Upload
roy-taylor
View
217
Download
4
Tags:
Embed Size (px)
Citation preview
SCIAMACHY satellite validation during the field campaigns
CINDI and TRANSBROM
Enno Peters, Folkard Wittrock, Andreas Richter, Mark Weber and John P. Burrows
ENVIVAL-LIFE Meeting Bremen, 06/07.12.2010
I. Introduction
1. MAX-DOAS measurements
2. Instrumentation (the ENVIVAL sponsored instrument)
II. The CINDI campaign
1. Campaign overview
2. Validation results (NO2, Ozone)
III. The TRANSBROM campaign
1. Transbrom campaign overview
2. Set up at ship, challenges
3. Validation results (NO2, Ozone, HCHO)
IV. Summary
Outline
I. Introduction
MAX-DOAS measurements
Multi Axis - Differential Optical Absorption Spectroscopy
• Measuring spectra of scattered sunlight• Deriving trace gas columns and profiles from absorption features• High sensitivity for stratospheric absorbers during twilight ( am and pm values)
Light
Y-shaped optical fibre
Telescope unitSpectrometers
Scheme of a MAX-DOAS instrumentZenith DOAS geometry
MAX-DOAS measurements
Multi Axis - Differential Optical Absorption Spectroscopy
• Measuring spectra of scattered sunlight• Deriving trace gas columns from absorption features• High sensitivity for stratospheric absorbers during twilight ( am and pm values)• High sensitivity for tropospheric absorbers using off-axis measurements• Converting slant columns into vertical columns/profiles
using radiative transfer models
Light
Y-shaped optical fibre
Telescope unitSpectrometers
Scheme of a MAX-DOAS instrumentMAX-DOAS geometry
Optical bank with lens and optical fiber
HgCd line lampfor calibration
Video camera
Entrance window (fused silica)
Shutter for dark measurements,covered withPTFE (white) forcalibration
Telescope unit:30x30 cm metal box mounted on Pan/Tilt Head(+- 90° elevation, +-180° azimuth, 100°/sec)
The Bremen MAX-DOAS campaign instrument
Y-shaped optical fiber bundle in
• UV-spectrometer: 315 – 384 nm (0,033 nm/pixel, resolution ~ 0,4 nm)
• Vis-spectrometer: 400 – 573 nm (0,13 nm/pixel, resolution ~ 0,8 nm)
The Bremen MAX-DOAS campaign instrument
II. The CINDI campaign
CINDI campaign - overview
Participating institutes: 17
Host: KNMI (Royal Dutch Meteorological Institute)
Location: Cabauw, Netherlands June/July 2009
Instruments: - 22 DOAS instruments- 4 NO/NOx in situ instruments- Lidars: Aerosol, NO2, trop. O3
- meteorologic systems- several NO2 sondes launched during campaign
From Bremen: - 1 MAX-DOAS instrument- 1 NO/NOx in situ instrument
Cabauw Intercomparison campaign of Nitrogen Dioxide (NO2) measuring Instruments
www.geomon.eu
CINDI campaign - overview
Location: Cabauw, Netherlands51o 58' N 4o 55' E(semirural area)
Cabauw tower(in situ instruments, meteo data)
Remote sensing site,(DOAS instruments, Lidars)
287° Boundary Layer ~ 1.5 km
Elevation angle 2°
km 43)2tan(/km 5.1
287°~ 43 km
NO2 tropospheric vertical columns
NO2 trop. VC June/July 09 over Cabauw
MAX-DOASSCIAMACHY (r = 50 km)GOME-2 (r = 50 km)
• Time resolution: 30 min• Spatial resolution: Satellite data averaged within 50 km around site
Period of (mostly) good weather (esp. June 24 & 25 “Golden Days”).
NO2 tropospheric vertical columns
NO2 trop. VC over Cabauw
MAX-DOASSCIAMACHY (r = 50 km)GOME-2 (r = 50 km)
“Golden Day” June 25 Zoom in
NO2 tropospheric vertical columns
NO2 trop. Columns and ground layer (BREAM profiling) comparison at June 25, 2009
MAX-DOASSCIAMACHY (r = 50 km)GOME-2 (r = 50 km)
In situ monitorMAX-DOAS Ground Layer (profiling)
For this day (almost no clouds, sunny) MAX-DOAS is successfully closingthe gap between satellite measurements (huge spatial averaging) and in situ measurements (point measurements).
Trop. Col.VMR (ppb)
Morning inversion
NO2 tropospheric vertical columns
NO2 trop. VC over Cabauw
MAX-DOASSCIAMACHY (r = 50 km)GOME-2 (r = 50 km)
“Golden Day” June 25 Great (by chance?)
