PubTalk 07/2023: From Snow To Flow — When Snow Falls On A Mountain, Where Does It Go?

Hello, everyone, and thank you for joining us tonight.

Uh we'd like to welcome you to the United States Geological Survey virtual public lecture for this evening.

My name's Christy Ryan, and I'm going to be your host and moderator tonight.

Before we get started here, I do want to point out a few things, take a few minutes if this is your first time using this Teams Live platform, I just want to point out a few things, and also give you an overview of what the lecture will be for next month.

Uh so one really great feature about this Teams Live platform is that you can use the Q and A panel to submit questions at any point during the lecture.

Just look for the question mark icon, which is going to be located in the upper right hand corner of your screen.

And we do encourage you to ask questions all throughout the lecture as you think of them.

Uh then at the end of the lecture, we will try to get to all the questions, but depending on how many we get, we may not have time uh to get to all of them, but we'll do our best.

Another feature we want to point out is um close captioning.

So if you're on a desktop computer, just look at the bottom right hand corner of your screen for the CC icon.

You can also use the stream text link that I provided in the Q and A window if you want to view live close captions.

Um and just one more thing before we get started um is I wanted to let you know about our lecture for next month.

On August 31st, we will have the pleasure of welcoming three speakers, um Aparna Bamzai Dodson, who's a USGS physical scientist, Nicole Herman Mercer,

who's a USGS social scientist, and Sheri Watson, who's a USGS ecologist.

The title of their talk will be Indigenous Communities in the United States leaders in climate adaptation.

So we really hope you'll mark your calendars and join us next month.

And at the end of this lecture, I will give you information on how to join our mailing list.

Um and we only send two emails a month.

They're just reminders on what the lecture is um and then that way you'll always know what's coming up.

Um so now that we've gotten all that business out of the way, uh let's go ahead and start our lecture for tonight.

Um I'd like to introduce our speaker, Dr. Andy Craiton, who's a hydrologist and tribal liaison with our USGS Colorado Water Science Center.

Her work focuses on geophysical applications for alpine hydrology and snowpack dynamics.

She started with the USGS in 2020, and before that, she worked with the Forest Service and the National Park Service.

She received her PhD from the University of Wyoming in 2019, where her work focused on geophysical investigation of permafrost thaw dynamics.

She's very excited to be here with with everyone tonight, and she will present on her current and ongoing work on snowpack dynamics in Colorado.

So let's go ahead and get started, and let's give a warm virtual welcome to Dr. Craiton.

Andy, the floor is yours.

Thank you.

Thank you, Christy.

I'm so excited to be here uh to talk with you all about snowpack dynamics.

Um so without further ado, let's go from snow to flow.

When snow falls on a mountain, where does it go?

In a chilly cloud up high, where the wintry winds do fly, water vapor it floats around, ready to create snowflakes profound.

Tiny particles start the show, nuclei for crystals to grow.

They gather round, oh so neat, water molecules to meet.

With a shiver and a chill, ice begins its frozen thrill.

Growing slowly, flake by flake, nature's art it starts to make.

Temperature and humidity sway, shaping snowflakes along the way.

Branches sprout, delicate and fine, creating patterns so divine.

Down they fall, through the air, each unique, oh so rare.

A masterpiece, both small and grand, in snowflakes formed by nature's hand.

Now promise, I won't rhyme the entire time.

I'm not creative enough for that.

So let's jump into a little bit about how snowflakes form in a not Dr. Seuss manner.

Snowflakes are intricate and delicate ice crystals that form in the Earth's atmosphere when water vapor condenses and freezes around tiny particles such as dust or pollen that's in the air.

This process of snowflake formation begins with the cooling of moist air causing water vapor to transform into tiny ice crystals.

As these crystals grow, they adopt a hexagonal structure due to the molecular arrangement of those water molecules.

