-sustaining system,&quot; arguing it&#039;s thermodynamically unrealistic because it lacks an external energy source. This is a scientific argument about the physics of ENSO, not a denial of global warming.

    Acknowledging External Forcing: The paper explicitly states that the &quot;external energy source&quot; is the &quot;hemispheric asymmetry in sea surface warming&quot;. This directly links the ENSO mechanism to a global warming trend.

    Connecting to Anthropogenic Warming: The paper&#039;s core prediction is that as this hemispheric warming imbalance intensifies, the frequency of El Niño events and related climate extremes will increase. This is a prediction of future impacts consistent with mainstream climate projections.

&lt;b&gt;In fact, the paper appears to align with established climate science.&lt;/b&gt; The abstract explicitly acknowledges a human role by stating that &lt;b&gt;the intensifying &quot;hemispheric imbalance in surface warming&quot; is a trend that &quot;may potentially be attributed to anthropogenic influences&quot; and says this &quot;warrants further investigation&quot; &lt;/b&gt; 


Genuine science philosophy and methodology proponents would not be making the unfounded claims allegations made by others above. They be addressing the Data and Reasoning within the published paper itself.]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/07/this-new-el-nino-is-different/#comment-850375">Nabil Swedan</a>.</p>
<p>Nigelj says 11 Aug 2026 at 4:10 PM</p>
<p>Paul Pukite says: “This is Nabiil Swedan’s work from circa 2013 onwards:<br />
“This is a nonsense. There is no greenhouse gas effect; it is a fiction.”</p>
<p>Nigel: ”&#8221; —his theories place him entirely outside the mainstream scientific consensus. &#8221; </p>
<p>KM : An apostate is a person who has completely given up or rejected their religious faith, a political party, or a specific cause they once believed in and supported.</p>
<p>Nigel Jones is an admitted climate science denying Apostate. Nigel Jones changed his mind and beliefs about the topic long ago. </p>
<p>Should I deploy my own AI to track down his public comments which were anti-global warming, his disbelief in climate science formerly held by Nigel Jones before 2013 and re-post them here too? </p>
<p>Do people change their opinions about things Nigel Jones? </p>
<p>And will Nigel Jones and Paul Pukite and Piotr xxxxxx CA  retract their ad hominem attacks, their gratuitous innuendos and admit the topic being discussed here was Nabil Swedan&#8217;s peer reviewed paper published in 2026 ? </p>
<p>Of course they will not. Performative tribal anti-denier drama is what maintains this forum now. </p>
<p><b>It should be obvious to anyone professional enough to read Nabil&#8217;s paper that it contains nothing contrary to the basic science of AGW and it&#8217;s impacts. </b> There is no evidence in the paper&#8217;s abstract or description that suggests he rejects established climate science norms or the reality of anthropogenic global warming</p>
<p>What the Paper Actually Argues</p>
<p>The paper&#8217;s central argument seems to be a proposal of a new physical mechanism for ENSO, rather than a denial of climate change:</p>
<p>    Challenging Established Theory: It critiques the traditional view of ENSO as a &#8220;self-sustaining system,&#8221; arguing it&#8217;s thermodynamically unrealistic because it lacks an external energy source. This is a scientific argument about the physics of ENSO, not a denial of global warming.</p>
<p>    Acknowledging External Forcing: The paper explicitly states that the &#8220;external energy source&#8221; is the &#8220;hemispheric asymmetry in sea surface warming&#8221;. This directly links the ENSO mechanism to a global warming trend.</p>
<p>    Connecting to Anthropogenic Warming: The paper&#8217;s core prediction is that as this hemispheric warming imbalance intensifies, the frequency of El Niño events and related climate extremes will increase. This is a prediction of future impacts consistent with mainstream climate projections.</p>
<p><b>In fact, the paper appears to align with established climate science.</b> The abstract explicitly acknowledges a human role by stating that <b>the intensifying &#8220;hemispheric imbalance in surface warming&#8221; is a trend that &#8220;may potentially be attributed to anthropogenic influences&#8221; and says this &#8220;warrants further investigation&#8221; </b> </p>
<p>Genuine science philosophy and methodology proponents would not be making the unfounded claims allegations made by others above. They be addressing the Data and Reasoning within the published paper itself.</p>
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		Comment on Unforced Variations: Aug 2026 by Piotr		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850397</link>

		<dc:creator><![CDATA[Piotr]]></dc:creator>
		<pubDate>Wed, 12 Aug 2026 02:41:50 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850397</guid>

					<description><![CDATA[In reply to &lt;a href=&quot;https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850377&quot;&gt;Barton Paul Levenson&lt;/a&gt;.

