WEBVTT FILE

1
00:00:00.466 --> 00:00:01.766
It’s autumn

2
00:00:01.766 --> 00:00:03.100
and things are changing.

3
00:00:03.100 --> 00:00:04.100
Cool air,

4
00:00:04.100 --> 00:00:05.433
hot cider,

5
00:00:05.433 --> 00:00:06.966
and leaves!

6
00:00:07.166 --> 00:00:07.933
As humans

7
00:00:07.933 --> 00:00:09.466
we can see this striking change

8
00:00:09.466 --> 00:00:10.533
in our neighborhoods

9
00:00:10.533 --> 00:00:11.600
or even on a trip.

10
00:00:11.600 --> 00:00:13.166
Fall foliage tourism brings

11
00:00:13.166 --> 00:00:14.633
in tens of billions of dollars

12
00:00:14.633 --> 00:00:15.833
in the U.S. alone.

13
00:00:16.066 --> 00:00:17.033
But there’s more to it

14
00:00:17.033 --> 00:00:18.000
than just a

15
00:00:18.000 --> 00:00:18.966
pretty scene.

16
00:00:19.133 --> 00:00:19.900
The fall colors

17
00:00:19.900 --> 00:00:21.833
signal changes with our food,

18
00:00:21.833 --> 00:00:23.866
our air, our ecosystems.

19
00:00:23.966 --> 00:00:25.500
Photosynthesis ends,

20
00:00:25.500 --> 00:00:27.600
carbon and water balance change,

21
00:00:27.600 --> 00:00:28.800
and leaf color changes

22
00:00:28.800 --> 00:00:30.766
how much sunlight is absorbed.

23
00:00:31.400 --> 00:00:32.966
Now with the PACE satellite,

24
00:00:32.966 --> 00:00:33.400
we’re seeing

25
00:00:33.400 --> 00:00:34.800
seasonal fall foliage

26
00:00:34.800 --> 00:00:36.333
in a whole new view.

27
00:00:36.533 --> 00:00:38.266
PACE can see more information

28
00:00:38.266 --> 00:00:39.600
in leaf color changes

29
00:00:39.600 --> 00:00:41.100
than our eyes can detect,

30
00:00:41.100 --> 00:00:43.033
especially in leaf pigments.

31
00:00:43.033 --> 00:00:43.733
These pigments

32
00:00:43.733 --> 00:00:44.600
protect plants

33
00:00:44.600 --> 00:00:45.700
and allow them to thrive

34
00:00:45.700 --> 00:00:46.733
in changing conditions

35
00:00:46.733 --> 00:00:47.800
and seasons.

36
00:00:48.000 --> 00:00:49.166
Before PACE, we’d

37
00:00:49.166 --> 00:00:50.400
have to infer the timing

38
00:00:50.400 --> 00:00:51.433
of seasonal changes

39
00:00:51.433 --> 00:00:52.500
by how much “green-ness”

40
00:00:52.500 --> 00:00:53.733
has decreased.

41
00:00:54.600 --> 00:00:56.033
By looking at how PACE’s

42
00:00:56.033 --> 00:00:57.400
pigment indices change

43
00:00:57.400 --> 00:00:58.866
relative to one another,

44
00:00:58.866 --> 00:00:59.833
it can give us a view

45
00:00:59.833 --> 00:01:01.500
into the health of ecosystems.

46
00:01:01.733 --> 00:01:02.500
For instance,

47
00:01:02.500 --> 00:01:04.400
a shift in the start of fall colors

48
00:01:04.400 --> 00:01:06.566
could mean drier or colder years.

49
00:01:06.566 --> 00:01:08.000
And data on leaf pigments

50
00:01:08.000 --> 00:01:08.833
could help answer

51
00:01:08.833 --> 00:01:09.933
other science questions.

52
00:01:10.100 --> 00:01:11.700
Like why do trees even turn red?

53
00:01:11.700 --> 00:01:12.933
Is it sun protection

54
00:01:12.933 --> 00:01:14.300
in colder temperatures?

55
00:01:14.300 --> 00:01:15.133
Or warning against

56
00:01:15.133 --> 00:01:16.300
insect damage?

57
00:01:16.300 --> 00:01:18.000
Or something else entirely?

58
00:01:18.133 --> 00:01:19.600
As PACE repeatedly covers

59
00:01:19.600 --> 00:01:21.000
both the land and ocean,

60
00:01:21.000 --> 00:01:22.133
we’ll gather more data

61
00:01:22.133 --> 00:01:23.466
to help us decode

62
00:01:23.466 --> 00:01:24.700
these colors.