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Tropical Rainforests make for Rain in California

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 There is nothing more noble than a coastal redwood tree.

Tree huggers, of which I am one, have general notions about weather, and rainfall in particular, that science doesn’t put at the top of weather discussions. Notable weather expert Dan Swain of Weather West  never mentioned trees in his discussion of the California High pressure ridge that is blocking normal rainfall:Dan Swain discusses RRR


The most notable tree hugger notion is that trees are principal in the water cycle. A more complete science discussion regarding the biotic  pump theory and world weather can be found here:Tree process of water

https://www.treehugger.com/process-of-using-water-by-trees-1343505#:~:text=Trees supply leaves with water because of a,is eventually dispersed and released from leaf stomata.

and here:




  Here is my take on trees and the California drought.


In the upper reaches of the Sea of Cortez, the brilliant sun beats down upon the warm water. One might expect evaporation of the seawater and the high temperature of the air to initiate some kind of natural precipitation to cool the thirsty Baja to the west and Sonoran desert to the east. The desert heat comes right down to the waters edge. But no clouds ever form.


The enclosed sea is not alone in this predicament. The Red Sea and many areas around he world that set directly adjacent to seas are desert. The air parcel containing the evaporated water is at the same temperature as the surrounding air. It is not buoyant. There is no natural mechanism for the development of CN rainclouds. The dry air of the highs of the descending Hadley cell dilute and desiccate the surface air that might hold any evaporated moisture. 


Opposed to that:   The Tropical Amazonian rain forest is the initial source for the Pacific ITCZ moisture as the equatorial thunderstorms come off the western side of the South American Continent. It is this air borne moisture that starts and maintains the long chain of thunderstorm events that keep the far eastern Pacific part of the ITCZ very active and is the fuel for ignition of Pacific Hurricanes. The same can be said for the storms that come off the African coast and start the Atlantic hurricane. The same can be said of the cyclones that  form from moisture that departs the Indonesian archipelago to savage the Indian subcontinent and East Africa.


All three of these areas owe their rain making ability to land masses that heat quickly in the equatorial sunlight and thick tropical forests that transpire huge quantities of water into the air. The Amazon rain forest is the most active region of the ITCZ and is fueled by the almost continuous draw of wet Caribbean and Atlantic air into its region of low pressure. That combination builds thunderstorms that move with the equatorial easterly winds off of the continent and sustain the convergence zone over the water. Each day the chain of storms is reinforced as new storms move off the coast. The continuing storms create the low pressure over the ITCZ  that pulls up some additional moisture in the thin layer of high humidity air that lies just above the ocean surface. Most of that moisture is remnant from the previous days ITCZ thunderstorm activity. But this day to day cycle can’t continue indefinitely. The further west along the ITCZ less and less moisture is available and the thunderstorm activity slows and completely disappears near West 160; depending on the vagaries of ENSO.

Without the initial thunderstorm activity created by tropical rain forests, the ITCZ would not exist as we know it. Evaporation from the ocean surface alone is not capable of creating the CN cloud necessary for thunderstorm development. The seawater will not heat up as the land will. The exception to this is of course the hurricane because  the cyclone low pressure covers such a huge area of hot sea surface moisture and becomes self sustaining as it moves northwest away from the ITCZ. Without the tropical rainforest of the Amazon, the normal circulation of the Hadley cell over the eastern Pacific would languish and slow down to a near standstill. Jet streams intermingled with winds of the Hadley, Ferrell, and polar cells distribute the moisture around the world. Local instabilities of world environments create rain. Orographic lifting and low pressure systems that produce copius amounts of rain are distributing the moisture initially provided from the ITCZ. The great Boreal forest that circles the top of the northern hemisphere redistributes water it received from the ITCZ. The once huge deciduous and evergreen temperate forest of the eastern half of North America, mostly chopped down now, was redistributing water from the ITCZ. The temperate “rainforest" of the Pacific Northwest  can originate rain from near surface Pacific air;  much less now as a large portion of the forest has been cut down and historically never more than a small fraction of the rainfall created by tropical forests along the equator. But again, the water for the temperate rainforest there is protected by the ITCZ not so dry descending air via a long looping route over the top of the Pacific high from around 160E of the ITCZ into the area of the Aleutian low. Many areas of this temperate rainforest receive over 80+ inches annual rainfall. The dramatic rise of the Hawaiian volcanoes recycle ITCZ water by turning fair weather cumulus clouds, returning on Northeast trade winds created by the wet Hadley/ITCZ loop, into downpours along the rapidly ascending flanks of the larger volcanic peaks.


