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Occasional Thoughts on Climate Change


donsutherland1
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2 hours ago, Typhoon Tip said:

You know it's funny ... the circulation was always about the slow moving thermal-haline cycle/forcing with the fresh water inclusion at surface density/buoyancy effecting the chimney fall rates ... ultimately slowing the overturning cross hemispheric oceanic circulation.  We've actually been discussing that for ... wow 30 years at this point.

That's still out there as far as I'm aware. Particularly if Greenland decides to unburden it's Millennial mass.  etc...

But wait, now we have these other circulation mode catastrophes emerging that show the not-so-slow moving characteristic. Beautiful.   

We now have competing explanations on that North Atlantic cold blob. Some studies find it’s related to the slowing AMOC and others to stronger winds from increased storminess and +NAO. So it may take some time to figure out which feature is having a bigger influence. 
 


https://www.psu.edu/news/institute-computational-and-data-sciences/story/increased-storminess-may-give-rise-north-atlantics/

In a study published in Climate Dynamics, the researchers report that a northward shift in the jet stream is contributing to a cooling of about .7 degrees Fahrenheit over the past century. Using computer simulations, the researchers found that more than half — 54% — of the observed cooling trend is a result of increased heat loss from the ocean induced by the overlying atmosphere. Strengthened local convection — whereby ocean mixing brings cold water from depth to the surface — explains another 38% of the trend.

According to the team, storminess increased in the region because the jet stream moved northward. As a result, there are more frequent and more intense storms in this region.  The increase in storminess creates a stronger heat loss from the ocean and induces stronger convection in winter, leading to cooler temperatures in the region.

https://www.psu.edu/news/research/story/north-atlantic-oscillation-contributes-cold-blob-atlantic-ocean/

 

UNIVERSITY PARK, Pa. — A patch of ocean in the North Atlantic is stubbornly cooling while much of the planet warms. This anomaly — dubbed the "cold blob" — has been linked to changes in ocean circulation, but a new study found changes in large-scale atmospheric patterns may play an equally important role, according to an international research team led by Penn State.

“People often think the atmosphere has a very short memory, but here we provide evidence that atmospheric circulation change is significant enough to induce some long-term impact on the climate system,” said corresponding author Laifang Li, assistant professor of meteorology and atmospheric science at Penn State.

Sea surface temperatures in the subpolar North Atlantic have decreased by about .7 degrees Fahrenheit over the last century, and a trend toward a more frequent positive phase of the North Atlantic Oscillation (NAO) may have contributed significantly, the scientists reported in the journal Climate Dynamics.

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14 minutes ago, bluewave said:

We now have competing explanations on that North Atlantic cold blob. Some studies find it’s related to the slowing AMOC and others to stronger winds from increased storminess and +NAO. So it may take some time to figure out which feature is having a bigger influence. 
 


https://www.psu.edu/news/institute-computational-and-data-sciences/story/increased-storminess-may-give-rise-north-atlantics/

In a study published in Climate Dynamics, the researchers report that a northward shift in the jet stream is contributing to a cooling of about .7 degrees Fahrenheit over the past century. Using computer simulations, the researchers found that more than half — 54% — of the observed cooling trend is a result of increased heat loss from the ocean induced by the overlying atmosphere. Strengthened local convection — whereby ocean mixing brings cold water from depth to the surface — explains another 38% of the trend.

According to the team, storminess increased in the region because the jet stream moved northward. As a result, there are more frequent and more intense storms in this region.  The increase in storminess creates a stronger heat loss from the ocean and induces stronger convection in winter, leading to cooler temperatures in the region.

https://www.psu.edu/news/research/story/north-atlantic-oscillation-contributes-cold-blob-atlantic-ocean/

 

UNIVERSITY PARK, Pa. — A patch of ocean in the North Atlantic is stubbornly cooling while much of the planet warms. This anomaly — dubbed the "cold blob" — has been linked to changes in ocean circulation, but a new study found changes in large-scale atmospheric patterns may play an equally important role, according to an international research team led by Penn State.

“People often think the atmosphere has a very short memory, but here we provide evidence that atmospheric circulation change is significant enough to induce some long-term impact on the climate system,” said corresponding author Laifang Li, assistant professor of meteorology and atmospheric science at Penn State.

