Finding Deformation Zones

#2570 "Cirrus Sunset from the Bottom of the Atmospheric Ocean"
October 2021, 11x14

If you want to find deformation zones, it really helps if you know where to look!  It is best to start with the entire globe and gaze down from space - the satellite view of the atmosphere. 

The world has changed much since I became a meteorologist in 1976. Atmospheric scientists were well aware of the impacts of fossil fuels consumption on the atmosphere as early as 1824.  I wrote about the history of climate change science in "True Confessions from Singleton Philly". I updated the current state of climate change, where we are headed and why in "The Weather Makers by Tim Flannery - Become Informed and Involved in a Good Way" and "The Weather Makers  - What has happened in Fifteen Years?". Mankind is rewriting climate which is the average weather, with each passing year. To witness these impacts in a single lifetime is unthinkable. Deformation zones are just another indication that this is true. 

All of the deformation zone flavours are on the increase with climate change. The poles are warming up much faster than the equator as the snow and ice melts to expose darker, less reflective surfaces. These low albedo surfaces absorb the sun's energy and in turn, warms the atmosphere. The temperature difference between the equator and the poles drive the jet stream. As a result, the jet stream is transforming more into a meandering trickle than a fast flowing river of high speed air. The ox bow patterns of the weakening jet stream are the perfect place to create swirls and deformation zones.

Historical Jet Stream Left - Weaker Jet Today Right

The distribution of the mountain ranges and oceans of the earth also play important roles in deviating the atmospheric currents. As a result the preferred number of waves around the globe is seven. That means that seven troughs of low pressure are separated by seven ridges of high pressure along a line of mid-latitude encircling the globe. You can safely expect a predominance of cyclonic swirls in those troughs and anticyclonic swirls in the ridges. Your extended Coriolis Hand with its fingers pointing with the flow, will convince you that this is true. 

Where to Find the Different Flavours of Swirls

Where do cyclonic swirls dominate? Cyclonic swirls can be found in upper troughs of low pressure in the atmosphere. The trough is the red area in the above graphic. 

Where do anticyclonic swirls dominate? Anticyclonic swirls can be found in upper ridges of high pressure in the atmosphere. The ridge is the blue area in the above graphic. 

Double Cyclonic Deformation Zone -
Big X added to another Big X

A deformation zone that is wholly within a trough will look like a backward s – a double cyclonic DZ. Such a deformation zone is typically generated by a flow that is associated with ascending warm air moving toward the north. I wrote about that process in "Cloud Edge Shapes - The "Backward S" Deformation Zone" and also "Warming Winds and Deformation Zones". The beauty of a conceptual model is that having worked through the theory a few times, you can appreciate what a pattern means by simple observation. You do not need to reinvent the conceptual model every day. If you witness a line in the sky that is a double cyclonic DZ, then you are in a trough of low pressure with warming weather. 

Double Anticyclonic Deformation Zone -
Big N added to another Big N

A deformation zone that is wholly within a ridge will look like an s – a double anticyclonic DZ. Such a deformation zone is generated by a flow that is associated with descending, cold air moving toward the south. 

Winds that veer (turn clockwise) with height and/or time will generate a double cyclonic DZ. Similarly winds that back (turn counter-clockwise) with height and/or time will generate a double anticyclonic DZ. 

A larger deformation zone that spans a trough into a ridge with a bowed shaped pattern pointing northward (and rising) is characteristic of a large warm conveyor belt and a storm. Similarly a deformation zone that spans a ridge into a downstream trough with a bowed shaped pattern pointing southward (and sinking) is characteristic of a large cold outbreak following in the wake of a storm.  

Bowed Deformation Zone -
Big X added to a Big N

The best place to view these deformation zone is certainly water vapour satellite imagery. Typically, one can only few a small segment of a deformation zone from the ground. From space, one can see the entire conceptual model at work.

Jim Day Rapids Double Anticyclonic DZ

For those who are interested, the same patterns can be seen not only in duckweed, but also in oatmeal and your coffee cup if you use cream. In fact, every fluid can be investigated and better understood by applying these conceptual models. 

