The primary
climate event
at night
is our planet
cooling off.
Outgoing longwave infrared radiation
is how Earth loses excess energy
into space.
An increasing greenhouse effect
would slow this energy loss.
( If that energy loss is increasing,
then Earth’s surface is warming
for reasons other than an increasing
greenhouse effect. )
Based on laboratory experiments,
it's expected, although not proven,
that CO2 will interfere with the
planet's cooling process, although
the actual effect in degrees is unknown.
If half the planet does not cool
as much, during it's night period,
because of more CO2 in the air,
or some other cause, that means
the lowest temperature of the day,
usually at night, would not be as low.
If a night doesn't cool as much,
then the average temperature
of that day will be warmer.
( measured by adding the
warmest temperature
of the day,
or ( Tmax ),
usually in the afternoon,
to the coolest temperature
of the day, or (Tmin),
usually at night,
and dividing by two,
to calculate the
average temperature
of a day (Tavg) ).
Tmax and Tmin tell us more about
the temperature, than Tavg alone,
and looking at the 48 US states,
provides more useful information
to 330 million Americans, than
a global average .
Averages always obscure details.
More important is knowing about your
local area, or at least about your nation.
And not only an average temperature.
You'd want to know the
% increase or % decrease
in diurnal range, along with
the % change in the average high,
and % change in the average low,
for each month.
The global average temperature
is not a temperature anyone on
this planet actually lives in !
Less night time cooling,
feels different than more
daytime warming, and is
probably considered
to be more pleasant,
by most people.
Most important about CO2 --
it's greatest greenhouse effect
should be where the air is dry.
That's because water vapor,
the primary greenhouse gas,
"overlaps" the greenhouse
effect of CO2
( they affect some of
the same wavelengths
of infrared energy, in
laboratory experiments,
and the night cooling IS
infrared energy, rising off
the surface of our planet,
into the atmosphere, and
some escapes into space ).
The driest air is found at high
( cold ) latitudes, during the
six coldest months of the year.
The Arctic and Antarctica
are where the greenhouse
effect should be strongest,
and the greenhouse effect
should be weakest in the
humid tropics.
The Arctic, in fact, has had
a lot of warming.
So the Arctic is used to "prove"
the greenhouse effect of CO2,
although there could be other
causes of the warming.
The Antarctic has had little
warming, and that warming
was "local" -- areas near the
edge of the glacier, that happen to
be near underseas volcanoes,
which warm the ocean enough
to melt some nearby ice.
The greenhouse effect could NOT
cause local warming --
it would affect the entire continent.
So Antarctica is used to disprove
the greenhouse effect of CO2.
A study of some NASA satellite data
was reported by Roy Spencer, PhD
on his website
Spencer is in charge of compiling
the UAH weather satellite global
average temperature compilation.
For his study, he looked at NASA data
for their AIRS satellite temperatures.
The AIRS is an infrared temperature
sounding instrument on the NASA
Aqua satellite, providing data since
late 2002.
Unlike the UAH satellites, that use
microwave temperature sounder
data ( data available since 1979 ),
AIRS data are from infrared measurements.
The study looks ONLY at AIRS surface
“skin” temperature measurements,
at 2 meters above the surface
( the traditional surface temperature measurement height ).
( although AIRS actually
retrieves temperature
profiles throughout
the troposphere
and stratosphere ).
For the United States,
48 contiguous states,
Spencer found,
that in the 16.5 years
from September 2002,
through March 2019:
( the 48 states cover only 2.5%
of Earth's surface area,
but are very important
to 330+ million Americans ),
the AIRS surface data show:
... the temperature trend at night (1:30 a.m.)
is a large +0.57 degrees C. per decade
... while the trend in daytime (1:30 p.m.)
is a small +0.15 degrees C. per decade.
( Note: This pattern also shows up
in globally-averaged land areas.
where the day-night difference
was greatest in winter,
and weakest in summer.)
CO2 is 410 ppm at 1:30 AM,
and 1:30 PM -- so its radiative
properties are constant
24 hours a day.
But the warming is very different
during days, versus nights.
Night warming
was 79%
of the
total warming:
total warming:
0.57 / (0.57 + 0.15) = 79%
And the actual warming
in those 16.5 years, was:
0.57 + 0.15 / 2
= +0.36 degrees C. per decade
Real science is
never certain,
and never "settled".
Only junk science
is claimed
to be "settled" !
Caveats for this study:
(1)
I don't know the actual
accuracy of AIRS data.
(2)
The day - night difference,
or the "diurnal" difference,
at 1:30 a.m., versus 1:30 pm,
is NOT the the actual lowest
and highest temperatures
of any of the days.
Using these fixed measurement
times simplifies calculations.
(3)
The lower troposphere and
surface temperatures
can only be measured
by AIRS between clouds,
or when there are no clouds.
That could cause sampling bias.