Sea surface temperatures in the subpolar North Atlantic have decreased by about .7 degrees Fahrenheit over the last century, and a trend toward a more frequent positive phase of the North Atlantic Oscillation (NAO) may have contributed significantly, the scientists reported in the journal Climate Dynamics.

 The avg NAO has, indeed, risen during winter since 1979-80. However, we also know that it has fallen during summer since 2007. So, might the NAO change in recent decades be close to a wash? Are they just talking about winter?

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4 hours ago, Typhoon Tip said:

I've wondered before how a 1936 heat wave would be if it occurred today.   The thing is, it's not just an arithmetic assumption - like ...we cannot just assume since the climate is X degrees warmer, add that difference to the outcome. That's not how things work.

The 'synergistic feedback,' a phenomenon that has been contributing to those heat explosions taking place all over the globe, cannot really be predicted as they are emergence that exceed the parametric input into the system ...i.e., "more than the sum of the contributing factors"  ... that is why modeling will fall shy of the extreme results. 

The idea here, if one is intuitive and clever, the "synergistic potential" in 1936 is different than it is in 2024.  For example, better land management and thus sustaining irrigation ... it's not clear how that would effect a feedback model. The daily "burst" temp is higher today than back whence...no doubt.  Just looking at London, the Pac NW ...France and Australia and SE Asia frequencies.  But the better land management may cap some of the extremeness too.  It's a lot of math there.

1936 is mostly a paper tiger. Doesn't stand up to scrutiny. Would be considered a summer of yesteryear if it happened today by the same people minimizing recent summertime heat.

Ice was present on the east end of Lake Erie until the end of May. June was cold as hell compared to recent years. July was fairly typical, but generally cooler than recent years. A formidable heat wave struck from July 8 - July 14, which is included in the July numbers and brings the month up to close to current norms. However, humidity was exceptionally low with dew points commonly in the 40s and 50s, even as air temperatures climbed well into the 90s and 100s. Every recent summer has seen more deadly heat indices/wetbulb readings. Excluding the 7-day stretch, July was way cooler than recent years for the other 24 days. August was a little bit above current norms, but nothing crazy.

Even in Des Moines, Iowa, where it was the hottest July on record, the humidity was unbelievably low. In fact, if you check on the Iowa Mesonet, they have data back to 1936. It was the driest July and summer on record, by mean dew point. All record heat indices [basically an analog for wet bulb reading] have been set in recent decades, including the highest on record just last summer [the one higher reading from 1936 appears to be erroneous].

Look at your local observations from that summer. You'll be surprised. This was pretty much the case everywhere from the east coast to Michigan, but even on the west shore of Lake Michigan at Chicago and Milwaukee. Some how they say this is the hottest summer on record, but its way cooler than all recent summers. Go figure.

 

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Just because we're not getting gigantic heat blobs doesn't mean it's not warming at an alarming clip. I responded to "you know who" who was going on about adjustments to the NCEI numbers for Harrisburg, PA. I noticed immediately his alleged adjustments actually cool the recent summertime warming trend. So I pulled up the data for MDT and CXY airports... Since 2001, MDT is warming at +10.4F/century in the summertime; CXY Airport is warming at +17.2F/century in the summertime.

This isn't even a cherrypicked start period. There were a lot of warm summers in the early years of this century. 2001 was hot - I remember Korey Stringer passing away at Vikings practice from the heat. 2002 was a ridiculous scorcher, as was 2005. 2006 was mostly hot. I think it reached 121F in South Dakota and was basically a statistical tie with 1936. And if you believe the people on this forum, recent summers haven't been too bad.

I realize it's too short of a timeframe to really draw any significant conclusions, but wow. It's like we're boiling frogs. Maybe it's not reaching 120F every summer, but quietly this century, every location is heating up in the summertime and heating up quickly.

