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!