Comparison of particle number size distribution trends in ground measurements and climate models
(2022) In Atmospheric Chemistry and Physics 22(19). p.12873-12905- Abstract
Despite a large number of studies, out of all drivers of radiative forcing, the effect of aerosols has the largest uncertainty in global climate model radiative forcing estimates. There have been studies of aerosol optical properties in climate models, but the effects of particle number size distribution need a more thorough inspection. We investigated the trends and seasonality of particle number concentrations in nucleation, Aitken, and accumulation modes at 21 measurement sites in Europe and the Arctic. For 13 of those sites, with longer measurement time series, we compared the field observations with the results from five climate models, namely EC-Earth3, ECHAM-M7, ECHAM-SALSA, NorESM1.2, and UKESM1. This is the first extensive... (More)
Despite a large number of studies, out of all drivers of radiative forcing, the effect of aerosols has the largest uncertainty in global climate model radiative forcing estimates. There have been studies of aerosol optical properties in climate models, but the effects of particle number size distribution need a more thorough inspection. We investigated the trends and seasonality of particle number concentrations in nucleation, Aitken, and accumulation modes at 21 measurement sites in Europe and the Arctic. For 13 of those sites, with longer measurement time series, we compared the field observations with the results from five climate models, namely EC-Earth3, ECHAM-M7, ECHAM-SALSA, NorESM1.2, and UKESM1. This is the first extensive comparison of detailed aerosol size distribution trends between in situ observations from Europe and five earth system models (ESMs). We found that the trends of particle number concentrations were mostly consistent and decreasing in both measurements and models. However, for many sites, climate models showed weaker decreasing trends than the measurements. Seasonal variability in measured number concentrations, quantified by the ratio between maximum and minimum monthly number concentration, was typically stronger at northern measurement sites compared to other locations. Models had large differences in their seasonal representation, and they can be roughly divided into two categories: for EC-Earth and NorESM, the seasonal cycle was relatively similar for all sites, and for other models the pattern of seasonality varied between northern and southern sites. In addition, the variability in concentrations across sites varied between models, some having relatively similar concentrations for all sites, whereas others showed clear differences in concentrations between remote and urban sites. To conclude, although all of the model simulations had identical input data to describe anthropogenic mass emissions, trends in differently sized particles vary among the models due to assumptions in emission sizes and differences in how models treat size-dependent aerosol processes. The inter-model variability was largest in the accumulation mode, i.e. sizes which have implications for aerosol-cloud interactions. Our analysis also indicates that between models there is a large variation in efficiency of long-range transportation of aerosols to remote locations. The differences in model results are most likely due to the more complex effect of different processes instead of one specific feature (e.g. the representation of aerosol or emission size distributions). Hence, a more detailed characterization of microphysical processes and deposition processes affecting the long-range transport is needed to understand the model variability.
(Less)
- author
- Leinonen, Ville
; Kokkola, Harri
; Yli-Juuti, Taina
; Mielonen, Tero
; Kühn, Thomas
; Nieminen, Tuomo
; Heikkinen, Simo
; Miinalainen, Tuuli
; Bergman, Tommi
; Carslaw, Ken
; Decesari, Stefano
; Fiebig, Markus
; Hussein, Tareq
; Kivekäs, Niku
LU
; Krejci, Radovan
; Kulmala, Markku
; Leskinen, Ari
; Massling, Andreas
; Mihalopoulos, Nikos
; Mulcahy, Jane P.
; Noe, Steffen M.
; Van Noije, Twan
; O'connor, Fiona M.
; O'dowd, Colin
; Olivie, Dirk
; Pernov, Jakob B.
; Petäjä, Tuukka
; Seland, Øyvind
; Schulz, Michael
; Scott, Catherine E.
; Skov, Henrik
; Swietlicki, Erik
LU
; Tuch, Thomas
; Wiedensohler, Alfred
; Virtanen, Annele
and Mikkonen, Santtu
(Less) - organization
- publishing date
- 2022-10
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Atmospheric Chemistry and Physics
- volume
- 22
- issue
- 19
- pages
- 33 pages
- publisher
- Copernicus GmbH
- external identifiers
-
- scopus:85140628856
- ISSN
- 1680-7316
- DOI
- 10.5194/acp-22-12873-2022
- language
- English
- LU publication?
- yes
- id
- 50a6b4d7-4115-4bc3-aac0-e450341d8c12
- date added to LUP
- 2022-12-13 15:15:41
- date last changed
- 2023-11-21 14:03:05
@article{50a6b4d7-4115-4bc3-aac0-e450341d8c12,
abstract = {{<p>Despite a large number of studies, out of all drivers of radiative forcing, the effect of aerosols has the largest uncertainty in global climate model radiative forcing estimates. There have been studies of aerosol optical properties in climate models, but the effects of particle number size distribution need a more thorough inspection. We investigated the trends and seasonality of particle number concentrations in nucleation, Aitken, and accumulation modes at 21 measurement sites in Europe and the Arctic. For 13 of those sites, with longer measurement time series, we compared the field observations with the results from five climate models, namely EC-Earth3, ECHAM-M7, ECHAM-SALSA, NorESM1.2, and UKESM1. This is the first extensive comparison of detailed aerosol size distribution trends between in situ observations from Europe and five earth system models (ESMs). We found that the trends of particle number concentrations were mostly consistent and decreasing in both measurements and models. However, for many sites, climate models showed weaker decreasing trends than the measurements. Seasonal variability in measured number concentrations, quantified by the ratio between maximum and minimum monthly number concentration, was typically stronger at northern measurement sites compared to other locations. Models had large differences in their seasonal representation, and they can be roughly divided into two categories: for EC-Earth and NorESM, the seasonal cycle was relatively similar for all sites, and for other models the pattern of seasonality varied between northern and southern sites. In addition, the variability in concentrations across sites varied between models, some having relatively similar concentrations for all sites, whereas others showed clear differences in concentrations between remote and urban sites. To conclude, although all of the model simulations had identical input data to describe anthropogenic mass emissions, trends in differently sized particles vary among the models due to assumptions in emission sizes and differences in how models treat size-dependent aerosol processes. The inter-model variability was largest in the accumulation mode, i.e. sizes which have implications for aerosol-cloud interactions. Our analysis also indicates that between models there is a large variation in efficiency of long-range transportation of aerosols to remote locations. The differences in model results are most likely due to the more complex effect of different processes instead of one specific feature (e.g. the representation of aerosol or emission size distributions). Hence, a more detailed characterization of microphysical processes and deposition processes affecting the long-range transport is needed to understand the model variability.</p>}},
author = {{Leinonen, Ville and Kokkola, Harri and Yli-Juuti, Taina and Mielonen, Tero and Kühn, Thomas and Nieminen, Tuomo and Heikkinen, Simo and Miinalainen, Tuuli and Bergman, Tommi and Carslaw, Ken and Decesari, Stefano and Fiebig, Markus and Hussein, Tareq and Kivekäs, Niku and Krejci, Radovan and Kulmala, Markku and Leskinen, Ari and Massling, Andreas and Mihalopoulos, Nikos and Mulcahy, Jane P. and Noe, Steffen M. and Van Noije, Twan and O'connor, Fiona M. and O'dowd, Colin and Olivie, Dirk and Pernov, Jakob B. and Petäjä, Tuukka and Seland, Øyvind and Schulz, Michael and Scott, Catherine E. and Skov, Henrik and Swietlicki, Erik and Tuch, Thomas and Wiedensohler, Alfred and Virtanen, Annele and Mikkonen, Santtu}},
issn = {{1680-7316}},
language = {{eng}},
number = {{19}},
pages = {{12873--12905}},
publisher = {{Copernicus GmbH}},
series = {{Atmospheric Chemistry and Physics}},
title = {{Comparison of particle number size distribution trends in ground measurements and climate models}},
url = {{http://dx.doi.org/10.5194/acp-22-12873-2022}},
doi = {{10.5194/acp-22-12873-2022}},
volume = {{22}},
year = {{2022}},
}