KM: &quot;And stop personalizing the dilemma by foolishly blaming Trump. Trump’s got nothing specific to do with todays climate impact&quot;

BPL &quot;Data centers. Drilling. Shutting down wind projects. Removing subsidies for solar and for electric vehicles.&quot;

and the list goes on:

- entrenching in the tens of millions of Americans who voted for him and in Republican Party he controls his view that “&lt;i&gt; The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.&lt;/i&gt;  

- defunding and degrading climate science in NASA and NOAA, 

- using DoE and EPA to question the existence/threats of climate change 

- threatening to hurt American universities financially if they pursue directions of research contrary to Trumps agenda  that includes climate change

- trying to scuttle international efforts to reduce CO2 emissions by
-  withdrawing US from Paris accord
- encouraging others to follow the suit (if the US that has  4.7% of global population but is responsible for 1/4 of cumulative emissions of CO2, withdrew from the emission reductions, then why on Earth would the rest of the world do anything when their per capita emissions are typically several times LOWER than those of the US, and reducing their emissions would put their manufacturing at the competitive disadvantage  compared to their US counterparts exempted from these costs?)

- by questioning value of rule-based world and international cooperation on the actions that would benefit all - and replacing it with the appeal to national egoism  - seeing CO2 mitigation as a zero-sum gain - China&#039;s gain at the US loss. 

For a true extremist, the real enemy is never the opposite extremist - but those  in the middle, moderates -  seeing the same problems, but not going to the extreme on them as does the extremist. That&#039;s why the doomer&#039;s attacks are not focused on the deniers, but on  mainstream science. The Doomers see themselves  as badly-maligned  prophets - brilliant to see the future, but not believed  until it was too late ( (e.g. &quot;&lt;i&gt; “ I have been telling you this for over a decade[...] but you never listen“ &lt;/i&gt; )

For a similar reason, Christians persecuted Jews more than other religions because  &quot;Jews were given a chance to welcome Our Lord, Jesus, and they rejected Him&quot; . And the Islamist fundamentalists may tolerate Christians in their midst, but a conversion of a Muslim to Christianity must be punished by death. 
For both the left and right-wing extremism - the main target are not each other, but the democracy and the moderates 

And that&#039;s why Doomers so often land in the same bed as  Deniers - here with both Mr. KiA and Mr. Multi-troll - defending Trump and seeing the problem in Trump&#039;s critics. 

And they both need each other - Deniers need Doomers to help them discredit the mainstream science and people relying on its advice. And conversely, Doomers  need Deniers - for the same thing.

