Aerosols, Dust, Saudi Arabia, Sunsets

Was it smog or dust? How to tell

OK, climbing down off soapbox today….just don’t read the Hockey Stick Illusion by A. W. Montford unless you want to be upset by some climate scientists pretending to be scientists when they are being something antithetical to science.  Reminds me of the 30-odd years of cloud seeding reanalysis experiences I had as a skeptic in that domain.  Oops, haven’t climbed completely down yet.  Montford should get a Pulitzer for this well documented tale, and his main protagonist, Steve McIntyre, the Rossby Medal or maybe a couple of Nobel Prizes for diligence.  Just about off “box” now….but this tale REALLY does remind me of the shenanigans that happened in cloud seeding to repeat myself again and again and again.

It got pretty hazy yesterday afternoon into the time of sunset.   This is what it looked like as the sun rotated away from the earth (hahahah).  Note the yellowish tinge of the sun.  Smog (urban, biomass smoke and hazes, are comprised of smaller aerosol particles, around a 0.01 to 0.1 microns in diameter, whereas dust particles, something that you find around the house everyday here in AZ (to quote Groucho Marx from his quiz program, “You Bet Your Life”) are generally much larger and can extend into sizes of  1-10 microns in diameter.    So, in interfering with the transmission of the incoming white sunlight, small aerosol particles in smog take out (scatter) the short wavelengths like the blueish ones) and only the longer wavelengths, the reddish ones,  giving the sun an orange or reddish hue.  Dust particles, because they are larger, and do not interfere with the short wavelengths of light coming from the as much produce a whitish yellow colored sun.   Below yesterday’s sunset is a smokey one from Cuiaba, Brazil,  during the burn season, a strawman to show a large, obvious difference.  It’s often more subtle than this, so you need to practice labeling sunsets for aerosol sizes.  Your neighbors will be impressed.

Since dust particles are larger than smoke particles, they don’t stay afloat as long as smoke particles do, though dust can still drift away from where it was generated before dissipating.  It depends on the nature of the surface dust.   In Saudi Arabia, dust was often observed without much wind due to the fine nature of the sand (see last photo from Qassim, SA–looks pretty much like pure dust whereas the Catalina sunset suggests dust with smoke due to its more orange coloring).

Factoid:   some Gobi Desert dust has impacted the West Coast of the US from time to time!

Clouds?  Well, if you looked, you saw a few low cloud shreds called Cumulus fractus (Cu fra) over the Catalinas yesterday afternoon.  Some rain fell as close as central AZ as a cold front blew by.  But only the cooler air got here.  Its 13 deg cooler here than it was yesterday at this time (4:30 AM LST), a sure sign of an air mass change and “fropa” (frontal passage).

Climate issues, Definitions, Soapbox

Weathering extremes: what goes around comes around

Some brutal storms over the past year or so, such as the recent one that dropped 1-2 feet of snow from Tulsa to Chicago and beyond with sometimes hurricane force winds, have been labeled with all sorts of monikers, “Frankenstorm”, “snowmageddon”, etc.,  to emphasize how bad, and perhaps, how unique they were.  Some incautious observers have assigned such events to signs of global warming.  Moreover,  there have been seemingly oxymoronic,  perhaps ad hoc statements due to recent record cold spells that purport that it will be getting colder as it gets warmer (that is, we’ll have more severe cold winters as global warming progresses).

The impact of global warming to date is “relatively” slight, and no one can discern that a particular flood, typhoon, tornado, drought, that cloud over there, etc.,  was due to global warming.

We meteorologists know that “what goes around comes around”; that the “50 year”, the “100 year” floods will recur.  Namely, we know that extreme events will occur without the need to implicate global warming.

Furthermore, proxy climate records, such as tree rings that are rather good at delineating past droughty and wet periods–they are problematic in reconstructing temperature–but,  you can get quite a good handle on the precipitation regimes of the past few hundred years.  These, too, can tell us about the extremes of past climate over hundreds of years, and therefore, what to expect in the future sans global warming effects.

