Analysis and interpretation of satellite measurements in the near-infrared spectral region with the focus on carbon monoxide [Elektronische Ressource] / von Iryna G. Khlystova

Ik Je

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• Physik

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• Publié par: universitat_bremen
• Publié le: 01 janvier 2010
• Nombre de lectures: 30
• Langue: English
• Poids de l'ouvrage: 41 Mo

Extrait

Analysis and interpretation of satellite
measurements in the near-infrared spectral region
with the focus on carbon monoxide












Iryna G. Khlystova



2010


Analysis and interpretation of satellite
measurements in the near-infrared spectral region
with the focus on carbon monoxide



Von Fachbereich für Physik und Elektrotechnik
der Universität Bremen




zur Erlangung des Akademischen Grades eines

Doktor der Naturwissenschaften (Dr. rer. nat.)

genehmigte Dissertation





Von
Dipl. Phys. Iryna G. Khlystova
aus Belarus




































Gutachter: Prof. Dr. John P. Burrows
Gutachter: Prof. Dr. Monika Rhein


Eingereicht am 4 Februar, 2010

Tag des Promotionskolloquiums: 27 May, 2010 Abstract

Carbon monoxide (CO) plays an important role in the Earth’s atmosphere. Through its reaction
with the hydroxyl radicals (OH) (Logan et al., 1981), CO affects the lifetime of atmospheric
methane (CH ), and non-methane hydrocarbons (NMHCs). A main product of this oxidation is 4
carbon dioxide (CO ). Therefore, containing no direct green-house potential, CO still has an 2
indirect effect on the global warming. Concerning radiative forcing, it is estimated that the
emission of 100 Tg of CO is equivalent to the emission of 5 Tg of CH (Wild and Prather, 2000). 4
Due to its lifetime of about 1-3 months, CO is an important tracer of air-masses in the atmosphere.
CO is also one of the most important health hazardous pollutants, which can cause diseases of
different degrees of complexity.
The nadir near-infrared measurements of scattered and reflected solar radiation by SCanning
Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument on
board the ENVISAT satellite contain information about CO concentration in all atmospheric
layers including the boundary layer, closest to the location of main CO sources. However, the
retrieval of CO total column from the radiometric measurements in this spectral region is
complicated as the CO overtone lines are weak, and overlapped by strong absorptions of water
vapour and methane. Moreover, several known instrumental issues, like an ice layer on the
detector and degradation of the detector pixels with time, additionally complicate the retrieval of
CO vertical column from the of SCIAMACHY measurements in channel 8. In the scope of this
work, the WFM-DOAS (Weighting Functions Modified Differential Optical Absorption
Spectroscopy) retrieval algorithm, developed at the University of Bremen, have been improved in
order to establish the retrieval of a multi-year CO dataset from SCIAMACHY nadir
measurements.
The modifications have led to an improved CO fit quality, i.e., to an overall much smaller fit
residual. An error analysis and sensitivity studies based on the simulated measurements have
shown that the error is generally less than 10%, which is comparable to the required precision for
space-based CO measurements. However, due to high instrument noise, the error of the real
measurements has been found to be much higher and considerably less stable.
The retrieved CO columns have been validated by comparison with ground-based Fourier
Transform Spectroscopy (FTS) measurements. A good agreement within 10-20% was found for
nearly all considered stations. Furthermore, high correlation between the SCIAMACHY CO and
CO from independent space-based total columns measurements performed by the MOPITT
(Measurements of Pollution in the Troposphere) instrument onboard the Terra satellite indicates a
good performance of the SCIAMACHY CO measurements globally. The overall difference of
about 10% can be well explained by the moderate sensitivity of the thermal-infrared MOPITT
measurements to lower atmospheric layers.
To determine the SCIAMACHY potential for a quantitative estimation of CO sources, a detailed
analysis of the obtained CO dataset has been has been carried out on country level. Due to the
presence of strong anthropogenic sources and prevailing west wind conditions, a positive
difference of CO concentration is expected from the west to the east side of the United Kingdom.
The analysis shows that SCIAMACHY is able to capture the positive 5% west-to-east CO
gradient over the UK. These results are consistent with the direct airborne measurements during
the AMPEP campaign, which estimated the CO concentration enhancement from the west to the
east coast of the UK to be about 10-100 ppb, corresponding to the total column enhancement of 1-
10% within the 1 km boundary layer. Different filtering criteria, including explicitly developed
wind filtering algorithm, were applied to the SCIAMACHY CO total columns in order to estimate the influence of different meteorological conditions on the absolute value of gradient. In many
cases, the filtering resulted in a considerable reduction of data points, which often led to
insignificant gradient. The presence of clouds and the lower data quality over water as well as
overall data availability over the relatively small UK region are discussed as possible limitations
of such an analysis. From this study we have learned that the estimation of emissions over
relatively weak anthropogenic sources with state-of-the-art satellite measurements is rather
difficult.
Over much stronger sources, such as a large biomass burning events, the quantitative potential of
SCIAMACHY CO data is expected to be much higher due to much higher levels of CO signal and
respectively more available (“good”) satellite measurements. To use this fact for further
quantitative investigation, the SCIAMACHY simultaneously measurements of CO, nitrogen
dioxide (NO ) and formaldehyde (HCHO) over well-known biomass burning events in 2004, were 2
analysed in the scope of the well-established bottom-up emission estimation Excess Mixing
Ratios (EMR) method. The EMR method, previously used exclusively with local measurements,
has been adapted for usage with the SCIAMACHY space-based global atmospheric columns. In
general, the calculated SCIAMACHY excess ratios (ER) of ΔCO/ΔHCHO and ΔCO/ΔNO show 2
reasonable agreement with the values obtained during different field measurements over a number
of similar biomass burning events in the past. Principally, this definite behaviour of ratios reflects
the fact that fires in different ecosystems produce a different relative amount of emitted
pollutants. In many cases, much higher ΔCO/ΔNO values were obtained, which can be mainly 2
related to the strong diurnal variability of NO and comparably low NO in the troposphere at the 2 2
time of SCIAMACHY measurements time (10:00 local time). However, as the overall behaviour
of both SCIAMACHY ratios is as expected behaviour from the literature references, it can be
speculated that even much higher ΔCO/ΔNO might have some natural origin, indicating a strong 2
overestimation of the emission factors currently used in the global inventories.
Additionally, the information content of the SCIAMACHY CO total column and the magnitude of
total column error were analysed with the help of an assimilation procedure (Tangborn et al.,
2009). The results of this study have demonstrated that the valid CO total column errors are
probably overestimated and typically are about two times smaller than the errors estimated on
basis of the retrieval statistics.














