The ocean conditions beneath the ice cover play a key role in understanding the sea ice mass balance in the polar regions.An integrated high-frequency ice-ocean observation system,including Acoustic Doppler Velocimete...The ocean conditions beneath the ice cover play a key role in understanding the sea ice mass balance in the polar regions.An integrated high-frequency ice-ocean observation system,including Acoustic Doppler Velocimeter,Conductivity-Temperature-Depth Sensor,and Sea Ice Mass Balance Array(SIMBA),was deployed in the landfast ice region close to the Chinese Zhongshan Station in Antarctica.A sudden ocean warming of 0.14℃(p<0.01)was observed beneath early-frozen landfast ice,from(−1.60±0.03)℃during April 16-19 to(−1.46±0.07)℃during April 20-23,2021,which is the only significant warming event in the nearly 8-month records.The sudden ocean warming brought a double rise in oceanic heat flux,from(21.7±11.1)W/m^(2) during April 16-19 to(44.8±21.3)W/m^(2) during April 20-23,2021,which shifted the original growth phase at the ice bottom,leading to a 2 cm melting,as shown from SIMBA and borehole observations.Simultaneously,the slowdown of ice bottom freezing decreased salt rejection,and the daily trend of observed ocean salinity changed from+0.02 d^(-1) during April 16-19,2021 to+0.003 d^(-1) during April 20-23,2021.The potential reasons are increased air temperature due to the transit cyclones and the weakened vertical ocean mixing due to the tide phase transformation from semi-diurnal to diurnal.The high-frequency observations within the ice-ocean boundary layer enhance the comprehensive investigation of the ocean’s influence on ice evolution at a daily scale.展开更多
During recent decades, the tropical Indo-Pacific Ocean has become increasingly warmer. Meanwhile, both the northern and southern hemispheric polar vortices (NPV and SPV) have exhibited a deepening trend in boreal wi...During recent decades, the tropical Indo-Pacific Ocean has become increasingly warmer. Meanwhile, both the northern and southern hemispheric polar vortices (NPV and SPV) have exhibited a deepening trend in boreal winter. Although previous studies have revealed that the tropical Indian Ocean warming (IOW) favors an intensifying NPV and a weakening SPV, how the tropical Pacific Ocean warming (POW) influences the NPV and SPV remains unclear. In this study, a comparative analysis has been conducted through ensemble atmospheric general circulation model (AGCM) experiments. The results show that, for the Northern Hemisphere, the two warmings exerted opposite impacts in boreal winter, in that the IOW intensified the NPV while the POW weakened the NPV. For the Southern Hemisphere, both the IOW and POW warmed the southern polar atmosphere and weakened the SPV. A diagnostic analysis based on the vorticity budget revealed that such an interhemispheric difference in influences from the IOW and POW in boreal winter was associated with different roles of transient eddy momentum flux convergence between the hemispheres. Furthermore, this difference may have been linked to different strengths of stationary wave activity between the hemispheres in boreal winter.展开更多
The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC cha...The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ(1 zetta J = 1021 J) using the IAP/CAS dataset and by16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Nino-Southern Oscillation(ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans,and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.展开更多
The deep ocean below 2000 m is a large water body with the sparsest data coverage,challenging the closure of the sea-level budget and the estimation of the Earth’s energy imbalance.Whether the deep ocean below 2000 m...The deep ocean below 2000 m is a large water body with the sparsest data coverage,challenging the closure of the sea-level budget and the estimation of the Earth’s energy imbalance.Whether the deep ocean below 2000 m is warming globally has been debated in the recent decade.However,as the regional signals are generally larger than the global average,it is intriguing to investigate the regional temperature changes.Here,we adopt an indirect method that combines altimetry,GRACE,and Argo data to examine the global and regional deep ocean temperature changes below 2000 m.The consistency between high-quality conductivity-temperature-depth(CTD)data from repeated hydrographic sections and our results confirms the validity of the indirect method.We find that the deep oceans are warming in the Middle East Indian Ocean,the subtropical North and Southwest Pacific,and the Northeast Atlantic,but cooling in the Northwest Atlantic and Southern oceans from 2005 to 2015.展开更多
A global mean ocean model including atmospheric heating, heat capacity of the mixed layer ocean, and vertical thermal diffusivity in the lower ocean, proposed by Cess and Goldenberg (1981), is used in this paper to st...A global mean ocean model including atmospheric heating, heat capacity of the mixed layer ocean, and vertical thermal diffusivity in the lower ocean, proposed by Cess and Goldenberg (1981), is used in this paper to study the sensitivity of global warming to the vertical diffusivity. The results suggest that the behaviour of upper ocean temperature is mainly determined by the magnitude of upper layer diffusivity and an ocean with a larger diffusivity leads to a less increase of sea surface temperature and a longer time delay for the global warming induced by increasing CO2 than that with smaller one. The global warming relative to four scenarios of CO2 emission assumed by Intergovernmental Panel of Climate Change (IPCC) is also estimated by using the model with two kinds of thermal diffusivities. The result shows that for various combinations of the CO2 emission scenarios and the diffusivities, the oceanic time delay to the global warming varies from 15 years to 70 years.展开更多