Perhaps one of the most important papers published in this proxy climate domain in this writer’s opinion was in 1994.  It was a study of rainfall epochs deduced from tree rings in central California by Haston and Michaelsen, published in J. Climate.  It is fortunate that this study was published before the global warming “media blitz” in which otherwise reasonable people/media assign all kinds of anomalous weather events to signs of global warming.

What was the main conclusion of that J. Climate paper regarding rainfall regimes over the past 600 years in California???

It was astonishing.

The authors concluded that the California water retention and flood control infrastructure had been built based on an unusually low degree of climate variability during the instrumental record, largely confined to the period after 1900.  The longer tree ring record, however,  CLEARLY indicated that much LARGER fluctuations in the rainfall regimes of California had occurred prior to the instrumental record.   These findings led the authors to suggest that California was not likely to be well prepared for the floods and droughts of the future since it can be assumed that larger variability in rainfall found in the past will occur in the future.

The record rains of the 1997-98 El Nino and 2004-2005 rainfall seasons accompanied by an almost unheard of water flows into the basins of Death Valley in 2005,and  the “unprecedented” drought of the 2001-2002 rainfall season in which some coastal southern California sites received less than 2 inches (!) were largely foretold by those 1994 findings.   Moreover, due to the “teleconnection” aspect, the larger climate variance found in central California prior to record keeping can be expected to have repercussions in the adjacent states.

What “goes around”, has already begun to come around.

But in today’s world, these anomalous weatther events will not be seen as just,  “what goes around comes around”, but rather will be labeled en toto as evidence of the pernicious effects of global warming.

That’s just plain wrong, and most meteorologists understand this.

The extreme events of late, if you are onboard the GW bandwagon, could reasonably have been said to have been “tweaked” by GW at best.  Perhaps without GW, that snowstorm in Chicago would have dropped “only” 18.3 inches instead of 20  associated with overall slightly higher temperatures and the attendant enhanced moisture content.

The late Prof. Joanne Simpson, former president of the American Meteorological Society, warned, in the early days of global warming claims in 1989,  claims that many scientists were dubious of at that time, about the dangers of exaggeration.  She recounted her experiences with the exaggerated claims promulgated in the cloud seeding domain in which she worked.   In her talk at the Conference on Statistics and Probabilty in the Atmosphere, Monterrey, 1989, and as President-elect of the American Meteorological Society, Dr. Simpson warned:

“Lacking that lesson, our community has once again stumbled into the weather modification paradox concerning global warming-where again we may be damaging our credibility again for the same basic reason.

“What is the weather modification paradox?  It is the tendency to exaggerate man-made alterations to the atmosphere owing to the great difficulty in distinguishing definitively between natural variability in the system and anthropogenic effects-whether the perceived man-made change is small-scale rain produced produced by intentional cloud seeding or whether in it long-range global warming as a by-product of industry and agriculture.”

and, near the end of her talk that day, she re-emphasized this point:

“While it is not entirely clear what the decision makers of the world can and should do, I hope at least that we meteorologists have learned some hard lessons.  I hope that we have learned enough from the harm that we and our colleagues have caused over the years by exaggerated claims and exaggerated scare stories.  I hope that we will be more cautious in how we express ourselves, especially to the media–that is a difficult challenge to say the least.”

Joanne Simpson was not too skeptical about a global warming future, but she was concerned about how we spoke to the public about it.

Amen.

PS:  Prof. Simpson’s full address, which she provided to me soon after it was delivered, can be found here:  all of Joanne Simpson’s banquet talk wx mod and GW_1989.