The shapes of snowflakes are influenced by the temperature and the humidity levels they encounter during their formation.

colder temperatures create snowflakes with more sophisticated and symmetrical patterns, while slightly warmer conditions result result in simpler and less intricate designs.

As the snowflake descends through the atmosphere, it encounters varying temperature and humidity conditions, leading to the the development of all of those unique patterns you see.

And all of those shapes that we admire on snowy wintry days.

So from those snowflake formation, we've now entered the water cycle as precipitation overland as that snow falls.

As the snow falls and accumulates at high elevation throughout the winter, it creates what's called the snowpack.

Snowpack persists throughout the winter until the arrival of warmer weather when it begins to melt.

Um which we'll talk about later.

Snowpack dynamics can be complicated though.

So other USGS scientists and I are trying to better understand snowpack and how it melts and what that means for water users throughout the year.

You might think since snow is made of water, the same depth of snow would contain the same amount of liquid water.

But the type of snow matters.

How much liquid water do you think would be in 3 ft of snow?

Like 3 ft, 3 ft?

Do you think it would be different for 3 ft of fresh, dry, fluffy snow versus 3 ft of compacted, wet, slushy spring snow?

It can be different.

So we have a water measurement called snow water equivalent.

That 3 ft of fresh, dry, fluffy snow may represent only 4 to 5 in of snow water equivalent, while 3 ft of compacted, wet, spring snow may contain 12 in or more of snow water equivalent.

This is why as hydrologists, we're more interested in the amount of water stored in the snow, that not necessarily its depth, since that's just going to melt and create our water supply.

So let's talk about some of the ways we measure snow.

One way we measure snow water equivalent is by using a snow sampler.

It's a tube that was invented in the early 1900s, and we're still using that technology today.

We insert the tube into the snow, then we weigh that snow using our handy dandy mixing bowl and a scale to convert it from weight to inches of water.

Another advancement that was not around in the early 1900s are permanent monitoring stations.

Uh these are specialized facilities strategically placed in snowy areas to monitor and collect data about snowfall and its impact.

These stations use various instruments to measure snow depth, water content, and the weather conditions.

These advanced stations uh that the USGS is implementing now account for processes like sublimation and particle flux, which were previously not very well characterized.

Sublimation is the process by which snow directly transitions from a solid to a vapor without melting into liquid water.

And it can significantly impact snowpack levels and water availability.

Particle flux refers to the movement of snow particles caused by wind and other environmental factors such as snow distribution and accumulation patterns.

These are of particular importance in areas above tree line, like the station that you see here on the left.

By incorporating data on sublimation and particle flux, these snow stations uh offer a more comprehensive understanding of snow dynamics, especially in complex terrain and in extreme climat climate conditions.

This enhanced knowledge only improves water resource management, uh but also avalanche forecasting, and it contributes to our understanding of snow's role in global climate patterns and ecosystems.

So the next time you see snowflakes falling, know that there are dedicated stations out there diligently recording valuable information about all the snow for your benefit.

Next, we have snow pits.

As you can see, these are deep, and you can only imagine how much effort it takes to dig these.

The snow pits are excavated to reveal the different snow layers um and how they formed over time.

It allows snow scientists and avalanche forecasters to assess snow stability and the potential for avalanche risks.

Additionally, snow pits enable the collection of snow samples for further analysis, including chemistry, which helps researchers understand snow metamorphism, density, and water content.

Snow crystal structure, which we can get from these snow pits, is of paramount importance in snow studies because it directly influences the behavior and the characteristics of the snowpack.

The intricate and unique structures of snow crystals determines how that snow interacts with the environment, impacts water resources, and can pose potential hazards.

So here's an example of those snow crystals.

And as you can see, here's me looking at exams crystals like that on our little crystal card.

All right, next we have a snow probe, which is basically a long fancy ruler with a GPS attached to it to measure snow depths across transects.

These give us less detailed information than the snow pit, but obviously we can take a lot more samples in the same amount of time.