The Hadley cell rotates with varying speed around the world; near 115 W water vapor streams away to the northeast

 from the ITCZ  at a brisk pace aided by the sub-tropical jet. This is the result of the very active  thunderstorms along the ITCZ at this longitude and the low pressure here frequently pulls the jet into the area to intercept and guide the moisture. This feeds the water vapor to the eastern US and Gulf Coast to clash with cool temperate storms and where average annual rainfall is near 60+ inches. Further west along the ITCZ near 160 W, the thunderstorm momentum imparted by the tropical rainforest is depleted such that there is little CN development. The ENSO moves, expands, and contracts the ITCZ quiet zone between 140W and 180. The Hadley cell rotation is slow and little moisture is moving northeast towards the California coast. The lack of low pressure aloft seldom attracts the subtropical jet.


The gist of this idea is that the destruction of the Amazon tropical forest is creating a worsening drought for the US west coast and interior. It means drier conditions around the world as tropical rainforests and temperate forests are destroyed.


The world has little choice but to stop the cutting of forests as there is no other natural mechanism to create the lift necessary to get water vapor to cool and form clouds. Normal atmospheric evaporative physics alone cannot create near 100 percent relative humidity and still maintain buoyancy. But trees can “pump” water into the air to super saturate the air with water vapor. The buoyant water vapor removes the heat from the leaf canopy generated by the sunlight  beaming down on the forest. The water vapor leaving the leaf surfaces is hot and even beyond supersaturation, the vapor is forced out as the biological processes of the tree requires cooling. At it’s base, a 300 foot tall coastal redwood can produce a head pressure of 300 ft (9 atmospheres). All trees can of course do something similar depending on height, but only tropical rainforests, because of their equatorial location, can do that initial lift of water. Forests in general are needed to continue the redistribution of that fresh water. 


 The world must help those countries with tropical rainforests to protect and preserve existing rainforest and to fund the planting and nurture of canopy trees. An estimated 20 percent of the Amazonian rainforest has been cut down. That has reduced the extent of the thunderstorm activity of the ITCZ. The really active daily deluge doesn’t extend west as far into the equatorial blue Pacific as it once did; before men cut down the huge canopy trees of the rainforest. That means the idle zone ITCZ portion of the Hadley cell can now only deliver bone dry air to the north horse latitudes where it keeps California in semi-permanent drought. 


Using the US Gulf coast as an example, the conventional weather scenario describes a cold front with associated low pressure approaching from the northwest plains area. Moist wet Gulf air is pulled into the storm and cool air circulating from the north surges under the moist air and lifts it to produce CN clouds and ensuing rainfall. No mention of trees. But where and how did the moist Gulf air come from? The Gulf coast sets near the 30 degree latitude and descending air of the region is not bone dry-it contains some residual moisture from the active ITCZ region near 105-115 degrees west. The water flow is visible with the IR satellite view. As the air descends, it does not desiccate the low altitude and shallow layer of moisture laden air just above the Gulf water.

The relationship of the drier conditions as one travels west across the US and the faltering and less frequent thunderstorms of the ITCZ as one sails westward along the ITCZ is apparent. At Pensacola, Florida (87 W ) the descending air contains moisture from the ITCZ 115 W; an active storm region of the ITCZ. At San Diego, California (117 W) the descending air is bone dry and originates at 145 W of the ITCZ ; a weak area of ITCZ storms.