Contrasting decrease and increase trends of sea surface temperature(SST)have been documented in the western Subarctic(WSA)and the rest of the Northwest Pacific(NWP)from 1958 to 2017,respectively.Consequently,more(less...Contrasting decrease and increase trends of sea surface temperature(SST)have been documented in the western Subarctic(WSA)and the rest of the Northwest Pacific(NWP)from 1958 to 2017,respectively.Consequently,more(less)total carbon dioxide(TCO_(2))due to ocean cooling(warming)is transported to the surface,which leads to increase(decrease)of oceanic surface partial pressure of carbon dioxide(pCO_(2)).With the combined influence of the rising atmospheric carbon dioxide(CO_(2))level and changing ocean conditions,a prominent increase in oceanic surface pCO_(2) occurred with different rates of increase in summer and winter in the NWP.The oceanic surface pCO_(2) is mainly controlled by the variation of TCO_(2) at the interdecadal timescale and by SST at the seasonal timescale.Our results also indicate that increasing SST tends to strengthen the capability of ocean in absorbing anthropogenic CO_(2) in the NWP,while ocean’s uptaking ability is weakened in the cooling area of the WSA.展开更多
During boreal winter,the invasion of cold air can lead to remarkable temperature drops in East Asia which can result in serious socioeconomic impacts.Here,we find that the intensity of strong synoptic cold days in the...During boreal winter,the invasion of cold air can lead to remarkable temperature drops in East Asia which can result in serious socioeconomic impacts.Here,we find that the intensity of strong synoptic cold days in the East China Sea and Indochina Peninsula are increasing.The enhanced synoptic cold days in these two regions are attributed to surface warming over the South China Sea and Philippine Sea(SCSPS).The oceanic forcing of the SCSPS on the synoptic cold days in the two regions is verified by numerical simulation.The warming of the SCSPS enhances the baroclinicity,which intensifies meridional wind and cold advection on synoptic timescales.This leads to a more extended region that is subject to the influence of cold invasion.展开更多
Extreme summer heat can have serious socioeconomic impacts in North China.Here,we explore the decadal variability of the number of extreme heat days in early-to-mid summer(June and July)and a related potential mechani...Extreme summer heat can have serious socioeconomic impacts in North China.Here,we explore the decadal variability of the number of extreme heat days in early-to-mid summer(June and July)and a related potential mechanism consistent with the major seasonal occurrence period of extreme heat events in North China(NCSH).Observational analyses show significant decadal variability in NCSH for 1981–2021,potentially linked to the Indo-Pacific warm pool and Northwest Pacific Ocean dipole(IPOD)in early-to-mid summer.Dynamic diagnostic analysis and the linear baroclinic model(LBM)show that the positive IPOD in early-to-mid summer can excite upward vertical wind anomalies in the South China-East China Sea region,shifting the position of the western Pacific subtropical high(WPSH)to the east or weakening the degree of its control of the South China-East China Sea region,thus generating a positive geopotential height quadrupole(EAWPQ)pattern in the East Asia-Northwest Pacific region.Subsequently,the EAWPQ can cause air compression(expansion)over North China by regulating the tropospheric thickness anomalies in North China,thus increasing(decreasing)NCSH.Finally,an empirical model that incorporates the linear trend can better simulate the decadal NCSH compared to an empirical model based solely on the IPOD index,suggesting that the decadal variability of NCSH may be a combined contribution of the decadal IPOD and external linear forcing.展开更多
The record-breaking mei-yu in the Yangtze-Huaihe River valley(YHRV)in 2020 was characterized by an early onset,a delayed retreat,a long duration,a wide meridional rainbelt,abundant precipitation,and frequent heavy rai...The record-breaking mei-yu in the Yangtze-Huaihe River valley(YHRV)in 2020 was characterized by an early onset,a delayed retreat,a long duration,a wide meridional rainbelt,abundant precipitation,and frequent heavy rainstorm processes.It is noted that the East Asian monsoon circulation system presented a significant quasi-biweekly oscillation(QBWO)during the mei-yu season of 2020 that was associated with the onset and retreat of mei-yu,a northward shift and stagnation of the rainbelt,and the occurrence and persistence of heavy rainstorm processes.Correspondingly,during the mei-yu season,the monsoon circulation subsystems,including the western Pacific subtropical high(WPSH),the upper-level East Asian westerly jet,and the low-level southwesterly jet,experienced periodic oscillations linked with the QBWO.Most notably,the repeated establishment of a large southerly center,with relatively stable latitude,led to moisture convergence and ascent which was observed to develop repeatedly.This was accompanied by a long-term duration of the mei-yu rainfall in the YHRV and frequent occurrences of rainstorm processes.Moreover,two blocking highs were present in the middle to high latitudes over Eurasia,and a trough along the East Asian coast was also active,which allowed cold air intrusions to move southward through the northwestern and/or northeastern paths.The cold air frequently merged with the warm and moist air from the low latitudes resulting in low-level convergence over the YHRV.The persistent warming in the tropical Indian Ocean is found to be an important external contributor to an EAP/PJ-like teleconnection pattern over East Asia along with an intensified and southerly displaced WPSH,which was observed to be favorable for excessive rainfall over YHRV.展开更多
Record-breaking heavy and persistent precipitation occurred over the Yangtze River Valley(YRV)in June-July(JJ)2020.An observational data analysis has indicated that the strong and persistent rainfall arose from the co...Record-breaking heavy and persistent precipitation occurred over the Yangtze River Valley(YRV)in June-July(JJ)2020.An observational data analysis has indicated that the strong and persistent rainfall arose from the confluence of southerly wind anomalies to the south associated with an extremely strong anomalous anticyclone over the western North Pacific(WNPAC)and northeasterly anomalies to the north associated with a high-pressure anomaly over Northeast Asia.A further observational and modeling study has shown that the extremely strong WNPAC was caused by both La Niña-like SST anomaly(SSTA)forcing in the equatorial Pacific and warm SSTA forcing in the tropical Indian Ocean(IO).Different from conventional central Pacific(CP)El Niños that decay slowly,a CP El Niño in early 2020 decayed quickly and became a La Niña by early summer.This quick transition had a critical impact on the WNPAC.Meanwhile,an unusually large area of SST warming occurred in the tropical IO because a moderate interannual SSTA over the IO associated with the CP El Niño was superposed by an interdecadal/long-term trend component.Numerical sensitivity experiments have demonstrated that both the heating anomaly in the IO and the heating anomaly in the tropical Pacific contributed to the formation and maintenance of the WNPAC.The persistent high-pressure anomaly in Northeast Asia was part of a stationary Rossby wave train in the midlatitudes,driven by combined heating anomalies over India,the tropical eastern Pacific,and the tropical Atlantic.展开更多
