Welcome back & Happy New Year
Today I'm presenting part 2: how pressure systems control climate, focusing on the shifts in the intertropical convergence zone, or ITCZ, and why warmer temperatures attract more rain and thus why the ITCZ determines the location of both rainforests and deserts
Mainstream media's narrative suggests that global warming increases evaporation and thus makes worse droughts
But science flips that warming narrative on its head. As you will see conclusively, it is drought that causes higher temperatures.
And it is the reduced transport of moisture from the oceans to the land that causes drought.
You will see that during the coldest periods of the last 10,000 years, societies experienced the worst droughts, and contrary to media narratives, the science shows warmer temperatures will bring more rain
The ITCZ is easily recognized from satellite imagery showing a belt of clouds encircling the earth. It moves northward and southward with the seasonal position of the sun and determines what tropical regions experience a wet season or a dry season
In the northern hemisphere as summertime warmth moves north, the ITCZ, seen in red, brings the rainy season to the northern tropics, while south of the equator, cooler temperatures experience seasonal drought
In the southern hemisphere's summer, the ITCZ then moves southward, as seen in orange, while regions north of the equator experience seasonal drought On average the ITCZ migrates between 9 degrees north and 2 degrees north over the pacific and Atlantic oceans, but it migrates further north and south over Asia and Africa because land masses heat up faster than the ocean
Thus, over the lands bordering the Indian ocean, the ITCZ brings rainfall further poleward, on average migrating between 20 degrees north and 8 degrees south,
Published science shows that during cooler periods, such as the little ice age, that great width of the tropical rain bands contract, reducing the extent of monsoon rains
The little ice age was the earth's coldest period in over 10,000 years, yet despite global warming theory, it created some of the worst droughts, droughts that caused the collapse of many societies such as the Ming dynasty in china and the Khmer empire in Cambodia
The ITCZ represents the dynamical region that drives energy and momentum from the equator towards the poles and drives the Hadley atmospheric circulation
The ITCZ is the region of intense convection where moist air rises, then cools & precipitates heavy rainfall to regions below, enabling the world's tropical rainforests
The remaining dry air then diverges towards the poles where it sinks between 20 & 40 degrees poleward of the equator, generating regions of dry high-pressure that marks the edge of the Hadley circulation
This global map of precipitation illustrates the location of heavy rainfall from convergence zones (seen in reds and dark blue) around the equator And the regions of dry high-pressure systems symmetrically located north and south of the equator shown in yellow
A map of the earth’s great desert regions shows the correlation between deserts and the Hadley high pressure systems
I've overlayed the pressure systems to see this more clearly The high-pressure systems border the western edge of the USA’s western deserts and South America's Atacama They border west of the Sahara in northern Africa and the Kalahari in southern Africa And border the west of Australia's deserts
High pressure systems create warmer temperatures in several ways. The dry descending air in a high-pressure system produces clear skies
Without clouds or mist to block out sunlight, surfaces are heated more strongly by solar radiation
Water vapor is a greenhouse gas. So, without clouds and reduced water vapor more infrared heat escapes directly to space so clear skies also reduce the greenhouse effect. Nonetheless increased solar heating has a greater warming impact and offsets any decreased greenhouse effects
Even if there was no increase in solar or greenhouse radiation an increase in dryness amplifies temperatures
Known as specific heat, scientists determined that different substances require different amounts of energy to increase that substance's temperature To raise one kilogram of water by one degree Celsius requires 4200 joules. Joules is just a measure of energy.
To raise one kilogram of sand one degree requires much less energy, just 830 joules. Thus, by removing a kilogram of water from the land's surface the energy that would have raised water by one degree, will instead, raise the sand by 5 degrees.
In addition, over 2 million joules of energy are required to evaporate a kilogram of water without raising the temperature. These dynamics are just one reason why average temperatures can be unreliable science. An average temperature does not reflect changes in radiation from added carbon dioxide, unless all temperature effects induced by dryness are first accounted for. And that is not being done.
High pressure systems further generate regions of dryness by blocking the westerly flow of moist winds from the ocean to the land
High pressure systems cause the winds in the northern hemisphere to circulate in a clockwise manner, thus deflecting moist winds from the west northwards. For example, the pacific high-pressure system strengthens each summer because descending winds more readily descend over a cooler ocean relative to the warmer land.
By deflecting moisture northwards, the strengthened summer high causes California to be dry from June thru October, while simultaneously bringing summer rains to drench the coasts from Oregon to Alaska
Because this dryness amplifies temperatures, Death Valley in southeastern California still holds the record for hottest observed air temperature, reaching 134 degrees Fahrenheit on July 10th, 1913, long before any significant rise in CO2
The world's Mediterranean climates (shown here in red) are symmetrically located around the equator centered between 30 & 40 degrees north and south of the equator.
All Mediterranean climates are characterized by hot dry summers and cool wet winters. The opposite of tropical seasons As the ITCZ moves northward each summer, so do the high-pressure systems of the Hadley circulation cooler ocean surfaces relative to warmer land intensifies the highs which block the flow of moisture from the ocean to the land This is why the naturally dry summers in California and Greece and all Mediterranean climates are highly susceptible to wildfire As the ITCZ moves southward during the winter, so do the high-pressure systems, and as the highs weaken it allows ocean moisture to bring winter rains to the land
What might seem peculiar is that Mediterranean climates are restricted to relatively narrow bands along the coast
The reason Mediterranean climates don’t expand further inland is because the warmer land temperatures of summer create a low-pressure system that draws in the monsoonal rains from elsewhere
The North American monsoons draw moisture from the Gulf of California and Gulf of Mexico As seen by the weather data from Albuquerque, New Mexico, the greatest precipitation is brought inland during the hottest months of July thru September.
Like the ITCZ transport of rains, summer monsoons illustrate how higher temperatures bring more moisture, not drought.
So up next: Part 3 How the Sun Controls the ITCZ
Until then embrace renowned scientist Thomas Huxley’s advice:
“Skepticism is the highest of duties; blind faith the one unpardonable sin"