Tom Thomson's Studio "Morning Cloud"

 

The story behind Tom Thomson’s Sketch The Morning Cloud 1913, was described in the previous (linked) Blog. I wish to return to that cloud to try another approach to explain the meteorology included in those oils. I think of this as a Mid-Term Refresher Blog that examines the most vital material. I initially considered just moving on but no one needs to be left behind...  the weather is just too important, especially now...

Morning Cloud
 Alternate title: Dawn, Smoke Lake and Morning Cloud
Winter 1913–14 Oil on canvas
28 3/8 x 40 1/16 in. (72 x 101.8 cm)

The Studio Building, 25 Severn Street
 Studio 1 on the ground floor in 
more ways than one...

Tom would paint a larger version of the sketch in the winter of 1913-1914. The Studio Building was completed in March 1914 but many of the artists moved in before that date - Lawren Harris, A.Y. Jackson, J. (William) Beatty, Arthur Heming, Albert Curtis Williamson, and J.E.H. MacDonald. Tom Thomson was not on that list of original Studio Building Artists but was sharing Studio 1 with A.Y. Jackson starting in January 1914. Dr. MacCallum was sponsoring Jackson and Thomson for a year (1914) and paying for their expenses if only they would devote their time to painting. That sounds like a great arrangement to me!

The "Morning Cloud" would have been one of the first paintings completed in Studio 1 surrounded by all of his artist friends and the finished result reveals that influence. The studio painting "Morning Cloud" may also be found in the Art Gallery of Ontario. It is worth the trip to pay a visit to these brush strokes. 

I employ the Conveyor Belt Conceptual Model (CBCM) of weather systems throughout  "Tom Thomson Was A Weatherman" in order to place Tom’s location in relation to his subject matter. Sleuthing the location and direction of view is typically feasible through deciphering the cloud types and their stability. I have written about this subject extensively in "The Art And Science of Phil the Forecaster". That blog is searchable with many more in-depth descriptions.

The Cogs in the Weather Machine Turn with the Wind.
Red "X" Cogs turn Cyclonically with the thumb
of your Coriolis Hand pointing Up. 
Blue "N" Cogs turn Anticyclonically with the thumb
of your Coriolis Hand pointing Down. 
Together the Cogs Turn the Weather Machine and
Redistribute Energy to keep the Earth in Balance

In light of the importance of the CBCM, I wish to approach the science again using the Coriolis Hand - a more physical approach. Repetition of the science from a different angle using new vocabulary often switches on the bulb. New light might shine on the weather and why Thomson painted what he did. I own any deficiencies in this attempt to reveal the wonders of the weather to you. If you find this material challenging, it is the result of my inadequacies… but I keep trying and I hope that you do as well. 

A mid-latitude weather system is comprised of three conveyor belt flows. The Warm Conveyor Belt (WCB) brings heat and moisture energy into the system from the tropics. The Cold Conveyor Belt (CCB) supplies the contrasting cold and dry air from polar regions. The Dry Conveyor Belt (DCB) is essentially the jet stream that separates the warm from the cold but also supplies the wind energy that results from those contrasting temperatures to spin up the storm. The flows typically glide along the constant energy surfaces in the atmosphere that slope upward from low levels in the tropics to higher levels over the poles.

Each conveyor belt is composed of two complementary flows. Always point the fingers of your Coriolis hand in the direction of the flow.

My Companion Arms: Cyclonic with Thumb Up -
Anticyclonic with Thumb Down

On the cold side of the combined flow, typically toward the poles, your fingers will curl cyclonically and your thumb points upward in the direction of the rising air mass. Rising air is more prone to instability and convective clouds. This is the Cyclonic Companion and is found in each of the three conveyor belts.

On the warm side of the combined flow comprising a conveyor belt (typically toward the equator), your fingers must curl anticyclonically and your thumb must biologically point downward in the direction of the descending air mass. Descending air is likely to be stable and associated with gravity wave clouds. The Anticyclonic Companion is described by your Coriolis Hand with the thumb pointing down.

Deformation Zones can be Analysed from
Either side - The result is the same.

Deformation Zones (DZ's) as observed by Thomson in the "Morning Cloud" are the most important dynamic feature in the atmosphere and are a big part of the Conveyor Belt Conceptual Model (CBCM). In fact, every line in the atmosphere is a deformation zone within the atmospheric frame of reference. Recall that each line is in fact just an indicator of the vertical, three-dimensional skin that separates the volume of warm and moist air from that of the cold and dry. The quasi-horizontal line is simply the intersection of that 3-D skin with a layer of moisture. We require water vapour as tracers to reveal atmospheric circulations. Dry air forms a three-dimensional boundary as well. Every conveyor belt is led by a deformation zone. The col of the deformation zone marks where the cyclonic companion diverges from the anticyclonic companion.

Deformation zones can be found at all time and space scales in the atmosphere. They can be observed whenever air moves within the atmospheric frame of reference. I have used deformation zones to explain climate by using the seasonal gyres in the atmosphere. Deformation zones can also be found within air masses where the circulations create boundaries between flows with slightly different characteristics. Weather fronts are also deformation zones. Deformation zones are also evident in convective clouds and in the stroke of my paddle in the lake. Every line resulting from a moving fluid is a deformation zone and we see lines everywhere.

For a more in-depth explanation of these concepts
please refer to A Jet Streak with a Paddle

The DZs are sharpest and parallel to the flow in regions just upstream from where that flow increases in speed. DZs are perpendicular to the flow downstream whenever that flow decreases in speed.

The science really is this simple. The complications arise because these conveyor belt circulations move in three dimensions and change with time. These weather systems are essentially engines fuelled by heat and moisture. Weather is a vital necessity required to redistribute these quantities globally in an attempt to keep the Earth in balance.

The Warm Conveyor Belt is the star of the Conveyor Belt Conceptual Model. Perhaps one more graphic will shine the light more brightly and send the message home. 

I try to use graphics from my days at COMET and those constructed recently in my attempt to further illustrate the above. Pictures can be worth thousands of words. If anyone, sees the light based on this discussion, the effort was well spent and thank you. I really appreciate those staying with me and taking the time to understand the fascinating atmospheric ocean. We may live at the bottom of that ocean but that is a great vantage point from which to observe and appreciate the weather.

Tom Thomson was enthralled with the atmospheric ocean as well. You can feel it in his art. Any serious Tom Thomson catalogue raisonné must include an examination of the weather displayed in his art. Otherwise, we are certainly missing his true motivation. Happily, there is considerable overlap between my meteorological career and Tom’s portfolio. I felt that it would be irresponsible not to try to contribute to understanding the genius of the man and putting his work into the context that it deserves.

"Morning Cloud" Analysed

The next Blog will get back to a weather painting. None of this material will be on any exam although it should be. 

Warmest regards and keep your paddle in the water,

Phil Chadwick

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date.