The larger the area covered by the Amazon rain forest, the further west along the ITCZ the strong thunderstorms will occur. More thunderstorms further west means more water vapor in descending air of California and less drought.



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  • 3 weeks later...

Big business thinks protecting rainforests is important. Here is an interesting article about the LEAF worldwide effort to protect and restore rainforests. project LEAF

I hope the effort includes the rainforests of Columbia. The Columbian area of the Amazonian rain forest is most important as it is the last of the forested areas before the storms leave the continent to join the train of thunderstorms that constantly  reinforce the ITCZ west of South America.

Columbia has always allowed the unrestricted cutting of the giant mahogany and other hardwoods of the rainforest. In addition, destruction of the forest for cattle ranching, palm oil farms, gold mining, cocaine growing, and many other activities are without regulation. The forest and native people suffer.

These activities should be sanctioned by every country that needs water-that's every country of the world. Each large and old forest tree may transpire 500 gallons a day; multiplied by the millions of trees destroyed that's a lot of water into the atmosphere to spawn CN thunderstorms. All those missing trees impacts California and the drought. And all nations must restore the forests they have destroyed in their own countries.

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This article points out the futility of giving in to a 10 Billion dollar a year ransom payment to Brazil in order to protect the Amazon rain forest. Rain forest ransome . In lieu of getting Brazil to stop destroying the rainforest, the US should lead a movement in the UN to sanction Brazil and force the Brazilian government to protect the rainforest. If the UN will not go along with sanctions, then the US should have unilateral sanctions on Brazil. The US western states drought and global warming will only get worse as more of the rainforest is destroyed.

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  • 4 weeks later...

Seems President Bolsonaro of Brazil has changed direction on protecting the Amazon rainforest as outlined in this article. Brazil Army to protect Amazon rainforest

The drought on Brazils' Atlantic Coast is severe. Maybe treehuggers have convinced Bolsonaro of the worth of the rainforest.

The warm water of the far eastern Pacific and the Central American rainforest provide abundant thunderstorm anvil tops that the Hadley cell moves north to the US. The moisture can be seen moving north on the satellite views. Arkansas south central region all the way over to South Carolina is getting soaking rains. The eastern US is wet with summer monsoon rains. A few cyclones have flared up only to die away as they move up Mexico's south coast. That's helping Mexico. New Mexico, Texas and Oklahoma get some showers. But the Pacific storms don't extend far enough west along the ITCZ to really help Arizona and SoCal.

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  • 2 weeks later...

I haven't read everything you've posted, but from what I've read, it is interesting.

I guess I am commenting to say what you are sharing isn't being ignored.  People are looking, even if they don't say anything.



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Our rainforests are the lungs and pharmaceuticals of the planet.  They’re a World Heritage and as such must be proactively protected.  

Good articles.  Keep it up.  

Before You Diagnose Yourself With Depression or Low Self-Esteem,...First Make Sure You Are Not In Fact, Just Surrounded By A$$holes.


2018 Rainfall - 62.65" High Temp. - 110.03* Low Temp. - 8.4*

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Thanks for the encouragement. I know I am mostly preaching to the choir but maybe new readers will join in understanding how important all forests are Hadleyflow.thumb.png.b5b10cbc566e1a5444d79a72f53e04da.pngto the world well being and economy. I'll continue. 

The high pressure ridge that blocks storms potentially headed for California is shaped as an ellipse with a major axis perpendicular to the lines of longitude (parallel with the equator). The shape of the high is mantained by the descending dry air from the Hadley cell that originates at the ITCZ between latitudes 120 and 170. Poor thunderstorm development at these latitudes of the ITCZ during summer months and drought periods in general (LA Nina) are causing drought in the US West and California in particular.