 Additionally, Trump and other deniers, by delaying and weakening mitigation of Co2 emissions by increasing the chance that the worst scenario gets realized - help the Doomers with what they crave most -  to be right  For a Doomer - the worse the future for humans, the better for his ego - &lt;i&gt; You all got what you deserved - I was warning you for years, but you never listened. Who is laughing now?!&quot; &lt;/i&gt;]]></description>
			<content:encoded><![CDATA[<p>In reply to <a href="https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850377">Barton Paul Levenson</a>.</p>
<p>KM: &#8220;And stop personalizing the dilemma by foolishly blaming Trump. Trump’s got nothing specific to do with todays climate impact&#8221;</p>
<p>BPL &#8220;Data centers. Drilling. Shutting down wind projects. Removing subsidies for solar and for electric vehicles.&#8221;</p>
<p>and the list goes on:</p>
<p>&#8211; entrenching in the tens of millions of Americans who voted for him and in Republican Party he controls his view that “<i> The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.</i>  </p>
<p>&#8211; defunding and degrading climate science in NASA and NOAA, </p>
<p>&#8211; using DoE and EPA to question the existence/threats of climate change </p>
<p>&#8211; threatening to hurt American universities financially if they pursue directions of research contrary to Trumps agenda  that includes climate change</p>
<p>&#8211; trying to scuttle international efforts to reduce CO2 emissions by<br />
&#8211;  withdrawing US from Paris accord<br />
&#8211; encouraging others to follow the suit (if the US that has  4.7% of global population but is responsible for 1/4 of cumulative emissions of CO2, withdrew from the emission reductions, then why on Earth would the rest of the world do anything when their per capita emissions are typically several times LOWER than those of the US, and reducing their emissions would put their manufacturing at the competitive disadvantage  compared to their US counterparts exempted from these costs?)</p>
<p>&#8211; by questioning value of rule-based world and international cooperation on the actions that would benefit all &#8211; and replacing it with the appeal to national egoism  &#8211; seeing CO2 mitigation as a zero-sum gain &#8211; China&#8217;s gain at the US loss. </p>
<p>For a true extremist, the real enemy is never the opposite extremist &#8211; but those  in the middle, moderates &#8211;  seeing the same problems, but not going to the extreme on them as does the extremist. That&#8217;s why the doomer&#8217;s attacks are not focused on the deniers, but on  mainstream science. The Doomers see themselves  as badly-maligned  prophets &#8211; brilliant to see the future, but not believed  until it was too late ( (e.g. &#8220;<i> “ I have been telling you this for over a decade[&#8230;] but you never listen“ </i> )</p>
<p>For a similar reason, Christians persecuted Jews more than other religions because  &#8220;Jews were given a chance to welcome Our Lord, Jesus, and they rejected Him&#8221; . And the Islamist fundamentalists may tolerate Christians in their midst, but a conversion of a Muslim to Christianity must be punished by death.<br />
For both the left and right-wing extremism &#8211; the main target are not each other, but the democracy and the moderates </p>
<p>And that&#8217;s why Doomers so often land in the same bed as  Deniers &#8211; here with both Mr. KiA and Mr. Multi-troll &#8211; defending Trump and seeing the problem in Trump&#8217;s critics. </p>
<p>And they both need each other &#8211; Deniers need Doomers to help them discredit the mainstream science and people relying on its advice. And conversely, Doomers  need Deniers &#8211; for the same thing.</p>
<p> Additionally, Trump and other deniers, by delaying and weakening mitigation of Co2 emissions by increasing the chance that the worst scenario gets realized &#8211; help the Doomers with what they crave most &#8211;  to be right  For a Doomer &#8211; the worse the future for humans, the better for his ego &#8211; <i> You all got what you deserved &#8211; I was warning you for years, but you never listened. Who is laughing now?!&#8221; </i></p>
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		<title>
		Comment on Unforced Variations: Aug 2026 by patrick o twentyseven		</title>
		<link>https://www.realclimate.org/index.php/archives/2026/08/unforced-variations-aug-2026/#comment-850396</link>

		<dc:creator><![CDATA[patrick o twentyseven]]></dc:creator>
		<pubDate>Tue, 11 Aug 2026 23:43:52 +0000</pubDate>
		<guid isPermaLink="false">https://www.realclimate.org/?p=26579#comment-850396</guid>

					<description><![CDATA[Me @ https://www.realclimate.org/index.php/archives/2026/07/unforced-variations-july-2026/#comment-849537 : &lt;blockquote&gt; I *believe* collisions act like observations of a quantum system eg. molecule; in isolation, during a transition between a pair of states, the system is in an evolving superposition of the states. So collisions turn this into a probability; eg. if they occur when the transition is 1% of the way done, then 99% of the transitions are aborted, but the 1 % that occur have been forced to happen 100 times faster (causing collisional line broadening), […] &lt;/blockquote&gt; - or, … maybe not?