We then use those depths to estimate uh the volume of snow and potentially the snow water equivalent in larger areas.

Art?

Okay.

I'm not an artist.

But what we have here is an example of real data from the Senator Back site, which is that same snow station we were referring to before.

So on that y-axis, we have depth from zero being where that skier is.

Do note that the stick people are not to scale.

Um so we have the the snow surface down to about a meter, and then we have approximately 30-ish meters on the x-axis.

So here's an example of the probe being used, and it's hitting that snow ground interface at 0.53 m.

All right, so then we move along, we take another probe measurement.

This one is at 0.58 m.

And what we can get is a map of that variability.

And you can see in this map where we've interpolated between all of our points at Senator Back, we are ranging from about 0.4 m to over 1.2 m.

And so you can see in these alpine areas where wind distribution and sublimation are impacting the snow, there is quite a bit of variability.

To see that variability better, we move into ground penetrating radar, which is a non-invasive geophysical technique used to investigate surface features and structures.

It works by sending high-frequency radio waves into the subsurface that then echo off differences in electromagnetic properties, creating these wavelets.

So where those big spikes are, that's where we expect to see um an interface.

And so air to snow, those have very different electromagnetic properties, and then snow to ground have different electromagnetic properties, making it an ideal geophysical target.

So as we drag that radar in our sled behind us, we get multiple traces, and they stack together, which eventually leads us to a radargram,

which we can interpret.

Here is our sled-mounted design with a GPS attached, and that is me dragging it all over the place at our Senator Back site.

So now we're back to our same uh transect from before.

It's the exact same one from the snow probes, but now we're able to visualize some of that variability with the ground penetrating radar.

So you can see that really strong reflection at the bottom, which I've outlined in pink here, is that snow ground interface.

And so what we see here is we caught um two points at the with the probe, which were actually some of the deepest points.

So if that's all we had, we might overestimate how much snow is available in this catchment versus being able to see a lot of that variability with the ground penetrating radar.

So stepping it up even more, we bring in the drones.

Drones can access remote or difficult to reach areas such as high alpine mountains or rugged terrain where those traditional measurements may be challenging or even dangerous.

Um this expands the range of locations that can be studied, leading to a more comprehensive understanding of snow dynamics.

Here's an example of some of the flight paths from Berthoud Pass.

As you can see, one, we can cover a much larger area with the drones.

They don't have to ski up the 2 and 1/2 mi of uphill with all the equipment getting tired and sweaty.

They just take off from the parking lot.

They don't care.

Um they're also able to go into those red areas where there's avalanche danger, where obviously we don't want to send people.

So we're able to collect a ton of data safely and quickly.

One of the types of data we collect is lidar, which stands for light detection and ranging.

Lidar uses pulses, laser pulses, to measure distances and create detailed 3D models of the snow surface and the underlying terrain.

This enables precise snow depth measurements and the creation of digital elevation models of snow covered areas.

So this is an area outside of Winter Park, and we flew the radar or the lidar in September 2020 to get the bare Earth or snow off elevations.

Then we collected data about snow accumulation in February 2021 and April of 2021, which we can then subtract those out those snow on elevations from the snow off and we get our snow depth.

And now these technologies are so incredibly precise.

I can tell you that it's centimeter accuracy, but I can also show you.

So, this was during that awful time in 2021 when the Colorado backcountry was so scary and no one was going out.

So, this is a slab that I triggered.

You can see the depression out line in red, but you can also see it in this photo um and my look of bewilderment.

So, that's a snow slab that we triggered.

It didn't slide because it's it's far too shallow.

But anyway, um this is the level of detail we can get from these types of maps.

Okay.

So, now we've measured all of the snow while it's on.

What happens next?

Snow melts, right?

Which then creates stream flow.

Um at high elevations, all that snowpack can be several feet thick and store several inches of snow water water equivalent.

In this graphic, this is a typical amount of snowpack.

