Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld
Aircraft measurements of NO 2 using an imaging differential optical absorption spectrometer (iDOAS) instrument over the South African Highveld region in August 2007 are presented and compared to satellite measurements from OMI and SCIAMACHY. In situ aerosol and trace-gas vertical profile measurement...
Published in: | Atmospheric Measurement Techniques |
---|---|
Main Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/amt-11-2797-2018 https://doaj.org/article/96879853d3e6476cb234d7cd43f1fbb7 |
id |
ftdoajarticles:oai:doaj.org/article:96879853d3e6476cb234d7cd43f1fbb7 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:96879853d3e6476cb234d7cd43f1fbb7 2023-05-15T13:06:24+02:00 Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld S. Broccardo K.-P. Heue D. Walter C. Meyer A. Kokhanovsky R. van der A S. Piketh K. Langerman U. Platt 2018-05-01T00:00:00Z https://doi.org/10.5194/amt-11-2797-2018 https://doaj.org/article/96879853d3e6476cb234d7cd43f1fbb7 EN eng Copernicus Publications https://www.atmos-meas-tech.net/11/2797/2018/amt-11-2797-2018.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-11-2797-2018 1867-1381 1867-8548 https://doaj.org/article/96879853d3e6476cb234d7cd43f1fbb7 Atmospheric Measurement Techniques, Vol 11, Pp 2797-2819 (2018) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2018 ftdoajarticles https://doi.org/10.5194/amt-11-2797-2018 2022-12-31T13:11:49Z Aircraft measurements of NO 2 using an imaging differential optical absorption spectrometer (iDOAS) instrument over the South African Highveld region in August 2007 are presented and compared to satellite measurements from OMI and SCIAMACHY. In situ aerosol and trace-gas vertical profile measurements, along with aerosol optical thickness and single-scattering albedo measurements from the Aerosol Robotic Network (AERONET), are used to devise scenarios for a radiative transfer modelling sensitivity study. Uncertainty in the air-mass factor due to variations in the aerosol and NO 2 profile shape is constrained and used to calculate vertical column densities (VCDs), which are compared to co-located satellite measurements. The lower spatial resolution of the satellites cannot resolve the detailed plume structures revealed in the aircraft measurements. The airborne DOAS in general measured steeper horizontal gradients and higher peak NO 2 vertical column density. Aircraft measurements close to major sources, spatially averaged to the satellite resolution, indicate NO 2 column densities more than twice those measured by the satellite. The agreement between the high-resolution aircraft instrument and the satellite instrument improves with distance from the source, this is attributed to horizontal and vertical dispersion of NO 2 in the boundary layer. Despite the low spatial resolution, satellite images reveal point sources and plumes that retain their structure for several hundred kilometres downwind. Article in Journal/Newspaper Aerosol Robotic Network Directory of Open Access Journals: DOAJ Articles Atmospheric Measurement Techniques 11 5 2797 2819 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
spellingShingle |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 S. Broccardo K.-P. Heue D. Walter C. Meyer A. Kokhanovsky R. van der A S. Piketh K. Langerman U. Platt Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
Aircraft measurements of NO 2 using an imaging differential optical absorption spectrometer (iDOAS) instrument over the South African Highveld region in August 2007 are presented and compared to satellite measurements from OMI and SCIAMACHY. In situ aerosol and trace-gas vertical profile measurements, along with aerosol optical thickness and single-scattering albedo measurements from the Aerosol Robotic Network (AERONET), are used to devise scenarios for a radiative transfer modelling sensitivity study. Uncertainty in the air-mass factor due to variations in the aerosol and NO 2 profile shape is constrained and used to calculate vertical column densities (VCDs), which are compared to co-located satellite measurements. The lower spatial resolution of the satellites cannot resolve the detailed plume structures revealed in the aircraft measurements. The airborne DOAS in general measured steeper horizontal gradients and higher peak NO 2 vertical column density. Aircraft measurements close to major sources, spatially averaged to the satellite resolution, indicate NO 2 column densities more than twice those measured by the satellite. The agreement between the high-resolution aircraft instrument and the satellite instrument improves with distance from the source, this is attributed to horizontal and vertical dispersion of NO 2 in the boundary layer. Despite the low spatial resolution, satellite images reveal point sources and plumes that retain their structure for several hundred kilometres downwind. |
format |
Article in Journal/Newspaper |
author |
S. Broccardo K.-P. Heue D. Walter C. Meyer A. Kokhanovsky R. van der A S. Piketh K. Langerman U. Platt |
author_facet |
S. Broccardo K.-P. Heue D. Walter C. Meyer A. Kokhanovsky R. van der A S. Piketh K. Langerman U. Platt |
author_sort |
S. Broccardo |
title |
Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld |
title_short |
Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld |
title_full |
Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld |
title_fullStr |
Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld |
title_full_unstemmed |
Intra-pixel variability in satellite tropospheric NO 2 column densities derived from simultaneous space-borne and airborne observations over the South African Highveld |
title_sort |
intra-pixel variability in satellite tropospheric no 2 column densities derived from simultaneous space-borne and airborne observations over the south african highveld |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/amt-11-2797-2018 https://doaj.org/article/96879853d3e6476cb234d7cd43f1fbb7 |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
Atmospheric Measurement Techniques, Vol 11, Pp 2797-2819 (2018) |
op_relation |
https://www.atmos-meas-tech.net/11/2797/2018/amt-11-2797-2018.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-11-2797-2018 1867-1381 1867-8548 https://doaj.org/article/96879853d3e6476cb234d7cd43f1fbb7 |
op_doi |
https://doi.org/10.5194/amt-11-2797-2018 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
11 |
container_issue |
5 |
container_start_page |
2797 |
op_container_end_page |
2819 |
_version_ |
1766004093253320704 |