https://scienceinsights.org/what-is-broadened-collision-spectral-lines-explained/  - the explanation given here is what I’ve been familiar with;

but these sources give different explanations, which might result in the familiar one when simplified or … &lt;b&gt;or not??&lt;/b&gt;:

https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf (relatively easy read, but long; I read ~ p.4 through 14 (and then to p.25, then I skipped over to ~ p.30, read a few more pp., … but reading 14-25, 30-? Was on my phone and that version didn’t have any figures – wait, neither does the one on the computer … )

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/pressure-broadening

https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/The_Fundamentals_of_Stellar_Astrophysics_(Collins)/14%3A_Shape_of_Spectral_Lines/14.05%3A_Collisional_Broadening 

https://bklein.ece.gatech.edu/laser-photonics/broadening-mechanisms/

and then there’s this one, which I haven’t looked through much (not that I’ve gone through any of these thoroughly)
https://chem.libretexts.org/Courses/University_of_California_Davis/Chem_205%3A_Symmetry_Spectroscopy_and_Structure/02%3A_Electronic_Spectroscopy/2.03%3A_Broadening_Mechanisms
…

A few things I’ve learned… I think… 

Elastic collisions: leave the quantized states (ie. rotational (I presume this is included), vibrational, electronic, nuclear (just covering the bases)) unchanged in a categorical sense, but during the collision, the field(s) of the colliding matter smoothly shift the energies of said states (they are a function of the relative arrangement of the subject molecule and the interacting matter) and thus potentially the energies of any transitions that would occur (as well as the Einstein coefficient A_{i,j} for spontaneous emission (the source https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf didn’t discuss absorption but the other coefficients would have to change, too, I’d think, unless this is an effective change in the real component of the refractive index…) (this is actually (a part of?) what defines a collision in this context).

Inelastic collisions cause such changes (in internal quantum states: vibrational/etc.).

If a transition occurs in such a short time frame that the relative arrangement is nearly constant during it, then that leads to quasi-static broadening.

If a transition is interrupted by many elastic collisions, each causes a shift in the phase of the emitted photon, breaking the wave train up into segments that are not coherent with each other, contributing to broadening. 

https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf   p.14 (of the file)
&lt;blockquote&gt; If the atom was in the excited state, it remains in the excited state after an elastic collision. However, these collisions are not without effect! They &#039;modify the oscillator phase without changing state population.&#039; Imagine the atom&#039;s wavefunction, or more classically, its radiating dipole, as an oscillating system. An elastic collision can abruptly change the phase of this oscillation. While the atom is still excited and capable of radiating, the coherence of its emission is interrupted. These random phase interruptions also lead to line broadening, typically Lorentzian as well, and can also cause shifts in the line center. We&#039;ll explore this phase perturbation in more detail later. &lt;/blockquote&gt;

(Given something Ray Ladbury said about photons not having individual (me: trackable?) identities, I wonder if the broken-up photon segments from interrupted emissions &#038; absorptions (including due to inelastic collisions) end up combining to make new whole photons.)

https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf :

PS p.11-12 (of the file): the duration of a collision may be ~ 2 ps (2 E−12 s) (for the parameters considered) (this is *not* the mean period between collisions).  P.12 has a seeming contradiction: they say the typical duration of an electronic transition is much less than 2 ps:
&lt;blockquote&gt; Let&#039;s clarify this. The act of absorbing or emitting a photon is an electronic process that happens very rapidly, on a timescale typically much shorter than even the picosecond collision time. Think of it as an almost instantaneous quantum jump for the electrons. During this very brief moment of photon interaction, the nuclei, which are much heavier, barely have time to move. Therefore, the internuclear separation  can be considered essentially constant &lt;i&gt;during the optical transition itself&lt;/i&gt;. &lt;/blockquote&gt;
And yet, above that on the same page (some formatting may be lost in C&#038;P):
&lt;blockquote&gt; The first point of interpretation is crucial: &quot;2 picoseconds is extremely short compared with typical radiative lifetimes.&quot; Radiative lifetimes, rad (lowercase tau subscript r-a-d), which is the average time an isolated atom spends in an excited state before spontaneously emitting a photon, are typically in the range of nanoseconds (ns, 10−9 seconds) to microseconds (s, 10−6 seconds) for many common transitions. So, we have c, the collision duration, around 2 × 10−12 seconds, while rad is around 10−9 seconds or longer. This means rad is at least a thousand to a million times longer than c. A single collision is a very fleeting event compared to the natural lifetime of an excited state. However, in a gas at reasonable pressure, an atom might undergo many such collisions during one radiative lifetime. &lt;/blockquote&gt; - and they’re referring to isolated atoms so presumably these are electronic states and transitions (PS I don’t remember offhand if this is based on Earth’s atmosphere or not…)