So, what we see is all of the snow in white, we see the frozen rivers, and then at the bottom, we see a reservoir with some ice on it, okay?

In the early summer, when snowpack melts, the liquid water races down the hill recharging the streams with lots of fresh water.

Do you see how fat those streams are now?

They're like big bright blue.

Uh there's often a peak of maximum stream flow during this time, and that stream flow can be captured by downstream diversions or reservoirs, um which are now a new section of our water cycle that we've brought in.

So, what about something like this year with a high snow spring?

So, it looks kind of the same, right?

It's just very white um and the rivers are frozen, but that's going to be thicker snow, and that ice on the reservoir is even thicker.

Now, as we move into that high snow summer, we have higher stream flows.

The reservoir is refilling.

Um there is more snow on the mountain that you can see, those little snow patches, and those are going to keep continue to recharge the streams well into the late summer, so we have a more continuous uh supply of water.

Like I said, this year, let's take a snapshot.

This is Rocky Mountain National Park looking at the Gorge Lakes.

Uh this is from June 9th.

That watch that snow.

Watch how it changes to then June 23rd, and then to just over a week ago in in July.

You can go back and you can see how much more or snow there really was uh in the beginning of June.

And this is quite a bit of snow for mid-July um in Rocky Mountain National Park.

Um it really is a high snow year.

So, why is that snow still there, and how does snow melt?

In this graphic, we can see in the hydrograph on the right, the top hydrograph represents in gray the snow water equivalent, more typical of a high snow year, um how we have a lot of snow water equivalent stored,

and then the melt is faster, but also later.

Versus a lower snow year where we have that earlier but longer melt and those lower peak stream flows.

So, what influences snowmelt?

There's many factors that influence how quickly and for how long the snow melts.

The first is the density of the snow.

The more water, the heavier, the longer the snow will take to melt.

The next is air temperature.

Of course, above freezing temps will allow the snow to melt faster.

The next is solar radiation.

Heat from the sun heats us up, and the amount of solar radiation will vary based on cloud cover as well as sun angle.

The higher the sun angle, the more solar radiation will heat whatever it touches.

Is wind speed.

A stronger wind will allow for more melting thanks to the evaporation process.

And lastly, we have albedo.

This term describes how reflective an object is, and fresh snowfall has one of the highest albedos of any naturally occurring substance on the earth.

Think of it when the sun hits fresh, beautiful white snow as a mirror.

It just reflects it right back.

But as the snow gets older, it gets darker or gets covered in dust, which has become a bigger problem in the west.

It's kind of like putting on a black sweater in the sun.

You're no longer reflecting it all off.

You're absorbing all that heat and getting really hot.

Snowpack significantly influences both water supply and the water quality in our reservoirs.

This snowmelt runoff and the dynamics that affect the timing and magnitude of melt play a crucial role in replenishing our reservoirs, increasing their water levels, and providing a reliable water source for drinking water,

irrigation, and industrial uses.

Uh we can see the corresponding high water year um and the lower water year in this hydrograph from the Never Summer Range, Colorado, in low water years and its impacts on the Lake Powell reservoir.

So, we talked about year and its high snow, what about a low snow spring?

Uh which is becoming more common now due to climate change.

Climate change can mean less snow accumulation, warmer winters, and earlier springs.

Climate change is influencing when and for how long that snowpack melts.

The liquid water is released earlier and slower than it would be prior to climate change influences, and there may not be a stream a spring stream flow peak like there would be in a typical season.

So, looking at this dynamic, uh you can see how low that reservoir is and how skinny those rivers are.

We still have little patches of snow, but they're not recharging those streams the same way as before.

And it's even worse in our little snow summer.

This means that summer stream flow will be low, and downstream reservoirs may only receive a fraction of their usual water budget.

So, even though we've had a high water year this year, it's not enough to our reservoirs.

You've probably heard about uh Lake Powell and Lake Mead being at historic lows recently.

