Wang, Jingyu

Reliable Subseasonal-to-Seasonal (S2S) forecasts of precipitation are critical for disaster prevention and mitigation. In this study, an innovative hybrid method CSG-UNET combining the UNET with the censored and shifted gamma distribution based ensemble model output statistic (CSG-EMOS), is proposed to calibrate the ensemble precipitation forecasts from ECMWF over the China mainland during boreal summer. Additional atmospheric variable forecasts and the data augmentation are also included to deal with the potential issues of low signal-to-noise ratio and relatively small sample sizes in traditional S2S precipitation forecast correction. The hybrid CSG-UNET exhibits a notable advantage over both individual UNET and CSG-EMOS in improving ensemble precipitation forecasts, simultaneously improving the forecast skills for lead times of 1–2 weeks and further extending the effective forecast timeliness to ∼4 weeks. Specifically, the climatology-based Brier Skill Scores are improved by ∼0.4 for the extreme precipitation forecasts almost throughout the whole timescale compared with the ECMWF. Feature importance analyze towards CSG-EMOS model indicates that the atmospheric factors make great contributions to the prediction skill with the increasing lead times. The CSG-UNET method is promising in subseasonal precipitation forecasts and could be applied to the routine forecast of other atmospheric and ocean phenomena in the future.

The Kuroshio intrusion (KI) is a northwestward-flowing branch of the Kuroshio Current, which enters the South China Sea (SCS) and regulates its temperature, salinity, and water mass exchanges. However, limited direct observations hinder our understanding of KI's mechanisms and responses to climate change. Here, we present a 60-year bi-monthly resolved coral oxygen isotope (δ¹⁸Oc) record from Dongsha Atoll, the northern SCS. The dry-season (December–March) δ¹⁸Oc record reveals interannual to decadal variabilities of the KI. The impact of the East Asian winter monsoon (EAWM) on Dongsha δ¹⁸Oc was more pronounced during the 1970s and 1980s and after the early 2000s, while the influence of the El Niño-Southern Oscillation (ENSO) on Dongsha δ¹⁸Oc was higher between the 1980s and 1990s. The Pacific Decadal Oscillation (PDO) may have a relatively minor effect on KI strength or may indirectly modulate KI strength through its influence on ENSO activities. Our Dongsha δ¹⁸Oc record highlight the importance of the EAWM, ENSO, and PDO in predicting future KI changes.

The heavy global demand for sand in various sectors of the economy subjects the Vietnamese Mekong Delta to correspondingly high amounts of sand mining—a process that started in the early 1990s contributing significantly to the Vietnamese economy. The impacts of intensive sand mining and mining-related industries damage the integrity of the river and local communities. Much of the literature focuses on the former, exposing people to the deleterious implications of sand mining on the physical environment. This study aims to fill the gap on the less explored latter through the lenses of place and landscape per human geography tradition, using qualitative methods of thirty-five interviews with locals, video recordings, and sound measurements to highlight the impacts of sand mining and mining-related industries. This study revealed that sand mining and its associated activities are responsible for people’s perceptions of notable air, land, and noise pollution, as well as substantial harm to the urban environment. Over 80 percent of interviewed locals acknowledged the disruptions to their daily lives and a substantial loss of their sense of place. These findings shed light on narratives frequently overlooked by policymakers, emphasizing the urgency of addressing these issues for a sustainable future.