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| Titel |
A feasibility study for the monitoring of diurnal variations of the tropospheric NO2 over Tokyo from a geostationary satellite |
| VerfasserIn |
Katsuyuki Noguchi, Andreas Richter, Andreas Hilboll, John Burrows, Hitoshi Irie, Sachiko Hayashida, Yu Morino |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250035959
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| Zusammenfassung |
| We have conducted a feasibility study for the monitoring of diurnal variations of
anthropogenic nitrogen dioxide (NO2) in the lower troposphere over Tokyo, Japan, assuming
a geostationary satellite’s measurement. First we simulated Earth’s atmospheric spectra by
using a radiative transfer model, SCIATRAN, in the visible wavelength domain. In the
simulation, we implemented the diurnal variations of the vertical profiles of NO2 for summer
and winter based on results from the CMAQ model. Using the synthesized spectra, we
performed a Differential Optical Absorption Spectroscopy (DOAS) analysis to retrieve NO2
slant column densities (SCDs) and also estimated the precision of the retrieved SCDs. Before
the DOAS analysis, we added pseudo-noise components to the synthesized spectra
to take into account sensor specification as currently discussed for geostationary
instruments.
The retrieval simulation showed that the total NO2 SCD (4.0-6.0Ã1016 molecules/cm2,
depending on local time and season) could be measured with the precision of 20% at
signal-to-noise ratio (SNR) =~100 and 2% at SNR=~1000, respectively. In our estimation,
the precision of SCD did not much depend on local time (LT05-18 in summer and LT07-16 in
winter) or season (summer and winter). We found that the diurnal variation of total NO2 SCD
from the morning to the evening (about 2.0Ã1016 molecules/cm2) could be well detected by
the sensor with SNR>100. We also discuss the effect of uncertainties in surface reflectivity on
the retrieval. |
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