Warming Events Research Articles

Increased exposure of rice to compound drought and hot extreme events during its growing seasons in China

Against the backdrop of global warming, compound drought and hot extreme events (CDHEEs) have intensified markedly, attracting attention from both the scientific community and society. However, a comprehensive understanding of the characteristics of the CDHEEs and their impacts on rice production during growing seasons remains limited. Thus, in this study, we use daily maximum and minimum air temperatures to derive a meteorological drought composite index for CDHEE identification. Additionally, we employ the Crop Calendar and the CROPGRIDS data to define the rice-growing seasons and regions. Detailed analyses reveal that from 1961 to 2023, the CDHEE frequency in both single-cropping rice regions (Rice1) and double-cropping rice regions (Rice2) increased at rates of 0.79 days (decade)−1 and 1.26 days (decade)−1, respectively, with a notable acceleration in the post-1990 s. The duration of the CDHEEs has lengthened, and prolonged events have become more frequent. The intensity of the CDHEEs has also enhanced, primarily driven by hot extreme events in Rice1 and the synergistic effects of droughts and hot extreme events in Rice2. Furthermore, the time span of CDHEE occurrence has expanded, starting earlier (rates of − 3.21 days (decade)−1 in Rice1 and − 4.37 days (decade)−1 in Rice2) and ending later (rates of 4.81 days (decade)−1 in Rice1 and 8.20 days (decade)−1 Rice2) during rice-growing seasons, thereby extending the exposure duration of rice. Since the 1990 s, rice exposure to the CDHEEs has also intensified, especially for the persistent CDHEEs. These findings indicate the upward trends in the frequency, intensity and duration of the CDHEEs, as well as the exposure of rice to the CDHEEs, during the rice-growing seasons in China. This research provides crucial insights into CDHEE impacts and underscores the necessity of implementing targeted adaptation and mitigation strategies to safeguard rice production amidst escalating climate challenges.

Subsurface Temperature Anomalies Off Central Oregon During 2014–2021

AbstractWe use moored observations in 80 m water depth at the NH‐10 site along the historic Newport Hydrographic Line from 1999 to 2021 to calculate water temperature anomalies at the surface, near surface, and bottom. Analysis is focused on the subsurface temporal and spatial characteristics of marine heatwaves (MHWs) during 2014–2016 and 2019–2020 on the continental shelf and slope. Warm anomalies extend throughout the water column in fall/winter 2014–2016 when winds are predominantly downwelling‐favorable, while the 2019–2020 period is characterized by shallower summer and fall anomalies on the shelf. Sustained temperature anomalies during the bottom MHW in late 2016 are the largest in the NH‐10 time series. Analysis of temporal patterns in wind stress during MHW and non‐MHW periods shows the onset of upwelling‐favorable winds interrupts warm events. Indices of cumulative upwelling and annual spring transition dates reveal the spring transition was unusually late in 2014, with only five years with later spring transitions since the upwelling index record began in 1967. In 2015 and 2019, in contrast, spring transition is close to the climatological mean of April 15. In 2016 and 2020, anomalous warming is observed when cumulative upwelling decreases after an early spring transition.

Coastal ocean response during the unprecedented marine heatwaves in the western Mediterranean in 2022

Abstract. The western Mediterranean Sea suffered unprecedented marine heatwaves (MHWs) in 2022. This study focuses on the response of coastal ocean, which is highly vulnerable to global warming and extreme events that threaten the biodiversity, as well as goods and services that humans rely on. Using remote sensing and in situ observations, strong spatiotemporal variations in the MHW characteristics are observed in the coastal ocean over the last decade (2013–2022). In 2022, shallow-water moorings in the western Mediterranean Sea detected between 23 and 131 d of MHWs. While the highest MHW mean and maximum intensities were detected at the surface in French waters, the highest duration was observed nearshore at 17 m depth in the Balearic Islands. As thermal stress indicators for marine ecosystems, the highest cumulative intensity and total days were found at the surface at Tarragona, and MHW temperatures warmer than 28 °C were observed to last up to 58 d at Palma. Differences between datasets are also highlighted. In 2022, depending on the sub-regions, satellites underestimated or overestimated MHW duration and intensity compared with in situ measurements at the surface. In addition, daily data underestimate maxima reached during the extreme warm events up to 1.52 °C difference compared with hourly measurements. These results invite us to continue the efforts in deploying and maintaining multi-platform observing systems in both open-ocean and coastal ocean waters to better address the coastal adaptation and mitigation in the context of climate change.

