Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Inverse modeling of cloud-aerosol interactions: Part 1: Detailed response surface analysis
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).ORCID-id: 0000-0002-5940-2114
Visa övriga samt affilieringar
2011 (Engelska)Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 11, nr 14, s. 7269-7287Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

New methodologies are required to probe the sensitivity of parameters describing cloud droplet activation. This paper presents an inverse modeling-based method for exploring cloud-aerosol interactions via response surfaces. The objective function, containing the difference between the measured and model predicted cloud droplet size distribution is studied in a two-dimensional framework, and presented for pseudo-adiabatic cloud parcel model parameters that are pair-wise selected. From this response surface analysis it is shown that the susceptibility of cloud droplet size distribution to variations in different aerosol physiochemical parameters is highly dependent on the aerosol environment and meteorological conditions. In general the cloud droplet size distribution is most susceptible to changes in the updraft velocity. A shift towards an increase in the importance of chemistry for the cloud nucleating ability of particles is shown to exist somewhere between marine average and rural continental aerosol regimes. We also use these response surfaces to explore the feasibility of inverse modeling to determine cloud-aerosol interactions. It is shown that the "cloud-aerosol" inverse problem is particularly difficult to solve due to significant parameter interaction, presence of multiple regions of attraction, numerous local optima, and considerable parameter insensitivity. The identifiability of the model parameters will be dependent on the choice of the objective function. Sensitivity analysis is performed to investigate the location of the information content within the calibration data to confirm that our choice of objective function maximizes information retrieval from the cloud droplet size distribution. Cloud parcel models that employ a moving-centre based calculation of the cloud droplet size distribution pose additional difficulties when applying automatic search algorithms for studying cloud-aerosol interactions. To aid future studies, an increased resolution of the region of the size spectrum associated with droplet activation within cloud parcel models, or further development of fixed-sectional cloud models would be beneficial. Despite these improvements, it is demonstrated that powerful search algorithms remain necessary to efficiently explore the parameter space and successfully solve the cloud-aerosol inverse problem.

Ort, förlag, år, upplaga, sidor
2011. Vol. 11, nr 14, s. 7269-7287
Nyckelord [en]
RAINFALL-RUNOFF MODELS, SIZE DISTRIBUTION, PARAMETER-ESTIMATION, GLOBAL OPTIMIZATION, HYDRAULIC-PROPERTIES, DROPLET ACTIVATION, HYDROLOGIC-MODELS DATA ASSIMILATION, CALIBRATION DATA, CCN ACTIVATION
Nationell ämneskategori
Geovetenskap och relaterad miljövetenskap
Forskningsämne
tillämpad miljövetenskap
Identifikatorer
URN: urn:nbn:se:su:diva-60002DOI: 10.5194/acp-11-7269-2011ISI: 000293125100031OAI: oai:DiVA.org:su-60002DiVA, id: diva2:432569
Anmärkning
6Tillgänglig från: 2011-08-04 Skapad: 2011-08-04 Senast uppdaterad: 2025-02-07Bibliografiskt granskad
Ingår i avhandling
1. Inverse Modeling of Cloud – Aerosol Interactions
Öppna denna publikation i ny flik eller fönster >>Inverse Modeling of Cloud – Aerosol Interactions
2011 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The role of aerosols and clouds is one of the largest sources of uncertainty in understanding climate change. The primary scientific goal of this thesis is to improve the understanding of cloud-aerosol interactions by applying inverse modeling using Markov Chain Monte Carlo (MCMC) simulation.

Through a set of synthetic tests using a pseudo-adiabatic cloud parcel model, it is shown that a self adaptive MCMC algorithm can efficiently find the correct optimal values of meteorological and aerosol physiochemical parameters for a specified droplet size distribution and determine the global sensitivity of these parameters. For an updraft velocity of 0.3 m s-1, a shift towards an increase in the relative importance of chemistry compared to the accumulation mode number concentration is shown to exist somewhere between marine (~75 cm-3) and rural continental (~450 cm-3) aerosol regimes.

Examination of in-situ measurements from the Marine Stratus/Stratocumulus Experiment (MASE II) shows that for air masses with higher number concentrations of accumulation mode (Dp = 60-120 nm) particles (~450 cm-3), an accurate simulation of the measured droplet size distribution requires an accurate representation of the particle chemistry. The chemistry is relatively more important than the accumulation mode particle number concentration, and similar in importance to the particle mean radius. This result is somewhat at odds with current theory that suggests chemistry can be ignored in all except for the most polluted environments. Under anthropogenic influence, we must consider particle chemistry also in marine environments that may be deemed relatively clean.

The MCMC algorithm can successfully reproduce the observed marine stratocumulus droplet size distributions. However, optimising towards the broadness of the measured droplet size distribution resulted in a discrepancy between the updraft velocity, and mean radius/geometric standard deviation of the accumulation mode. This suggests that we are missing a dynamical process in the pseudo-adiabatic cloud parcel model.  

Ort, förlag, år, upplaga, sidor
Stockholm: Department of Applied Environmental Science (ITM), Stockholm University, 2011. s. 64
Nyckelord
stratocumulus, marine, cloud, aerosol, interactions, MCMC, inverse modeling, droplet closure, global sensitivity
Nationell ämneskategori
Meteorologi och atmosfärsvetenskap
Forskningsämne
tillämpad miljövetenskap
Identifikatorer
urn:nbn:se:su:diva-60454 (URN)978-91-7447-343-8 (ISBN)
Disputation
2011-09-23, Nordenskiöldsalen, Geovetenskapens hus, Svante Arrhenius väg 12, Stockholm, 13:00 (Engelska)
Opponent
Handledare
Anmärkning
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Manuscript.Tillgänglig från: 2011-09-01 Skapad: 2011-08-17 Senast uppdaterad: 2025-02-07Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltext

Person

Partridge, Daniel G.Tunved, PeterEkman, A. M. L.

Sök vidare i DiVA

Av författaren/redaktören
Partridge, Daniel G.Tunved, PeterEkman, A. M. L.
Av organisationen
Institutionen för tillämpad miljövetenskap (ITM)Meteorologiska institutionen (MISU)
I samma tidskrift
Atmospheric Chemistry And Physics
Geovetenskap och relaterad miljövetenskap

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 188 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf