page 1 validation by balloons and aircraft - esrin - 9– 13 december 2002 observations of aerosol...
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Page 1Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Observations of aerosol and clouds obtained during the
M-55 Geophysica ENVISAT Validation Campaigns
Marco Cacciani University of Rome “La Sapienza”, Italy
Stephan Borrmann University of Mainz, Germany
Francesco Cairo ISAC-CNR, Italy
Giorgio Fiocco University of Rome “La Sapienza”, Italy
Anastasios Kentarchos ERS-srl, Italy
Valentin Mitev Observatoire Neuchatel, Switzerland
Leopoldo Stefanutti Geophysica-GEIE, Italy
Page 2Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Summary
• Review of the instruments and performances
• Results of the July campaign in terms of total backscatter ratio, cloud top altitude, optical depth
• Internal consistency of the data and comparison with ground-based lidar measurements
• Samples of the results obtained during the October campaign
• Conclusions
Page 3Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Table I: Instruments, flights and performances
JULY CAMPAIGNABLE
University ofRome
MALdownObserv.
Neuchatel
MALupObserv.
Neuchatel
MASISAC-CNR
Rome
FSSP-3000University of
Mainz
COPASUniversity of
Mainz13/07/02ChemicalDaylight
NadirNo clouds
Nadir, 532Nothing detect.Some windowfreezing
Zenith, 532Clouds at endof flight.
Data @532No cloud
No dataavailable
2 identicalchannels, (allparticles> 10 nm),
15/07/02Aerosol
Night-time
Nadir, 355,532nmClouds andSaharan dust
Nadir, 532Few cloudsdetected.Some windowfreezing
Zenith, 532Nothingdetected. Somewindowfreezing.
Data @532Very smallcloud
No dataavailable
2 identicalchannels
18/07/02Aerosol
Night-time
Nadir355,532,1064 nmClouds andsaharan dust
Nadir, 532Clouds andaerosol.
No data. Data @532Cloud deck atthe end of theflight
Low clouds inascent anddescent, nodata at highaltitude
2 identicalchannels,only secondhalf of flight
22/07/02ChemicalDaylight
ZenithNo aerosol
Nadir, 532Clouds at endof flight.
Zenith, 532Clouds at endof flight.
Data @532No cloud
Low clouds inascent, nofurther dataavailable
COPAS notflown
OCTOBER CAMPAIGN8/10/02
Test flightDaylight
Nadir355,532,1064 nmClouds
Nadir, 532Clouds
Zenith, 532Clouds
Data @532Minor clouds
No dataavailable
1 channel, (allparticles> 10 nm)
11/10/02AerosolDaylight
Nadir355,532,1064 nmClouds
Nadir, 532Clouds
Zenith, 532Clouds
Data @532Several clouds
Low clouds,aerosols
1 channel
14/10/02AerosolDaylight
Nadir355,532,1064 nmClouds
Nadir, 532Clouds
Zenith, 532Clouds
Data @532No depol.Clouds at theend
Low clouds,aerosols
1 channel
17/10/02Air trafficDaylight
Nadir355,532,1064 nmClouds
Nadir, 532Clouds
Zenith, 532Clouds
Data@532Cloud deck atthe end offlight
Low cloudsonly ascent
2 channels,non-volatileparticles,clouds andcontrails
22/10/02ChemicalDaylight
NadirLaser failureOnly Zt
Nadir, 532Clouds
Zenith, 532Clouds
Noisy data@532possible clouds
Low cloudsonly ascent
test, noatmosphericdata
24/10/02ChemicalDaylight
NadirLaser failureOnly Zt
Nadir, 532Clouds
Zenith, 532Clouds
Data @532Two differentcloud
No data,instrument test
1 channel
28/10/02Chemical
Night-time
Nadir355,532,1064 nmClouds
Nadir, 532Clouds
Zenith, 532Clouds
Noisy data@532Some clouds
Low clouds,only ascent anddescent
1 channel
Page 4Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Figure 1. July 15 flight path
Page 5Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
FIGURE 2. First aerosol flight (July15); top:total aerosol backscatter ratio vs. time and altitude (the color bar on the left side represents the typical error in the value of the backscatter ratio; the flight altitude is indicated by a black line); middle: cloud top altitude (±30 m); bottom: thin clouds optical depth at 532 nm (error bars are shown; red color is used when a second layer is present in the same profile).
Page 6Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
ABLE & LAMPEDUSA 15/07/02
0
1000
2000
3000
4000
5000
6000
0 1 2 3 4 5 6 7 8 9 10
532 total backscatter ratio
Alt
itu
de
[m
]
lampedusa 12:00
lampedusa 9:30
able 19:35
able 19:34
Figure 3. Backward isentropic trajectories starting from the lowest point of the dive and passing over Lampedusa at different times. Numbers refer to the number of day. The July 15 flight path is shown with a color scale proportional to the altitude
Figure 4. Backscatter ratio vertical profiles observed by ABLE at the lowest point of the dive (lines) and by the Lampedusa Lidar in coincidence with the air mass passage (dots)
Page 7Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Figure 5. July 18 flight path
Page 8Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Figure 6. Second aerosol flight (July 18). Same as figure 2.
Page 9Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
ABLE & MAL
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
0 1 2 3 4 5 6 7 8 9 10
532 nm Total Backscatter Ratio
Altit
ude
[m]
able 70262
mal 71217
able 70206
mal 70186
ABLE & MAL
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
0 50 100 150 200 250 300 350 400 450 500
532 nm Total Backscatter Ratio
Altit
ude
[m]
able 74829
mal 70803
able 74767
mal 74773
Figure 7. Second aerosol flight (July 18): comparisons between observations of the total backscatter ratio obtained by in situ (MAS) and remote sensing (MALdown) instruments.
Figure 8. Second aerosol flight (July 18). Comparison between ABLE and MALdown observations; left: in the presence of Saharan dust; right: in the presence of high and middle level tropospheric clouds.
Cloud top altitude: ABLE-MAL mean difference= (-5.5±3.5) m
Page 10Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Figure 9. First aerosol flight (October 11). Plot of the aerosol backscatter ratio at 1064 nm (ABLE) and at 532 nm (MAL) vs. time and altitude. Preliminary results.
Page 11Validation by Balloons and Aircraft - ESRIN - 9–13 December 2002
Conclusions
•During the July campaign observations of Saharan dust and tropospheric clouds were carried out using remote sensing and in situ techniques.
•Values of the cloud top altitude and visible optical depth are available to perform the validation of the ENVISAT aerosol products.
•Profiles of the aerosol extinction coefficient can be retrieved by the aerosol backscatter ratio profiles.
•Inter-comparisons show a good consistency of the results obtained by the onboard instruments as well as the agreement with ground- based observations.
•Preliminary analysis of the results obtained during the October campaign:–very good performances of almost all instruments;–aerosol data for validation will be available in both types of flight (aerosol and chemical);–day-time observations are directly usable for the validation.