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Clouds are one of the most important
aspects of climate and we need to
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understand how clouds work better.
Y’know, we have instrumentation that
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can measure physical properties of clouds,
but actually being able to collect samples
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of the cloud water we’re flying through
to analyze the chemistry of those cloud
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droplets is an important part of the
puzzle that we haven't yet been able
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to do in this mission.
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People have collected cloud water. I mean,
clearly when the aircraft flies through
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clouds the airframe collects water.
Unfortunately, that fine detail that
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were trying to tease out from the cloud
chemistry is lost when you contaminated
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with everything that the aircraft has
been picking up through it’s flight.
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So the idea here is essentially it's a
control. We have a way of controlling
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what we take in as cloud water and we
try to reject the stuff they don't want
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to include.
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The clouds we are measuring here are
what is known as boundary layer clouds.
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And that's really what's important for
the NAAMES mission, is understanding
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those low boundary layer
clouds over the water.
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So, these clouds have, essentially, a
fairly well defined profile of liquid
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water.
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As you go higher, the cloud gets generally
thicker so there is more cloud water
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available.
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Down at the bottom of the cloud the cloud
droplets aren't as large and there's not
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as much clout water
available for collection.
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We want to target both of those regions,
both the cloud base and the cloud top,
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because even though the cloud base is
harder to get a large volume of cloud
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water collected, it has interesting
information about the aerosols that
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were involved in activating
those cloud water droplets.
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The top of the cloud, it's juicier
there's more liquid water content
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availablefor us to collect, but
essentially it's potentially more dilute.
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The interesting thing is we know how
the water mass changed vertically, but
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if the concentrations show something
different that's essentially information
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about chemistry that's happening within
the cloud, which is one of the areas of
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study that I'm really interested
in trying to understand better.
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What were trying to understand is the
small amount of impurities that are
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in the cloud.
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They may have come from locally produced,
uh, in-situ production of these species
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in the cloud water through this wet
chemistry, if you like in the cloud.
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Or it could have been dry chemistry
below the cloud, so it didn’t need
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the cloud to perform
that chemical reaction.
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We’re measuring below the cloud.
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We know what the composition of aerosol
and gases are below the cloud.
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With this cloud water we add
another piece of the puzzle.
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We try to understand other things like
sulfate chemistry which is an important
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aspect of this study.
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The ideas that within clouds you have
gasses, you have aerosols, and you have
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activated aerosol particles
which are the cloud droplets.
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The chemistry becomes that much more
difficult when you have this phase change.
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You have liquid water in abundance and
it acts as this new medium where chemical
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reactions can take place. When you’re
out of the cloud you don’t have that.
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That's an experiment
we’ll do off-line.
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So now that we've collected this cloud
water—it’s going to be done with Luke
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we’ll set up an experiment and the
lab and, again, it's a new technique
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and I don't believe that anybody has
looked at biological particles in cloud
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water in this way, certainly in
connection with a mission such
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as NAAMES, where there is a strong focus
on ocean and aerosols interactions and
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how that interacts with clouds,
so this is a new thing.
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We've had requests to use the cloud
water we collect during this mission
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to supplement other investigators work.
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People who are outside of my knowledge
in biology have taken an interest in the
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cloud water to do their analysis,
particularly the kind of analysis
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that's done on seawater and use that as
a comparison to see whether stuff comes
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off the ocean and makes it into clouds
and how it affects the clouds.
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It's a tracer, essentially. The nice
thing about using those biological
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particles is that they are a tracer that
doesn't necessarily change in the same
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way that chemical tracers change.
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Chemical tracers can evolve
and react into other species,
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but these biological tracers are
somewhat inert in that sense to
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chemical transformations.
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That's another exciting technique that
we may do to try and understand the
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connection between the clouds locally
and potentially regionally transported
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particles that affect clouds.
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This probe that hangs down here is
called the AC3, the axial cyclone
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cloud water collector.
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This is the new prototype collector
for collecting in situ cloud water.
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In the inside of the probe, the stator
which basically generates that swirl,
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it is made out of stainless steel.
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The rest of the probe is aluminum.
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To make that part out of aluminum using
conventional milling would have been very
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very difficult, and taken a long
time and been very costly.
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We used an experimental technique.
It's steel powder that we start off with.
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It’s a process called laser sintering.
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Essentially the laser melts the steel
powder and builds the shape
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in the same way that a printer would
accept that it's three-dimensional.
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it's 3-D printing but for steel.