Multi‐Elemental Statistical Features of Early Paleogene Sediments From the Mid‐Latitude Eastern Indian Ocean

AbstractThe early Paleogene, including the Paleocene and Eocene, is characterized by Warmhouse and Hothouse climate states with superimposed transient warming events known as hyperthermals. While these paleoenvironmental changes are well‐documented in the Pacific and Atlantic Oceans, records of such changes in the Indian Ocean are limited. Here, we present a new data set of bulk chemical composition and stable isotopic ratios from the late Paleocene to middle Eocene sediments on the Exmouth Plateau in the mid‐latitude eastern Indian Ocean. The bulk δ13C and δ18O suggest a warming period called the Early Eocene Climatic Optimum (EECO) and cooling toward the middle Eocene in a long‐term perspective. In the short‐term, we identified at least six hyperthermals (Paleocene–Eocene Thermal Maximum, H2, I1, J, ETM3, and L) in the studied sections. By applying independent component (IC) analyses (ICA) to the bulk chemical composition data, we identified six ICs corresponding to sediment source materials and post‐depositional processes. The ICA result infers an increase in detrital materials or a decrease in carbonate rain flux, and an increased population of higher‐order consumers in the oceanic ecosystem during both long‐term (EECO) and short‐term (hyperthermal) warmings around the Exmouth Plateau. Furthermore, ICs representing diagenetic processes and post‐depositional remobilization of elements showed excursions across the hyperthermal horizons, indicating that changes in the redox state of pore or bottom water are associated with hyperthermals. This study provides critical insights into the paleoceanography of the Indian Ocean, highlighting the response of marine environments to both long‐term and short‐term climatic events during the early Paleogene.

Warming events and their causes at the Bering Sea section B in summer of 1999–2019

Based on hydrological data for the Bering Sea from 1999 to 2019 during the Chinese National Arctic Research Expeditions (CHINAREs), along with oceanographic and meteorological data from the National Centers for Environmental Information (NCEI) and the European Centre for Medium-Range Weather Forecasts (ECMWF), we investigated trends in summer at the Bering Sea section B over the past 20 years and their underlying causes. The results revealed a pronounced rise in temperature at the Bering Sea section B in 2003, 2014, 2016, 2018, and 2019, suggesting a shift towards a new phase of warmth starting in 2014. In warm years (2003, 2014, 2016, 2018, and 2019), the mean maximum temperature in the upper layer in the basin north of 57°N and on the continental shelf were roughly 2.7 °C, 2.6 °C higher than that in cold years (1999, 2008, 2010, and 2012). Additionally, the mean minimum temperature of the cold water in the middle layer in the basin was roughly 0.7 °C higher in the warm years compared to the cold years. This difference between the warm and cold years was evident in the heat content: the average heat content in the upper to middle layers in the basin north of 57°N and on the continental shelf were about 1.2 and 0.9 GJ/m2 higher, respectively, in the warm years than the cold years. However, there was a modest warming trend in the basin south of 57°N, and the temperature in the mid-layer on the continental shelf showed year-to-year stability, in contrast to the significant warming observed elsewhere. Further study suggested that temperature fluctuation in the basin was closely tied to seasonal 2-m air temperature. In addition, the southern basin, divided at 57°N, experienced larger positive or negative anomalous wind stress curl compared to the northern basin. This discrepancy resulted in differing causes of temperature variation between the two regions. Temperature change in the upper layer on the continental shelf was attributed to an increase in cumulative net heat flux resulting from reduced sea ice, while the temperature in the middle layer on the continental shelf was limited by the enhanced density gradient between the upper and middle layer caused by melt ice, preventing significant warming. Overall, the thermal state for the Bering Sea section B was influenced by a combination of factors, including net heat flux, sea ice, and atmospheric conditions, contributing to the year-to-year variation characterized by alternating cold and warm regimes.

