Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections
Heatwaves can produce catastrophic effects on public health and natural systems, especially under global warming. There are two methods to measure heatwaves, computed by relative and absolute thresholds, namely relative and absolute heatwaves (RHWs and AHWs). Generally, AHWs mostly occur in hot area...
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| Format: | Article |
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MDPI AG
2022-04-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/13/5/649 |
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| author | Haoran Xu Guwei Zhang |
| author_facet | Haoran Xu Guwei Zhang |
| author_sort | Haoran Xu |
| collection | DOAJ |
| description | Heatwaves can produce catastrophic effects on public health and natural systems, especially under global warming. There are two methods to measure heatwaves, computed by relative and absolute thresholds, namely relative and absolute heatwaves (RHWs and AHWs). Generally, AHWs mostly occur in hot areas because of fixed thresholds, while RHWs represent anomalous events for the local climate, making them possible everywhere in the warm season. Based on observations and CMIP6 outputs, this study compared AHWs and RHWs in Eastern China (EC) with five sub-regions [Northeast China (NEC), North China (NC), Lower Yangtze River (LYR), Middle Yangtze River (MYR) and South China (SC)]. Similarities among RHWs and AHWs were found in present-day trends (1995–2014) and spatial distributions. The heatwave intensity/days for RHWs and AHWs both displayed highest future increases in northern/southern EC, and the increases for 2081–2100 would be 1.5 times as high as 2041–2060. All these similarities illustrate that applying either relative or absolute thresholds in EC, historical temporal variations, changing future spatial patterns, and increasing ratio from 2081–2100 to 2041–2060, would show reliable results. As far as differences are concerned, RHWs were observed across the entire EC, while AHWs did not show up in parts of NC and NEC. Considering model performance, RHWs would perform better than AHWs in most areas of EC. The annual heatwave intensity/days were higher for RHWs than for AHWs during present-day and future periods, which might overestimate heat-related risks. Overall, this study recommended RHWs for heatwave analyses, particularly for future projections, but for risk assessment, the choice of thresholds is crucial. The results reinforced the necessity to further improve model performance to address various needs. |
| first_indexed | 2024-03-10T03:22:14Z |
| format | Article |
| id | doaj.art-38acfe12addb4b08a4968a5625c5623e |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T03:22:14Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-38acfe12addb4b08a4968a5625c5623e2023-11-23T10:00:42ZengMDPI AGAtmosphere2073-44332022-04-0113564910.3390/atmos13050649Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future ProjectionsHaoran Xu0Guwei Zhang1Climate, Environment and Sustainability Center, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaInstitute of Urban Meteorology, China Meteorological Administration, Beijing 100089, ChinaHeatwaves can produce catastrophic effects on public health and natural systems, especially under global warming. There are two methods to measure heatwaves, computed by relative and absolute thresholds, namely relative and absolute heatwaves (RHWs and AHWs). Generally, AHWs mostly occur in hot areas because of fixed thresholds, while RHWs represent anomalous events for the local climate, making them possible everywhere in the warm season. Based on observations and CMIP6 outputs, this study compared AHWs and RHWs in Eastern China (EC) with five sub-regions [Northeast China (NEC), North China (NC), Lower Yangtze River (LYR), Middle Yangtze River (MYR) and South China (SC)]. Similarities among RHWs and AHWs were found in present-day trends (1995–2014) and spatial distributions. The heatwave intensity/days for RHWs and AHWs both displayed highest future increases in northern/southern EC, and the increases for 2081–2100 would be 1.5 times as high as 2041–2060. All these similarities illustrate that applying either relative or absolute thresholds in EC, historical temporal variations, changing future spatial patterns, and increasing ratio from 2081–2100 to 2041–2060, would show reliable results. As far as differences are concerned, RHWs were observed across the entire EC, while AHWs did not show up in parts of NC and NEC. Considering model performance, RHWs would perform better than AHWs in most areas of EC. The annual heatwave intensity/days were higher for RHWs than for AHWs during present-day and future periods, which might overestimate heat-related risks. Overall, this study recommended RHWs for heatwave analyses, particularly for future projections, but for risk assessment, the choice of thresholds is crucial. The results reinforced the necessity to further improve model performance to address various needs.https://www.mdpi.com/2073-4433/13/5/649eastern Chinarelative and absolute heatwavesobservationsCMIP6 |
| spellingShingle | Haoran Xu Guwei Zhang Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections Atmosphere eastern China relative and absolute heatwaves observations CMIP6 |
| title | Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections |
| title_full | Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections |
| title_fullStr | Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections |
| title_full_unstemmed | Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections |
| title_short | Comparison of Relative and Absolute Heatwaves in Eastern China: Observations, Simulations and Future Projections |
| title_sort | comparison of relative and absolute heatwaves in eastern china observations simulations and future projections |
| topic | eastern China relative and absolute heatwaves observations CMIP6 |
| url | https://www.mdpi.com/2073-4433/13/5/649 |
| work_keys_str_mv | AT haoranxu comparisonofrelativeandabsoluteheatwavesineasternchinaobservationssimulationsandfutureprojections AT guweizhang comparisonofrelativeandabsoluteheatwavesineasternchinaobservationssimulationsandfutureprojections |