Analyzing Data for CERES

1
Analyzing Data for CERES SCOOL
Dave Young NASA Langley Research
Center SCOOL Teachers Workshop June 2003
2
Topics

• CERES comparisons
• Why do we need to compare data?
• What types of things do we compare?
• Where does SCOOL fit in?
• SCOOL comparisons
• What de we compare?
• How well do the student observations compare with
  CERES?
• What does it mean?
• Workshop data
• Can we make sense out of the balloon radiometer
  data?

3
CERES

• What does CERES Measure?
• What else do we need to know in order to
  understand the observations?
• Why types of data are available for comparison?

4
Clouds and the Earths Radiant Energy System
How is the global energy budget changing? Do
human-made aerosols affect the Earths
climate? Do clouds amplify or reduce climate
change?
5
Energy Balance of the Earth
6
The Effect of Clouds

• High clouds have an overall warming effect
• Low clouds have an overall cooling effect

7
CERES Terra ResultsJuly 2000
CERES Clear-Sky TOA Longwave Flux (W/m2)
CERES Total-Sky TOA Longwave Flux (W/m2)
8
CERES Cloud Retrievals June 2001
Monthly Mean Cloud Amount (Blue Clear, White
Overcast)
Cloud Properties Retrieved Amount
Height Optical Thickness Phase
Droplet Size
9
Collecting Data to Check Satellite Observations
10
Cloud Radars
14
Height (km)
0
0 5 10 15 20 GMT
July 19, 2002
11
Cloud Lidars
20 10 0
Height (km)
0 6 12
18 24
July 19, 2002
12
GOES Image from 1415 GMT July 19 2002
13
One Difficulty of Satellite-Surface Comparisons
14
Looking at the Workshop Radiometer Data (2002)
July 13 July 14 July 15 July 16 July 17
July 18
15
CERES SUrface LW Flux vs.Surface Radiometer
MeasurementsARM SGP CF February 1998
16
July 17, 2002 (Clear Day)
17
July 14, 2002 (Very Cloudy Day)
18
July 15, 2002 (Partly Cloudy Day)
19
June 23, 2003 (Monday)
20
SCOOL ComparisonsWhat is Compared?

• Cloud amount
• Clear (0-5)
• Partly Cloudy (5-50)
• Mostly Cloudy (50-95)
• Overcast (95-100)
• Cloud height
• Low (below 2000 meters)
• Mid (between 2000 and 6000 meters)
• High (above 6000 meters)

• Cloud layers
• Cloud Visual Opacity (how much light the cloud
  allows through)

21
Terra Comparison ExampleGloucester, VA June 4,
2001(http//scool.larc.nasa.gov/query_data.html)
22
GOES Visible Image June 4, 2001 1645 GMT
23
Second Terra Comparison ExampleGloucester, VA
June 4, 2001
24
GOES Visible Image June 7, 2001 1715 GMT
25
Clear Day ComparisonOctober 20, 1997 1745 GMT
Visible
Infrared
26
Comparison ResultsOctober 20, 1997 1745 GMT
Comment Comparisons of Clear-Sky Observations
Are Very Important!
27
Cloudy Day Comparison October 22, 1997 1745 GMT
Visible
Infrared
28
Comparison ResultsOctober 22, 1997 1745 GMT
Comment Poquoson observed contrails - These may
be what the Newport News students were reporting.
There also was a mid-level layer cloud to the
south.
29
Status of SCOOL Database (as of June 17, 2003)

• 25,154 student observations
• Matching with CERES
• Matched using reported UTC
• Observations must be within 15 minutes
• CERES data from TRMM, Terra, and Aqua
• A total of 4625 matches
• Why only 4625 out of 25,154? (only 18.4)
• Class times not in sync with satellites?
• Time reporting errors?
• Check overflight schedule

30
TRMM/SCOOL Cloud Amount Comparison(Observations
within 15 minutes)
31
Summary of Cloud Comparison

• The Students and Satellite Observations
• Agree 60 out of 99 times (60.6)
• Weakly Agree 29 out of 99 times (29.3)
• Disagree 9 out of 99 times (9.1)
• Strongly Disagree 1 out of 99 times (1.0)

32
Understanding the Comparisons

• The Importance of Time Matching
• The Need for Many Different Observations
• Guess the Cloud Amount Activity
• The Comparison with Random Observations

33
(No Transcript)
34
(No Transcript)
35
Looking at the Radiosonde (Weather Balloon) Data
36
SCOOL Radiosonde Measurements July 18, 2002
T
Dewpoint
37
Balloon Data from Washington D.
C.(http//weather.unisys.com/upper_air/skew/index
.html)
38
Balloon Data from Wallops Island
(http//twister.sbs.ohio-state.edu/skewt.html)
LCL 927 hPa
39
Comparing With Surface Observations(http//weathe
r.unisys.com/surface/meteogram/index.html)
40
Comparing With Surface Observations(http//www.wu
nderground.com/US/VA/Langley_Air_Force_Base.html)
41
End