Arctic Amplification of marine heatwaves under global warming

Marine heatwaves (MHWs) and total heat exposures (THEs), extreme warming events occurring across the global oceans, seriously threaten marine ecosystems and coastal communities as the climate warms. However, future changes in MHWs and THEs in the Arctic Ocean, where unique marine ecosystems are present, are still unclear. Here, based on the latest CMIP6 climate simulations, we find that both MHWs and THEs in the Arctic Ocean are anticipated to intensify in a warming climate, mainly due to Arctic sea ice decline and long-term warming trend, respectively. Particularly striking is the projected rise in MHW mean intensity during the 21st century in the Arctic Ocean, surpassing the global average by more than sevenfold under the CMIP6 SSP585 scenario. This phenomenon, coined the ‘Arctic MHW Amplification’, underscores an impending and disproportionately elevated threat to the Arctic marine life, necessitating targeted conservation and adaptive strategies.

Miocene Climatic Optimum and Middle Miocene Climate Transition: a foraminiferal record from the central Ross Sea, Antarctica

Abstract. The Ross Sea record of the Miocene Climatic Optimum (MCO; ∼ 16.9–14.7 Ma) and the Middle Miocene Climate Transition (MMCT; ∼ 14.7–13.8 Ma) provides critical insights into Antarctic ocean–cryosphere interactions during a time of extreme warmth and subsequent cooling. Here we report on Lower to Middle Miocene foraminiferal assemblages from the International Ocean Discovery Program (IODP) Site U1521 on the outer shelf of the central Ross Sea to identify regional shifts in environmental and water mass conditions and trace continental shelf evolution. We identified seven benthic biofacies clusters, dominated by abundant Globocassidulina subglobosa (a proposed indicator of proto-Circumpolar Deep Water, pCDW), Uvigerina cf. U. fueguina (high productivity and enhanced bottom-water currents), Nonionella spp. (high productivity), or Melonis spp. (high productivity) using a Q-mode cluster analysis to develop preliminary regional paleoenvironmental interpretations. Four unique assemblages, including Globobulimina cf. G. auriculata (high productivity and low oxygen), are also identified. Unit IV (representing the early MCO event) is a short-lived (∼ 80 ka), progradational, clast-poor sandy diamictite, likely deposited during deglaciation; the upper part of Unit IV is transitional with overlying Unit III. Unit IV sediments contain the most persistently abundant and diverse foraminiferal assemblages recovered at U1521 because they are mud-rich and diatom-poor, despite very high sedimentation rates. The benthic assemblages shift between Globocassidulina and Uvigerina dominance, suggesting changes in the pCDW influence relative to productivity and/or current activity. We suggest the abundance of Uvigerina (a shelf-edge proxy) in Unit IV records the northward progradation of the Ross continental shelf at this location during the late Early to Middle Miocene. Unit III (MCO) was deposited in an open-marine setting, evident by the ice-rafted detritus or debris (IRD) clast-free, diatom-rich/diatom-bearing muds. The sporadic nature of foraminiferal abundances in Unit III is likely due to intervals of terrigenous mud alternating with more diatom-rich/diatom-bearing muds. As in Unit IV, the muddier lithologies (higher natural gamma ray (NGR) values) are more likely to preserve calcareous foraminifera, whereas the most diatom-rich sediments (lower NGR values) are more corrosive to carbonate. We interpret the muddier intervals as interglacials with incursions of pCDW, as indicated by increased Globocassidulina subglobosa, and sporadic occurrences of rare warmer-water planktic foraminifera. Collectively, these multiple incursions of warmer-water planktic foraminifera provide evidence for polar amplification in the Ross Sea during the MCO and MMCT. The diatom-rich muds are interpreted as glacials during the MCO with open-marine conditions and higher productivity. The dominance of Globobulimina in the upper part of Unit III corresponds with the carbon maximum of Carbon Maxima 2 (CM2) and low-oxygen conditions in the sediments at ∼ 16.1 Ma. Subsequent glaciation (including Mi2, Miocene Isotope event 2), marine-based ice sheet grounding, and erosion on the shallow shelf are recorded by the widespread Ross Sea Unconformity 4 (RSU4; ∼ 15.95–14.2 Ma) at Site U1521. Unit II (MMCT) likely represents sedimentation in the interval between the RSU4 and the Mi3 (Miocene Isotope event 3) glaciation at ∼ 13.9–13.8 Ma. The benthic biofacies composition of Unit II shows a further increase in neritic taxa, including Elphidium magellanicum and Epistominella vitrea, suggesting continued shoaling of the continental shelf, which facilitated the growth of marine-based ice sheets during the Middle Miocene. Our initial correlation between Site U1521 and the ANtarctic geological DRILLing Project (ANDRILL) site, AND-2A, yields similar environmental interpretations, including peak warm events 3 and 4 during the MCO, supported by the foraminifera and unit lithologies. Suspected glacial intervals during the MCO, including Mi2 at the top of Unit III, correlate well with the reconstructed deep-sea estimates of ice volume changes (seawater δ18Osw record) from the Ocean Drilling Program (ODP) Site 1171 on the South Tasman Rise.

