Touring the Globe with PACE

0:01 The NASA Plankton, Aerosol,

0:02 Cloud and ocean Ecosystem mission has been in orbit for just a few years now.

0:07 Here’s a few highlights of some

0:09 of the exciting observations PACE has made since then,

0:12 and continues to make every day.

0:14 In some cases, these are first-ever measurements,

0:17 things that have not been observed from space before.

0:20 Others are new and unexpected.

0:22 PACE, as its name suggests, is an inherently multidisciplinary mission.

0:27 Not only can we observe the atmosphere, ocean, and land surfaces from space,

0:32 but connections can be made between these different observations.

0:36 Let’s start with an example of how PACE observes wildfires and smoke.

0:41 This is a large scale, true color image,

0:44 and we can see the very destructive fires

0:46 that occurred in Southern California in January of 2025.

0:51 What we’re looking at in this image are smoke plumes,

0:53 and you can see them blowing off from the Los Angeles region out over the ocean.

0:59 But we can also look at the impact of these fires on the surface itself.

1:03 So PACE can measure the relative burn severity from these fires.

1:07 We can also look at the smoke

1:08 from those fires as it’s transported away from the region.

1:11 So smoke is a particle, in other words, an aerosol.

1:14 An aerosol is a terminology that scientists use

1:17 to describe any sort of particulate matter in the atmosphere,

1:19 which includes smoke.

1:21 So what we see in this image is aerosol optical depth.

1:25 This is a measure of how much

1:27 aerosols are present in the entire atmospheric column,

1:30 meaning from the surface to the top of the atmosphere.

1:33 If you look to the top left, you can see the Palisades and Eaton wildfire

1:36 smoke plume as it’s blowing out over the ocean.

1:39 If you look more towards the middle of the image,

1:42 you can see another plume, and this is coming from Baja California.

1:46 The question is, is that also smoke?

1:49 We believe it’s not.

1:50 We believe this is dust because of the other measurements we’re

1:53 making with PACE that give more clues as to what’s present.

1:57 So one clue is to look at the light absorption of the aerosols.

2:01 Dark particles, very absorbing particles, are usually associated with smoke,

2:06 whereas brighter particles can be dust

2:09 or other types of particles in the atmosphere.

2:12 Another piece of information is the aerosol size.

2:16 Smoke particles tend to be very small

2:18 relative to dust particles, which are larger.

2:21 Now let’s move to another event that’s crucial to monitor.

2:24 This is from the OCI sensor on PACE,

2:27 and it’s an indication of cyanobacteria in the Great Lakes and nearby areas.

2:32 Some cyanobacteria are toxic.

2:34 That means that they affect drinking water,

2:37 and through that, humans and other organisms in and around the Great Lakes.

2:42 This animation is from several weeks over the summer of 2024,

2:45 and we can see a couple of regions

2:48 in the Great Lakes that are affected by cyanobacteria.

2:52 So now let’s zoom out a bit and look at aerosols in a different way.

2:57 So now we’re looking at the aerosol index.

2:59 And this is really great for exploring large scale phenomena from aerosols.

3:04 And it relies on the sensitivity of the OCI

3:06 sensor to the ultraviolet part of the spectrum.

3:11 One of the great sources of aerosols globally is a Saharan Desert.

3:15 So we’re looking at in this animation here is some

3:19 of that dust from the Sahara Desert blowing west over the Atlantic Ocean.

3:24 If we look to the north, we can see another plume.

3:27 And this is related to wildfire smoke

3:29 from fires in Canada and the United States.

3:33 And these smoke particles are transported out

3:35 across the Atlantic Ocean to the east, sort of in a circulation pattern.

3:39 Dust moving west; smoke moving east.

3:42 So now let’s move to one of the great strengths of the OCI sensor,

3:46 which is to identify phytoplankton type in the ocean.

3:50 Right now we’re visualizing Picoeukaryotes,

3:52 which are a type of small algae that really thrive in coastal areas

3:58 where there are more nutrients and the conditions are right for their growth.

4:02 Next is Prochlorococcus.

