Insights of climate-driven changes in CH4 and CO2 source contributions at European coastal observatories
Adame, J. A. ; Karstens, U. LU
; Busetto, M.
; Tranchida, G.
; Yela, M.
; Aalto, T.
; Leppänen, A.
and Cristofanelli, P.
(2026)
In Atmospheric Research
340.
- Abstract
Regional carbon dioxide (CO₂) and methane (CH₄) source contributions were analysed at two European coastal observatories, El Arenosillo (ARN) in southwestern Spain and Capo Granitola (CGR) in southern Italy, using in situ observations and STILT model simulations from 2006 to 2023, enabling source attribution to biogenic, fossil fuel, anthropogenic, and natural contributions. Model-observation agreement was robust, with CO₂ and CH₄ correlation coefficients of 0.599–0.900 and 0.693–0.859, respectively. Footprints revealed ARN's sensitivity to Atlantic and Iberian airflows, while CGR was influenced by the central Mediterranean, southern Italy and North Africa. Background dominated (∼98%), with regional CO₂ sources being biogenic... (More)
Regional carbon dioxide (CO₂) and methane (CH₄) source contributions were analysed at two European coastal observatories, El Arenosillo (ARN) in southwestern Spain and Capo Granitola (CGR) in southern Italy, using in situ observations and STILT model simulations from 2006 to 2023, enabling source attribution to biogenic, fossil fuel, anthropogenic, and natural contributions. Model-observation agreement was robust, with CO₂ and CH₄ correlation coefficients of 0.599–0.900 and 0.693–0.859, respectively. Footprints revealed ARN's sensitivity to Atlantic and Iberian airflows, while CGR was influenced by the central Mediterranean, southern Italy and North Africa. Background dominated (∼98%), with regional CO₂ sources being biogenic (0.81–0.91%) and fossil fuel (0.47–0.56%), and CH₄ sources anthropogenic (∼1.4%) and natural (0.25–0.29%). STILT-simulated source contributions exhibited consistent seasonal and diurnal patterns at both stations. Total CO2 and CH4 concentrations increased in line with global trends. However, source-specific Theil–Sen trend analysis revealed significant shifts between the sub-periods 2006–2010 and 2019–2023. Overall trends accelerated by a factor of 1.6 for CO₂ and by factors of 2.9 and 3.6 for CH₄ at ARN and CGR, respectively. The biogenic CO₂ trend at ARN increased 22-fold between the early and recent sub-periods, while at CGR it transitioned from negative to positive. At ARN, natural CH₄ trends weakened by 46%, whereas at CGR they reversed in sign, suggesting reduced sink strength or enhanced emissions. Anthropogenic reductions weakened or stabilized. These results highlight shifting greenhouse gas sources in European coastal regions, driven by climate feedbacks, urging broader-scale studies.
(Less)
- author
- Adame, J. A.
; Karstens, U.
LU
; Busetto, M.
; Tranchida, G.
; Yela, M.
; Aalto, T.
; Leppänen, A.
and Cristofanelli, P.
- organization
- publishing date
- 2026-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Carbon dioxide, Climate change, ICOS, Methane, Source attribution, STILT model
- in
- Atmospheric Research
- volume
- 340
- article number
- 109076
- publisher
- Elsevier
- external identifiers
-
- scopus:105038933743
- ISSN
- 0169-8095
- DOI
- 10.1016/j.atmosres.2026.109076
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/
- id
- 2f8dd0f3-45bc-471c-905b-62a9848d319f
- date added to LUP
- 2026-07-14 15:41:32
- date last changed
- 2026-07-14 15:42:48
@article{2f8dd0f3-45bc-471c-905b-62a9848d319f,
abstract = {{<p>Regional carbon dioxide (CO₂) and methane (CH₄) source contributions were analysed at two European coastal observatories, El Arenosillo (ARN) in southwestern Spain and Capo Granitola (CGR) in southern Italy, using in situ observations and STILT model simulations from 2006 to 2023, enabling source attribution to biogenic, fossil fuel, anthropogenic, and natural contributions. Model-observation agreement was robust, with CO₂ and CH₄ correlation coefficients of 0.599–0.900 and 0.693–0.859, respectively. Footprints revealed ARN's sensitivity to Atlantic and Iberian airflows, while CGR was influenced by the central Mediterranean, southern Italy and North Africa. Background dominated (∼98%), with regional CO₂ sources being biogenic (0.81–0.91%) and fossil fuel (0.47–0.56%), and CH₄ sources anthropogenic (∼1.4%) and natural (0.25–0.29%). STILT-simulated source contributions exhibited consistent seasonal and diurnal patterns at both stations. Total CO<sub>2</sub> and CH<sub>4</sub> concentrations increased in line with global trends. However, source-specific Theil–Sen trend analysis revealed significant shifts between the sub-periods 2006–2010 and 2019–2023. Overall trends accelerated by a factor of 1.6 for CO₂ and by factors of 2.9 and 3.6 for CH₄ at ARN and CGR, respectively. The biogenic CO₂ trend at ARN increased 22-fold between the early and recent sub-periods, while at CGR it transitioned from negative to positive. At ARN, natural CH₄ trends weakened by 46%, whereas at CGR they reversed in sign, suggesting reduced sink strength or enhanced emissions. Anthropogenic reductions weakened or stabilized. These results highlight shifting greenhouse gas sources in European coastal regions, driven by climate feedbacks, urging broader-scale studies.</p>}},
author = {{Adame, J. A. and Karstens, U. and Busetto, M. and Tranchida, G. and Yela, M. and Aalto, T. and Leppänen, A. and Cristofanelli, P.}},
issn = {{0169-8095}},
keywords = {{Carbon dioxide; Climate change; ICOS; Methane; Source attribution; STILT model}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Atmospheric Research}},
title = {{Insights of climate-driven changes in CH<sub>4</sub> and CO<sub>2</sub> source contributions at European coastal observatories}},
url = {{http://dx.doi.org/10.1016/j.atmosres.2026.109076}},
doi = {{10.1016/j.atmosres.2026.109076}},
volume = {{340}},
year = {{2026}},
}