Thoughts From My Garden

I have been on fire mitigation detail all summer long around my place.  Those of you who know my place know that my house along with the 2 other houses on the property are surrounded by trees. Well, there are fewer trees than there were a couple years ago because we changed our lease and now don't have the walnut and olive orchards that we used to.  However, I think that we still have as many leaves as before.  As a result, leaf management is an ongoing job.  During the summer, I had the opportunity to work with Maureen Clark on a presentation on how to manage our gardens for fire safety and prevention.  If you were unable to attend that presentation, I hope to do it again in 2025.  It was an excellent learning experience.  If you want to go down a rabbit hole to see what to do over the winter for summer prevention, visit the ANR as there are easily 100 pages of information. Here is one link to look over: https://ucanr.edu/sites/fire/Preparedness/

 

So, how did I get here from there you might ask?  Well, while filling my green waste container while raking the leaves from just one of the remaining walnut trees, I got to thinking about the weather reports on the Today Show detailing the horrid weather and fire conditions across our nation.  (I must confess that I have been pretty myopic over the years in thinking that fires and drought stopped at the California borders.)  The weather reporter talked about the drought conditions across the country and how those awful hurricanes happened and flooded areas previously unaffected by hurricanes.  Then comes the report of yet another atmospheric river heading our way.  I got very curious about all these terms I had been hearing but never really thought that much about at those specific times.  So, I got onto the internet and headed down another information rabbit hole.  I chose these sites for research -- DOE, NOAA, Accuweather, and USGS.

 

Firstly, just what is an atmospheric river?  "It is a large, narrow section of the Earth's atmosphere that carries moisture from the tropics near the equator to the poles."  Studies have found that these "rivers" can be up to 300 miles wide and can transport water vapor at a rate equal to 7 to 15 times the average daily discharge rate of the Mississippi River. They carry massive amounts of moisture. On average, 4 or 5 of these active "rivers" at any given time.    They are a major factor in cloud formation and responsible for 90% of the movement of moisture from the tropics towards the north and south poles. They significantly influence air temperatures, sea ice, and other climate components.  Essentially, they are like "rivers in the sky" carrying the largest amounts of freshwater on earth.  A very common name, 

especially in Southern California, is "The Pineapple Express".  As mentioned before, they usually begin in tropical regions where warm ambient temperatures cause the ocean water to evaporate and rise up into the atmosphere where strong winds carry it.  Then, as it moves over land, it is pushed farther up into the atmosphere, cooling the vapor.  Because climate change is warming the planet, atmospheric river days are expected to increase.

 

That brings me to my next question.  What is a "Bomb cyclone"?  By definition, it is a storm that undergoes rapid strengthening over a 24-hour period.  Essentially, it means "Explosive storm strengthening." It can be tropical or non-tropical in nature.  It mostly occurs over the oceans as a giant rising column of air that spins counter-clockwise in the Northern hemisphere and clockwise in the Southern.  As the air rises, the surrounding pressure lowers quickly, dropping the barometric pressure.  As the air rises and cools, the moisture condenses, producing clouds and rain or snow.  The faster this happens, the heavier the resulting precipitation.  This can also happen when a cold air mass collides with a warm air mass.

 

Now, to get to the fire mitigation part of my wandering thought process.  Here in California, we are all too aware of wildfires.  We have lived through a couple way too close to home in the recent past.  We all appreciate the beautiful green hills after a good rainy season, but also are aware of the dry, brown, flammable vegetation that follows in the summer and fall.  Whenever there is a fire, a prayer for rain goes up, however, once a fire severely burns an area, little vegetation remains and the burn makes the top layer of soil non-absorptive for a short time causing the water to run off, especially downhill, carrying mud and debris with it.   For example, a forest's ground is usually like a sponge and can absorb and filter large amounts of water, but after a fire, the water can't penetrate the soil, causing runoff.  Hence, we have seen massive mudslides on the news.

 

Well, as I sit inside, listening to the rain, my curiosity is mostly satisfied.  The last question is:  Will we have a decently wet winter, or are we going to get what we get now and not much more?

 

I hope that everyone has a happy and safe holiday season.

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