Water isotopes measured in Antarctic ice cores enable reconstruction at the first order of the past temperature variations. However, the seasonality of the precipitation and episodic events, including synoptic‐scale disturbances, influence the isotopic signals recorded in ice cores. In this study, we adopted an isotope‐enabled atmospheric general circulation model from 1981 to 2010 to investigate variations in climatic factors in δ¹⁸O of precipitation (δ¹⁸O_p) at Dome Fuji, East Antarctica. The Southern Annular Mode (SAM), the primary mode of atmospheric circulation in the southern midhigh latitudes, significantly contributes to the isotope signals. Positive δ¹⁸O_p anomalies, especially in the austral winter, are linked to the negative polarity of the SAM, which weakens westerly winds and increases the southward inflow of water vapor flux. Daily variations in temperature and δ¹⁸O_p in Dome Fuji are significantly small in the austral summer, and their contribution to the annual signals is limited. The isotope signals driven by the SAM are a locational feature of Dome Fuji, related to the asymmetric component of the large‐scale atmospheric pattern.

The rising humid heat is regarded as a severe threat to human survivability, but the proper integration of humid heat into heat-health alerts is still being explored. Using state-of-the-art epidemiological and climatological datasets, we examined the association between multiple heat stress indicators (HSIs) and daily human mortality in 739 cities worldwide. Notable differences were observed in the long-term trends and timing of heat events detected by HSIs. Air temperature (T_air) predicts heat-related mortality well in cities with a robust negative T_air-relative humidity correlation (C_T-RH). However, in cities with near-zero or weak positive C_T-RH, HSIs considering humidity provide enhanced predictive power compared to T_air. Furthermore, the magnitude and timing of heat-related mortality measured by HSIs could differ largely from those associated with T_air in many cities. Our findings provide important insights into specific regions where humans are vulnerable to humid heat and can facilitate the further enhancement of heat-health alert systems.

Glacial cycles during the early Pleistocene are characterised by a dominant 41,000-year periodicity and amplitudes smaller than those of glacial cycles with ~100,000-year periodicity during the late Pleistocene. However, it remains unclear how the 41,000-year glacial cycles during the early Pleistocene respond to Earth’s astronomical forcings. Here we employ a three-dimensional ice-sheet model to simulate the glacial cycles at ~1.6–1.2 million years before present and analyse the phase angle of precession and obliquity at deglaciations. We show that each deglaciation occurs at every other precession minimum, and when obliquity is large. The lead-lag relationship between precession and obliquity controls the length of interglacial periods, the shape of the glacial cycle, and the glacial ice-sheet geometry. The large amplitudes of obliquity and eccentricity during this period helped to establish robust 41,000-year glacial cycles. This behaviour is explained by the threshold mechanism determined by ice-sheet size and astronomical forcings.

Phuket, the study area of this work with 33 sandy beaches, provides about 15% of the nation’s gross domestic product from the tourism industry. Many factors cause shoreline changes affecting beach areas, such as seasonal erosion and rising sea levels. In this study, shoreline position was the key parameter for evaluating shoreline changes. The CoastSat open-source software was selected to analyze the shoreline changes using a publicly available satellite imagery API. The future shoreline recession was projected using the Bruun rule integrated with field observation data and sea level rise scenarios from Coupled Model Intercomparison Project Phase 6 (CMIP6). The result indicated that eight of the study site’s locations were under mild erosion from 2013 to 2021. The average shoreline change varied between −4.10 and 5.47 m/year. The projection of future beach loss due to sea level rise found that 20 beaches and 32 beaches will be lost entirely under SSP1 2.6 and SSP5 8.5, respectively. Beach morphology is influenced by human-induced activities, such as coastal urbanization and the development of structures along the coast. This study discusses the effectiveness of the present coastal protection structure with data from field observations and suggests possible future management strategies.

The climate impact contribution of lakes to sustain the Green Sahara in the mid-Holocene (MH, 6000 years ago) is still under debate. To assess the lake-induced climate response over North Africa, we investigated the roles of western Sahara lakes and Megalake Chad using reconstructions of MH Sahara lake maps as surface boundary conditions for the isotope-enabled atmospheric model MIROC5-iso. Our results show that the western Sahara lakes pushed the West African monsoon northward and extended it eastward by expanding Megalake Chad. This lake–climate impact was caused by the cyclonic circulation response related to the weakened African Easterly Jet and enhanced Tropical Easterly Jet. According to the Budyko aridity index, the northwestern Sahara climate region shifted from hyper-arid to arid or semi-arid with the lake expansion. Moreover, precipitation scarcity could have been reduced by up to 13 % to sustain the semi-humid conditions. Such lake–climate impacts could alleviate Sahara aridity, relying on lake positions in the monsoon regions. Our findings are promising for understanding the contribution of lakes to sustaining the Green Sahara.

Stable water isotopes in inland Antarctic ice cores are powerful paleoclimate proxies; however, their relationship with dynamical atmospheric circulations remains controversial. Using a water isotope climate model (MIROC5‐iso), we assessed the influence of the Last Glacial Maximum (LGM; ∼21,000 years ago) sea surface temperatures (SST) and sea ice (SIC) on Antarctic precipitation isotopes (δ ¹⁸ O _p ) through atmospheric circulation. The results revealed that the synoptic circulation mostly maintained southward moisture transport, reaching inland Antarctica. The steepened meridional SST gradient in the mid‐latitudes increased δ ¹⁸ O _p in inland Antarctica with the enhanced baroclinic instability and synoptic moisture transport. In contrast, expanded SIC distribution decreased δ ¹⁸ O _p over Antarctica by enhanced preferential removal of heavy isotopes during vapor transport due to the increased transport distance and enhanced surface cooling. These findings propose to use Antarctic ice cores to describe the southern hemisphere atmospheric circulation, represented by the westerly jets, during the LGM and other past climates.