Risk Assessment of Community-Scale High-Temperature and Rainstorm Waterlogging Disasters: A Case Study of the Dongsi Community in Beijing

With the advancement of urbanization and acceleration of global warming, extreme weather and climate events are becoming increasingly frequent and severe, and climate risk continues to rise. Each community is irreplaceable and important in coping with extreme climate risk and improving urban resilience. In this study, the Dongsi Community in the functional core area of Beijing was explored, and the risk assessment of high temperatures and rainstorm waterlogging was implemented at the community scale. Local navigation observations were integrated into a theoretical framework for traditional disaster risk assessment. The risk assessment indicator system for community-scale high-temperature and rainstorm waterlogging disasters was established and improved from a microscopic perspective (a total of 22 indicators were selected from the three dimensions of hazard, exposure, and vulnerability). Geographic Information Systems (GIS) technology was used to integrate geographic information, meteorological, planning, municipal, socioeconomic and other multisource information layers, thus enabling more detailed spatial distribution characteristics of the hazard, exposure, vulnerability, and risk levels of community-scale high temperatures and rainstorm waterlogging to be obtained. The results revealed that the high-risk area and slightly high-risk area of high-temperature disasters accounted for 13.5% and 15.1%, respectively. The high-risk area and slightly high-risk area of rainstorm waterlogging disasters accounted for 9.8% and 31.6%, respectively. The high-risk areas common to high temperatures and waterlogging accounted for 3.9%. In general, the risk of high-temperature and rainstorm waterlogging disasters at the community scale showed obvious spatial imbalances; that is, the risk in the area around the middle section of Dongsi Santiao was the lowest, while a degree of high temperatures or rainstorm waterlogging was found in other areas. In particular, the risk of high-temperature and rainstorm waterlogging disasters along Dongsi North Street, the surrounding areas of Dongsi Liutiao, and some areas along the Dongsi Jiutiao route was relatively high. These spatial differences were affected to a greater extent by land cover (buildings, vegetation, etc.) and population density within the community. This study is a useful exploration of climate risk research for resilient community construction, and provides scientific support for the planning of climate-adaptive communities, as well as the proposal of overall adaptation goals, action frameworks, and specific planning strategies at the community level.

Data-driven discovery of potent small molecule ice recrystallisation inhibitors

Controlling the formation and growth of ice is essential to successfully cryopreserve cells, tissues and biologics. Current efforts to identify materials capable of modulating ice growth are guided by iterative changes and human intuition, with a major focus on proteins and polymers. With limited data, the discovery pipeline is constrained by a poor understanding of the mechanisms and the underlying structure-activity relationships. In this work, this barrier is overcome by constructing machine learning models capable of predicting the ice recrystallisation inhibition activity of small molecules. We generate a new dataset via experimental measurements of ice growth, then harness predictive models combining state-of-the-art descriptors with domain-specific features derived from molecular simulations. The models accurately identify potent small molecule ice recrystallisation inhibitors within a commercial compound library. Identified hits can also mitigate cellular damage during transient warming events in cryopreserved red blood cells, demonstrating how data-driven approaches can be used to discover innovative cryoprotectants and enable next-generation cryopreservation solutions for the cold chain.