In the attached sketch, note how the Hadley cell routes rising ITCZ air/vapor of the thunderstorm anvil head. Initially moving north, the air/vapor begins to turn to the right under the influence of the Coriolis force. In most cases, the air begins to descend around 25-30 north latitude. The pale blue wobbly lines represent the weak Hadley flow of moisture around 160 west into the area of the blocking high. The brighter and heavy blue lines represent the dense moisture from the 100 west area. We can view this descent on the satellite upper IR view. The dry and not so cold air (white color vs colder green) heats as it descends into the warmer bright blue of the middle IR view. The limited water vapor is not lost. It just moves to the warmer temperature and resulting lower relative humidity. Continuing to descend, the air/vapor finally reaches the lower IR view with ever higher temperatures and lower relative humidity of the orange and reds of the near surface.


This huge patch of dry air provides no fuel for cyclones that approach and attempt to continue on a westerly course. Cyclones are dependent on the condensation of water vapor and subsequent release of heat. In the dry air pile of the high pressure the storm is starved, weakened, and dies.   Or, more lkley, the cyclone is forced over the top of the pressure ridge into the northern interior of North America. California is bypassed entirely.


If the blocking pile of air can be wetted up with increased water vapor, the cyclone can gain strength such that the high pressure is cut in half, pushed to the side, or otherwise warped to allow passage of the cyclone on a direct course to the west coast of North America. The ENSO cycle adds and subtracts to the thunderstorm activity. In recent history, deforestation of the Amazon rainforest has dampened thunderstorm activity of the ITCZ.


The high pressure ridge can be wetted up by using Aquariusradar to slow rainfall rates at the thunderstorms of the ITCZ. Of the available thunderstorms of drought periods, Mother Nature lifts water to great heights as CN anvil heads at the ITCZ, Aquariusradar is used limit rainfall of targeted storms and to hold more of that water aloft. The Hadley cell moves that water north to wet up - increase the relative humidity- of the blocking high. Low pressure cyclones now have more fuel and greater opportunity to continue to the west coast.

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The worst heavy rains in 200 yrs have hit Germany, Belgium, and Netherlands.  Devastating floods and mudslides have crippled the area.  

Just more unusual weather. This time it hit Western Europe.  



Before You Diagnose Yourself With Depression or Low Self-Esteem,...First Make Sure You Are Not In Fact, Just Surrounded By A$$holes.


2018 Rainfall - 62.65" High Temp. - 110.03* Low Temp. - 8.4*

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  • 2 weeks later...


Far below the massive trunk of rainforest giants lies the expansive root system that delivers 100s of gallons of water for the tree canopy above to transpire into a receptive and volatile atmosphere. Millions of Amazon rainforest trees work together to produce an atmospheric river that flows to the west off the South American  continent. The river is studded with CN thunderstorm complexes that rain down millions of gallons water every day. Some of that water is held aloft in the towering anvil heads of the largest of the thunderstorms. While the continuous river moves west, the clouds and water vapor of the upper reaches of the storms is swept northward by the Hadley cell rotation. 

 The total of rainforest trees have declined and continue to decline as mankind invades the forest in pursuit of economic wealth. The river of water produced by the Amazon rainforest declines every year such that the thunderstorm activity doesn’t extend as far west along the ITCZ and California and the west of North America is in drought because the Hadley cell now cannot deliver as much moisture as in former times.

 The only long term natural solution is to regenerate the rainforest to its’ former expanse. That could take hundreds of years. An alternative is to find a way to limit the rainfall in the ITCZ zone that impacts California such that more moisture remains aloft and can move north with the Hadley cell rotation.

  Aquariusradar is a method by which microwave energy is directed at the developing CN storm. The rainfall from the targeted storm is reduced and more water is held aloft for the Hadley cell to circulate north.

 The forces of nature lift the water to great height and before the CN builds to maximum the microwave energy is applied to stop growth. The delayed growth provides more time for the Hadley cell to transport water to the north. 

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