…
I’ll also note that I think I’ve seen this now in multiple places: the quantum uncertainty effect of broadening the line due to finite durations is not applied directly to the photon (duration of emission or absorption process) but to the excited state’s lifetime.]]></description>
			<content:encoded><![CDATA[<p>Me @ <a href="https://www.realclimate.org/index.php/archives/2026/07/unforced-variations-july-2026/#comment-849537" rel="ugc">https://www.realclimate.org/index.php/archives/2026/07/unforced-variations-july-2026/#comment-849537</a> : </p>
<blockquote><p> I *believe* collisions act like observations of a quantum system eg. molecule; in isolation, during a transition between a pair of states, the system is in an evolving superposition of the states. So collisions turn this into a probability; eg. if they occur when the transition is 1% of the way done, then 99% of the transitions are aborted, but the 1 % that occur have been forced to happen 100 times faster (causing collisional line broadening), […] </p></blockquote>
<p> &#8211; or, … maybe not?</p>
<p><a href="https://scienceinsights.org/what-is-broadened-collision-spectral-lines-explained/" rel="nofollow ugc">https://scienceinsights.org/what-is-broadened-collision-spectral-lines-explained/</a>  &#8211; the explanation given here is what I’ve been familiar with;</p>
<p>but these sources give different explanations, which might result in the familiar one when simplified or … <b>or not??</b>:</p>
<p><a href="https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf" rel="nofollow ugc">https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf</a> (relatively easy read, but long; I read ~ p.4 through 14 (and then to p.25, then I skipped over to ~ p.30, read a few more pp., … but reading 14-25, 30-? Was on my phone and that version didn’t have any figures – wait, neither does the one on the computer … )</p>
<p><a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/pressure-broadening" rel="nofollow ugc">https://www.sciencedirect.com/topics/earth-and-planetary-sciences/pressure-broadening</a></p>
<p><a href="https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/The_Fundamentals_of_Stellar_Astrophysics_(Collins)/14%3A_Shape_of_Spectral_Lines/14.05%3A_Collisional_Broadening" rel="nofollow ugc">https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/The_Fundamentals_of_Stellar_Astrophysics_(Collins)/14%3A_Shape_of_Spectral_Lines/14.05%3A_Collisional_Broadening</a> </p>
<p><a href="https://bklein.ece.gatech.edu/laser-photonics/broadening-mechanisms/" rel="nofollow ugc">https://bklein.ece.gatech.edu/laser-photonics/broadening-mechanisms/</a></p>
<p>and then there’s this one, which I haven’t looked through much (not that I’ve gone through any of these thoroughly)<br />
<a href="https://chem.libretexts.org/Courses/University_of_California_Davis/Chem_205%3A_Symmetry_Spectroscopy_and_Structure/02%3A_Electronic_Spectroscopy/2.03%3A_Broadening_Mechanisms" rel="nofollow ugc">https://chem.libretexts.org/Courses/University_of_California_Davis/Chem_205%3A_Symmetry_Spectroscopy_and_Structure/02%3A_Electronic_Spectroscopy/2.03%3A_Broadening_Mechanisms</a><br />
…</p>
<p>A few things I’ve learned… I think… </p>
<p>Elastic collisions: leave the quantized states (ie. rotational (I presume this is included), vibrational, electronic, nuclear (just covering the bases)) unchanged in a categorical sense, but during the collision, the field(s) of the colliding matter smoothly shift the energies of said states (they are a function of the relative arrangement of the subject molecule and the interacting matter) and thus potentially the energies of any transitions that would occur (as well as the Einstein coefficient A_{i,j} for spontaneous emission (the source <a href="https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf" rel="nofollow ugc">https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf</a> didn’t discuss absorption but the other coefficients would have to change, too, I’d think, unless this is an effective change in the real component of the refractive index…) (this is actually (a part of?) what defines a collision in this context).</p>