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BTW, and unexpectedly, global temperatures have stabilized over the past 10 years or so in spite of continuing increases in CO2, as many of you knowWhat happened to GW_Sci_Oct 2, 2009.  One explanation posited for this is a drying of the stratosphere, something that would allow more of the earth’s heat to escape into space–Solomon et al. 2010,  Science). Another explanation for at least part of this “stabilization” arises from an climate model using recent ocean current data.  The output from this model predicted that cooling of the northern hemisphere continents was due to a recent slowing of Atlantic Ocean currents, and furthermore, that this slowing and continental cool spell was likely to last 10-20 more years (Keenleyside et al. 2008 in the journal Nature, summarized by Richard Kerr in Science).  Finally, we have an aerosol “wild card” out there. Aerosols are thought to have the net effect of lowering global temperatures, but the models used by the IPCC4 were only able to crudely parameterize those effects.  One down-sized climate model (20-25 km grid spacing instead of 200-250 km), in preliminary runs has suggested a larger role for aerosols in cooling the planet, a kind of inadvertent “geoengineering.” (These latter results have not been published that I know of, and so this comment can only be considered little more than gossip at this time, but it was from a good “insider” source.)

However, imagine how pathetic such a smoggier world would be, with smog everywhere, views of the Grand Canyon mucked up, even thin, smog-laden stratocu looking dark and ugly on the bottom as as more light was reflected back into space from their tops due to smaller drops, etc.   Getting upset here even thinking about how awful that smoggier, less warm, world would be!  Don’t “geoengineer” in this way!!!

 

Cumulus clouds, Definitions, Ice crystals, Record cold day

24 h of temperature infamy, Catalina, AZ

What an awful past 24 h here in “Catland”!  We’ve not only had low, perhaps, unprecedented low temperatures for a day with full sun, but also a noxious 15-30 mph north wind.  (Why didn’t we retire to Kauai where we would never be this cold????!!!  Just kidding, sort of.)

In some quarters(such as in a recent commentary by Al Gore),  it has been reported that we should expect colder winters as it gets warmer due to global warming (I am not kidding here-check the last paragraph here).

If this is the case, and our current godawful cold spell here in AZ has been enhanced by GW, then we had better reconsider where we grow citrus crops!  South Florida just had a record cold December.  Perhaps Florida is too far north for citrus crops as global warming proceeds and winters get colder, or at least cold spells more severe.  California, Arizona, are you listening?

Now, for a diatribe on clouds, about which Mr. Cloud-Maven person, me, is an expert (he sez).

If you saw the few small clouds we had yesterday, you saw something extraordinary for SE AZ.  Why?  Because of all the ice crystals that formed in such tiny clouds (ones called, cumulus fractus).

Below is a photo of cumulus fractus clouds forming lots of ice from yesterday afternoon.  The top most cloud is a pure cumulus fractus cloud, not yet showing ice.  But beyond that cloud, farther to the east, are similar clouds spewing forth a large plume of ice crystals, seen as the wispy, semi-transparent cloud downwind toward the right half of this photo.   Cu fra forming ice are common in the high elevation areas of the Rockies, but not here because our lower clouds that are small are almost never as cold as those, even in the wintertime.  Our clouds, according to the NWS sounding launched from Tucson around 5 PM LST yesterday were about -25 C, an extraordinarily low temperature for clouds not having any depth to speak of.   And, due to that low temperature, voila, ice forms!

So, a good eye with a little knowledge about ice formation could have guessed that these little clouds would have to be colder than about -20 C to have been so prolific in ice production, those veils seen downwind of them.  Ice forming in such shallow clouds are too small to fall out as precip as a rule, though some “virga” or flurries were observed here and there in SE AZ, such as at Stafford yesterday afternooon and west of Wilcox as well.  (Of course, I had hoped a couple of days ago that we here in Catalina would see a flurry.  Still, with flurries at Stafford, it was a damn close call, astronomically speaking, so I don’t feel that bad for getting a little too excited about the possibility of snow here a couple of days ago.  Besides, it was a “learning experience” as well….)

Amaze your friends with such trivia!!!

