At first I am going to say
what is the Earth
Radiation Budget or ERB
why is it important?
I give a brief
history of Nimbus.
The Nimbus-6 and 7,
what was new and
different about that;
primary results from
the Nimbus-6 and 7;
a comparison to the ERBE,
which is Earth Radiation
Budget Experiment,
as opposed to ERB,
that was after Nimbus,
and some conclusions.
All right, what is the
Earth Radiation Budget
for those who don't know?
Here is a diagram showing
the globe as a whole,
averaged over
the entire year
and the 342W per meter square
of incoming solar
radiation on the average
and you can see
what's happening,
it's scattering
off of clouds,
it's scattering
from the earth,
it's being absorbed by
the surface of the earth,
it's being emitted,
there is a whole lot of things
going on as you can see.
But the main thing is,
if you look at the 107W per
meter square going out
from reflected radiation
and the 235 outgoing,
if you add those two
numbers it adds up to 342,
which would imply a
net radiation of zero
which would mean no global
warming; not true.
There is global warming
but this diagram
doesn't really show it,
but it's different from this.
Now why is the Earth Radiation
Budget important?
First of all it's a driver in
the earth's weather and climate,
as we will see,
accurate data on
ERB is important
to weather and
climate models,
and the next surplus and
deficit of ERB will tell us
where the earth is
warming or cooling.
Global warming doesn't mean
the whole globe is warning,
I think you all
know that here,
but some of it is
warming in certain places
and it's cooling on other,
but on the average it's warming.
Here is a slide I got from
Professor Vonder Haar
who gave this
talk 10 years ago
and he said that I could
use anything of his slides
and I would have
gladly used some of it,
but here is one of his that
he presented still meaningful
is the radiation budget at
the top of the atmosphere,
annual radiation budget
as a function of latitude,
and it shows a
surplus of radiation
in the tropical area...
oh, I didn't want
do that, all right...
let me go forward...
all right,
surplus of radiation in tropics
and the deficit outside that,
and you could see here
the amount and space-time
distribution
is a fundamental driver of the
earth's weather and climate
because of that
surplus and deficit,
it's got to go somewhere.
All right, here is an
early history of measuring
the Earth's Radiation Budget.
During the 1960s TIROS
and the first experimental
US Air Force sun-synchronous
satellite
gave us early low
resolution view
of the Earth's
Radiation Budget.
And I have a quote here, I want
to read from Verner E. Suomi,
it said, we found that the earth
was a warmer and darker planet
than previously believed;
especially in the
tropical region
we found that 40% more energy
must be transported forward
by the atmosphere and ocean
circulations, that's dramatic,
and if true we
could better understand
and model atmospheric
and oceanic circulations,
air-sea interactions
in both the earth's energy
and water cycles,
we can do a whole lot better.
All right, a brief
history of Nimbus ERB
going before the Earth Radiation
Budget experiment itself
from Nimbus-6 and 7
that I was involved in,
the Nimbus-2 and 3,
Medium-Resolution Infrared
Radiometer Experiments
at Nimbus-6 and 7 ERB results,
they were designed to check,
verify and expand the results
from these early 1960s
and the Nimbus-2
Medium-Resolution Experiment
was unfortunately
short but did provide
the first Medium-Resolution
ERB measurements
over the polar ranges.
Now, the Nimbus-3
Medium-Resolution
was a great success
and more than a year
of pole-to-pole local noon
midnight ERB was obtained
at medium spatial resolution,
great success.
Now many regional
features were explored
and we didn't have
before as much,
ocean, stratus regions,
major deserts Amazoria,
you could see,
seasonal variations
over the continents,
you could read
this for yourself,
and significant differences
over the Arctic and Antarctic.
Now because the early Nimbus MRI
are used 5 spectral bands
to estimate the total
earth radiation
and reflective radiation,
it did not measure
the direct solar radiation
or solar radiance,
and so a more complete ERB
measurement package
was developed for
Nimbus-6 and 7.
So with the Nimbus-6 and 7
era, Bill Smith was here,
was the principal
investigator,
I worked with him and we
had a number of others,
Don Hillary, John Hickey, Bob
Maschhoff, Lee Kyle and others
who developed an
eclectic experiment
for both Nimbus-6 and 7,
had low resolution
fixed radiometers
and we had... and this
is very significant,
medium resolution
by axial scanners
and what I mean by that,
it would scan,
we had 4 shortwave channels
and 4 infrared channels
that would scan
to the horizon
and then come back,
actually move over to
try to fill in spaces
and then scan back
to the nader
and then made a
90 degree rotation
and then scan... didn't go
all the way to the horizon,
it was some difficulties
there in designing that,
but we went almost
to the horizon
and scanned back and then
did another 90 degree,
so you could get at all
different directions,
that was very significant.