<p>Inelastic collisions cause such changes (in internal quantum states: vibrational/etc.).</p>
<p>If a transition occurs in such a short time frame that the relative arrangement is nearly constant during it, then that leads to quasi-static broadening.</p>
<p>If a transition is interrupted by many elastic collisions, each causes a shift in the phase of the emitted photon, breaking the wave train up into segments that are not coherent with each other, contributing to broadening. </p>
<p><a href="https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf" rel="nofollow ugc">https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf</a>   p.14 (of the file)</p>
<blockquote><p> If the atom was in the excited state, it remains in the excited state after an elastic collision. However, these collisions are not without effect! They &#8216;modify the oscillator phase without changing state population.&#8217; Imagine the atom&#8217;s wavefunction, or more classically, its radiating dipole, as an oscillating system. An elastic collision can abruptly change the phase of this oscillation. While the atom is still excited and capable of radiating, the coherence of its emission is interrupted. These random phase interruptions also lead to line broadening, typically Lorentzian as well, and can also cause shifts in the line center. We&#8217;ll explore this phase perturbation in more detail later. </p></blockquote>
<p>(Given something Ray Ladbury said about photons not having individual (me: trackable?) identities, I wonder if the broken-up photon segments from interrupted emissions &amp; absorptions (including due to inelastic collisions) end up combining to make new whole photons.)</p>
<p><a href="https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf" rel="nofollow ugc">https://faculty.kfupm.edu.sa/PHYS/magondal/Phys608/Lecturedetails/3.3.pdf</a> :</p>
<p>PS p.11-12 (of the file): the duration of a collision may be ~ 2 ps (2 E−12 s) (for the parameters considered) (this is *not* the mean period between collisions).  P.12 has a seeming contradiction: they say the typical duration of an electronic transition is much less than 2 ps:</p>
<blockquote><p> Let&#8217;s clarify this. The act of absorbing or emitting a photon is an electronic process that happens very rapidly, on a timescale typically much shorter than even the picosecond collision time. Think of it as an almost instantaneous quantum jump for the electrons. During this very brief moment of photon interaction, the nuclei, which are much heavier, barely have time to move. Therefore, the internuclear separation  can be considered essentially constant <i>during the optical transition itself</i>. </p></blockquote>
<p>And yet, above that on the same page (some formatting may be lost in C&amp;P):</p>
<blockquote><p> The first point of interpretation is crucial: &#8220;2 picoseconds is extremely short compared with typical radiative lifetimes.&#8221; Radiative lifetimes, rad (lowercase tau subscript r-a-d), which is the average time an isolated atom spends in an excited state before spontaneously emitting a photon, are typically in the range of nanoseconds (ns, 10−9 seconds) to microseconds (s, 10−6 seconds) for many common transitions. So, we have c, the collision duration, around 2 × 10−12 seconds, while rad is around 10−9 seconds or longer. This means rad is at least a thousand to a million times longer than c. A single collision is a very fleeting event compared to the natural lifetime of an excited state. However, in a gas at reasonable pressure, an atom might undergo many such collisions during one radiative lifetime. </p></blockquote>
<p> &#8211; and they’re referring to isolated atoms so presumably these are electronic states and transitions (PS I don’t remember offhand if this is based on Earth’s atmosphere or not…)</p>
<p>…<br />
I’ll also note that I think I’ve seen this now in multiple places: the quantum uncertainty effect of broadening the line due to finite durations is not applied directly to the photon (duration of emission or absorption process) but to the excited state’s lifetime.</p>
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