4:04 So they thrive in conditions of low nutrient loads.

4:08 And so you can see that they are dispersed much farther

4:10 from the shore out in the middle of circulating ocean gyres.

4:16 And finally, Synechococcus is a type of algae that thrives

4:20 in sort of borderline between high and low nutrient areas.

4:26 So each of these are interesting

4:28 to consider as different ecosystems in the ocean.

4:31 It’s almost like on land we have grasslands and we have forests,

4:35 and they’re that way because of how much water is there,

4:37 how much nutrients are there.

4:38 And it’s the same thing in the oceans.

4:40 And what’s very important in the oceans is that these areas move,

4:43 you know, forests don’t move quickly, but these regions do.

4:47 And this is something that we can track with the PACE mission.

4:50 So now let’s move to the other side of the world off the coast of Russia.

4:53 What we’re visualizing is another class of phytoplankton diatoms.

4:58 Diatoms, like all types of phytoplankton, follow ocean currents.

5:02 And you can see the swirls and interesting patterns here

5:04 that are associated with how water is moving in the area.

5:07 So this particular class of phytoplankton is

5:10 important because they transfer carbon into the ocean.

5:12 This interacts with ecosystems and ultimately fisheries.

5:17 Now let’s move to South Australia where there’s

5:19 another type of harmful algal bloom in progress.

5:23 This is not cyanobacteria.

5:24 These are larger organisms.

5:25 But just like cyanobacteria,

5:27 they create harmful compounds in the water which can adversely affect humans.

5:32 So OCI is sensitive to this type of harmful algal bloom

5:35 by looking at the combination of backscattered light and fluorescence of light.

5:40 In other words, using the optical properties of particles in the ocean,

5:44 we can determine what’s there and if it’s dangerous.

5:48 So now let’s look at clouds.

5:49 One of the aspects of PACE is that two of the sensors on pace are multiangle,

5:55 meaning that they observe the Earth from different geometries.

5:58 What we can do with that is reconstruct the 3D nature of clouds,

6:02 in this case from the HARP2 instrument.

6:06 So this is important for understanding climate,

6:08 weather and, of course, aviation.

6:11 This is a product that’s in development.

6:13 We’re making use of new machine learning tools

6:15 so that we can produce this product globally.

6:19 So that’s not the only measurements of clouds that we can make from PACE.

6:22 If we move to the west off the coast of California,

6:25 we see a very persistent cloud deck

6:27 of a type of clouds called marine stratocumulus clouds.

6:31 So these are low level clouds that are persistent off the coast of California.

6:35 If you look at them, you can see little streaks through here.

6:38 These streaks are due to the presence

6:40 of humans specifically shipping throughout the area.

6:43 We call them ship tracks because the emissions

6:45 from ships interact with clouds and change their nature.

6:50 In this image, a true color image,

6:51 we can see how they’re brighter because of this.

6:54 But we can also look at the cloud droplet size distribution,

6:58 how big or small the cloud droplets are.

7:01 Another product is the cloud droplet effective radius.

7:04 It’s sort of like the average size of the particles in the cloud.

7:08 You can see here a change in the size

7:10 of the cloud droplets indicating the presence of ships.

7:14 Now let’s focus our attention on OCI’s ability to monitor land surfaces,

7:18 which is something that was not in the original plan of PACE.

7:22 So OCI is sensitive to concentrations of leaf pigments around the globe.

7:27 This advances our ability to measure things like forest and crop health,

7:31 and we can do so globally.

7:33 So here we can see the advance of fall colors

7:36 as we transition from a chlorophyl or green pigment dominated state,

7:41 to other pigments, which are associated with the yellows

7:44 and reds that we expect to see in fall colors.

7:48 So those are just a few examples

7:50 of the measurements that we’re making from PACE.

7:53 The highlighted scenes are specific examples,

7:55 but these measurements are made globally throughout the Earth.

7:59 Some of the products are still in development,

8:01 but others are free and available to the public, including scientists,

8:05 decision makers or anybody who’s interested in exploring

8:09 the connections between different elements of our changing planet Earth.