All of the Colorado Compact and water budgets and all of the negotiations around that.

This has been a great year.

We've filled them up a little bit, but it's definitely not enough to account for all of those low snow years we've had in the past.

All right.

So, from all of this from the snow to the snowpack to the snowmelt to the stream flow, it flows to you.

You don't have to live in the mountains to receive your water from snow.

Mountain snowpack water has a much broader impact than you might think.

Water in the deserts of California or the agricultural fields of Kansas can come from Colorado mountain snowpack due to transmountain water diversions and these reservoir systems.

The water cycle is so much more connected, and a lot of it does depend on mountain snowpack.

I know you might think that it has nothing to do with you, but we talked about transmountain diversions.

Um I'm based in Pueblo, Colorado, and one-third of the water that flows through the Arkansas River, which is like a quarter mile from my house, comes from the west slope, comes from Colorado River tributaries.

So, that water flows past me, it flows out into eastern Colorado, out into Kansas, and eventually into the Mississippi River.

Um beyond that, if you've eaten any of the food that was irrigated with that water or if you've ever enjoyed a salad in the winter, all of that salad is grown in Yuma,

Arizona, and watered from Colorado River water, which has its headwaters and is so reliant on the snowpack that we have up here.

So, needless to say, this is an incredibly complicated system, and we only touched on a little bit.

Um so, this is our new water cycle diagram.

It was uh debuted last year.

A ton of work went into this, updating all of the complex processes that go into our water.

Um and so, if you'd like to learn more, please go to the Water Science School, visit us at uh our snow depth flow group by scanning the QR code.

If you want to learn any more about drones, visit our National Uncrewed Systems Office, and any questions in general about Colorado, please visit us at the Colorado Water Science Center.

Um at this point, I'd be happy to take questions, comments, concerns, and emotional outbursts.

Thank you so much, Andy.

That was all the photos and the graphics.

It really makes me jealous seeing all your field photos.

I mean, I'm sure that definitely beats working in an office all the time.

So, this is my favorite field site um

out near Silverton, Colorado.

Wow.

Yeah, and you know, just throughout your talk, I was just thinking in my mind, I'm like, I'm out here in California, and you know, just kind of thinking what you were talking about and how it works out here, and and in fact, which I was anticipating,

we it looks like we did get a few questions um about California.

So, um

Okay.

Yeah, and and it's been great.

Folks have been asking all throughout your talk, and you know, just a reminder, if you do want to ask a question, please feel free um to click that that question mark icon, uh submit your question.

I'm I'm going to be actively asking Andy all those now, so we'll get through as many as we can.

So, let's see.

Let's give you a a good one here.

Well, actually, the first one is more of a comment.

Um couple people have liked it.

Uh great poem to start the lecture with.

Did you write it yourself?

Yes.

Awesome.

Yeah, that was a great way to kick it off.

Uh

Um another one rhymes.

The title rhymes.

We had to roll with it.

No, I thought it was great.

Yeah, it was a great way to kick it off, and uh people agree.

Um somebody else wrote in, "How does the USGS choose the locations of the snow monitoring stations and snow survey sites?"

Fantastic question.

So, some of that is based upon historic areas where snow has been studied for a really long time.

So, like the Senator Back station has had um previous entities who have studied there.

Um also, some of them we install near SNOTEL stations, which um the NRCS runs.

Um those are typically below tree line, so it's a great opportunity to pair those alpine stations with the tree line stations, so we can really cover all of that area.

Um and then some of it is uh bureaucracy where we can get permits for things um as well as funding, who's interested in that data and paying for it.

Um they're not cheap to install.

Right.

Makes sense.

Um let's see.

Someone else is asking um does the snowmelt result in a steady flow of water or does the rate of water accumulation vary with time?

It can vary with time.

Um so, this year um

we had an unusually cool spring, and so sometimes you can get a little surge of uh melt, and then other times uh it it is a little bit more steady.