However, it will be a long time before you see such clouds, as low and small as these were, produce ice like this.  Well, we hope so anyway, or we are moving to Costa Rica where I will not have to experience even one second of being too cold!  If you want a really good look at what they were doing, go to the U of A’s timelapse for yesterday (here).  (Forgot to point this out until now…darn.)

Graupel, Hail, Sunsets, The weather ahead

All’s well that ends well

What a nice day yesterday was, ending with this fabulous, but run-of-the mill sunsets we get to see here in the Catalina area on a regular basis.  Yesterday was interesting because we had two graupel (soft hail) showers, the first about noon, and the second with a blast of thunder (1) at 1605 PM.   If you weren’t lucky enough to get any, measure it and report it to the National Bureau of Standards, or the NWS, here’s what it looked like on our old chaise lounge a  couple of minutes after it fell (see below).  Some of it was “conical graupel”, pointed on one side, though that is not visible here.  Graupel, soft hail form when there aren’t many ice crystals in the cloud and the cloud is chock full of droplets at below freezing temperatures.  Those droplets freeze instantly onto the ice crystal as it makes it way down to the ground, eventually losing all of its identity as it become a little snowball.  Usually, where this happens in the cloud is in a very limited region, and, it usually doesn’t last for a long time.  So, consider yourself especially “lucky” to see graupel/soft hail, hail.  I do.  If you want to relive yesterday’s clouds, as seen from the U of A, go here.   “Above Catalina” is at the left, beyond Pusch Ridge.

What’s exciting now is that something akin to an atmospheric iceberg is barreling down on us (SE AZ) from the north.  This “cold low” center, representing a column of extraordinarily cold air in this case, goes from the ground all the way up through the “troposphere.”  IN this case, the troposphere is squashed down to less than 20,000 feet over Wy0ming right now. The stratosphere is above that, and above “cold lows”,  the stratosphere dips down over them.  Usually its twice that height at our latitude.

Here’s what I am talking about, shown in this morning’s 500 millibar pressure map (about 18,000 feet above the ground) or usually half way up through the troposphere (map courtesy San Francisco State U.)  The winds flow along the green lines, ones that bend gently toward the west over the Great Basin.  That bend in the wind represents an area where a small low center amid this giant river of wind will form in the next 24 h and that little center of circulation should pass right over us!

Now, not a single model output that I saw from last night’s runs had enough moisture in this forming upper center to have snow even fall on Mt. Sara Lemmon (e.g., the U of AZ regional model from last night).

A few days ago, the Canadian model was suggesting a signficant storm here from this center. I really believe it.   Well, that’s “bye-bye” since the center is not well to the west of us as that Enviro Can model indicated it would be, but rather will end up right over us (which means much drier).    The U of WA model run from this morning’s data says that a little “L” will be right over my house on Thursday morning (see reddish map below) !  Man, it will be cold over me!    Might lose some plants in this one before its over.

However, I am going to stick my neck out and expect (hope) there will be just enough moisture for flurries around here (Catalina area) anyway tomorrow into tomorrow evening.

BTW, the U of A has just issued a special weather discussion here.  You’ll want to check this out!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Definitions, The weather ahead

Snowball Earth? Well, maybe a Snowball Tucson on the doorstep!

The computer models are diverging significantly on the “tail of the scorpion” on this incoming front and the two troughs that pass over us in the next few days.  First, a Pacific front blows through on Monday with its upper air accompaniment racing to the northeast.  But then this monumentally strong wave disturbance barges in from Canada over the Rockies and actually deploys toward the SSW while intensifying and curling into an upper center, this center trailed by a gigantic mass of cold air that oozes over most of the US.  High pressure levels in the cold air,  1060-1065 millibars initially, may set some records here and there in the northern Rockies.

The “best/worst” full display of this predicted sequence is here from our friends at Environment Canada, and the output from last night, of which one panel is shown below.

This panel at left, from that Canadian model run, is the most exciting panel of future weather I have seen this winter!