Coffee and Cream Swirls and Deformation Zones

The shape of the lines in the sky tell the story of the weather. The vocabulary of these tales has been developed in the past few Blogs. It took me many Night Shifts when the weather was quiet (which was not often), to piece all of this together. Some of this material can be found in various Modules on the COMET Website. The rest is being presented here for the first time although this material was certainly the content of many fireside chats in the Weather Centre when the team was determining what the concern of the day would be and where the resources would be most wisely allocated. 

This content has been a bit more meteorological and scientific that I had intended but it illustrates just how much information can be gleaned from those lines in the sky. I will return to more art than science in the next Blog. 

Keep you paddle in the water and warmest regards... 

Phil the Forecaster Chadwick

Deformation Zone Flavours

#1828 "Just Another November Sunset"

What can the shape of the deformation zone reveal? How are these different shapes created? Deformation zones come in three flavours and they are all very different but all equally tasty. 

It is helpful to examine each confluent asymptote separately. If the confluent asymptote is curved cyclonically, the vorticity maximum or cyclonic swirl is the stronger of the paired swirls on either side of that confluent asymptote. 

Cyclonic Asymptote - The Red X Swirl Stronger 
in the Paired Swirls across the Asymptote
Let's Call this Asymptote Pattern "Big X"

If the confluent asymptote is curved anticyclonically, the vorticity minimum or anticyclonic swirl must be the stronger of the paired swirls on either side of that confluent asymptote. It is really that simple but it was a challenge to explain this stuff back in the nineties. 

Anticyclonic Asymptote - The Blue N Swirl Stronger
in the Paired Swirls across the Asymptote
Let's Call this Asymptote Pattern "Big N"

Now let's put a  "Big X" Asymptote Pattern together with a "Big N". Aside from my clumsy graphics, this pattern is the same as the paddle swirl in the duck weed from Sunrise or Sunset - Gravity Waves and the Deformation Zone. This deformation zone pattern is typically called a "bow" as in "bow and arrow".  

"Big X" Asymptote Pattern together with a "Big N"
The Bowed Deformation Zone

Now let's put a  "Big X" Asymptote Pattern together with another  "Big X".

"Big X" Asymptote Pattern together with another  "Big X"
The Double Cyclonic DZ

Now let's put a   "Big N" Asymptote Pattern together with another   "Big N". You guessed it already! This isn't so hard... 

"Big N" Asymptote Pattern together with another  "Big N"
The Double Anticyclonic DZ

One more thing, the Coriolis force that helps to create the swirls, is strongest at the poles and zero at the equator. You can easily prove this to yourself. 

Imagine yourself standing at the equator with your arms outstretched - one arm pointing north and the other pointing south. In a full day of earth’s rotation, you will experience no rotation at all. 

Now do the same thing at say the North Pole. You will note that both of your outstretched arms must point south. You will rotate with the full measure of the Earth’s rotation. It is certainly no coincidence that when you direct the fingers of your Coriolis Hand in the direction of the Earth's rotation while at either the South or North Pole, that your Coriolis Thumb points upward. Nature always makes sense if we take the time to understand. 

The swirls that shape the confluent asymptotes are much stronger at higher latitudes than they are at the equator as a result of the Coriolis force. The shapes of those swirls reveal much about the weather but we will save that for the next day. It is enough to taste the three different favours of the deformation zone conceptual model in one sitting. This might explain why I really enjoy the weather and meteorology of the high latitudes. The cloud and moisture patterns are full of stories just waiting to be read. 

Keep you paddle in the water and warmest regards... 

Phil the Forecaster Chadwick

Applied Conceptual Models on the Space and the Earth Views

#2361 "Singleton Sunset Swirl" 
with Conceptual Models Applied
as viewed from the Earth Vantage

The last several Blogs laid the foundation for this next step - practical practice. We are about to apply the conveyor belt and deformation zone conceptual models to an actual weather situation and painting - from the satellite, atmosphere and earth frames of reference. The features are all the same from the three different vantages – and we can learn about the weather. Stay with me… you can do this. 

In “The Swirls and Deformation Zone Revisited”  I concentrated on the view from space. I thought the explanation of the cloud features would be easier from a single satellite perspective. Let’s revisit those cloud features but this time from the ground up as well. After all, we do our paddling and cloud gazing from the earth’s surface. 