Recent studies found that in the context of global warming, the observed tropical cyclones (TCs) exhibit signific-ant poleward migration trend in terms of the mean latitude where TCs reach their lifetime-maximum int...Recent studies found that in the context of global warming, the observed tropical cyclones (TCs) exhibit signific-ant poleward migration trend in terms of the mean latitude where TCs reach their lifetime-maximum intensity in the western North Pacific (WNP). This poleward migration of TC tracks can be attributed to not only anthropogenic for-cing (e.g., continuous increase of sea surface temperature (SST)), but also impacts of other factors (e.g., natural vari- ability). In the present study, to eliminate the impacts of other factors and thus focus on the impact of unvaried SST on climatological WNP TC tracks, the mesoscale Weather Research and Forecasting (WRF) model is used to con- duct a suite of idealized sensitivity experiments with increased SST. Comparisons among the results of these experi- ments show the possible changes in climatological TC track, TC track density, and types of TC track in the context of SST increase. The results demonstrate that under the warmer SST conditions, the climatological mean TC track sys-tematically shifts poleward significantly in the WNP, which is consistent with the previous studies. Meanwhile, the ocean warming also leads to the decreased (increased) destructive potential of TCs in low (middle) latitudes, and thus northward migration of the region where TCs have the largest impact. Further results imply the possibility that under the ocean warming, the percentage of TCs with westward/northwestward tracks decreases/increases distinctly.展开更多
In summer 2020,extreme rainfall occurred throughout the Yangtze River basin,Huaihe River basin,and southern Yellow River basin,which are defined here as the central China(CC)region.However,only a weak central Pacific(...In summer 2020,extreme rainfall occurred throughout the Yangtze River basin,Huaihe River basin,and southern Yellow River basin,which are defined here as the central China(CC)region.However,only a weak central Pacific(CP)El Niño happened during winter 2019/20,so the correlations between the El Niño–Southern Oscillation(ENSO)indices and ENSO-induced circulation anomalies were insufficient to explain this extreme precipitation event.In this study,reanalysis data and numerical experiments are employed to identify and verify the primary ENSO-related factors that cause this extreme rainfall event.During summer 2020,unusually strong anomalous southwesterlies on the northwest side of an extremely strong Northwest Pacific anticyclone anomaly(NWPAC)contributed excess moisture and convective instability to the CC region,and thus,triggered extreme precipitation in this area.The tropical Indian Ocean(TIO)has warmed in recent decades,and consequently,intensified TIO basinwide warming appears after a weak El Niño,which excites an extremely strong NWPAC via the pathway of the Indo-western Pacific Ocean capacitor(IPOC)effect.Additionally,the ENSO event of 2019/20 should be treated as a fast-decaying CP El Niño rather than a general CP El Niño,so that the circulation and precipitation anomalies in summer 2020 can be better understood.Last,the increasing trend of tropospheric temperature and moisture content in the CC region after 2000 is also conducive to producing heavy precipitation.展开更多
The changing environmental factors exerted great influences on coastal macroalgal communities.To study the responses of the brown seaweed Sargassum horneri to temperature and light,S.horneri was cultured under three t...The changing environmental factors exerted great influences on coastal macroalgal communities.To study the responses of the brown seaweed Sargassum horneri to temperature and light,S.horneri was cultured under three temperatures(20,25 and 30℃)and three light intensities(30,60,and 120μmol photons m-2 s-1)for seven days.The growth rate,chlorophyll a(Chl a)and carotenoids(Car)contents,chlorophyll fluorescence,and photosynthetic oxygen evolution rate were measured.The results show that the highest relative growth rate(RGR),maximal electron transport rate(rETRmax);the net photosynthetic rate(Pn)were observed at the lowest temperature(20℃)and highest light intensity(120μmol photons m-2 s-1);and the RGR and Pn were significantly inhibited by the highest temperature(30℃),especially at the lowest light intensity(30μmol photons m-2 s-1)(P<0.05).Additionally,the highest light intensity enhanced the non-photochemical quenching(NPQ)even under the highest temperature(30℃),indicating that the higher light intensity could induce photo-protection reaction of thalli.These results suggest that the higher temperature and lower light intensity exerted negative influences on S.horneri.展开更多