Now, if you’re a bit jingoistic about models and want to know about our US model results for this situation, I have to tell you, sadly,  that they do not have this “good” a configuration over the SW as far as precip goes.

There is no upper vortex, Virginia, over western AZ in the US models, as in shown in the upper left panel here.

And that makes all the difference in whether AZ will get much precip out of this second of a two part event. In the US models, such an upper low does not form over AZ but rather just a bitterly cold slug of air, mainly dry, intrudes on us and that second strong upper trough just trucks on by.

So, its a dicey situation, but, because my dad was Canadian (from Winnipeg) and I really want to see some precipitation here after a rainless January, I am going to say that this Canadian model is the correct one, jingoism aside.

Furthermore, in order to have precipitation, which I believe will be rain changing to SNOW here at about 3200 feet on Wednesday, there will first have to be clouds (silly, haha), the latter my specialty at the University of Washington.

I love clouds and the way they present themselves in this gorgeous Sonoran Desert environment that we are so lucky to live in.  So, there oughta be some interesting clouds beginning today as the cirrus zipping on by begin to announce this monumental change from our mundane, but glorious weather of late.  And, of course with that fast moving river of air called the jet stream settles over us, there’ll be some windy periods, too.

The worst part of this scenario is the bitter cold that will likely get here after this mammoth upper low center goes by, and if the US models are correct, it will only get here that bit sooner.

Below, this morning’s cirrus, full of portent, over Mt. Sara Lemmon.

 

 

 

 

 

 

 

 

 

 




Climate issues, Cloud seeding, Definitions, Science stories, Soapbox

Montford’s The Hockey Stick Illusion, p269: climate change meets cloud seeding

“McIntyre’s first step in trying to replicate a paper was to collate the data.   While data might be cited correctly and accurately in the papers, it was always possible that what had been used was different in some way to the official versions, whether due to an error in the archive or one made by the authors.”

Almost at every turn in this monumental exposé by A. W. Montford, I see parallels in the many cloud seeding reanalyses I did at the University of Washington with Peter Hobbs.  The two sentences quoted above from Montford’s book, so fundamental a step in checking results, literally leapt off the page since that is exactly where the most basic replication starts, and where we always began in our cloud seeding (CS) reanalyses.

In our re-evaluation of perhaps the most important randomized wintertime cloud seeding experiments ever conducted, those at Climax, Colorado, 1961-1970, we started with the raw data that the experimenters said they had used.  This was precipitation measurements at the cloud seeding target gage that were taken by an independent organization and archived by NOAA, thus making it publicly available.  The experimenters high lighted this independence in their publications.

But when those values from NOAA were used in the re-evaluation of those Climax experiments, discrepancies were found, just as Montford reports that Steve McIntyre found so often in his proxy raw data examinations.   In our case, the seeded days generally had more snow in the experimenters’ data at the NOAA target gage, and control days less than was actually the case according to the NOAA data.   Furthermore,  these discrepancies were only observed in the second “confirmatory” experiment (1966-1970) on the days that were supposed to respond the most to seeding.  In our re-evaluation of the second experiment (aka, Climax II) the use of the NOAA precipitation values, along with other data corrections,  degraded the results so badly that they did not confirm the first five season experiment after all.   The experimenters had previously reported that Climax II had been a confirmation of the first (aka, Climax I) experiment.

As one might imagine, the initial reports of a the “confirmation” of the earlier “exploratory” CS experiment gave those two experiments together a great deal of caché as strong evidence that snow could be increased on a determinant basis through wintertime cloud seeding.   And they were cited as having done so by the prestigious National Academy of Sciences Panel on Climate and Weather Modification in 1974.    (As an interesting aside, the NAS Panel was also concerned at that time about the “…recent equatorward shift in ice boundaries.”)

Further work “de-constructing” those experiments at Climax, that is, the discovery of more discrepancies, can be found here.

Eventually the experimenters acknowledged the source of their errors in precipitation at the target gage in a journal exchange in 1995.

