Changes in near-surface winds across Sweden over the past decades - Observations and simulations
Driven by a combination of anthropogenic activities and climate changes, near- surface terrestrial winds displayed a large decrease in their magnitude in the past decades, named “stilling”, and a recent recovery in their slowdown. Understanding how wind has changed and identifying the factors behind...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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2020
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Online Access: | http://hdl.handle.net/2077/66844 |
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openpolar |
institution |
Open Polar |
collection |
University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive) |
op_collection_id |
ftunivgoeteborg |
language |
English |
topic |
mean and gust wind speed stilling-reversal phenomena regional climate models climate reanalyses ERA5 parametrization NAO extratropical cyclones surface roughness Sweden |
spellingShingle |
mean and gust wind speed stilling-reversal phenomena regional climate models climate reanalyses ERA5 parametrization NAO extratropical cyclones surface roughness Sweden Lorenzo, Minola Changes in near-surface winds across Sweden over the past decades - Observations and simulations |
topic_facet |
mean and gust wind speed stilling-reversal phenomena regional climate models climate reanalyses ERA5 parametrization NAO extratropical cyclones surface roughness Sweden |
description |
Driven by a combination of anthropogenic activities and climate changes, near- surface terrestrial winds displayed a large decrease in their magnitude in the past decades, named “stilling”, and a recent recovery in their slowdown. Understanding how wind has changed and identifying the factors behind the observed variabilities is crucial so that reasonable future wind scenarios can be constructed. In this way, adaptation strategies can be developed to increase society’s resilience to the plausible future wind climate. This is particularly important for Sweden, which is largely vulnerable to changes in mean wind speed conditions and to the occurrence of extreme winds. Therefore, this thesis investigates past variations in near-surface winds across Sweden and explores the mechanisms behind their variabilities and changes. This is done by using the first homogenized dataset of in-situ observations and by analyzing current simulations of wind gusts. Results show that, during the past decades, both observed mean and gust wind speed underwent nonlinear changes, driven by the dominant winter variability. In particular, consistent with the stilling-reversal phenomena, the significant stilling ceased in 2003, followed by no clear trend afterwards. The detected stilling-reversal is linked to large- scale atmospheric circulation changes, in particular to the North Atlantic Oscillation, and the intensity changes of extratropical cyclones passing across Sweden. The comparison with reanalysis outputs reveals that, in addition to the large-scale interannual variability, changes in surface roughness (e.g. changes in forest cover) have most likely contributed to the observed wind change across Sweden. Moreover, this thesis finds that current regional climate models and reanalyses do not have adequate skills in simulating past wind gusts across inland and mountain regions. Major improvements are achieved when the elevation differences are considered in the formulation of the gust parametrization and the convective gust ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Lorenzo, Minola |
author_facet |
Lorenzo, Minola |
author_sort |
Lorenzo, Minola |
title |
Changes in near-surface winds across Sweden over the past decades - Observations and simulations |
title_short |
Changes in near-surface winds across Sweden over the past decades - Observations and simulations |
title_full |
Changes in near-surface winds across Sweden over the past decades - Observations and simulations |
title_fullStr |
Changes in near-surface winds across Sweden over the past decades - Observations and simulations |
title_full_unstemmed |
Changes in near-surface winds across Sweden over the past decades - Observations and simulations |
title_sort |
changes in near-surface winds across sweden over the past decades - observations and simulations |
publishDate |
2020 |
url |
http://hdl.handle.net/2077/66844 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Safaei Pirooz, A. A., Flay, R. G. J., Minola, L., Azorin- Molina, C., Chen, D. (2020). Effects of sensor response and moving average filter duration on maximum wind gust measurements. Journal of Wind Engineering & Industrial Aerodynamics 206: 104354. ::doi::10.1016/j.jweia.2020.104354 Deng, K., Azorin-Molina, C., Minola, L., Zhang, G., Chen, D. (2020). Global near-surface wind speed changes over the last decades revealed by global reanalyses and CMIP6 model simulations. (Revision submitted to Journal of Climate) Minola, L., Azorin-Molina, C., Guijarro, J. A., Zhang, G., Son, S.