Top Down Space View - Images Oriented North Up

The Water Vapour and Visible Satellite Imagery for this painting are all that you really need. The Water Vapour Imagery senses the high level moisture and depicts the leading edge deformation zone that is followed by the cirrostratus (CS). The thinnest CS is essentially invisible in the Visible Imagery while the thicker and more opaque altocumulus (AC), is well depicted. All of these images have north pointing upward on the page. 

In the following graphic, I have turned the imagery so that it closely fits the earth view that I enjoyed while doing the painting. North is pointing to the right on the page. 

Across the top of the graphic, I have again included the Water Vapour image from satellite, followed by the view looking downward at duckweed from my kayak which is followed by the conveyor belt and deformation zone conceptual models. The view as identified on the water vapour imagery is toward the southwest and Lake Ontario. The dynamic features identified are the same in every image, including my painting which was my interpretation of the same sunset sky on May 22nd, 2020. If you faithfully paint what you observe, the physics, mathematics and meteorology must be true and accurate. Nature always tells the truth... 

Top Down Space View Application of the
Conceptual Models at  the Top of the Graphic
Superimposed on the Earth View Painting

From the space view one can only see the tops of the cloud. The earth bound view allows one to see the bottom structure of the cloud. Both views are complementary in that they provide unique information about the features that might not be apparent in the other displays. The more facts that fit together like pieces in a puzzle, the more confidence we can place in our solution of the weather riddle. 

The highest level of the warm conveyor belt leading the spring storm, has already passed east of Singleton. The sky above is not the deep blue of clear skies but is blanketed by thin cirrostratus that follows behind that highest level deformation zone. 

The swells in the mid level altocumulus layer of moisture of the warm conveyor belt are not easily discernible from the satellite view. The details of the mid level cloud are masked by the highest layer of increasingly thick cirrostratus. Those swells are readily apparent from the earth bound view! Recall that atmospheric swells, like those in the ocean, are large amplitude and long wavelength gravity waves located far from the strong winds that originated them. Atmospheric swells are very common on the jet stream side of the deformation zone. Swells propagate right to the deformation zone largely unaffected by the divergence of the atmospheric frame relative winds at the col.

Atmospheric Gravity Waves
Swells and Wind Waves

I even observed and painted the gravity waves created by the wind swirling behind the mid level deformation zone. One can only expect these wind waves where there is sufficient atmospheric frame winds blowing – ie some distance away from the col. You will not witness significant atmospheric frame of reference winds near the col which is where the winds diverge from. Winds increase with distance from the col when you move along the divergent confluent asymptotes. 

Note that the winds are calm in the sheltered eastern bay of Singleton Lake. This is the calm before the storm commonly found in the cold conveyor belt region of the conceptual model. The calm waters mirror the red sunset on the western horizon. The easterly breeze does create some ripples with the extended fetch by the time the breeze reaches the western basin of Singleton Lake. These ripples reflect the bluer, thin cirrostratus of the sky overhead and not the fiery sunset. I describe the Calm Before the Storm in "Weather Lessons for Everyone from the Cold Conveyor Belt Wizard". 

These conceptual models and the associated science were in the back of my mind while I paint. When I am deep within the creative zone with a brush in my hand, the colours and shapes required to interpret the beauty of nature are all that matter. The science and the art can be fused together at a later, more contemplative time such as this. 

Keep you paddle in the water and warmest regards... 

Phil the Forecaster Chadwick

The Swirls and Deformation Zone Revisited

#2361 "Singleton Sunset Swirl"

Our reality really depends on our point of view – our vantage point. We live on a spinning Globe and this requires that we view our non-inertial frame of reference using our Coriolis Hand. I wrote about this in more detail in The Solution to Cloud Swirls Can Be Found in Your Hands.

Cloud shapes are formed within the free atmosphere that covers our spinning Globe. There are low clouds that are influenced by their life in the planetary boundary layer but we have not talked about them yet. The best vantage point to view and understand the lines and swirls is from the atmosphere itself. In Cloud Shapes and Lines in the Atmosphere , I described how cloud shapes develop and how it is so much easier to understand them from a frame of reference attached to the mean flow of the atmosphere. 