Seagrass meadows provide important ecological functions,particularly by serving as carbon sinks and breeding grounds for marine species.Climate change has threatened seagrass communities,causing their replacement,loss...Seagrass meadows provide important ecological functions,particularly by serving as carbon sinks and breeding grounds for marine species.Climate change has threatened seagrass communities,causing their replacement,loss and increased vulnerability.This review examined scholarly articles published between 2010-2021 to comprehensively present the impacts of climate change on seagrass meadows.It shows that ocean warming negatively affects seagrass communities by favouring communities of lower structuring capacities,thus reducing the effectiveness of their ecological functions.Ocean warming also promotes the propagation and spread of invasive species,and changes the trophic structures leading to further loss of seagrasses of value.Higher seawater temperature is associated with shoot mortality and retarded growth of certain seagrasses.Sea level rise causes more wave energy to be received by coastal seagrass communities,thus,creating more damage to the communities.Deepening sea limits light penetration and alters distribution of seagrass meadows.Carbon dioxide enrichment of seawater increases photosynthetic rate of seagrasses but ocean warming and acidification counteract this beneficial effect.Carbon dioxide enrichment affects different seagrass species and different parts of a seagrass species differently,and,where beneficial to seagrass communities,could enhance their ecological services.Temperature extremes could kill seagrasses while marine heatwaves and flooding could act synergistically to increase carbon demand of certain seagrasses and unfavourably change their biomass.These impacts are often aggravated by anthropogenic activities.This review calls for more studies and conservation efforts to understand the impacts of climate change on seagrass communities and future-proof them against the changing climate.展开更多
The spatial-temporal patterns of tropical cyclone(TC) intensity changes caused by the warm ocean mesoscale eddy(WOME) distribution are evaluated using two sets of idealized numerical experiments. The results show that...The spatial-temporal patterns of tropical cyclone(TC) intensity changes caused by the warm ocean mesoscale eddy(WOME) distribution are evaluated using two sets of idealized numerical experiments. The results show that the TC was intensified and weakened when a WOME was close to and far away from the TC center, respectively.The area where the WOME enhanced(weakened) TC intensity is called the inner(outer) area in this study.Amplitudes of the enhancement and weakening caused by the WOME in the inner and outer area decreased and increased over time, while the ranges of the inner and outer area diminished and expanded, respectively. The WOME in the inner area strengthened the secondary circulation of the TC, increased heat fluxes, strengthened the symmetry, and weakened the outer spiral rainband, which enhanced TC intensity. The effect was opposite if the WOME was in the outer area, and it weakened the TC intensity. The idealized simulation employed a stationary TC, and thus the results may only be applied to TCs with slow propagation. These findings can improve our understanding of the interactions between TC and the WOME and are helpful for improving TC intensity forecasting by considering the effect of the WOME in the outer areas.展开更多
In the past decades, with the increasing frequency of extreme weather and climate events, the world has suffered huge losses. Based on NCEP/NCAR reanalysis data and China regional precipitation data provided by China ...In the past decades, with the increasing frequency of extreme weather and climate events, the world has suffered huge losses. Based on NCEP/NCAR reanalysis data and China regional precipitation data provided by China Meteorological Administration, the extreme precipitation events in eastern China are defined by relative threshold method, and the temporal and spatial characteristics of summer extreme precipitation in eastern China from 1961 to 2016 are analyzed by empirical orthogonal function (EOF), and the reverse distribution of extreme precipitation in the middle and lower reaches of the Yangtze River and south China by Indian Ocean warm pool is revealed influence. The results show that the total amount and frequency of extreme precipitation in summer are concentrated in the Yangtze River Basin and south China. EOF1 decomposition of extreme precipitation reflects the interannual oscillation characteristics of reverse spatial distribution in the Yangtze River Basin and south China. The time series corresponding to EOF1 has significant interannual characteristics. The Pacific-Japan (PJ) teleconnection pattern is a circulation system that significantly affects the spatial-temporal pattern of extreme precipitation in southern China. When the PJ pattern is in the positive phase, the anticyclone controls the south China region, and restrains the convective activity, which results in the decrease of extreme precipitation. The anomalous southwest wind to the south of 30<span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">°</span></span>N and the anomalous northerly wind to the north of 30<span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">°</span></span>N converge in the middle and lower reaches of the Yangtze River. Combining with the sufficient water vapor carried by the anomalous southwest airflow at the edge of anticyclone, it is more conducive to the formation of extreme precipitation. The east propagating Kelvin wave in the warm pool of the Indian Ocean is an important reason for the formation of the PJ pattern and finally the formation of extreme precipitation anomalies in China.展开更多
Subject Code:D05Under support of the National Natural Science Foundation of China,a concerted study by Dr.Huang Gang(黄刚)from the Institute of Atmospheric Physics,Chinese Academy of Sciences,climate scientist Jing-Ji...Subject Code:D05Under support of the National Natural Science Foundation of China,a concerted study by Dr.Huang Gang(黄刚)from the Institute of Atmospheric Physics,Chinese Academy of Sciences,climate scientist Jing-Jia Luo from the Australian Bureau of Meteorology,Dr.Yao Shuailei(姚帅磊)from the Institute展开更多
