1. Internal Climate Variability Obscures Future Freezing Rain Changes Despite Global Warming Trend.
- Author
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Zhuang, Haoyu, DeGaetano, Arthur T., and Lehner, Flavio
- Subjects
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ATMOSPHERIC models , *HUMIDITY , *CLIMATOLOGY , *GLOBAL warming , *MACHINE learning , *SOIL freezing - Abstract
Although numerous studies have projected changes in freezing rain under future climate conditions, the internal variability of freezing rain remains poorly quantified. Here, we introduce a framework utilizing a novel machine‐learning algorithm to diagnose freezing rain in reanalysis and climate model simulations. By employing multivariate quantile mapping, we decompose the projected freezing rain trend into contributions from changes in temperature, relative humidity, and precipitation, which helps separate the forced response from internal climate variability. Our finding reveals a notable decrease in freezing rain occurrence in most areas. Despite a substantial temperature increase, internal variability overshadows climate forcing across a large portion of the eastern United States until about 2050. This insight has implications for practitioners, suggesting that the observed freezing rain frequency climatology continues to provide a relevant baseline for decision‐making in the near term. However, longer‐term design and adaptation plans should consider the projected changes in these regions. Plain Language Summary: Freezing rain is a hazardous type of winter precipitation that can lead to significant transportation delays and power outages. This study explores future changes in freezing rain by using a combination of machine‐learning and statistical methods. We find that freezing rain frequency is expected to decline as temperatures rise across much of the eastern United States. However, natural variations in freezing rain occurrence are more significant than the impact of climate change in the Northern Great Plains, a small portion of the Midwest, and the northeastern United States throughout the 21st century. Across other regions of the eastern United States, the projected decline in freezing rain frequency emerges from the background natural climate variability around 2050. This means that, in the near term, the potential impacts of freezing rain on travel and infrastructure will not be substantially different than those in the past. Key Points: Multivariate quantile mapping is used to separate the forced response of freezing rain from internal climate variabilityInternal variability dominates projected freezing rain changes in numerous regions despite a clear temperature increaseProperly accounting for internal variability is critical for risk assessments of future freezing rain events [ABSTRACT FROM AUTHOR]
- Published
- 2024
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