Epilogue

However, unlike the situation that McIntyre repeatedly encounters in Montford’s HSI account, where climate researchers refuse to honor requests for raw data, in our re-analysis of cloud seeding experiments in Colorado, the experimenters at Colorado State University were totally cooperative in supplying data that was occasionally requested by the present writer.  They did this even though they KNEW that the requestor was a critic/skeptic, might challenge their earlier results.  To their great credit, the ideals of science were given a higher priority than their egos by those at CSU and that finding problems and discrepancies were recognized as a way of advancing science, not hindering it.

 

 

Climate issues, Definitions, Science stories, Soapbox

The FAA and the Ideals of Science


 


Today, its not unusual to see researchers publishing seemingly important findings in journals accompanied by a global news release at the time the article appears.  At this point, such research has perhaps been reviewed prior to journal publication by only several individuals.

However, it has become fairly common for researchers asscociated with globally impactful findings to withhold methodologies that led to them.   The natural result, particularly in the climate change domain, is a firestorm since critics in that research domain are SURE that there are misdeeds or errors due to “confirmation bias.”

An example in point is the important “Hockey Stick” paper by Mann et al. 1998 (Nature), one that was to have tremendous influence before it could be checked by outsiders on how exactly it came about.  This paper showed a sharp rise in global temperatures during the past 30-40 years, one commensurate with the thought that rising CO2 concentrations were already having a noticeable effect on global temperatures.   Eventually, a number of errors were found in this paper, and the Hockey Stick, as presented, was thrown in doubt.  It should be kept in mind, however, that just because the original paper was flawed, that there is not going to be such a rise–the author tends to agree with this proposition that global temperatures will gradually rise in the future.

This long, tortured chapter involving the “Hockey Stick” should not have happened.   It was clearly due to the original researchers believing that their results were too important for others to learn how they got them.   Sadly, in this writer’s opinion, it is a position of the National Science Foundation well that researchers can hide their methodologies and the exact data they used under a “proprietary” umbrella.  A scientific horror story in concerning the Hockey Stick has been laid out in detail by A. W. Montford, in “The Hockey Stick Illusion”, a book I highly recommend.

Withholding methodologies and data suggests that something is wrong with the outcome of the research, and, furthermore, is anti-science.  Imagine, a lab announces that it has cured cancer, but can’t tell us exactly how they did it, and so no one can replicate their results!  In the domain of medicine, this would be a ludicrous, surreal example; it wouldn’t happen.  It should not happen in the important climate change domain,  either.

On the other hand, the view that opening the door to skeptics of your work can lead to a lessening of conflict in research domains, and even more likely,  an improvement in the robustness of the orignal work, is one that is shared by numerous scientists.

Who among us as science workers, is so arrogant that we think our work cannot be improved upon?

While we depend on peer-review to catch errors, it has been this writer’s experience that hundreds of pages of peer-reviewed literature in the domain of cloud seeding research can reach the journals and stand untouched, uncritiqued for years at a time.   This is because peer-review in conflictive environments can easily fail with soft reviews by advocates of the conclusions being reached in a manuscript.  No scientist reading this doubts this.

The Federal Aviation Administration is fully aware of the hazards of “soft reviews”.  The attached statement at left concerning work on the writer’s former research aircraft at the University of Washington might well be a metaphor for our science environment.   “….there will be a paper trail.”   “…there will be an inspection by someone other than the person doing the work.”

We all know that these kinds of rules established by the FAA is to protect us from plane crashes.   But imagine, that there is no “paper trail”, no documentation of what’s in and what’s off the aircraft!  That’s how we get journal “plane crashes.”

It is the same with journal articles on scientific results.  How our results were arrived at is mandatory for purposes of replication, of which the first, most basic step is to use exactly the methodologies and data that the original researcher (s) claimed they used and see if you get the same result.

 

 

Altostratus clouds, Cirrus clouds, Definitions, Sunsets

“‘Altostratus'” at 30,000?”