Using 32 CMIP5(Coupled Model Intercomparison Project Phase 5) models, this study examines the veracity in the simulation of cloud amount and their radiative effects(CREs) in the historical run driven by observed e...Using 32 CMIP5(Coupled Model Intercomparison Project Phase 5) models, this study examines the veracity in the simulation of cloud amount and their radiative effects(CREs) in the historical run driven by observed external radiative forcing for 1850-2005, and their future changes in the RCP(Representative Concentration Pathway) 4.5 scenario runs for2006-2100. Validation metrics for the historical run are designed to examine the accuracy in the representation of spatial patterns for climatological mean, and annual and interannual variations of clouds and CREs. The models show large spread in the simulation of cloud amounts, specifically in the low cloud amount. The observed relationship between cloud amount and the controlling large-scale environment are also reproduced diversely by various models. Based on the validation metrics,four models-ACCESS1.0, ACCESS1.3, Had GEM2-CC, and Had GEM2-ES-are selected as best models, and the average of the four models performs more skillfully than the multimodel ensemble average.All models project global-mean SST warming at the increase of the greenhouse gases, but the magnitude varies across the simulations between 1 and 2 K, which is largely attributable to the difference in the change of cloud amount and distribution. The models that simulate more SST warming show a greater increase in the net CRE due to reduced low cloud and increased incoming shortwave radiation, particularly over the regions of marine boundary layer in the subtropics. Selected best-performing models project a significant reduction in global-mean cloud amount of about-0.99% K^-1and net radiative warming of 0.46 W m^-2K^-1, suggesting a role of positive feedback to global warming.展开更多
Coral fluorescence phenotypes have been suggested as an adaptation to a broad range of environmental conditions,yet the mechanisms linking thermal bleaching tolerance in reef-building coral populations,associated with...Coral fluorescence phenotypes have been suggested as an adaptation to a broad range of environmental conditions,yet the mechanisms linking thermal bleaching tolerance in reef-building coral populations,associated with fluorescence phenotypes due to GFP-like proteins,remains unclear.In this study,the relationship between the thermal sensitivity and phenotypic plasticity of corals was investigated using two phenotypes of Galaxea fascicularis,green and brown.The results reveal that brown G.fascicularis was more susceptible to bleaching than green G.fascicularis when exposed to a higher growth temperature of 32℃.Both phenotypes of G.fascicularis were associated with the thermotolerant Symbiodiniaceae symbiont,Durusdinium trenchii.However,the brown G.fascicularis showed a significant decrease in Symbiodiniaceae cell density and a significant increase in pathogenic bacteria abundance when the growth temperature was raised from 29 to 32℃.The physiological traits and transcriptomic profiles of Symbiodiniaceae were not notably affected,but there were differences in the transcriptional levels of certain genes between the two phenotype hosts of G.fascicularis.Under heat stress of 32℃,the gene encoding green fluorescent protein(GFP)-like and chromosome-associated proteins,as well as genes related to oxidative phosphorylation,cell growth and death showed lower transcriptional levels in the brown G.fascicularis compared to the green G.fascicularis.Overall,the results demonstrate that the green form of G.fascicularis is better able to tolerate ocean warming and defend against pathogenic bacteria,likely due to higher gene transcription levels and defense ability.展开更多
The oceans are taking up over one million tons of fossil CO_(2) per hour,resulting in increased/ρCO_(2) and declining pH,leading to ocean acidification(OA).At the same time,accumulation of CO_(2) and other greenhouse...The oceans are taking up over one million tons of fossil CO_(2) per hour,resulting in increased/ρCO_(2) and declining pH,leading to ocean acidification(OA).At the same time,accumulation of CO_(2) and other greenhouse gases is causing ocean warming,which enhances stratification with thinned upper mixed layers,exposing planktonic organisms to increasing levels of daytime integrated UV radiation.Ocean warming also reduces dissolved oxygen in seawater,resulting in ocean deoxygenation.All these ocean global changes are impacting marine ecosystems and effects are well documented for each individual driver(pH,oxygen,temperature,UV).However,combined effects are still poorly understood,strongly limiting our ability to project impacts at regional or local levels.Different regions are often exposed(and often adapted)to contrastingly different physical and chemical environmental conditions and organisms,and ecosystems from different parts of the world will be exposed to unique combinations of stressors in the future.Understanding the modulating role of adaptation,species niche and stressors’interaction is key.This review,being a non-exhaustively explored one.aims to provide an overview on understandings of ecophysiological effects of OA and its combination with covarying drivers,mainly warming,deoxygenation and solar UV radiation.We propose a testable hypothetical model as well as future research perspectives.展开更多
基金The National Natural Science Foundation of China under contract Nos 42276251,42211530033,and 41876212the Taishan Scholars Program.
文摘The ocean conditions beneath the ice cover play a key role in understanding the sea ice mass balance in the polar regions.An integrated high-frequency ice-ocean observation system,including Acoustic Doppler Velocimeter,Conductivity-Temperature-Depth Sensor,and Sea Ice Mass Balance Array(SIMBA),was deployed in the landfast ice region close to the Chinese Zhongshan Station in Antarctica.A sudden ocean warming of 0.14℃(p<0.01)was observed beneath early-frozen landfast ice,from(−1.60±0.03)℃during April 16-19 to(−1.46±0.07)℃during April 20-23,2021,which is the only significant warming event in the nearly 8-month records.The sudden ocean warming brought a double rise in oceanic heat flux,from(21.7±11.1)W/m^(2) during April 16-19 to(44.8±21.3)W/m^(2) during April 20-23,2021,which shifted the original growth phase at the ice bottom,leading to a 2 cm melting,as shown from SIMBA and borehole observations.Simultaneously,the slowdown of ice bottom freezing decreased salt rejection,and the daily trend of observed ocean salinity changed from+0.02 d^(-1) during April 16-19,2021 to+0.003 d^(-1) during April 20-23,2021.The potential reasons are increased air temperature due to the transit cyclones and the weakened vertical ocean mixing due to the tide phase transformation from semi-diurnal to diurnal.The high-frequency observations within the ice-ocean boundary layer enhance the comprehensive investigation of the ocean’s influence on ice evolution at a daily scale.