Tracing 40,000 years of vegetation change in the Baetic-Rifan biodiversity hotspot

This study presents a 40,000-year-old pollen record from Los Tollos Lake in the Baetic-Rifan region of southernmost Spain. The data offer insights into the past ecosystems of a current biodiversity hotspot situated at the ecotone between the Atlantic and the Mediterranean. This new sequence encompasses Mediterranean and Ibero-North African sclerophylls, broad-leaf trees, conifers, and Tertiary relicts. The full-glacial abundance of mesothermophytes, particularly oaks, is among the highest recorded for the European Quaternary. Notably, the presence of ecologically significant pollen taxa, which are poorly dispersed and currently occur outside the study area, suggests that this biodiversity hotspot was more extensive in the Pleistocene. During the period of c. 40.8–36.5 ka, three Artemisia maxima at 40.6, 38.9, and 36.9 ka coincide with decreases in Quercus, indicating the spread of steppes in response to the abrupt coolings of the GS10, GS9 (HS4), and GS8 events. Similarly, increases in Quercus around 41, 40, and 37.2–38.3 ka parallel the GI10, GI9, and GI8 warm events. A forested period from 36.5–32 ka includes oak expansions during the GI7 and GI6 interstadials. From 32 to 19.2 ka, more xerophytic vegetation is observed, including the HS3, GS5-GS3, HS2, and GS2.1b-c cold spells, although the correlation with vegetation changes is not synchronous. As early as approximately 21 ka, Artemisia definitively declines, while the region was reforesting, likely due to the presence of stationary populations of broadleaf trees and conifers in the southern Baetic mountains. From approximately 12 ka onwards, the highest values of angiosperm trees are recorded, with oaks dominating throughout most of the Holocene. The pollen record and the correlation with marine records suggest a more intense hydrological regime during the first half of the Holocene, but there is also archaeobotanical evidence for human activity during the second half, resulting in a more open landscape, making it difficult to discriminate the impact of each factor. Some abrupt aridity events during the Holocene coincide with small variations in tree cover, particularly at 9.2, 8.2, 6.8, 5.5–4.8, 4.2, and 2.8 ka. Since the Neolithic and during the metallurgic stages, forest species, especially broad-leaf trees, experienced range retraction accompanied by population extinctions. The region's plant communities have been subject to fire regimes since the Pleistocene, seemingly dependent on the available tree biomass.

The timing and duration of large-scale carbon release in the Early Jurassic

The Toarcian oceanic anoxic event (T-OAE, ca. 183 Ma) in the Early Jurassic was one of the most significant warming events of the Phanerozoic, associated with large-scale carbon emissions, mass extinction, and perturbations to hydrology and ocean chemistry. However, the age and duration of this hyperthermal have long been uncertain, hindering our understanding of the timing and pace of carbon release and the associated environmental and biotic changes. We present high-precision radioisotopic dates bracketing a biostratigraphically constrained record of the T-OAE in Japan. Our geochronology reveals an unexpectedly short T-OAE duration of ∼300 k.y. and a temporal coincidence with Ferrar large igneous province (LIP) magmatism. Our dates refute previous work linking the T-OAE to the earlier Karoo LIP, which was coincident with an earlier carbon cycle perturbation at the Pliensbachian−Toarcian boundary. Our results suggest both events were driven by extremely rapid (perhaps sub-millennial scale) thermogenic carbon degassing during LIP sill intrusion.

The Study of Synergistic Changes in Extreme Cold and Warm Events in the Sanjiang Plain

Extreme climate events are occurring frequently under global warming. Previous studies primarily focused on isolated extreme climate events, whereas research on the synergistic changes between extreme cold (EC) and extreme warm (EW) events remains limited. This study conducted trend, correlation, and dispersion analyses on EC and EW, as well as their synergistic changes, in the Sanjiang Plain from 1960 to 2019, using inverse distance weighting, statistical methods, and the Mann–Kendall test. The results indicated that cold-to-warm (C2W) and warm-to-cold (W2C) events were significantly and positively correlated with elevation, with correlation coefficients (r) of 0.76 and 0.84, respectively. Meanwhile, C2W showed a significant negative correlation with latitude (r = −0.55), while W2C also exhibited a significant negative correlation with latitude (r = −0.71). However, there was a significant positive correlation between (EC) and latitude (r = 0.65). After 1980, both the declining trend of EC and the increasing trend of EW slowed down, and the trends in C2W and W2C changed from decline to increase. The dispersion of EC and EW shows an increasing trend, while the dispersion of C2W and W2C exhibits a decreasing trend. This study provides important references for studying temperature fluctuations and addressing extreme climate changes.