I’m glad you asked that question.  Has to do with rules, cloud rules.   It is true that at that altitude above the ground, 30,000 to 40,000 feet, we mostly think of cirrus or “cirriform” clouds.  But those clouds, by our cloud definitions, cannot have shading during the daytime with ONE exception, Cirrus spissatus, a thick, but PATCHY ice cloud. Cirrus clouds CAN have shading when the sun is low in the sky, say, near sunset and sunrise.  Widespread sheets of gray during the daytime, as we saw over Catalina two days ago,  cannot, therefore, be called “Cirrus” unless you want to seem quite ill-informed about clouds.  Below is an example of just plain Cirrus clouds, ones that floated overhead at about 100 mph (!) yesterday.   In the first photo below, you would not be wrong, however, by referring to that thicker patch in the center as “Cirrus spissatus”, or more colloquially, “Cis spis.”

An example of “conversational meteorology” concerning Cirrus:  you and your friend are horseback riding  (as I do twice a week, really!)  and you see this scene.   The correct thing to say to your friend (in this case, “Nora”, who, interestingly,  is not my wife)  is;  “Looks like we got us some Cis spis today.  Maybe we’ll have one o’ them great sunsets again tonight.”

Well, that’s the way I would say it, anyway.  And we DID have one of those GREAT sunsets last evening that make living here in Arizona so special.  Below are a coupla shots of “Cis spis” at sunset yesterday.   (There are some other varieties of Cirrus in these shots, but I won’t bore you with a list.)  ((BTW, as an aside, a footnote, I’ve learned as a novice rider here in Catalina, that an awful lot of the guys don’t ride but their spouses do.   One husband told me, “I don’t get on anything that doesn’t have a motor.”))


Altostratus clouds, Definitions, Ice crystals, Stratus clouds

Altostratus: a misunderstood cloud and for good reason

Yesterday afternoon the clouds thickened and dimmed the sun, and our high temperature struggled only into the mid-50s.  What cloud was that?  Here it is, with Twin Peaks on the horizon.

Our names for clouds, originating with English pharmacist, Luke Howard, are based on visual attributes from the ground.  Here, “Altostratus”  (As) does RESEMBLE its lower namesake cloud, Stratus, a low fog-like cloud with little definition often found in summer along the West Coast.  See a rare example of Stratus (St) hereabouts below.  Note that it is topping the Tortolita Mountains to the west, it is that low.

However, about the only thing that these clouds have in common is that they are both relatively smooth looking clouds.  Inside them, they are totally different. Also, St is a shallow cloud usually less than 1 km (3,000 feet) in depth, while As is normally 2-3 km  6,000 to 10,000 feet) in depth.  In Stratus, you just have cloud drops and maybe, as below, a few drizzle drops (mist-like)  falling out.  OK, once in awhile in cold locales you have a few ice crystals falling out, but drops rule!  On the other hand, in Altostratus, if you were flying in them with a 1998 version of the Stratton Park Engineering Company’s Cloud Particle Imager ($130,000 or so–I’ve added a link in case some of you want to go shopping now),  you would find nothing but ice crystals for the most part.  Water droplet clouds are sometimes found in them, and, oddly, if the top is not too cold (warmer than about -30 C), at cloud top, the coldest place!  So, it is not unusual to see, even in journals, a thin layer cloud consisting of drops called, As.  Makes sense really.   (A name change of As to “Altonimbostratus” would be helpful to emphasize its internal ice and falling snow particles.)

An example of the kinds of crystals found in a As clouds is shown below, collected over Barrow, AK, in a 1998 project called FIRE/ACE/SHEBA.

These typical crystals, having grown on the way down from simple plates or tiny columns, or sphere-like  “germs”, are called “bulett rosettes.”


Aircraft Produced Ice Particles, Altocumulus clouds, Cirrocumulus clouds, Cloud seeding, Contrails, Definitions, Science stories

What’s Up with This?

