Micro-Season: “Thunder Lowers Its Voice”

We have entered the micro-season of “Thunder Lowers Its Voice”.  This is the first micro-season of the mini-season of Autumn Equinox.  The micro-seasons within Autumn Equinox are:

• Thunder Lowers Its Voice (Sep 22 – Sep 27) 
• Hibernating Creatures Close Their Doors (Sep 28 – Oct 02) 
• The Paddy Water is First Drained (Oct 03 – Oct 07)

These seasons were established in 1685 by Japanese astronomer Shibuka Shunkai and are specific to Japan. However, just because the calendar focuses on Japan doesn’t mean it isn’t applicable to others.  No matter where you live you can use these seasons as a starting point for your personal exploration of the world around you. 

As a way to celebrate this season, we will investigate the conditions needed to create thunder and lightning. Then we read some thunder and lightning-themed haiku by Basho, Issa, and Kerouac.

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“Thunder Lowers Its Voice” (Sep 22 -Sep 27) is a counter-season to “Thunder Raises Its Voice” (Mar 30 – Apr 03).  These two micro-seasons indicate distinct shifts in environmental temperatures. These shifts are associated with the cooling and warming that occurs as a result of the earth’s movement around the sun and are marked by the equinoxes. 

Autumn Equinox

This year, in the northern hemisphere, the autumn equinox occurred on Thursday, September 22, 2022.  An equinox marks the time when the length of the day equals the length of the night. 

After the autumn equinox, the days begin to get shorter and the temperatures in the northern hemisphere begin to cool.  The reason for these seasonal changes is a result of the earth’s 23.5-degree tilt.  The tilt places the northern hemisphere farther away from the sun in the winter months and closer in the summer.  The graphic below from the National Weather Service illustrates this process.

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What is Thunder?

Thunder is the sound that accompanies lightning.  Thunder is most common in thunderstorms which are rainstorms that have rain, thunder, and lightning. Thunder can either be a low rumbling noise or a more abrupt sound sometimes called a thunderclap.

How Are Thunderstorms Formed?

Unstable Air

When a warm air mass settles under a cold air mass, the combined air mass is called “unstable”. 

A “stable” air mass is one where the cold air lies under the warm air.  This type of air mass is called “stable”  because cold air is denser than warm air and prefers to settle closer to the earth’s surface.⁽²⁾

.A thunderstorm is created when warm moist air rises and comes in contact with colder air in the upper atmosphere. These conditions exist when there is an “unstable” air mass.

Updrafts and Downdrafts

When the warm moist air rises to meet the colder air, the water vapor in the air begins to condense and creates a cloud. As the warm air continues to rise, it creates a cloud formation that is known as a towering cumulus cloud.  

As the towering cumulus cloud continues to grow, it will eventually reach a high enough altitude that the warm air updrafts flatten out and create an anvil-like shaped cloud that is known as cumulonimbus incus.⁽³⁾  At this time, water vapor has frozen in the cloud’s upper reaches and begins to fall back to earth. As the ice falls, it thaws and becomes rain.  The falling rain then creates a downdraft.

The rising and falling of water molecules in the cloud create a static electric charge within the cloud.  When the cloud’s negative charge reaches its maximum limit, it looks for a place to discharge.  The earth’s surface offers a great discharge point.  When the negatively charged clouds release their energy, we see a lightning flash.

When lightning is created, it rapidly heats the atmosphere which creates the initial crack of thunder.  The following rumble of thunder is created as the atmosphere cools.⁽⁴⁾

Why Does The Thunder Lower Its Voice?

Once we reach autumn, the likelihood of thunderstorms decreases.  Part of the reason for this is that unstable air masses are less likely to develop in the cooler months.  

The opposite is true in the micro-season of “Thunder Raises its Voice”  which happens in late spring.  At this time the earth is beginning to warm up and there is more opportunity for unstable air masses and more moisture in the air.

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Seasonal Haiku

Thunder and lightning have the potential to be multi-season kigo according to the World Kigo Database. However, “thunder” without another seasonal descriptor is considered a summer kigo, and “lightning” without a specific seasonal descriptor is an autumn kigo.⁽⁵⁾  With this in mind, let’s read a few haiku about “thunder” and “lightning”

Basho

How admirable!
to see lightning and not think
life is fleeting. 
(Translated by Robert Hass)

lightning— 
into the darkness
a night-heron's cry.
(Translated by David Landis Barnhill)

Yellow rose petals
thunder – 
a waterfall. 
(Translated by Lucien Stryk)

Issa

hey there, mountain
charred by lightning,
it's autumn rain
(Translated by Chris Drake)

in the lightning
how he laughs...
Buddha!
(Translated by David Lanoue)

Jack Kerouac

Drunk as a hoot owl
writing letters 
By thunderstorm

A bubble, a shadow - 
woop -
The lightning flash

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A Haiku Invitation

This week’s haiku invitation is to write a haiku or senryu that references Thunder or Lighting.  Try and keep in mind thunder and lightning’s default seasons.  Consider using other seasonal descriptors if you choose to place these elements in other seasons.  

Share your haiku in the comments below, or post on your own page and link back to this post. I can’t wait to read what you write!

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Resources:

1. “The Seasons, the Equinox, and the Solstices”; National Weather Service
2. Highs and Lows/High and Low Air Flow: Iowa State University
3. “Thunderstorms”: Wikipedia
4. “What Causes Lightning and Thunder?”; SciJinks NOAA
5. “Thunder and Lightning”; Dr. Gabi Greve (WKD)

Basho’s haiku were retrieved from “Matsuo Bashō’s haiku poems in romanized Japanese with English translations” Editor: Gábor Terebess.  Issa’s haiku were retrieved from “Thunder and Lightning”; Dr. Gabi Greve (WKD). Jack Kerouac’s haiku were retrieved from “Jack Kerouac Collected Haikus”; Terebess Asia Online

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