Reef refugia in the aftermath of past episodes of global warming

In the face of rising global temperatures, coral reefs experience coral mass bleaching and mortality. Subtropical and mesophotic environments may represent refugia for reef corals under climate change, where they can survive and eventually recolonize degraded areas. Using a comprehensive database of fossil reefs, we empirically assess the efficacy of subtropical, deeper, and turbid mesophotic environments to restore coral reefs after past global warming events. We focus on tropical coral reefs over the last 275 million years and four rapid climate warming events, which coincided with global reef crises in the geological record. In the aftermath of such hyperthermal events, we observed an increase in the proportions of reefs occurring in deeper (blue) mesophotic environments. Additionally, we found a trend of reef distributions and coral shifting towards higher latitudes. The number of coral occurrences in turbid (brown mesophotic) environments also increased after hyperthermal events. Our results suggest that subtropical, blue, and brown mesophotic environments may have served as immediate refugia for shallow-water coral species escaping warming seawater. While the patterns of reef range shifts and the establishment of blue and brown mesophotic refugia following ancient hyperthermal events provide some hope for coral reefs under current climate change, re-establishement of background reef conditions took most times millions of years.Ante el incremento de temperatura global, los arrecifes coralinos están experimentando eventos masivos de blanqueamiento y mortalidad. Los ambientes subtropicales y mesofóticos pueden representar refugios para los corales arrecifales, en los cuales pueden escapar de los efectos del cambio climático, sobrevivir y desde allí recolonizar áreas previamente degradadas. Mediante el uso de una exhaustiva base de datos en arrecifes coralinos, en este estudio se evaluó empíricamente la eficacia de los ambientes subtropicales y mesofóticos, tanto de aguas turbias someras (marrones) como de aguas claras profundas (azules), en la recuperación de arrecifes coralinos después de eventos hipertermales en el pasado. Nuestro enfoque estuvo en los arrecifes coralinos tropicales durante los últimos 275 millones de años y cuatro eventos de calentamiento climático rápido, los cuales coinciden con crisis globales en la ocurrencia de arrecifes en el registro fósil. Como consecuencia de dichos eventos hipertermales, observamos un aumento del número de arrecifes en ambientes mesofóticos de aguas profundas (azules). Además, encontramos una tendencia en la distribución de arrecifes y corales que se desplazan hacia latitudes más altas. También se observó un aumento en el número de corales que estuvieron presentes en ambientes de aguas turbias (marrones) después de dichos eventos hipertermales. Nuestros resultados sugieren que, en el pasado, los ambientes subtropicales, mesofóticos azules y mesofóticos marrones pudieron haber servido como refugios inmediatos para las especies de coral de aguas someras, en los cuales encuentran condiciones atenuantes ante el calentamiento oceánico. Si bien los patrones de desplazamiento de los arrecifes en el rango latitudinal y el establecimiento de refugios mesofóticos de aguas marrones y azules posteriores a eventos hipertermales brindan una luz de esperanza para el futuro de los arrecifes coralinos de cara al cambio climático actual, nuestros resultados evidencian que el restablecimiento de los arrecifes puede tomar millones de años.

Deciphering the Prevalence of Warm‐Wet Extremes in Ice‐Covered Zones

AbstractCompound warm extremes exert profound impacts on environment, health, and socioeconomics. Yang et al. (2024) indicated a shift or transition from warm‐dry extremes (WDEs), common in non‐ice‐covered areas, to warm‐wet extremes (WWEs) in ice‐covered zones. Utilizing ERA5 reanalysis data, this study determined the duration and frequency of WDEs and WWEs across ice‐covered and non‐ice‐covered regions. A comprehensive analysis uncovers the physical mechanisms responsible for the paradigm differences and attributes them to the weakening of land‐atmosphere interaction caused by ice‐cover, which inhibits soil moisture feedback and reduces the intensity and duration of warm events in ice‐covered areas. Both WDEs and WWEs are associated with high‐pressure systems (HPs). WDEs, situated directly beneath HPs, intensify due to adiabatic warming from subsidence motions. Conversely, WWEs, located beneath the poleward fringes of HPs, emerge from advective warming and moistening associated with poleward intrusions of warm‐moist air.

