This fog is just a stratocumulus cloud where its base is at the surface

but we don't think of it that way

we think of of fog as this grey kind of haze

when it's actually just individual cloud droplets

that are obscuring our view

I think if people realize they're walking through a cloud

that's probably the most important cloud type on earth

they might think that's pretty cool

clouds are complicated because there's so many different types

some are liquid, some are ice, some are both

some grow all the way from the base of the atmosphere to the top

and there's seasonal timings to worry about

the biggest question that cloud physicists are investigating right now are

how cloud droplets and aerosol particles interact with each other

any particle in the atmosphere is considered an aerosol

you only make a cloud when you have a particle

for the water vapor to condense upon

in general, if you think of a cloud over the ocean

the majority of particles that serve as the center of a cloud drop are usually

this combination of sea salt and some biologically produced sulfur from algae

If we look over land dust is a huge component right because there's lots of

dust over the desert there's lots of dust over land

and then for industrial areas particles from say power plants or from industrial processes

wherever you are regionally the particle distribution changes

so places where there's lots of fires our clouds have smoke centers

the smoke is actually amazing and complicated

because it does two things

if it's on top of the cloud like in San Francisco bay

if you look down from space the sunlight's coming straight from above

the smoke, it would look much darker so it wouldn't reflect as much like back

it would actually heat the earth in that sense

now eventually the smoke can actually intermingle with the cloud and not only

does that change how the cloud behaves it gives us a lot of other things to worry about too

It changes whether or not it rains

which determines how long the cloud will stay there

if we start infusing the cloud with more particles

we can have new particle formation and have lots of smaller ones

and now our cloud looks brighter because now we've got more droplets to reflect light

the stratocumulus example is great where you'll have actually off the California coast it's

actually very easy to see with the ship's going to and from Hawaii

the ship track streak will be so much brighter and it looks thicker and fluffier

than the cloud near it

so when it's above it makes the cloud look darker,

when it's intermingled it makes it look brighter so it's a really complex system

because you could have both happening at the same time

so how much does one cancel out the other is really complicated

you can see that added smoke and added particles

from us doing something as a species is changing clouds

it's not just there's lightning and there's some fires

the amount of clouds that are on the earth determine how much light is bounced back

if we get rid of those huge cloud masses then there won't be as much energy going back to space

and the overall temperature of the earth would go up

we have to know why it is doing what it's doing right now so that we can be better informed

about how to calculate what's going to change in the future especially in

regions that are developing more people are doing farming

there's more particles being emitted and then that could exacerbate the problem

and maybe deplete the cloud and then it gets warmer on top of that

the future of our work is to really get an understanding of those interactions

across a range of aerosols and a range of cloud types

clouds are that important to what temperature the earth is

that we need to know what those changes are