基金supported by the National Key Basic Research Program of China(Grants No.2010CB428602 and No. 2009CB421401)the Innovative Key Project of the Chinese Academy of Sciences(Grant No.KZCX2-YW-BR-14)the National Natural Science Foundation of China(Grant No.40775053)
文摘During recent decades, the tropical Indo-Pacific Ocean has become increasingly warmer. Meanwhile, both the northern and southern hemispheric polar vortices (NPV and SPV) have exhibited a deepening trend in boreal winter. Although previous studies have revealed that the tropical Indian Ocean warming (IOW) favors an intensifying NPV and a weakening SPV, how the tropical Pacific Ocean warming (POW) influences the NPV and SPV remains unclear. In this study, a comparative analysis has been conducted through ensemble atmospheric general circulation model (AGCM) experiments. The results show that, for the Northern Hemisphere, the two warmings exerted opposite impacts in boreal winter, in that the IOW intensified the NPV while the POW weakened the NPV. For the Southern Hemisphere, both the IOW and POW warmed the southern polar atmosphere and weakened the SPV. A diagnostic analysis based on the vorticity budget revealed that such an interhemispheric difference in influences from the IOW and POW in boreal winter was associated with different roles of transient eddy momentum flux convergence between the hemispheres. Furthermore, this difference may have been linked to different strengths of stationary wave activity between the hemispheres in boreal winter.
基金supported by the National Natural Science Foundation of China(Grant No.42122046,42076202)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB42040402)+5 种基金National Natural Science Foundation of China(Grant No.42076202)National Key R&D Program of China(Grant No.2017YFA0603202)Key Deployment Project of Centre for Ocean Mega-Research of Science,CAS(Grant Nos.COMS2019Q01 and COMS2019Q07)NCAR is sponsored by the US National Science Foundationsupported by NASA Award 80NSSC17K0565the Regional and Global Model Analysis(RGMA)component of the Earth and Environmental System Modeling Program of the U.S.Department of Energy’s Office of Biological&Environmental Research(BER)via National Science Foundation IA 1844590。
文摘The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ(1 zetta J = 1021 J) using the IAP/CAS dataset and by16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Nino-Southern Oscillation(ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans,and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.
基金This work is supported by the National Natural Science Foundation of China(Grant No.41904081).
文摘The deep ocean below 2000 m is a large water body with the sparsest data coverage,challenging the closure of the sea-level budget and the estimation of the Earth’s energy imbalance.Whether the deep ocean below 2000 m is warming globally has been debated in the recent decade.However,as the regional signals are generally larger than the global average,it is intriguing to investigate the regional temperature changes.Here,we adopt an indirect method that combines altimetry,GRACE,and Argo data to examine the global and regional deep ocean temperature changes below 2000 m.The consistency between high-quality conductivity-temperature-depth(CTD)data from repeated hydrographic sections and our results confirms the validity of the indirect method.We find that the deep oceans are warming in the Middle East Indian Ocean,the subtropical North and Southwest Pacific,and the Northeast Atlantic,but cooling in the Northwest Atlantic and Southern oceans from 2005 to 2015.
文摘A global mean ocean model including atmospheric heating, heat capacity of the mixed layer ocean, and vertical thermal diffusivity in the lower ocean, proposed by Cess and Goldenberg (1981), is used in this paper to study the sensitivity of global warming to the vertical diffusivity. The results suggest that the behaviour of upper ocean temperature is mainly determined by the magnitude of upper layer diffusivity and an ocean with a larger diffusivity leads to a less increase of sea surface temperature and a longer time delay for the global warming induced by increasing CO2 than that with smaller one. The global warming relative to four scenarios of CO2 emission assumed by Intergovernmental Panel of Climate Change (IPCC) is also estimated by using the model with two kinds of thermal diffusivities. The result shows that for various combinations of the CO2 emission scenarios and the diffusivities, the oceanic time delay to the global warming varies from 15 years to 70 years.
基金The National Key Research and Development Program of China under contract No.2016YFC1401605the Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2020SP008+2 种基金the Open Fund of Marine Telemetry Technology Innovation Center of the Ministry of Natural Resourcesthe National Natural Science Foundation of China under contract No.41730536the Key Laboratory of Space Ocean Remote Sensing and Application,Ministry of Natural Resources under contract No.201901001.
文摘Contrasting decrease and increase trends of sea surface temperature(SST)have been documented in the western Subarctic(WSA)and the rest of the Northwest Pacific(NWP)from 1958 to 2017,respectively.Consequently,more(less)total carbon dioxide(TCO_(2))due to ocean cooling(warming)is transported to the surface,which leads to increase(decrease)of oceanic surface partial pressure of carbon dioxide(pCO_(2)).With the combined influence of the rising atmospheric carbon dioxide(CO_(2))level and changing ocean conditions,a prominent increase in oceanic surface pCO_(2) occurred with different rates of increase in summer and winter in the NWP.The oceanic surface pCO_(2) is mainly controlled by the variation of TCO_(2) at the interdecadal timescale and by SST at the seasonal timescale.Our results also indicate that increasing SST tends to strengthen the capability of ocean in absorbing anthropogenic CO_(2) in the NWP,while ocean’s uptaking ability is weakened in the cooling area of the WSA.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos. 42120104001, 41805042)the Science and Technology Program of Guangzhou, China (Grant No. 202102020939)+1 种基金the Fundamental Research Funds for the Central University, Sun Yat-Sen University (Grant No. 22qntd2202)a project of the Center for Ocean Research in Hong Kong and Macao (CORE)
文摘During boreal winter,the invasion of cold air can lead to remarkable temperature drops in East Asia which can result in serious socioeconomic impacts.Here,we find that the intensity of strong synoptic cold days in the East China Sea and Indochina Peninsula are increasing.The enhanced synoptic cold days in these two regions are attributed to surface warming over the South China Sea and Philippine Sea(SCSPS).The oceanic forcing of the SCSPS on the synoptic cold days in the two regions is verified by numerical simulation.The warming of the SCSPS enhances the baroclinicity,which intensifies meridional wind and cold advection on synoptic timescales.This leads to a more extended region that is subject to the influence of cold invasion.