Nocturnal Extreme Rainfall over the Central Yungui Plateau under Cold and Warm Upper-Level Anomaly Backgrounds during Warm Seasons in 1980–2020

The spatiotemporal and cloud features of the extreme rainfall under the warm and cold upper-level anomalies over the central Yungui Plateau (YGP) were investigated using the hourly rain gauge records, ERA5 reanalysis data, TRMM, and Fengyun satellite data, aiming to refine the understanding of different types of extreme rainfall. Extreme rainfall under an upper-level negative temperature anomaly (cold events) presents stronger convective cloud features when compared with the positive temperature anomaly (warm events). The maximum rainfall intensity and duration in cold events is much larger than that of warm events, while the brightness temperature of the cloud top is lower, and the ratio of convective rainfall is higher. In cold events, the middle-to-upper troposphere is dominated by a cold anomaly, and an unstable configuration with upper (lower) cold (warm) anomalies is observed around the central YGP. Although the upper-level temperature anomaly is positive, the anomalous divergence and convergence of southerly and northerly winds, as well as the strong moisture center and upward motions, are also found over the central YGP in warm events. The stronger atmospheric instability and higher convective energy under the upper-level cold anomalous circulation are closely associated with the rainfall features over the central YGP. The results indicate that the upper tropospheric temperature has significant influences on extreme rainfall, and thus more attention should be paid to the upper tropospheric temperature in future analyses.

Long-Term Distributed Temperature Sensing Monitoring for Near-Wellbore Gas Migration and Gas Hydrate Formation

Summary Well integrity monitoring has always been a critical component of subsurface oil and gas operations. Distributed fiber-optic sensing is an emerging technology that shows great promise for monitoring processes, both in boreholes and in other settings. In this study, we present a case study of using distributed temperature sensing (DTS) technology to monitor a cemented and plugged well in the Alaska North Slope (ANS). The well was drilled as part of a long-term gas hydrate study, and the downhole DTS data were recorded over a period of approximately 2 years. By applying a temporal gradient and removing instrument instability noise, we reveal subtle (<0.001°C/h) thermal anomalies, which are characterized by brief warming periods followed by longer cooling periods at discrete depths along the borehole. The observed coherent events show an upward trajectory from deeper formations into the overlying permafrost interval, with the thermal anomalies concentrated in relatively coarse-grained sandstone layers. We also observe that the upward migration rate of the DTS anomalies varies with formation lithology and that there is a spatial and temporal correlation between the subsurface events and measured wellhead annular pressures. We interpret that the observed warming events represent the exothermic process of gas hydrate formation that is occurring in association with the upward migration of gas outside the well casing, and this interpretation is confirmed by numerical simulations. These observations demonstrate the ability of suitably processed DTS data to detect subtle processes and highlight the value of DTS technologies for wellbore integrity monitoring.

Biomarkers Indicate Pliocene Uplift of the Maxian Mountains, Northeastern Tibetan Plateau

AbstractKnowledge of Late Miocene‐Early Pliocene environmental change is critical for understanding the interactions among global cooling, regional tectonic activity and Asian climatic evolution. However, their relationships remain unclear, partly due to the scarcity of quantitative reconstructions of temperature and hydroclimatic conditions, which limits our understanding of the effect of topography on montane climatic evolution. Here, we quantitatively reconstructed the Late Miocene‐Early Pliocene temperature, hydroclimate, and pH of the Xiaoshuizi peneplain, northeastern Tibetan Plateau (NETP), based on glycerol dialkyl glycerol tetraethers. Our results indicate that the Xiaoshuizi temperature was relatively high with large fluctuations during 6.2–4.6 Ma. The temperature then gradually decreased until 4.0 Ma, when this trend was interrupted by an intensive warming event. Additionally, the combined Ri/b and pH proxies revealed that the Xiaoshuizi region experienced a hydroclimatic transition from relatively wet to dry conditions after 4.0 Ma. Our integrated results show that the Xiaoshuizi climate became warm and dry during 4.0–3.6 Ma, in contrast to the global cooling trend and the occurrence of a humid climate on the eastern Chinese Loess Plateau and the North China Plain. We ascribe this anomalous change to a warm and dry climate during 4.0–3.6 Ma to a topographic Foehn effect triggered by surface uplift of the Maxian Mountains associated with extensive tectonic uplift of the NETP during the Middle Pliocene.

