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Abstract Radiative climate feedbacks in the Arctic have been extensively studied, but their spatial and seasonal variations have not been thoroughly examined. Using ERA5 reanalysis data, we examine seasonal variations in Arctic climate feedbacks and their relationship to sea‐ice loss based on changes from 1950–1979 to 1990–2019. The spring and summer seasons experienced large sea‐ice loss, strong surface albedo feedback, and large oceanic heat uptake. Arctic clouds exerted small net cooling in May‐June‐July but moderate warming during the cold season, especially over areas with large sea‐ice loss where cloud liquid and ice water content increased. Arctic water vapor feedback peaked in summer but was weak and uncorrelated with sea‐ice loss. Arctic positive lapse rate feedback (LRF) was strongest in winter over areas with large sea‐ice loss and weak inversion but uncorrelated with atmospheric stability, suggesting that oceanic heating from sea‐ice loss led to enhanced surface warming and the positive LRF.
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Contributions of Arctic Sea‐Ice Loss and East Siberian Atmospheric Blocking to 2020 Record‐Breaking Meiyu‐Baiu Rainfall
Abstract Heavy Meiyu‐Baiu rainfall occurred over central‐east China and Japan in June–July 2020. This study analyzes observational and reanalysis data and performs atmospheric model simulations to investigate its causes. It is found that low Arctic sea ice cover (SIC) in late spring‐early summer of 2020 along the Siberian coast was an important factor. The low SIC caused local warming and high pressure, resulted in excessive atmospheric blockings over East Siberia, which caused cold air outbreaks into the Meiyu‐Baiu region, stopped the seasonal northward march of the Meiyu‐Baiu front, and increased the thermal contrast across the front, leading to record‐breaking rainfall in June–July 2020. Our results suggest that the 2020 extreme Meiyu‐Baiu was partly caused by the low SIC around the Siberian coast through its impact on East Siberian blockings. As sea ice along the Siberian coast decreases under global warming, its variations and thus influence on Meiyu‐Baiu rainfall may weaken.
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- PAR ID:
- 10444487
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 48
- Issue:
- 10
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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