Got pretty mad yesterday when I saw this overhead in some Altocumulus perlucidus clouds.  You’ll have to hold your monitor or Ipad, or cell phone, or whatever, over your head to see it EXACTLY the way I saw this because it WAS overhead;  straight up.  (Actually, doing 3 sets of 12 might be good for you.)  Also, click on images to get the full view.

As you can see, the white strip below in these clouds is a contrail caused by an aircraft, but a special one that occurs in “supercooled” clouds.   Supercooled clouds are clouds that are composed of drops, yep, they’re still liquid, even though the temperature is FAR below freezing.  Here, the clouds were likely colder than -20 C (-4 F) and yet there is no ice forming in them!  (You don’t see trails of snow coming out, do you?  No.)  Run of the mill contrails occur at cirrus levels at temperatures below about -35 C  (-31 F).

Note that except for being much whiter than the surrounding cloud, the elements are exactly the same size and texture as those around it.  That is going to change, because this white strip is composed of “horrendous” concentrations (probably thousands per liter) of ice!   You can only know this by what happens later.

In the next shot below, is an example of what happens later, trails of tiny snow crystals fall out leaving a hole in the droplet cloud, so called, “hole punch” clouds, a form of inadvertent cloud seeding by aircraft.  Note the delicate strands of ice crystals falling out of this cloud from the hole, so pretty because they are so delicate looking.  Note, too, I am one of the “trailing authors” of the journal article above, like one of those itty bitty ice crystals in the second photo which are almost evaporated at the bottom of those fine strands.

So why be upset?

Rather than looking forward to good things in the coming year, this happenstance yesterday reminded me of all the trouble we had in the early 1980s trying to get our paper published on this phenomenon; namely, that an aircraft could produce tremendous amounts of ice when flying through supercooled clouds, inadvertently seeding them.

In the SECOND rejection of our manuscript (with Pete Hobbs), the Editors words still burn; “(the reviewers) are still unconvinced by these controversial claims.”

We had to do a LOT of extra work on this to convince those reviewers.  The third version was more convincing, I guess, for intransigent reviewers, and got published.  In fact, one of the great scientists of our time as far as clouds and ice crystals go, John Hallett (yes, the same one as in the “Hallett-Mossop” ice splintering process),  speaking at the Peter Hobbs Symposium Day in 2008 called this episode, “an embarrassment for the airborne research community.”  “Hey”, he wasn’t referring to our paper!

He was referring to the fact that such a phenemenon had been overlooked and not accounted for in research studies of clouds by aircraft.  Actually ground observers had been reporting this kind of thing (ice canals and hole punch clouds) since, if you can believe it, the 1930s!

BTW, this hole is not the one from the first shot; I got distracted and forgot to follow it until it was disappearing over the horizon.

BTW#2,, this shows what happens when you introduce ice into a supercooled cloud; “stuff” falls out.  Proves cloud seeding works, though for sure in limited venues like these (non-precipitating, supercooled clouds).

BTW#3:  The second photo is a nice example of the difference between supercooled clouds composed of tiny drops (probably less than 20 microns in diameter), and cirrus-ee ice clouds, composed of much larger crystals (here probably 100 or 300 or so microns in maximum size) that tend to settle with time. (Hence, those strands in most cirrus clouds.

BTW#4:  Today’s title is cribbed off the world’s most viewed climate website, “What’s Up With That?”  Mr. Watts, host of the site, has made significant contributions to our climate network by pointing out flaws, but has no “credentials” beyond having been a TEEVEE meteorologist.  He is excoriated on this point alone by “credentialists”, as I myself was when I first began to reanalyze other folks’ cloud seeding experiments such as this one.

BTW#5, a movie about credentialism is now out, called,  “The King’s Speech.”  I highly recommend it.   In this documentary, which I just saw yesterday, it will be seen that the credentialists in the King’s Court were royally put out by the help the King got by his uncredentialed therapist.