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Gotta love these oldies, but goodies. Like this passage from the Globe in 1991. You know who was right? Dr. Hansen. Pinatubo did drop global temperatures in 1992 & 1993, and then did rebound to record breaking levels in the 1990s. You know who was wrong? The so-called state climatologist.

image.png.ae16b016fa48bf6d3988a893e465a977.png

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Here's another good one from January 1, 1992. "The thermometer may have been placed at times over asphalt or dirt, rather than over grass as it is supposed to be." Meanwhile, the old records were taken on asphalt rooftops. Make it make sense. I wonder what Mr. Hendricksen's excuse would be today, when pretty much every year is as hot or hotter than 1991.

image.png.902602697f780206414fd1285fe62310.png

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2 minutes ago, TheClimateChanger said:

Here's another good one from January 1, 1992. "The thermometer may have been placed at times over asphalt or dirt, rather than over grass as it is supposed to be." Meanwhile, the old records were taken on asphalt rooftops. Make it make sense. I wonder what Mr. Hendricksen's excuse would be today, when pretty much every year is as hot or hotter than 1991.

image.png.902602697f780206414fd1285fe62310.png

I will grant him that the temperatures from that era were inflated, but not because of asphalt or dirt. The HO-83 hygrothermometer was defective and produced spuriously warm temperatures.

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You'd think the Midwest summertime climate change hole would show up in the data for Des Moines. I'm seeing a nearly 8F/century rise since 2001, and a 2.9F/century rise over the past 50 years. Wait until you guys get a load of the Td increases over that same time! Wet bulb temperatures are probably rising at twice the rate of the dry bulb readings.

 

 

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On 6/1/2024 at 6:35 PM, Stormchaserchuck1 said:

A lot of high temperature records from the late 1800s/early 1900s still stand.. I'm surprised reading the transcripts from settlers in the 1700s, about Winter weather that is not much different from today. It's obviously trended warmer, but they really had some warm Winters back then too. 

I think the threat is always there for some extreme flux, given the two polar blocking regions are land, Greenland and Alaska. remember that KC Chiefs playoff game this year when the windchill was -35F south in latitude of here? 

Dude, it's so much hotter today than the 19th century, that we could literally delete the entire summer and just transition from spring to fall and the annual mean would still be in the ballpark of the mean for the entire year from that era.

Look, here's Boston. 2024 is already warmer than 1888, 1904, and 1875. We could leap straight from early June to late September, skipping over almost the entirety of June, July, August, and September, and still beat some of those years. :arrowhead:

image.png.806667c4d33bc83c7a9acb6c668a3302.png

Boston is actually a very bad example, because it's been cooler. Look at Atlanta. No June 5-30, July, August, September, or October factored in, and 2024 is already warmer than or as warm as 76 full years! January & February are warmer than November and December. December is roughly between February and March means, November between March & April, October between April & May, June through September hotter than any of the first five months.

image.png.82b99fb1800e878e0277dfee45c50c0d.png

Without even factoring in June 5 through October, the hottest part of the year in South Florida, Miami's mean for 2024 to date would already place as 48th warmest on record - matching or exceeding 81 full years.

image.png.e5b66feca95fb3276ee4c7ddab7d92ca.png

Tl;dr: To get to some of the coldest 19th / early-mid 20th century means, we would need to forgo the entire summer and just leap from May into October.

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20 hours ago, TheClimateChanger said:

I will grant him that the temperatures from that era were inflated, but not because of asphalt or dirt. The HO-83 hygrothermometer was defective and produced spuriously warm temperatures.

It is kind of comical that an annual mean temperature that just 30-ish years ago was so astoundingly high that the NWS thought the thermometer was defective is routinely met or exceeded every single year. There's the 1990 & 1991 heat wave on there. While reported as tying the record, 1991 was actually 0.1F cooler than 1931. :clown:

image.png.beba7b885465d4c17920d74283e72e51.png

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Below is a chart splitting the Chester County PA Climate Period between almost down the middle since 1895. We have 64 years climate averages by month from 1895 thru 1959 with a comparison to the most recent average temperatures for the 63 year period from 1960 thru 2023. The top (Grey) includes all 27 Chester County stations (even those introduced with modest relative elevation increases). The next section (Yellow) shows the adjusted NOAA/NCEI Altered Adjusted Data. The bottom (green) only includes the 17 stations at a similar relatively lower elevation. Not surprising across all of the actual data there has been essentially no change in our average annual temperatures over the last 63 years vs. the prior 64 years. The only way we get any warming (+1.2 degrees) at all to appear is to apply the post observation adjustments to the data (as shown in the altered data in yellow). Of most interest overall Januaries have trended colder and Decembers warmer but all other months only show slight variations over the split climate periods of record.