It also I made it sound like it just goes from the snow to the flow.

Um it is a very complicated process with things like soil saturation, preferential uh flow paths that it it's a complicated question.

Um I'm sorry, that probably wasn't the answer you were looking for.

That is okay.

And you know, you shared your contact info, so I'm sure they can, you know, ask you more if they need to.

Um let's see.

Someone else is asking, "Do you share your data with other agencies, like the National Weather Service?

If so, how often are you collaborating and sharing?"

All of the data that the USGS has is publicly available.

It is all available on NWIS.

It is public-facing, and a lot of it goes out in near real time.

Um so, that is provisional data subject to revision, but you can go look at the conditions 15 minutes ago at any of these sites.

As far as collaborations, I'm not totally certain because I don't know who's accessing all of these websites, but I do know that places like the Bureau of Reclamation have software for their stream flow forecasting that pulls in that SNOTEL information.

It can automatically ingest uh USGS stream gauge data uh and our meteorological stations.

Great.

So, I guess the good part about that is they don't have to ask us.

We just it's all there.

Exactly.

Yep, and I'm sure everybody especially the weather service would know where to find it.

So, that's great.

Um here's one.

I it says this anonymous, "I'm in California.

Um do you study areas out here or is that a different office?

I'm so curious what our water levels will look like when all the snow melts.

We've had record snowfall."

Absolutely.

Uh so, those questions are probably better directed at the California Water Science Center, and maybe Chris, your Mitch could drop that link in the chat for you.

Yep, just did.

Perfect.

Thank you so much.

Yeah, um I don't know exactly how how that's going to work out there.

Different stream flows in different areas.

Some are really flashy and muddy, and um some are a little bit more consistent.

and so, I wouldn't want to make conjectures about California.

Yeah, no, absolutely.

And and this just illustrates, you know, we do have water science centers in every state.

So, you're with Colorado, we have one in California, we have them in all the states, which is great.

Um and I did put that link in there for how to contact the California office.

Um here's another good one.

How much of the run off the melt is actually penetrating and refilling the groundwater?

Oh, um that is a great question.

Um it depends.

In headwater streams, that's going to be a lot more than uh farther downstream, right?

Like I talked about how I live right next to the Arkansas River.

Well, partly because it's channelized here.

But we're going to see more of that up top and then it's really going to depend on what the subsurface is made of.

How easily can that water move into the groundwater?

Um but that is one of those things, right?

if you have a really dry soil because you haven't had any groundwater recharge, you know, there's more space to take in all of that water versus sending it off into the streams.

So, again, it's complicated.

Not surprised, not surprised.

Um there's a visualization on your website um and it looks like it has data going back to 2021. Um how soon does data from um 2022 and 2023 get added?

When we talk to the people who maintain that and we get around to doing it.

Um so, the data visualization snow to flow page is not like in least.

It's not automatically updated.

That was something that was put together by um some of the snow hydrologists to make it easier to understand what we're working on and why it's important.

And so was kind of uh done a little bit as a one-off, but if you scroll down to the bottom, you can click on different stream uh different snow sites and see what those water years look like um across the whole western US.

Great.

And I did add that link in to the Q and A panel as well if others want to take a look at that.

Um couple more here.

Anonymous uh commented, so well done, Woo, Silverton.

So wonderful area.

Um another one here.

When using drones to collect data in large areas, do the trees pose a problem in snow pack estimates?

That's a great question.

Um most of our lidar software has the ability to determine whether uh the points are vegetation or ground surface, meaning snow surface.

and this point.

So, classifying those points, we can generally get pretty good estimates.

Sometimes it's not perfect, nothing is.

Um but for the most part, that's fairly well accounted for.

Okay.

Uh looks like a few more have come in, at least two here right now.

Um another one on drones.

Does the USGS work closely with the FAA when working with drones?

Yes.

Uh everyone has a pilot's license.

