Analysing spatio-temporal patterns of the global NO2-distribution [NO subscript 2 -distribution] retrieved from GOME satellite observations using a generalized additive model
Name
Hayn-2009-Analysing spatio-temporal patterns of the global NO2-distribution retrieved from GOME satellite observations using a generalized additive model.pdf
Size
4.16 MB
Format
Adobe PDF
Checksum (MD5)
2e54cef12e6c26a188615b5f127aadc3
Author(s)
Hayn, M.
Beirle, S.
Hamprecht, Fred A.
Menze, Bjoern Holger
Wagner, T.
Date Issued
September 2009
Journal
Atmospheric Chemistry and Physics
Publisher
European Geosciences Union / Copernicus
Citation
Hayn, M. et al. “Analysing Spatio-temporal Patterns of the Global NO2-distribution Retrieved from GOME Satellite Observations Using a Generalized Additive Model.” Atmospheric Chemistry and Physics 9.17 (2009) : 6459-6477. © Author(s) 2009
Version
Final published version
Abstract
With the increasing availability of observational data from different sources at a global level, joint analysis of these data is becoming especially attractive. For such an analysis – oftentimes with little prior knowledge about local and global interactions between the different observational variables at hand – an exploratory, data-driven analysis of the data may be of particular relevance.
In the present work we used generalized additive models (GAM) in an exemplary study of spatio-temporal patterns in the tropospheric NO2-distribution [NO subscript 2 -distribution] derived from GOME satellite observations (1996 to 2001) at global scale. We focused on identifying correlations between NO2 [NO subscript 2] and local wind fields, a quantity which is of particular interest in the analysis of spatio-temporal interactions. Formulating general functional, parametric relationships between the observed NO2 [NO subscript 2] distribution and local wind fields, however, is difficult – if not impossible. So, rather than following a model-based analysis testing the data for predefined hypotheses (assuming, for example, sinusoidal seasonal trends), we used a GAM with non-parametric model terms to learn this functional relationship between NO2 [NO subscript 2] and wind directly from the data.
The NO2 [NO subscript 2] observations showed to be affected by wind-dominated processes over large areas. We estimated the extent of areas affected by specific NO2 [NO subscript 2] emission sources, and were able to highlight likely atmospheric transport "pathways". General temporal trends which were also part of our model – weekly, seasonal and linear changes – showed to be in good agreement with previous studies and alternative ways of analysing the time series. Overall, using a non-parametric model provided favorable means for a rapid inspection of this large spatio-temporal NO2 [NO subscript 2] data set, with less bias than parametric approaches, and allowing to visualize dynamical processes of the NO2 [NO subscript 2] distribution at a global scale.
MIT Department
Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory
Terms of Use
Creative Commons Attribution 3.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.5194/acp-9-6459-2009
