Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI
Simulations of a Regional Climate Model (RCM) driven by identical lateral boundary conditions but initialized at different times exhibit the phenomenon of so-called internal model variability (or in short, Internal Variability— IV ), which is defined as the inter-member spread between members in an...
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ftdoajarticles:oai:doaj.org/article:fea4c0e0bc2f4a6480adbd5c26538c4f 2023-05-15T18:18:52+02:00 Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI Ha Thi Minh Ho-Hagemann Stefan Hagemann Sebastian Grayek Ronny Petrik Burkhardt Rockel Joanna Staneva Frauke Feser Corinna Schrum 2020-02-01T00:00:00Z https://doi.org/10.3390/atmos11030227 https://doaj.org/article/fea4c0e0bc2f4a6480adbd5c26538c4f EN eng MDPI AG https://www.mdpi.com/2073-4433/11/3/227 https://doaj.org/toc/2073-4433 2073-4433 doi:10.3390/atmos11030227 https://doaj.org/article/fea4c0e0bc2f4a6480adbd5c26538c4f Atmosphere, Vol 11, Iss 3, p 227 (2020) climate modeling internal variability uncertainty rcm regional coupled system model air-sea coupling land-sea interaction euro-cordex gcoast extremes Meteorology. Climatology QC851-999 article 2020 ftdoajarticles https://doi.org/10.3390/atmos11030227 2022-12-31T15:08:04Z Simulations of a Regional Climate Model (RCM) driven by identical lateral boundary conditions but initialized at different times exhibit the phenomenon of so-called internal model variability (or in short, Internal Variability— IV ), which is defined as the inter-member spread between members in an ensemble of simulations. Our study investigates the effects of air-sea coupling on IV of the regional atmospheric model COSMO-CLM (CCLM) of the new regional coupled system model GCOAST-AHOI (Geesthacht Coupled cOAstal model SysTem: Atmosphere, Hydrology, Ocean and Sea Ice). We specifically address physical processes parameterized in CCLM, which may cause a large IV during an extreme event, and where this IV is affected by the air-sea coupling. Two six-member ensemble simulations were conducted with GCOAST-AHOI and the stand-alone CCLM (CCLM_ctr) for a period of 1 September−31 December 2013 over Europe. IV is expressed by spreads within the two sets of ensembles. Analyses focus on specific events during this period, especially on the storm Christian occurring from 27 to 29 October 2013 in northern Europe. Results show that simulations of CCLM_ctr vary largely amongst ensemble members during the storm. By analyzing two members of CCLM_ctr with opposite behaviors, we found that the large uncertainty in CCLM_ctr is caused by a combination of two factors (1) uncertainty in parameterization of cloud-radiation interaction in the atmospheric model. and (2) lack of an active two-way air-sea interaction. When CCLM is two-way coupled with the ocean model, the ensemble means of GCOAST-AHOI and CCLM_ctr are relatively similar, but the spread is reduced remarkably in GCOAST-AHOI, not only over the ocean where the coupling is done but also over land due to the land-sea interactions. Article in Journal/Newspaper Sea ice Directory of Open Access Journals: DOAJ Articles Atmosphere 11 3 227 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
climate modeling internal variability uncertainty rcm regional coupled system model air-sea coupling land-sea interaction euro-cordex gcoast extremes Meteorology. Climatology QC851-999 |
spellingShingle |
climate modeling internal variability uncertainty rcm regional coupled system model air-sea coupling land-sea interaction euro-cordex gcoast extremes Meteorology. Climatology QC851-999 Ha Thi Minh Ho-Hagemann Stefan Hagemann Sebastian Grayek Ronny Petrik Burkhardt Rockel Joanna Staneva Frauke Feser Corinna Schrum Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI |
topic_facet |
climate modeling internal variability uncertainty rcm regional coupled system model air-sea coupling land-sea interaction euro-cordex gcoast extremes Meteorology. Climatology QC851-999 |
description |
Simulations of a Regional Climate Model (RCM) driven by identical lateral boundary conditions but initialized at different times exhibit the phenomenon of so-called internal model variability (or in short, Internal Variability— IV ), which is defined as the inter-member spread between members in an ensemble of simulations. Our study investigates the effects of air-sea coupling on IV of the regional atmospheric model COSMO-CLM (CCLM) of the new regional coupled system model GCOAST-AHOI (Geesthacht Coupled cOAstal model SysTem: Atmosphere, Hydrology, Ocean and Sea Ice). We specifically address physical processes parameterized in CCLM, which may cause a large IV during an extreme event, and where this IV is affected by the air-sea coupling. Two six-member ensemble simulations were conducted with GCOAST-AHOI and the stand-alone CCLM (CCLM_ctr) for a period of 1 September−31 December 2013 over Europe. IV is expressed by spreads within the two sets of ensembles. Analyses focus on specific events during this period, especially on the storm Christian occurring from 27 to 29 October 2013 in northern Europe. Results show that simulations of CCLM_ctr vary largely amongst ensemble members during the storm. By analyzing two members of CCLM_ctr with opposite behaviors, we found that the large uncertainty in CCLM_ctr is caused by a combination of two factors (1) uncertainty in parameterization of cloud-radiation interaction in the atmospheric model. and (2) lack of an active two-way air-sea interaction. When CCLM is two-way coupled with the ocean model, the ensemble means of GCOAST-AHOI and CCLM_ctr are relatively similar, but the spread is reduced remarkably in GCOAST-AHOI, not only over the ocean where the coupling is done but also over land due to the land-sea interactions. |
format |
Article in Journal/Newspaper |
author |
Ha Thi Minh Ho-Hagemann Stefan Hagemann Sebastian Grayek Ronny Petrik Burkhardt Rockel Joanna Staneva Frauke Feser Corinna Schrum |
author_facet |
Ha Thi Minh Ho-Hagemann Stefan Hagemann Sebastian Grayek Ronny Petrik Burkhardt Rockel Joanna Staneva Frauke Feser Corinna Schrum |
author_sort |
Ha Thi Minh Ho-Hagemann |
title |
Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI |
title_short |
Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI |
title_full |
Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI |
title_fullStr |
Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI |
title_full_unstemmed |
Internal Model Variability of the Regional Coupled System Model GCOAST-AHOI |
title_sort |
internal model variability of the regional coupled system model gcoast-ahoi |
publisher |
MDPI AG |
publishDate |
2020 |
url |
https://doi.org/10.3390/atmos11030227 https://doaj.org/article/fea4c0e0bc2f4a6480adbd5c26538c4f |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Atmosphere, Vol 11, Iss 3, p 227 (2020) |
op_relation |
https://www.mdpi.com/2073-4433/11/3/227 https://doaj.org/toc/2073-4433 2073-4433 doi:10.3390/atmos11030227 https://doaj.org/article/fea4c0e0bc2f4a6480adbd5c26538c4f |
op_doi |
https://doi.org/10.3390/atmos11030227 |
container_title |
Atmosphere |
container_volume |
11 |
container_issue |
3 |
container_start_page |
227 |
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1766195619042426880 |