Um I think they I I'm not a drone pilot, so I'm not totally sure what goes into all of that, but I think they have to file all their flight plans.

Um and we also have to get Forest Service permissions to be able to fly these above public lands.

Um that may be something a bit more for our drone group out of our National Inventory Systems office.

They're the ones who handle all that.

It's a special group that we call out uh when we want to run drone surveys.

Yeah, and actually I was going to ask if you um work with that group for the drone work.

And I'll throw that a link to their program in the chat as well here.

I'll pull that up.

Um

Perfect.

And it looks like, oh, good, another one popped in.

Um let's see.

From anonymous, do you measure water temperature for any reason or is it not an important data point?

Um we measure water temperature at almost every stream gauge that we have.

Um and it's important for so many different things including, you know, biology even, you know, where fish can survive.

Um we don't really measure that at the the snow stations, uh but it's super important and in fact, uh there's been some talk of perhaps studying uh water temperature above and below these um water diversions trans mountain and seeing how bringing that water through the mountain is impacting those ecosystems.

Okay.

Um another one just came in from anonymous.

Do states in the Colorado River Compact use your snow melt data to predict future water distributions to member states?

I have no idea.

That is such a complicated question and such a complicated topic and that does seem like that's more Bureau of Reclamation's

uh job.

I do know that they use a lot of our data in their forecast.

Got it.

Bureau of Reclamation.

Okay.

Um what are the main impacts to the environment based on the change in snowfall, snow melt, and stream flow?

See what I can talk about.

Um there's so there's so many, right?

Uh having low snow years impacts nearly everything, right?

So, our streams are lower, uh the plants aren't getting as much water as they're used to.

Um also adding in things like dust on snow, which will cause the snow to melt even earlier than it used to.

So, now we have no late summer water supply.

So, everything's getting even dustier and it's getting drier.

Um and that even leads to things like uh beetle kill.

If you've been out in Colorado and you see all of the pine beetle kill, a lot of that's exacerbated by things like drought, uh which directly comes back to our snow pack.

Drought isn't just something that only happens in the summer.

It's all connected.

Um yeah, there's so many things, you know, like the trees become uh more susceptible to wildfire, to diseases, to pests, to bugs.

Um and also that widening gap between water availability and water consumption needs.

As things are drier and those pulses from the stream flows are not really matching up

with when we want the water, which is at the end of summer.

I could see that as its whole own public lecture.

Environmental impacts.

It really, yeah, it really could be and and I'm I may make a note of that for for the future.

Um and it, you know, it looks like those were all the I mean, there were a lot of questions there and it looks like we got to all of them.

Um so, yeah, I just, you know, want to thank you so much, Andy, for taking time out of your busy schedule.

I know you literally just got back from doing some of this field work, so we really appreciate it.

No thank you.

We really, yeah.

We really appreciate it.

I love talking about snow in July.

It's it's wonderful.

We could talk about snow all year long.

Yeah.

Of course.

It's my favorite.

Well, thank you.

Yes, thank you very much.

And we also want to thank everyone out there for joining us today and for asking all these wonderful questions.

Um in case you do want to watch this lecture again or if you want to share it with others, um Andy's lecture will be available in about a week for on-demand viewing on our public lecture website,

which is on the screen.

It's www.usgs.gov/pls.

And on that website, you can actually find videos of our past public lectures spanning the last few decades.

And our lecture schedule for the rest of this year.

Um we have great lectures lined up uh including talks from our Earthquake Hazards Group and our National Wildlife Health Center.

Um if you want to be added to our mailing list, so you'll always receive notices about the lecture of the month, just send us an email at wmc esic at usgs.gov and we can easily add you to the list.

And finally, we do hope you'll join us again next month on August 31st at 6:00 p.m. Pacific time for our talk Indigenous Communities in the United States, Leaders in Climate Adaptation.

So, until then, thank you again to Andy, thank you again to all of you out there, and we hope you all have a good night.

Goodbye.