A simple, straight line deformation zone forms with just a decrease in the wind speed as viewed from a vantage attached to the earth. That subtle change in wind speed is difficult to observe but the line that it creates is extremely obvious - which is the rationale behind the deformation zone conceptual model. That Blog goes into more detail with many  more graphics. The average winds with respect to the atmospheric frame average to zero to create a straight line deformation zone. 

If you want to paddle your canoe forward though, the atmospheric frame winds cannot average to zero and one creates a bowed shape deformation zone like we saw in the pool of duckweed in  Gravity Waves and the Deformation Zone.  

Let’s revisit the straight line deformation zone in terms of your Coriolis Hand to make certain we have these concepts firmly in hand. I made some "brains hurt" and I am sorry for that and want to do better. The fingers of your Coriolis Hand can only bend one way and aline with how the flow also swirls. 

If you point the thumb of you Coriolis Hand upward at every X, your fingers must curl in the direction of the flow. 

Northern Hemisphere Right Coriolis Hand
with Thumb pointing Up and
my Fingers Curled Cyclonically

If you point the thumb of you Coriolis Hand downward at every N, your fingers must curl in the direction of the flow. 

Northern Hemisphere Right Coriolis Hand
with Thumb pointing Down and
my Fingers Curled Anticyclonically

If you already know the direction of the flow, point the fingers of your Coriolis Hand in that direction. Your thumb must point in the direction of the vertical motion in the atmosphere. 

I have created a Coriolis Hand graphic to assist. These graphics were created to correspond with the view looking down from space toward the weather pattern or the pool of duckweed. 

The deformation zone conceptual model is an extremely powerful tool to thoroughly analyze and diagnosis the weather. Given a single line or any one of the four swirls, you can recreate the other four components as well as the the opposing winds along the axis of contraction (purple arrows above). The shape of the deformation zone reveals the relative strengths and characteristics of the swirls and opposing winds. In turn it reveals almost everything about the weather situation. I will leave this discussion for the next Blog. 

But the weather is three dimensional. We are confined to a flat surface in this Blog but if you look toward the 3D deformation skin along the axis of contraction, you will see that the swirls as depicted above are just quasi-horizontal cross-sections through the 3D smoke ring formed by the wind blowing toward the col. I have showed this vertical cross-section of the smoke ring before but it might make more sense now... Use you Coriolis hand and follow the ring around the puff of air blowing into the page at the centre of the ring. 

Next week we will look after different shapes of deformation zones and diagnosis what they mean. 

In #2361 "Singleton Sunset Swirl", the cloud behind the approaching deformation zone was drifting to the right. There were even some wind gravity waves embedded in the gravity swells that I described in Seeing Even More Gravity Wave Clouds. I imagined that I was within that cloud,  and pointing the fingers of my Coriolis Hand to the right forced my thumb to point upward. This made sense because the rising atmosphere would also support all of the cloud that I saw and painted. The cyclonic companion of the warm conveyor belt was approaching with more clouds and more weather. The col of the deformation zone was somewhere off to the left. I was looking toward the west and the setting sun so the col of the deformation zone was to the south of Singleton. Hope this helps... 

Keep you paddle in the water and warmest regards... 

Phil the Forecaster Chadwick

Sunrise or Sunset - Gravity Waves and the Deformation Zone

 

#2529 "Sleepy Time Sky Story"
Looking west into the centre of the DZ Col and
the Maw of the Approaching Storm... 
I love the weather!

Lines in the sky always tell a story. If there are lines, the air is moving… along the isentropic surfaces. And the air is always moving...

A  Paddler's View of a  Stroke in Duckweed 

The deformation zone (DZ) is the leading edge of any circulation. They are my very favourite meteorological conceptual model. A deformation zone is created with every stroke of my paddle. Everyone can clearly see the patterns of a paddle dipped into a pool of duckweed. Those exact same lines and swirls are created with every dip of the paddle in clear water too, although there are not tracers to reveal them. 

The absence of cloud in a clear blue sky is an identical limitation even though the circulations are still occurring. That is also why I love water vapour satellite imagery. With every stroke, a DZ line encases the two companion swirls formed by the stroke of the paddle. The flow is outward from the centre of the paddle stroke… meteorologists call this the col. The fluid swirls as it diverges in both directions away from the col. 

A  Meteorologist's View of a  Stroke in Duckweed 

The deformation zone (DZ) has several stories to tell. And there are also two sides to every line just like there is two sides to every story.  A single stroke of the paddle creates one line and four swirls. Each deformation zone line is composed of a col at the centre of the stroke, joining the starting point of the two divergent confluent asymptotes. Companion swirls are found on the opposite sides of the paddle stroke. Sympathetic, paired swirls develop on the opposite sides of those confluent asymptotes as a result of the fluid flow along the confluent asymptotes. In the duckweed frame of reference, these fluid vectors do not average to zero and the canoe (or kayak) is propelled forward. To transform this paddle stroke into the weather of the atmosphere, think of the paddle as moving the warm conveyor belt as it rises along the isentropic surface headed northward.  

Deformation zones (DZ) can become your new best friend so please try to follow the explanation. Aside from gravity waves, every line in the atmosphere is indeed a deformation zone. The shape and location of every DZ must also reveal the relative intensities and location of each of the four swirls - and that tells you everything about the weather. 

All of this bears repeating.. just in case you missed it the first time. Here is another way to look at the duckweed lines and swirls. 

Since the deformation zone is the leading edge of the flow… and if this flow is moisture laden .. we can see the cloud associated with the warm moist air rising along the isentropic surface. By examining the swirls, we can also deduce which portion of the storm is aimed at our location at that moment. The cyclonic companion has a more upward and unstable flow and thus more weather. The anticyclonic companion has more downward and stable flow and less weather.

Which swirl companion is directed toward you is typically best revealed by watching the motion of the clouds on the moist side of the deformation zone - there will be more to watch and study on the cloudy side of the line. This step will also reveal the relative location of the col in our field of view. Get ready to point the fingers of your Coriolis Hand in the direction that the cloud is moving. 

If the fingers of your right hand (Northern Hemisphere Coriolis Hand) following the motion of the clouds, point to your right, then you are looking at the cyclonic companion of the warm conveyor belt. There might even be gravity waves in the cloud on the moist side of the deformation zone angled downwind with the stronger flow along the DZ. Your fingers following that flow on the moist side of the DZ will have your Coriolis Thumb pointed upward in the direction of the rising air. Turning your Coriolis Fingers to point in the direction of the dry air on the paired side of the DZ, will have your Coriolis Thumb pointing downward. 

A similar discussion applies if the cloud is moving to the left along the moist side of the deformation zone - but you will be looking at the anticyclonic companion flow. Try it out. 

You can practice your Coriolis Hand on the DZ conceptual model. Point your right thumb upward at any cyclonic X to determine the sense of the atmospheric swirl. Point your right thumb downward to do the same at any anticyclonic N. The companion swirls are actually parts of a three dimensional ring. The paddle analogy can be replaced by the smoke ring. That science was described in "What do Smoke Rings have to do with Croquet?" as well as numerous other places in my Art and Science Blogs. 

Wind Waves Superimposed on Swells

Wind gravity waves in the clouds can also reveal the direction of the flow in a painting such as that above when animation is not possible. Locally stronger winds will be found along the confluent asymptotes. As described in the previous Blog "Seeing Even More Gravity Wave Clouds", the wind gravity waves generated by stronger winds, must also have a longer wavelength. This will cause the wind gravity waves to appear to twist downwind along the deformation zone or embedded  within the swells. 

#2529 "Sleepy Time Sky Story"
Further Practice available on the Painting
Reality can be more complicated than my graphics

I have been asked “Why Bother explaining this stuff? You have been retired a decade.” My simple answer is that nature, weather and climate are vital and if these explanations can excite just one person to pause and gaze up at the clouds or perhaps look at art, then the effort is worthwhile. The laws of nature are also something I can cling too in this modern world - nature makes sense.  Finally, some of this information was never published and I feel it is valuable science. 

Keep you paddle in the water and warmest regards... 

Phil the Forecaster Chadwick