Phytoplankton community structure at the eastern entrance of the Gulf of California during El Niño 2023

This work aims to report the phytoplankton species composition and cell density in the Mazatlán coastal region (eastern entrance of the Gulf of California (GC), Mexico) during the strong El Niño event of 2023. Surface water samples (at 2 m depth) for phytoplankton cell determinations were collected in December of 2023, a month in which the numerical value of the Oceanic Niño Index was 2.0. The results showed a total of 197 species, including 113 diatoms (with a total cell density of 51,444 cells L-1), 76 dinoflagellates (with a total cell density of 31,260 cells L-1), four silicoflagellates (with a total cell density of 420 cells L-1), two cyanobacteria (with a total cell density of 2,020 cells L-1), one Euglenophyta (with a total cell density of 900 cells L-1) and one ciliate (with a total cell density of 7,820 cells L-1). The diatom Dactyliosolen phuketensis (B.G.Sundström) G.R. Hasle, 1996 and the dinoflagellate Gyrodinium fusiforme (Kofoid & Swezy, 1921) presented the highest cell densities with 4,100 and 5,900 cells L-1, respectively, species that have been previously reported in high abundances in Mexican waters in years of warming events, including El Niño. The results presented here contribute to understanding the effects of strong El Niño events on the phytoplankton community structure of the southeastern GC. This topic still needs to be fully addressed. This study also provides an update on the taxonomic lists available for the region of a group of organisms whose nomenclature has been constantly changing in recent years.

Numerical Study on the Summer High-Temperature Climate Adaptation of Traditional Dwellings in the Western Plains of Sichuan, China

Ongoing global climate change, marked by sustained warming and extreme weather events, poses a severe threat to both the Earth’s ecosystems and human communities. Traditional settlements that underwent natural selection and evolution developed a unique set of features to adapt to and regulate the local climate. A comprehensive exploration of the spatial patterns and mechanisms of the adaptation of these traditional settlements is crucial for investigating low-energy climate adaptation theories and methods as well as enhancing the comfort of future human habitats. This study used numerical simulations and field measurements to investigate the air temperature, relative humidity, wind speed, wind direction, and thermal comfort of traditional settlements in Western Sichuan Plain, China, and uncovered their climate suitability characteristics to determine the impact mechanisms of landscape element configurations (building height, building density, tree coverage, and tree position) and spatial patterns on microclimates within these settlements. The results revealed the structural and layout strategies adopted by traditional settlements to adapt to different climatic conditions, providing valuable insights for future rural protection and planning and enhancing climate resilience through natural means. These findings not only contribute to understanding the climate adaptability of Earth’s ecosystems and traditional settlements but also offer new theories and methods to address the challenges posed by climate change.

Local and Remote Atmosphere‐Ocean Coupling During Extreme Warming Events Impacting Subsurface Ocean Temperature in an Antarctic Embayment

AbstractCoastal ocean temperatures can respond to different atmospheric and oceanic processes at local spatial scales or through remote teleconnections. This study focused on subsurface ocean temperatures (subT) at 10 m depth in Maxwell Bay, northern Antarctic Peninsula from February 2017 and January 2022. It investigated extreme warming events during austral summers and their interaction with atmospheric and oceanic conditions regionally and locally. The analysis identified active and extreme Marine Heat Waves (MHWs) in March 2017 and January‐February 2020 associated with a significantly negative Southern Annular Mode index observed 3–4 months before the temperature increase. In March 2017, temperatures exceeded the climatological mean by over 1°C. This anomaly was linked to a strengthened Amundsen Sea Low and a blocking anticyclone moving between the Scotia Sea and the South‐West Atlantic Ocean that deflected westerly winds and facilitated the anomalous transport of warmer northern air masses to the AP. In January‐February 2020, the highest recorded subT was observed (2.97°C), although air‐sea heat fluxes did not show a similar pattern. In February 2020, one of the most intense atmospheric heatwaves ever recorded in West Antarctica was observed. This heatwave corresponded with maximum subT and positive sea surface temperature anomalies extending throughout the western region of the Southern Ocean, related to an extremely negative Southern Annular Mode. This study provides valuable insights into the impact of strong MHWs, a phenomenon that has been less documented in Antarctic coastal regions.