image.png.9fad873026eb5557e0d2a1e2f04c893f.png

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7 hours ago, chubbs said:

Sea level rise was a record last year with a boost from el nino.

https://www.jpl.nasa.gov/news/nasa-analysis-sees-spike-in-2023-global-sea-level-due-to-el-nino

e1-PIA26183_sea_level_update_2023.width-1320.png

- There looks like an acceleration in the rise since 2011.

- The largest annual rises (based on peak to peak) have been associated with the four strongest El Niño years but also in 2012 (following a two year La Niña) and 1999. 1999 is hard to explain. 1999’s rise over 1998 was so large that it nearly rose back to the 1997 peak, which is weird since it was in the midst of a similar strong La Niña to the 1998 Niña!

- The biggest annual drops (based on peak to peak) were after the three strongest El Niño years. Thus, there’d be a nice drop for the 2024 peak vs 2023 peak assuming the pattern holds.

 Edit:

- Looking at the animation, the annual peaks have been mostly in Oct (22) although I see 4 in Sep. and 4 in Nov. Why are the peaks almost always in autumn?

- The one exception to the autumn peaks is 1998, which technically peaked on Jan 1st as it was slowly dropping from the big late Sep 1997 El Niño related peak. The 1998 autumn peak, which was in mid Sep, wasn’t able to quite reach the Jan 1st level. This can be clearly seen by slowing the animation way down. This slowdown can be done by pausing the animation and then manually controlling the animation via the bottom scroll bar.

- So, summary of the annual peaks:

  -22 in Oct

  -4 in Sep

  -4 in Nov.

  -1 in Jan

- There’s also a very minor secondary peak in most years within a month of March. Why? My hypothesis is that it is related to the typical  60N to 60S annual global ocean SST peak, which is in/near March as per the image at this link:

https://climate.copernicus.eu/july-2023-global-air-and-ocean-temperatures-reach-new-record-highs

- Based on peak to peak rises, 2015 looks like it was pretty close to 2023. Both peaks rose over 1 cm from their respective prior year peaks.

- This article attributes El Niño related rises to more rainfall over the oceans. But I would have thought it would be due to spikes of warmth during El Niño leading to ocean expansion. Any opinions about this?

 

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6 hours ago, GaWx said:

- There looks like an acceleration in the rise since 2011.

- The largest annual rises (based on peak to peak) have been associated with the four strongest El Niño years but also in 2012 (following a two year La Niña) and 1999. 1999 is hard to explain. 1999’s rise over 1998 was so large that it nearly rose back to the 1997 peak, which is weird since it was in the midst of a similar strong La Niña to the 1998 Niña!

- The biggest annual drops (based on peak to peak) were after the three strongest El Niño years. Thus, there’d be a nice drop for the 2024 peak vs 2023 peak assuming the pattern holds.

 Edit:

- Looking at the animation, the annual peaks have been mostly in Oct (22) although I see 4 in Sep. and 4 in Nov. Why are the peaks almost always in autumn?

- The one exception to the autumn peaks is 1998, which technically peaked on Jan 1st as it was slowly dropping from the big late Sep 1997 El Niño related peak. The 1998 autumn peak, which was in mid Sep, wasn’t able to quite reach the Jan 1st level. This can be clearly seen by slowing the animation way down. This slowdown can be done by pausing the animation and then manually controlling the animation via the bottom scroll bar.

- So, summary of the annual peaks:

  -22 in Oct

  -4 in Sep

  -4 in Nov.

  -1 in Jan

- There’s also a very minor secondary peak in most years within a month of March. Why? My hypothesis is that it is related to the typical  60N to 60S annual global ocean SST peak, which is in/near March as per the image at this link:

https://climate.copernicus.eu/july-2023-global-air-and-ocean-temperatures-reach-new-record-highs

- Based on peak to peak rises, 2015 looks like it was pretty close to 2023. Both peaks rose over 1 cm from their respective prior year peaks.

