Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT
It has become possible to retrieve the global, long-term trends of trace gases that are important to atmospheric chemistry, climate, and air quality from satellite data records that span more than a decade. However, many of the satellite remote sensing techniques produce measurements that have varia...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-11-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/13/11307/2013/acp-13-11307-2013.pdf |
| _version_ | 1818930550787801088 |
|---|---|
| author | J. Yoon A. Pozzer P. Hoor D. Y. Chang S. Beirle T. Wagner S. Schloegl J. Lelieveld H. M. Worden |
| author_facet | J. Yoon A. Pozzer P. Hoor D. Y. Chang S. Beirle T. Wagner S. Schloegl J. Lelieveld H. M. Worden |
| author_sort | J. Yoon |
| collection | DOAJ |
| description | It has become possible to retrieve the global, long-term trends of trace
gases that are important to atmospheric chemistry, climate, and air quality
from satellite data records that span more than a decade. However, many of
the satellite remote sensing techniques produce measurements that have
variable sensitivity to the vertical profiles of atmospheric gases. In the
case of constrained retrievals like optimal estimation, this leads to a
varying amount of a priori information in the retrieval and is represented by
an averaging kernel (AK). In this study, we investigate
to what extent the estimation of trends from retrieved data
can be biased by temporal changes of averaging kernels used in the retrieval
algorithm. In particular, the surface carbon monoxide data retrieved from the
Measurements Of Pollution In The Troposphere (MOPITT) instrument from 2001 to
2010 were analyzed. As a practical example based on the MOPITT data, we show
that if the true atmospheric mixing ratio is continuously 50% higher or
lower than the a priori state, the temporal change of the averaging kernel at
the surface level gives rise to an artificial trend in retrieved surface
carbon monoxide, ranging from −10.71 to +13.21 ppbv yr<sup>−1</sup> (−5.68
to +8.84 % yr<sup>−1</sup>) depending on location. Therefore, in the case of
surface (or near-surface level) CO derived from MOPITT, the AKs trends
multiplied by the difference between true and a priori states must be
quantified in order to estimate trend biases. |
| first_indexed | 2024-12-20T04:02:29Z |
| format | Article |
| id | doaj.art-841faf704c994722954b52197fb76951 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-20T04:02:29Z |
| publishDate | 2013-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-841faf704c994722954b52197fb769512022-12-21T19:54:07ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242013-11-011322113071131610.5194/acp-13-11307-2013Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITTJ. Yoon0A. Pozzer1P. Hoor2D. Y. Chang3S. Beirle4T. Wagner5S. Schloegl6J. Lelieveld7H. M. Worden8Atmospheric Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, GermanyAtmospheric Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, GermanyInstitute of Atmospheric Physics, Johannes Gutenberg University, 55099 Mainz, GermanyAtmospheric Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, GermanyAtmospheric Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, GermanyAtmospheric Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, GermanyInstitute of Atmospheric Physics, Johannes Gutenberg University, 55099 Mainz, GermanyAtmospheric Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, GermanyNational Center for Atmospheric Research (NCAR), Boulder, CO, USAIt has become possible to retrieve the global, long-term trends of trace gases that are important to atmospheric chemistry, climate, and air quality from satellite data records that span more than a decade. However, many of the satellite remote sensing techniques produce measurements that have variable sensitivity to the vertical profiles of atmospheric gases. In the case of constrained retrievals like optimal estimation, this leads to a varying amount of a priori information in the retrieval and is represented by an averaging kernel (AK). In this study, we investigate to what extent the estimation of trends from retrieved data can be biased by temporal changes of averaging kernels used in the retrieval algorithm. In particular, the surface carbon monoxide data retrieved from the Measurements Of Pollution In The Troposphere (MOPITT) instrument from 2001 to 2010 were analyzed. As a practical example based on the MOPITT data, we show that if the true atmospheric mixing ratio is continuously 50% higher or lower than the a priori state, the temporal change of the averaging kernel at the surface level gives rise to an artificial trend in retrieved surface carbon monoxide, ranging from −10.71 to +13.21 ppbv yr<sup>−1</sup> (−5.68 to +8.84 % yr<sup>−1</sup>) depending on location. Therefore, in the case of surface (or near-surface level) CO derived from MOPITT, the AKs trends multiplied by the difference between true and a priori states must be quantified in order to estimate trend biases.http://www.atmos-chem-phys.net/13/11307/2013/acp-13-11307-2013.pdf |
| spellingShingle | J. Yoon A. Pozzer P. Hoor D. Y. Chang S. Beirle T. Wagner S. Schloegl J. Lelieveld H. M. Worden Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT Atmospheric Chemistry and Physics |
| title | Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT |
| title_full | Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT |
| title_fullStr | Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT |
| title_full_unstemmed | Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT |
| title_short | Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT |
| title_sort | technical note temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from mopitt |
| url | http://www.atmos-chem-phys.net/13/11307/2013/acp-13-11307-2013.pdf |
| work_keys_str_mv | AT jyoon technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT apozzer technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT phoor technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT dychang technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT sbeirle technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT twagner technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT sschloegl technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT jlelieveld technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt AT hmworden technicalnotetemporalchangeinaveragingkernelsasasourceofuncertaintyintrendestimatesofcarbonmonoxideretrievedfrommopitt |