基金This work was jointly supported by the National Natural Science Foundation of China(Grant Nos.42130610,42075040,and 42175078)the Joint Research Project for Meteorological Capacity Improvement(Grant No.22NLTSQ002)+1 种基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)the Innovation and development project of China Meteorological Administration(Grant No.CXFZ2022J030).
文摘Extreme summer heat can have serious socioeconomic impacts in North China.Here,we explore the decadal variability of the number of extreme heat days in early-to-mid summer(June and July)and a related potential mechanism consistent with the major seasonal occurrence period of extreme heat events in North China(NCSH).Observational analyses show significant decadal variability in NCSH for 1981–2021,potentially linked to the Indo-Pacific warm pool and Northwest Pacific Ocean dipole(IPOD)in early-to-mid summer.Dynamic diagnostic analysis and the linear baroclinic model(LBM)show that the positive IPOD in early-to-mid summer can excite upward vertical wind anomalies in the South China-East China Sea region,shifting the position of the western Pacific subtropical high(WPSH)to the east or weakening the degree of its control of the South China-East China Sea region,thus generating a positive geopotential height quadrupole(EAWPQ)pattern in the East Asia-Northwest Pacific region.Subsequently,the EAWPQ can cause air compression(expansion)over North China by regulating the tropospheric thickness anomalies in North China,thus increasing(decreasing)NCSH.Finally,an empirical model that incorporates the linear trend can better simulate the decadal NCSH compared to an empirical model based solely on the IPOD index,suggesting that the decadal variability of NCSH may be a combined contribution of the decadal IPOD and external linear forcing.
基金This work was jointly supported by National Key R&D Program of China(2018YFC1505806)Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)+1 种基金National Science Foundation of China(41875100)the China Meteorological Administration Innovation and Development Project(CXFZ2021Z033),and China Three Gorges Corporation(Grant No.0704181).
文摘The record-breaking mei-yu in the Yangtze-Huaihe River valley(YHRV)in 2020 was characterized by an early onset,a delayed retreat,a long duration,a wide meridional rainbelt,abundant precipitation,and frequent heavy rainstorm processes.It is noted that the East Asian monsoon circulation system presented a significant quasi-biweekly oscillation(QBWO)during the mei-yu season of 2020 that was associated with the onset and retreat of mei-yu,a northward shift and stagnation of the rainbelt,and the occurrence and persistence of heavy rainstorm processes.Correspondingly,during the mei-yu season,the monsoon circulation subsystems,including the western Pacific subtropical high(WPSH),the upper-level East Asian westerly jet,and the low-level southwesterly jet,experienced periodic oscillations linked with the QBWO.Most notably,the repeated establishment of a large southerly center,with relatively stable latitude,led to moisture convergence and ascent which was observed to develop repeatedly.This was accompanied by a long-term duration of the mei-yu rainfall in the YHRV and frequent occurrences of rainstorm processes.Moreover,two blocking highs were present in the middle to high latitudes over Eurasia,and a trough along the East Asian coast was also active,which allowed cold air intrusions to move southward through the northwestern and/or northeastern paths.The cold air frequently merged with the warm and moist air from the low latitudes resulting in low-level convergence over the YHRV.The persistent warming in the tropical Indian Ocean is found to be an important external contributor to an EAP/PJ-like teleconnection pattern over East Asia along with an intensified and southerly displaced WPSH,which was observed to be favorable for excessive rainfall over YHRV.
基金This work was jointly supported by China National Key R&D Program 2018YFA0605604,NSFC Grant No.42088101,NOAA NA18OAR4310298,and NSF AGS-2006553This is SOEST contribution number 11354,IPRC contribution number 1524,and ESMC number 350.
文摘Record-breaking heavy and persistent precipitation occurred over the Yangtze River Valley(YRV)in June-July(JJ)2020.An observational data analysis has indicated that the strong and persistent rainfall arose from the confluence of southerly wind anomalies to the south associated with an extremely strong anomalous anticyclone over the western North Pacific(WNPAC)and northeasterly anomalies to the north associated with a high-pressure anomaly over Northeast Asia.A further observational and modeling study has shown that the extremely strong WNPAC was caused by both La Niña-like SST anomaly(SSTA)forcing in the equatorial Pacific and warm SSTA forcing in the tropical Indian Ocean(IO).Different from conventional central Pacific(CP)El Niños that decay slowly,a CP El Niño in early 2020 decayed quickly and became a La Niña by early summer.This quick transition had a critical impact on the WNPAC.Meanwhile,an unusually large area of SST warming occurred in the tropical IO because a moderate interannual SSTA over the IO associated with the CP El Niño was superposed by an interdecadal/long-term trend component.Numerical sensitivity experiments have demonstrated that both the heating anomaly in the IO and the heating anomaly in the tropical Pacific contributed to the formation and maintenance of the WNPAC.The persistent high-pressure anomaly in Northeast Asia was part of a stationary Rossby wave train in the midlatitudes,driven by combined heating anomalies over India,the tropical eastern Pacific,and the tropical Atlantic.