The other very
significant thing was,
we had 10 spectral bands
measuring the direct
solar radiance,
including the total solar
radiance reaching the earth.
Now the Nimbus-6
results were good,
yet they revealed some
challenging data processing
and analysis questions.
So this led to the
Nimbus-7 ERB science team.
I was the team leader and
you can see the names here,
Garrett Campbell, Lee Kyle,
Ken Coulson of UC Davis,
Maschhoff,
Fred House from Drexal,
Larry Stowe
and Ingcrsoll of Caltech,
Tom Vonder Haar, CSU,
Al Arking and Ben Dean were
NASA Project Scientists.
Now Bill Smith
wasn't involved
as you heard in pioneering new
weather observations for Nimbus,
so he could not take a
direct part in the team.
We would have loved
to have had him
but he can't be everywhere.
Now, our primary results
from the Nimbus-6 and 7 ERB
were that we produced the first
high precision measurements
of the direct solar radiance
reaching the earth the first
and we actually beat out
the Solar Max Mission
which was designed
to be more accurate
I mean it was special
and I'll show you
something about that,
but it helped check and
improve early climate models
that was an important thing.
Now here is a picture
of solar radiance,
the top part is
the Nimbus-7 ERB
and you could see the solar
cycle, sunspot cycle,
the solar cycle how it varies
and here is the
Solar Max Mission.
We actually beat
them by six months.
We know that they
are more accurate,
and down here is the
follow-on to the Nimbus,
the Earth Radiation Budget
satellite experiment,
and so we have a good record
of the solar radiance.
Now, this diagram shows
something different,
going away from the solar.
This is the measurements
of the variations
of the outgoing infrared
radiation over the globe
for this particular one;
June, July and August,
and the top one
is the CCMI...
the CCM1 rather,
climate model,
and the bottom
one is the Nimbus-7.
And what we are talking about
is the Standard Deviation.
For those who don't know,
it's the... it's a measure of
the variation of the radiation,
of the outgoing
infrared radiation;
the higher the
Standard Deviation
the greater the
variation from its Mean.
So what you'll
notice dramatically,
if you compare
these numbers,
you will see that there
are Standard Deviations
in many places.
On the average it's about
twice as much in the models
than you see with
the measurements
from the Earth Radiation Budget.
So as a result the models had
to be revised considerably
and they were
greatly improved
until they got something
in the order of
what we actually measure.
So that was an
important thing.
Another thing I want to show,
the follow-on to
the Nimbus-7 ERB
was the Earth Radiation
Budget Experiment (ERBE),
and this was the ERB's
part of that on NOAA-9,
and I want to
compare the...
a four-month average,
a particular figure,
and I have it circled.
It came out with 234.50 W per
meter squared for the outgoing
and the Nimbus-7
Wide Field-of-View at 234.88,
pretty close.
Also close on the albedo
the percent reflected
up from the... of
the solar radiation,
29.89 here, 29.88 here.
So excellent, and the
ERBE was the follow-on
which then led to the series;
Climate and Earth's Radiation
Energy System, I believe.
So I have some conclusions.
The Nimbus ERB
results confirmed
and greatly expanded
our knowledge
of the fundamental earth
science parameters.
It also provided a baseline
for the outgoing...
ongoing monitoring
of the Earth's climate
system from space.
It also guided development
of global models
and international climate
experiment such as GWACs,
and it led to the
highly successful
NASA ERBs and SIRIs programs
to continue the expansion of
knowledge for climate purposes.
But one last thing
I want to say,
I meant to say it before
when I was talking about the
science theme that we had.
And this is a happy
reminiscence of that time.
We had a number of team
members, in every three months
we would go to meet at
one of their locations,
be it Caltech or UC Davis,
different places,
and you know, after a while
you come in the evening,
go to dinner,
and it's you know...
you do not in a friendliest
surroundings as you would like.
So I discussed this with
my wife and she said,
"Why don't you have them all
over to the house for dinner?"
when we were
meeting in Maryland.
I said, "Great idea,"
and she prepared a dinner,
a buffet dinner
that we can take and they
can all come and meet.
And I remember that,
my two daughters were
very young at the time
and they came down and said
goodnight to the team members,
you know, I remember
this very fondly
and she and... we even set
up an easel that we...
my daughters would use for
doing a little painting
and we use that and had some
discussions, very relaxed,
and had dinner in a much
better surroundings
than we would have today,
a more formal setting.
So I remember
that very well.
So that's what I take
away from it personally
besides the conclusions,
the success of the
Nimbus-6 and 7 Radiation Budget
that provided.
Thank you!
[Applause]