-W., Chen D. (2020). Climatology of near-surface daily peak wind gusts across Scandinavia: observations and model simulations. (Submitted to Journal of Geophysical Research – Atmospheres) Minola, L., Zhang, F., Azorin-Molina, C., Safaei Pirooz, A. A., Flay, R. G. J., Hersbach, H., Chen, D. (2020). Near- surface mean and gust wind speeds in ERA5 across Sweden: towards an improved gust parametrization. Climate Dynamics 55: 887-907. ::doi::10.1007/s00382-020-05302-6 Minola, L., Azorin-Molina, C., Chen, D. (2016). Homogenization and assessment of observed near-surface wind speed trends across Sweden, 1956-2013. Journal of Climate 29: 7397-7415. ::doi::10.1175/JCLI-D-15-0636.1 Minola, L., Reese, H., Lai, H.-W., Azorin-Molina, C., Guijarro, J. A., Son, S.-W., Chen, D. (2020). Wind stilling- reversal across Sweden: The impact of land-use and large- scale atmospheric circulation changes. (Submitted to International Journal of Climatology) 978-91-8009-122-0 (PRINT) 978-91-8009-123-7 (PDF) http://hdl.handle.net/2077/66844 |
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ftunivgoeteborg:oai:gupea.ub.gu.se:2077/66844 2023-10-29T02:38:38+01:00 Changes in near-surface winds across Sweden over the past decades - Observations and simulations Lorenzo, Minola 2020-11-19 application/pdf http://hdl.handle.net/2077/66844 eng eng Safaei Pirooz, A. A., Flay, R. G. J., Minola, L., Azorin- Molina, C., Chen, D. (2020). Effects of sensor response and moving average filter duration on maximum wind gust measurements. Journal of Wind Engineering & Industrial Aerodynamics 206: 104354. ::doi::10.1016/j.jweia.2020.104354 Deng, K., Azorin-Molina, C., Minola, L., Zhang, G., Chen, D. (2020). Global near-surface wind speed changes over the last decades revealed by global reanalyses and CMIP6 model simulations. (Revision submitted to Journal of Climate) Minola, L., Azorin-Molina, C., Guijarro, J. A., Zhang, G., Son, S.-W., Chen D. (2020). Climatology of near-surface daily peak wind gusts across Scandinavia: observations and model simulations. (Submitted to Journal of Geophysical Research – Atmospheres) Minola, L., Zhang, F., Azorin-Molina, C., Safaei Pirooz, A. A., Flay, R. G. J., Hersbach, H., Chen, D. (2020). Near- surface mean and gust wind speeds in ERA5 across Sweden: towards an improved gust parametrization. Climate Dynamics 55: 887-907. ::doi::10.1007/s00382-020-05302-6 Minola, L., Azorin-Molina, C., Chen, D. (2016). Homogenization and assessment of observed near-surface wind speed trends across Sweden, 1956-2013. Journal of Climate 29: 7397-7415. ::doi::10.1175/JCLI-D-15-0636.1 Minola, L., Reese, H., Lai, H.-W., Azorin-Molina, C., Guijarro, J. A., Son, S.-W., Chen, D. (2020). Wind stilling- reversal across Sweden: The impact of land-use and large- scale atmospheric circulation changes. (Submitted to International Journal of Climatology) 978-91-8009-122-0 (PRINT) 978-91-8009-123-7 (PDF) http://hdl.handle.net/2077/66844 mean and gust wind speed stilling-reversal phenomena regional climate models climate reanalyses ERA5 parametrization NAO extratropical cyclones surface roughness Sweden Text Doctoral thesis Doctor of Philosophy 2020 ftunivgoeteborg 2023-10-04T21:07:30Z Driven by a combination of anthropogenic activities and climate changes, near- surface terrestrial winds displayed a large decrease in their magnitude in the past decades, named “stilling”, and a recent recovery in their slowdown. Understanding how wind has changed and identifying the factors behind the observed variabilities is crucial so that reasonable future wind scenarios can be constructed. In this way, adaptation strategies can be developed to increase society’s resilience to the plausible future wind climate. This is particularly important for Sweden, which is largely vulnerable to changes in mean wind speed conditions and to the occurrence of extreme winds. Therefore, this thesis investigates past variations in near-surface winds across Sweden and explores the mechanisms behind their variabilities and changes. This is done by using the first homogenized dataset of in-situ observations and by analyzing current simulations of wind gusts. Results show that, during the past decades, both observed mean and gust wind speed underwent nonlinear changes, driven by the dominant winter variability. In particular, consistent with the stilling-reversal phenomena, the significant stilling ceased in 2003, followed by no clear trend afterwards. The detected stilling-reversal is linked to large- scale atmospheric circulation changes, in particular to the North Atlantic Oscillation, and the intensity changes of extratropical cyclones passing across Sweden. The comparison with reanalysis outputs reveals that, in addition to the large-scale interannual variability, changes in surface roughness (e.g. changes in forest cover) have most likely contributed to the observed wind change across Sweden. Moreover, this thesis finds that current regional climate models and reanalyses do not have adequate skills in simulating past wind gusts across inland and mountain regions. Major improvements are achieved when the elevation differences are considered in the formulation of the gust parametrization and the convective gust ... Doctoral or Postdoctoral Thesis North Atlantic North Atlantic oscillation University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive) |