- This article attributes El Niño related rises to more rainfall over the oceans. But I would have thought it would be due to spikes of warmth during El Niño leading to ocean expansion. Any opinions about this?

 

NASA also gives shifting rainfall as the main enso sea level effect

https://sealevel.nasa.gov/faq/10/how-does-el-nino-fit-into-the-sea-level-rise-picture/

 

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As fossil fuels lose competitive advantage, investment is increasingly shifting from fossil fuels to clean energy. Our clean energy investment is growing but we are far behind China and Europe. Drill baby drill.

Investment.jpg

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With a high of 106° yesterday, Del Rio has now had its second extreme heat event (Clarke et al., 2014 methodology) of the year. For the first time, that city has had two extreme heat events in two consecutive years. All cases with two extreme heat events have occurred since 2000. Full-year records go back to 1906.

The list of extreme heat events is below. Years with two such events are highlighted in red.

image.png.87fd214b54b97ef01f7885416ba26742.png

Climate change has driven a warming of Del Rio's climate. Summers have warmed 2.1° from 1961-1990 84.3°) to 1991-2020 (86.4°).  During 1961-1990, the hottest summer (1980) had an average temperature of 87.4°. Since 2010, eight summers have been hotter, including the last six summers (2018-2023). The pre-2000 record of 88.6° from 1998 has been surpassed in five summers since 2010 and three of the last four summers. Put another way, what was once an extreme outlier summer is on track toward becoming a routine summer in the contemporary warmer climate.

This warming has led to a dramatic increase in the frequency of 100° and 105° days. The number of 100° days have increased from 21.0 days per year to 41.1 days per year (1961-1990 to 1991-2020). During the 1991-2020 period, 102° days (22.1 per year) were about as frequent as 100° days were during 1961-1990. During the same reference periods, the number of 105° days has risen from 1.4 days to 5.9 days per year. As summers have warmed and intense heat has grown more common, extreme heat events have increased in frequency. This year saw the two earliest such events on record.

Through June 7th, Del Rio has seen 23 100° days. It has also had 11 105° days.

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38 minutes ago, ChescoWx said:

Below is an analysis of 100 degree days by Decade. Not surprisingly about 50% of these extreme hot days all occurred between the 1930's through 1950's. We have noted a sharp decline in these type of extreme heat days across the County.

image.png.4ee417a93f5d5fefeb09a48227e0326e.png

# of highs of 100+/95+ in Savannah, GA:

1900s: 7/83

1910s: 7/108

1920s: 10/136

1930s: 18/178

1940s: 27/190

1950s: 24/221

1960s: 3/118

1970s: 10/112

1980s: 47/289

1990s: 26/228

2000s: 9/159

2010s: 26/293

AVG: 18/181

Largest#: 1980s/2010s

Smallest #: 1960s/1900s

(2020-3: 1/79)

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2 hours ago, GaWx said:

# of highs of 100+/95+ in Savannah, GA:

1900s: 7/83

1910s: 7/108

1920s: 10/136

1930s: 18/178

1940s: 27/190

1950s: 24/221

1960s: 3/118

1970s: 10/112

1980s: 47/289

1990s: 26/228

2000s: 9/159

2010s: 26/293

AVG: 18/181

Largest#: 1980s/2010s

Smallest #: 1960s/1900s

(2020-3: 1/79)

Thanks! looks very cyclical as our climate change always is and will be!!

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I was asked to also look at hot days >95 degrees over the same time frame. Plus I added in the average number per station as the number of stations have changed by decade with a dramatic increase in stations in the 2010's . Again the hottest decades were as we all know back in the 1930's thru 1950's.

image.png.3723239f0e8f61a0eddd8deeb5c8a311.png

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14 minutes ago, ChescoWx said:

I was asked to also look at hot days >95 degrees over the same time frame. Plus I added in the average number per station as the number of stations have changed by decade with a dramatic increase in stations in the 2010's . Again the hottest decades were as we all know back in the 1930's thru 1950's.

image.png.3723239f0e8f61a0eddd8deeb5c8a311.png

Chesco,

 Have you analyzed # of lows by decade at or above a certain high level, such as # aoa 75?

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