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I really thought this moderate La Nina would be enough to shift/buck the trend but all it did was give us false hope and we remain stuck in the 2013 pattern but nights are cooler though when it does clear. So what do you guys think do you think we can ever reverse this or are we in this long haul?
How disappointed were you with this La Nina if you took out the Feb snow/ice storm from the equation? as it was NOT region wide!
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
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.