Publications

Khlystova, I.G., Buchwitz, M., Burrows, J. P., Fowler, D., Bovensmann, H., Spatial gradient of
Carbon monoxide (CO) due to regional emissions as observed by SCIAMACHY/ENVISAT: A
case study for the United Kingdom., Adv. Space. Res, 234232-234234, 2009.
Khlystova, I. G., Richter, A., Wittrock, F., Burrows J. P., The synergetic analysis of the
SCIAMACHY CO, NO , and HCHO measurements over the large biomass burning events, 2
Atmos. Envir., Elsevier, in review.
Buchwitz, M. and Khlystova, I. G., Bovensman, H., Burrows, J. P., Three years of carbon
monoxide total column retrieved from satellite, Atmos. Chem. Phys, 7, 123123, 2007.
Buchwitz, M., de Beek, R., Noel, S., Burrows, J., P., Bovensmann, H., Schneising, O.,
Khlystova, I., Bruns, M., Bremer, H., Bergamaschi, P., Körner, S., and Heimann, M.,
Atmospheric Carbon gases retrieved from SCIAMACHY by WFM-DOAS: version 0.5 CO and
CH and impact of calibration improvements on CO retrieval, Atmos. Chem. Phys., 6, 2727-4 2
2751, 2006.
Tangborn, A., Stajner, I., Buchwitz, M., Khlystova, I., Pawson, S., Burrows, J., Hudman, R.,
and Nedelec, P., Assimilation of SCIAMACHY CO observations: Global and regional analysis
of data impact, J. Geophys. Res., 114, D07307, 1-11, 2009.
Dils, B., De Maziere, M., Blumenstock, T., Hase, F., Kramer, I., Mahieu, E., Demoulin, P.,
Duchatelet, P., Mellqvist, J., Strandberg, A., Buchwitz, M., Khlystova, I., Schneising, O.,
Velazco, V., Notho