June 29 Highly dependant an location of the satellite pixel
Total Ozone columns
MAX-DOAS measurementsSCIAMACHYGOME-2
Criterion for coincidence between Satellite and MAX-DOAS:Satellite pixel within 200 km around measurement site at day of respective MAX-DOAS measurements average of these pixels
Total Ozone columns
Criterion for coincidence between Satellite and MAX-DOAS:Satellite pixel within 200 km around measurement site at day of respective MAX-DOAS measurements average of these pixels
MAX-DOASSCIAMACHYGOME-2
III. The TRANSBROM campaign
(Planned)Cruise track
The TransBrom campaign
RV „Sonne“
Campaign‘sLogo
0°
180° 90°
270°
Relative winddirection between 90° and 180° is polluted (i.e. NO2)
x
x
Set up on the ship
NO2 validation
Total NO2
NO2 vertical columns timeseries
SCIAMACHYGOME-2MAX-DOAS morningMAX DOAS evening
monthly average(at ~ 10 LT)
Criterion for coincidence:Satellite pixel within 200/400 km around ship‘s positionat day of respective MAX-DOAS measurement Oct 10-12 maybe too polluted (or clean)
Tropospheric NO2
• SZA < 75°, Fiterror < 20%• Reference = closest 30° elevation spectrum ( tropospheric NO2 content)
NO2 DSCD (298 K, 450 – 497 nm)
2° Elevation8° Elevation15° Elevation
(Almost) no tropospheric NO2
over open ocean
Tropospheric NO2
• SZA < 75°, Fiterror < 20%• Reference = closest 30° elevation spectrum ( tropospheric NO2 content)
NO2 DSCD (298 K, 450 – 497 nm)
2° Elevation8° Elevation15° Elevation
Tropospheric NO2
• SZA < 75°, Fiterror < 20%• Reference = closest 30° elevation spectrum ( tropospheric NO2 content)
NO2 DSCD (298 K, 450 – 497 nm)
2° Elevation8° Elevation15° Elevation
Ship density10.10.-23.10.2009
Amver-data provided by Douglas Horton, CTR US Coast Guard Operations Systems Center (personal communication), www.amver.com
NO2 DSCD, Oct 10-112° Elevation8° Elevation15° Elevation
• Rel. wind direction ok during event• Positive peak• 2° higher SC than upper elevation• Camera picture:
Other ship‘s plume
Relative wind direction
Picture from the camera in the telescope box at10.10.2009 23:20 UT
Zoom in event
Tropospheric NO2
NO2 tropospheric vertical columns
NO2 trop. VC, October 10 - 12
2
14101.5cmmolecDetection Limit ~
MAX-DOASGOME-2 (r = 150 km)SCIAMACHY (r = 150 km)
monthly average(at ~ 10 LT)
GOME2 trop. NO2 October 2009
NO2 tropospheric vertical columns
NO2 trop. VC, October 10 - 12
MAX-DOASGOME-2 (r = 150 km)SCIAMACHY (r = 150 km)SCIAMACHY (r = 200 km) monthly
average(at ~ 10 LT)
GOME2 trop. NO2 October 2009
2
14101.5cmmolecDetection Limit ~
Ozone validation
Total Ozone columns
MAX-DOAS measurementsSCIAMACHYGOME-2
Criterion for coincidence between Satellite and MAX-DOAS:Satellite pixel within 200 km (400 km) around ship‘s position at 10 LT at day of respective MAX-DOAS measurements average of these pixels
HCHO validation
HCHO differential slant columns
anthropogenic,vegetation, lots ofbush fires (dry season)
Polluted region(ship traffic,influence from land)
?
October 14: Sunniest day of the cruise
HCHO VCD (335 – 357 nm)
HCHO tropospheric vertical columns
Oct 19: HCHO transport from vegetation (rainforest)?
HCHO VCD (335 – 357 nm) Oct 19-20 cruise track
October 19
October 20
~ 150 km
2
14105cmmolecDetection Limit for vertical column ~
HCHO tropospheric vertical columns
HCHO from Satellite and MAX-DOAS
MAX-DOAS (9-11 LT)Satellite (GOME-2)
Data binned to 2°-grid.
„Delay“ in MAX-DOAS increase probably due to bad weather at this time of the cruise.
HCHO tropospheric vertical columns
obtained HCHO-column along ship track is pure background signal!
IV. Summary
Summary
Validation (total Ozone, NO2 & HCHO) during 2 field campains in 2009 has beenperfomed.
CINDI campaign• SCIAMCHY and MAX-DOAS Ozone have same shape, MAX-DOAS VCs mostly smaller than SCIAMACHY values• Loss (and recovery) of 80 DU Ozone seen by both Satellite and MAX-DOAS• At particular days MAX-DOAS (via profiling, BREAM) is able to close the gap between in situ point measurements and satellite(s) measurements of tropospheric NO2
TRANSBROM• SCIAMACHY and GOME-2 Ozone in good agreement with each other, smoothed compared to MAX-DOAS• NO2 from SCIAMACHY and GOME-2 in good agreement with each other and MAX-DOAS, even tropospheric NO2
• HCHO background level during whole campaign (from methane oxidation) in good agreement with GOME-2
Thank you!