Atmospheric transport and deposition of cosmogenic 36Cl using ECHAM6.3-HAM2.3 model
Zheng, Minjie LU ; Muscheler, Raimund LU
; Adolphi, Florian
LU
; Mekhaldi, Florian
; Lu, Zhengyao
LU
; Wu, Mousong
LU
; Synal, Arno
; Beer, Juerg
and Lohmann, Ulrike
(2025)
In Earth and Planetary Science Letters
666.
- Abstract
The cosmogenic radionuclide 36Cl is a valuable tracer for studying Earth system processes, solar variability and geomagnetic field changes. These applications rely on a comprehensive understanding of 36Cl transport and deposition processes, which are still poorly studied. In this study, we apply a state-of-the-art climate model ECHAM6.3-HAM2.3 to investigate the source distribution and deposition of 36Cl. We configured 36Cl as gas in the stratosphere and as aerosol particles in the troposphere (E63H23CTL). Two sensitivity simulations were performed, with 36Cl configured solely as aerosol particles (E63H23AER) and solely as gas (E63H23GAS). The E63H23CTL simulation agrees well with... (More)
The cosmogenic radionuclide 36Cl is a valuable tracer for studying Earth system processes, solar variability and geomagnetic field changes. These applications rely on a comprehensive understanding of 36Cl transport and deposition processes, which are still poorly studied. In this study, we apply a state-of-the-art climate model ECHAM6.3-HAM2.3 to investigate the source distribution and deposition of 36Cl. We configured 36Cl as gas in the stratosphere and as aerosol particles in the troposphere (E63H23CTL). Two sensitivity simulations were performed, with 36Cl configured solely as aerosol particles (E63H23AER) and solely as gas (E63H23GAS). The E63H23CTL simulation agrees well with global 36Cl measurements in terms of absolute values and temporal variability. E63H23AER significantly underestimates polar 36Cl deposition compared to measurements, E63H23CTL and E63H23GAS, suggesting that polar regions are more sensitive to the ³⁶Cl state (aerosol or gas phase) than other regions. This is most likely attributed to the predominance of mixed-phase clouds in the polar regions, which have a higher scavenging efficiency for gaseous 36Cl compared to aerosol-bound 36Cl. This is further supported by comparison with the other cosmogenic radionuclide 10Be, which is exclusively aerosol-bound. The stratospheric contribution is dominant (65–70 %) in 36Cl deposition in polar and subtropical regions, while stratospheric and tropospheric contributions are of similar size (50–51 %) in tropical regions. When responding to changes in solar modulation, 36Cl deposition varies proportionally to global production rate changes. However, as response to geomagnetic field changes, 36Cl shows latitudinal-dependent deposition enhancements/decreases (10–33 %) relative to global production rate changes. This deposition response is insensitive to the forms of 36Cl (gaseous or aerosol-bound) and is similar to that shown by 10Be. The result indicates that differences in transport and deposition between 10Be and 36Cl may play a minor role when jointly using these two radionuclides for geomagnetic and solar reconstructions.
(Less)
- author
- Zheng, Minjie
LU
; Muscheler, Raimund
LU
; Adolphi, Florian
LU
; Mekhaldi, Florian
; Lu, Zhengyao
LU
; Wu, Mousong
LU
; Synal, Arno
; Beer, Juerg
and Lohmann, Ulrike
- organization
- publishing date
- 2025-09
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Be/Cl, Cl, Cosmogenic radionuclides, ECHAM6.3-HAM2.3, Transport and deposition
- in
- Earth and Planetary Science Letters
- volume
- 666
- article number
- 119494
- publisher
- Elsevier
- external identifiers
-
- scopus:105008102300
- ISSN
- 0012-821X
- DOI
- 10.1016/j.epsl.2025.119494
- language
- English
- LU publication?
- yes
- id
- 767b96b8-cedd-44e3-b080-7d6db38313bf
- date added to LUP
- 2025-11-04 11:03:53
- date last changed
- 2025-11-04 11:05:11
@article{767b96b8-cedd-44e3-b080-7d6db38313bf,
abstract = {{<p>The cosmogenic radionuclide <sup>36</sup>Cl is a valuable tracer for studying Earth system processes, solar variability and geomagnetic field changes. These applications rely on a comprehensive understanding of <sup>36</sup>Cl transport and deposition processes, which are still poorly studied. In this study, we apply a state-of-the-art climate model ECHAM6.3-HAM2.3 to investigate the source distribution and deposition of <sup>36</sup>Cl. We configured <sup>36</sup>Cl as gas in the stratosphere and as aerosol particles in the troposphere (E63H23CTL). Two sensitivity simulations were performed, with <sup>36</sup>Cl configured solely as aerosol particles (E63H23AER) and solely as gas (E63H23GAS). The E63H23CTL simulation agrees well with global <sup>36</sup>Cl measurements in terms of absolute values and temporal variability. E63H23AER significantly underestimates polar <sup>36</sup>Cl deposition compared to measurements, E63H23CTL and E63H23GAS, suggesting that polar regions are more sensitive to the ³⁶Cl state (aerosol or gas phase) than other regions. This is most likely attributed to the predominance of mixed-phase clouds in the polar regions, which have a higher scavenging efficiency for gaseous <sup>36</sup>Cl compared to aerosol-bound <sup>36</sup>Cl. This is further supported by comparison with the other cosmogenic radionuclide <sup>10</sup>Be, which is exclusively aerosol-bound. The stratospheric contribution is dominant (65–70 %) in <sup>36</sup>Cl deposition in polar and subtropical regions, while stratospheric and tropospheric contributions are of similar size (50–51 %) in tropical regions. When responding to changes in solar modulation, <sup>36</sup>Cl deposition varies proportionally to global production rate changes. However, as response to geomagnetic field changes, <sup>36</sup>Cl shows latitudinal-dependent deposition enhancements/decreases (10–33 %) relative to global production rate changes. This deposition response is insensitive to the forms of <sup>36</sup>Cl (gaseous or aerosol-bound) and is similar to that shown by <sup>10</sup>Be. The result indicates that differences in transport and deposition between <sup>10</sup>Be and <sup>36</sup>Cl may play a minor role when jointly using these two radionuclides for geomagnetic and solar reconstructions.</p>}},
author = {{Zheng, Minjie and Muscheler, Raimund and Adolphi, Florian and Mekhaldi, Florian and Lu, Zhengyao and Wu, Mousong and Synal, Arno and Beer, Juerg and Lohmann, Ulrike}},
issn = {{0012-821X}},
keywords = {{Be/Cl; Cl; Cosmogenic radionuclides; ECHAM6.3-HAM2.3; Transport and deposition}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Earth and Planetary Science Letters}},
title = {{Atmospheric transport and deposition of cosmogenic <sup>36</sup>Cl using ECHAM6.3-HAM2.3 model}},
url = {{http://dx.doi.org/10.1016/j.epsl.2025.119494}},
doi = {{10.1016/j.epsl.2025.119494}},
volume = {{666}},
year = {{2025}},
}