Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition
Forecasts with the European Centre for Medium-Range Weather Forecasts’ numerical weather prediction model are evaluated using an extensive set of observations from the Arctic Ocean 2018 expedition on the Swedish icebreaker Oden. The atmospheric model (Cy45r1) is similar to that used for the ERA5 rea...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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Online Access: | https://zenodo.org/record/4552401 https://doi.org/10.1002/qj.3971 |
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ftzenodo:oai:zenodo.org:4552401 2023-05-15T14:37:35+02:00 Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition Tjernström, Michael Svensson, Gunilla Magnusson, Linus Brooks, Ian M. Prytherch, John Vullers, Jutta Young, Gillian 2020-12-29 https://zenodo.org/record/4552401 https://doi.org/10.1002/qj.3971 unknown info:eu-repo/grantAgreement/EC/H2020/727862/ https://zenodo.org/communities/applicate https://zenodo.org/record/4552401 https://doi.org/10.1002/qj.3971 oai:zenodo.org:4552401 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Arctic boundary layer Arctic climate Arctic clouds Arctic reanalysis Arctic weather prediction model error model evaluation surface energy budget info:eu-repo/semantics/article publication-article 2020 ftzenodo https://doi.org/10.1002/qj.3971 2023-03-10T22:00:08Z Forecasts with the European Centre for Medium-Range Weather Forecasts’ numerical weather prediction model are evaluated using an extensive set of observations from the Arctic Ocean 2018 expedition on the Swedish icebreaker Oden. The atmospheric model (Cy45r1) is similar to that used for the ERA5 reanalysis (Cy41r2). The evaluation covers 1 month,with the icebreaker moored to drifting sea ice near the North Pole; a total of 125 forecasts issued four times per day were used. Standard surface observations and 6-hourly soundings were assimilated to ensure that the initial model error is small. Model errors can be divided into two groups. First, variables related to dynamics feature errors that grow with forecast length; error spread also grows with time. Initial errors are small, facilitating a robust evaluation of the second group; thermodynamic variables. These feature fast error growth for 6–12 hr, after which errors saturates; error spread is roughly constant. Both surface and near-surface air temperatures are too warm in the model. During the summer both are typically above zero in spite of the ongoing melt; however, the warm bias increases as the surface freezes. The warm bias is due to a too warm atmosphere; errors in surface sensible heat flux transfer additional heat from the atmosphere to the surface. The lower troposphere temperature error has a distinct vertical structure: a substantial warm bias in the lowest few 100m and a large cold bias around 1 km; this structure features a significant diurnal cycle and is tightly coupled to errors in themodelled clouds. Clouds appear too often and in a too deep layer of the lower atmosphere; the lowest clouds essentially never break up. The largest error in cloud presence is aligned with the largest cold bias at around 1 km. Article in Journal/Newspaper Arctic Arctic Ocean North Pole oden Sea ice Zenodo Arctic Arctic Ocean North Pole Quarterly Journal of the Royal Meteorological Society 147 735 1278 1299 |
institution |
Open Polar |
collection |
Zenodo |
op_collection_id |
ftzenodo |
language |
unknown |
topic |
Arctic boundary layer Arctic climate Arctic clouds Arctic reanalysis Arctic weather prediction model error model evaluation surface energy budget |
spellingShingle |
Arctic boundary layer Arctic climate Arctic clouds Arctic reanalysis Arctic weather prediction model error model evaluation surface energy budget Tjernström, Michael Svensson, Gunilla Magnusson, Linus Brooks, Ian M. Prytherch, John Vullers, Jutta Young, Gillian Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition |
topic_facet |
Arctic boundary layer Arctic climate Arctic clouds Arctic reanalysis Arctic weather prediction model error model evaluation surface energy budget |
description |
Forecasts with the European Centre for Medium-Range Weather Forecasts’ numerical weather prediction model are evaluated using an extensive set of observations from the Arctic Ocean 2018 expedition on the Swedish icebreaker Oden. The atmospheric model (Cy45r1) is similar to that used for the ERA5 reanalysis (Cy41r2). The evaluation covers 1 month,with the icebreaker moored to drifting sea ice near the North Pole; a total of 125 forecasts issued four times per day were used. Standard surface observations and 6-hourly soundings were assimilated to ensure that the initial model error is small. Model errors can be divided into two groups. First, variables related to dynamics feature errors that grow with forecast length; error spread also grows with time. Initial errors are small, facilitating a robust evaluation of the second group; thermodynamic variables. These feature fast error growth for 6–12 hr, after which errors saturates; error spread is roughly constant. Both surface and near-surface air temperatures are too warm in the model. During the summer both are typically above zero in spite of the ongoing melt; however, the warm bias increases as the surface freezes. The warm bias is due to a too warm atmosphere; errors in surface sensible heat flux transfer additional heat from the atmosphere to the surface. The lower troposphere temperature error has a distinct vertical structure: a substantial warm bias in the lowest few 100m and a large cold bias around 1 km; this structure features a significant diurnal cycle and is tightly coupled to errors in themodelled clouds. Clouds appear too often and in a too deep layer of the lower atmosphere; the lowest clouds essentially never break up. The largest error in cloud presence is aligned with the largest cold bias at around 1 km. |
format |
Article in Journal/Newspaper |
author |
Tjernström, Michael Svensson, Gunilla Magnusson, Linus Brooks, Ian M. Prytherch, John Vullers, Jutta Young, Gillian |
author_facet |
Tjernström, Michael Svensson, Gunilla Magnusson, Linus Brooks, Ian M. Prytherch, John Vullers, Jutta Young, Gillian |
author_sort |
Tjernström, Michael |
title |
Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition |
title_short |
Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition |
title_full |
Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition |
title_fullStr |
Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition |
title_full_unstemmed |
Central Arctic weather forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition |
title_sort |
central arctic weather forecasting: confronting the ecmwf ifs with observations from the arctic ocean 2018 expedition |
publishDate |
2020 |
url |
https://zenodo.org/record/4552401 https://doi.org/10.1002/qj.3971 |
geographic |
Arctic Arctic Ocean North Pole |
geographic_facet |
Arctic Arctic Ocean North Pole |
genre |
Arctic Arctic Ocean North Pole oden Sea ice |
genre_facet |
Arctic Arctic Ocean North Pole oden Sea ice |
op_relation |
info:eu-repo/grantAgreement/EC/H2020/727862/ https://zenodo.org/communities/applicate https://zenodo.org/record/4552401 https://doi.org/10.1002/qj.3971 oai:zenodo.org:4552401 |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.1002/qj.3971 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
147 |
container_issue |
735 |
container_start_page |
1278 |
op_container_end_page |
1299 |
_version_ |
1766309819515404288 |