A meta-analysis of particle water uptake reconciliation studies
Water uptake by aerosol particles controls their ability to form cloud droplets, and reconciliation between different techniques for examining cloud condensation nuclei (CCN) properties is important to our understanding of these processes and our ability to measure and predict them. Reconciliation b...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-11-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/11833/2014/acp-14-11833-2014.pdf |
| _version_ | 1818295767364796416 |
|---|---|
| author | J. D. Whitehead M. Irwin J. D. Allan N. Good G. McFiggans |
| author_facet | J. D. Whitehead M. Irwin J. D. Allan N. Good G. McFiggans |
| author_sort | J. D. Whitehead |
| collection | DOAJ |
| description | Water uptake by aerosol particles controls their ability to form cloud
droplets, and reconciliation between different techniques for examining cloud condensation nuclei (CCN)
properties is important to our understanding of these processes and our
ability to measure and predict them. Reconciliation between measurements of
sub-saturated and supersaturated aerosol particle water uptake was attempted
at a wide range of locations between 2007 and 2013. The agreement in derived
number of CCN (<i>N</i><sub>CCN</sub> or particle hygroscopicity
was mixed across the projects, with some data sets showing poor agreement
across all supersaturations and others agreeing within errors for at least
some of the supersaturation range. The degree of reconciliation did not seem
to depend on the environment in which the measurements were taken. The
discrepancies can only be attributable to differences in the chemical
behaviour of aerosols and gases in each instrument, leading to under- or
overestimated growth factors and/or CCN counts, though poorer reconciliation
at lower supersaturations can be attributed to uncertainties in the size
distribution at the threshold diameter found at these supersaturations. From
a single instrument, the variability in <i>N</i><sub>CCN</sub> calculated using particle
hygroscopicity or size distribution averaged across a project demonstrates a
greater sensitivity to variation in the size distribution than chemical
composition in most of the experiments. However, the discrepancies between
instruments indicate a strong requirement for reliable quantification of CCN
in line with an improved understanding of the physical processes involved in
their measurement. Without understanding the reason for discrepancies in the
measurements, it is questionable whether quantification of CCN behaviour is
meaningful. |
| first_indexed | 2024-12-13T03:52:52Z |
| format | Article |
| id | doaj.art-13303ca502e3471bab9d80b3a0d3a225 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-13T03:52:52Z |
| publishDate | 2014-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-13303ca502e3471bab9d80b3a0d3a2252022-12-22T00:00:41ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242014-11-011421118331184110.5194/acp-14-11833-2014A meta-analysis of particle water uptake reconciliation studiesJ. D. Whitehead0M. Irwin1J. D. Allan2N. Good3G. McFiggans4Centre for Atmospheric Science, SEAES, University of Manchester, Oxford Road, Manchester, M13 9PL, UKCentre for Atmospheric Science, SEAES, University of Manchester, Oxford Road, Manchester, M13 9PL, UKCentre for Atmospheric Science, SEAES, University of Manchester, Oxford Road, Manchester, M13 9PL, UKCentre for Atmospheric Science, SEAES, University of Manchester, Oxford Road, Manchester, M13 9PL, UKCentre for Atmospheric Science, SEAES, University of Manchester, Oxford Road, Manchester, M13 9PL, UKWater uptake by aerosol particles controls their ability to form cloud droplets, and reconciliation between different techniques for examining cloud condensation nuclei (CCN) properties is important to our understanding of these processes and our ability to measure and predict them. Reconciliation between measurements of sub-saturated and supersaturated aerosol particle water uptake was attempted at a wide range of locations between 2007 and 2013. The agreement in derived number of CCN (<i>N</i><sub>CCN</sub> or particle hygroscopicity was mixed across the projects, with some data sets showing poor agreement across all supersaturations and others agreeing within errors for at least some of the supersaturation range. The degree of reconciliation did not seem to depend on the environment in which the measurements were taken. The discrepancies can only be attributable to differences in the chemical behaviour of aerosols and gases in each instrument, leading to under- or overestimated growth factors and/or CCN counts, though poorer reconciliation at lower supersaturations can be attributed to uncertainties in the size distribution at the threshold diameter found at these supersaturations. From a single instrument, the variability in <i>N</i><sub>CCN</sub> calculated using particle hygroscopicity or size distribution averaged across a project demonstrates a greater sensitivity to variation in the size distribution than chemical composition in most of the experiments. However, the discrepancies between instruments indicate a strong requirement for reliable quantification of CCN in line with an improved understanding of the physical processes involved in their measurement. Without understanding the reason for discrepancies in the measurements, it is questionable whether quantification of CCN behaviour is meaningful.http://www.atmos-chem-phys.net/14/11833/2014/acp-14-11833-2014.pdf |
| spellingShingle | J. D. Whitehead M. Irwin J. D. Allan N. Good G. McFiggans A meta-analysis of particle water uptake reconciliation studies Atmospheric Chemistry and Physics |
| title | A meta-analysis of particle water uptake reconciliation studies |
| title_full | A meta-analysis of particle water uptake reconciliation studies |
| title_fullStr | A meta-analysis of particle water uptake reconciliation studies |
| title_full_unstemmed | A meta-analysis of particle water uptake reconciliation studies |
| title_short | A meta-analysis of particle water uptake reconciliation studies |
| title_sort | meta analysis of particle water uptake reconciliation studies |
| url | http://www.atmos-chem-phys.net/14/11833/2014/acp-14-11833-2014.pdf |
| work_keys_str_mv | AT jdwhitehead ametaanalysisofparticlewateruptakereconciliationstudies AT mirwin ametaanalysisofparticlewateruptakereconciliationstudies AT jdallan ametaanalysisofparticlewateruptakereconciliationstudies AT ngood ametaanalysisofparticlewateruptakereconciliationstudies AT gmcfiggans ametaanalysisofparticlewateruptakereconciliationstudies AT jdwhitehead metaanalysisofparticlewateruptakereconciliationstudies AT mirwin metaanalysisofparticlewateruptakereconciliationstudies AT jdallan metaanalysisofparticlewateruptakereconciliationstudies AT ngood metaanalysisofparticlewateruptakereconciliationstudies AT gmcfiggans metaanalysisofparticlewateruptakereconciliationstudies |