基金Supported by the National Natural Science Foundation of China(41430426 and 41605072)Natural Science Foundation of Jiangsu(BK20160768)
文摘Recent studies found that in the context of global warming, the observed tropical cyclones (TCs) exhibit signific-ant poleward migration trend in terms of the mean latitude where TCs reach their lifetime-maximum intensity in the western North Pacific (WNP). This poleward migration of TC tracks can be attributed to not only anthropogenic for-cing (e.g., continuous increase of sea surface temperature (SST)), but also impacts of other factors (e.g., natural vari- ability). In the present study, to eliminate the impacts of other factors and thus focus on the impact of unvaried SST on climatological WNP TC tracks, the mesoscale Weather Research and Forecasting (WRF) model is used to con- duct a suite of idealized sensitivity experiments with increased SST. Comparisons among the results of these experi- ments show the possible changes in climatological TC track, TC track density, and types of TC track in the context of SST increase. The results demonstrate that under the warmer SST conditions, the climatological mean TC track sys-tematically shifts poleward significantly in the WNP, which is consistent with the previous studies. Meanwhile, the ocean warming also leads to the decreased (increased) destructive potential of TCs in low (middle) latitudes, and thus northward migration of the region where TCs have the largest impact. Further results imply the possibility that under the ocean warming, the percentage of TCs with westward/northwestward tracks decreases/increases distinctly.
基金This study was jointly supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(Grant No.XDB40000000)the CAS(Grant No.QYZDJ-SSW-DQC021)+3 种基金the National Natural Science Foundation of China(Grant No.41630531)the State Key Laboratory of Loess and Quaternary GeologyWe thank the supercomputer center of the Pilot Qingdao National Laboratory for Marine Science and Technology and Beijing Super Cloud Computing Center,who offered computing servicesWe also thank Dr.X.Z.LI,H.LIU,and L.LIU from the Institute of Earth Environment,CAS,who offered suggestions for our numerical experiments.
文摘In summer 2020,extreme rainfall occurred throughout the Yangtze River basin,Huaihe River basin,and southern Yellow River basin,which are defined here as the central China(CC)region.However,only a weak central Pacific(CP)El Niño happened during winter 2019/20,so the correlations between the El Niño–Southern Oscillation(ENSO)indices and ENSO-induced circulation anomalies were insufficient to explain this extreme precipitation event.In this study,reanalysis data and numerical experiments are employed to identify and verify the primary ENSO-related factors that cause this extreme rainfall event.During summer 2020,unusually strong anomalous southwesterlies on the northwest side of an extremely strong Northwest Pacific anticyclone anomaly(NWPAC)contributed excess moisture and convective instability to the CC region,and thus,triggered extreme precipitation in this area.The tropical Indian Ocean(TIO)has warmed in recent decades,and consequently,intensified TIO basinwide warming appears after a weak El Niño,which excites an extremely strong NWPAC via the pathway of the Indo-western Pacific Ocean capacitor(IPOC)effect.Additionally,the ENSO event of 2019/20 should be treated as a fast-decaying CP El Niño rather than a general CP El Niño,so that the circulation and precipitation anomalies in summer 2020 can be better understood.Last,the increasing trend of tropospheric temperature and moisture content in the CC region after 2000 is also conducive to producing heavy precipitation.
基金financially supported by the National Key Research and Development Program of China(No.2016YFC1402106)the Technology Innovation Development Program of Yantai(No.2020MSGY058)+3 种基金the Technology Innovation Development Program of Yantai(No.2020MSGY068)the National Natural Science Foundation of China(No.31700327)the Shandong Provincial Natural Science Foundation,China(No.ZR2019QD017)the Key R&D Projects in Shandong Province(International Scientific and Technical Cooperation)(No.2019GHZ026)。
文摘The changing environmental factors exerted great influences on coastal macroalgal communities.To study the responses of the brown seaweed Sargassum horneri to temperature and light,S.horneri was cultured under three temperatures(20,25 and 30℃)and three light intensities(30,60,and 120μmol photons m-2 s-1)for seven days.The growth rate,chlorophyll a(Chl a)and carotenoids(Car)contents,chlorophyll fluorescence,and photosynthetic oxygen evolution rate were measured.The results show that the highest relative growth rate(RGR),maximal electron transport rate(rETRmax);the net photosynthetic rate(Pn)were observed at the lowest temperature(20℃)and highest light intensity(120μmol photons m-2 s-1);and the RGR and Pn were significantly inhibited by the highest temperature(30℃),especially at the lowest light intensity(30μmol photons m-2 s-1)(P<0.05).Additionally,the highest light intensity enhanced the non-photochemical quenching(NPQ)even under the highest temperature(30℃),indicating that the higher light intensity could induce photo-protection reaction of thalli.These results suggest that the higher temperature and lower light intensity exerted negative influences on S.horneri.
文摘Seagrass meadows provide important ecological functions,particularly by serving as carbon sinks and breeding grounds for marine species.Climate change has threatened seagrass communities,causing their replacement,loss and increased vulnerability.This review examined scholarly articles published between 2010-2021 to comprehensively present the impacts of climate change on seagrass meadows.It shows that ocean warming negatively affects seagrass communities by favouring communities of lower structuring capacities,thus reducing the effectiveness of their ecological functions.Ocean warming also promotes the propagation and spread of invasive species,and changes the trophic structures leading to further loss of seagrasses of value.Higher seawater temperature is associated with shoot mortality and retarded growth of certain seagrasses.Sea level rise causes more wave energy to be received by coastal seagrass communities,thus,creating more damage to the communities.Deepening sea limits light penetration and alters distribution of seagrass meadows.Carbon dioxide enrichment of seawater increases photosynthetic rate of seagrasses but ocean warming and acidification counteract this beneficial effect.Carbon dioxide enrichment affects different seagrass species and different parts of a seagrass species differently,and,where beneficial to seagrass communities,could enhance their ecological services.Temperature extremes could kill seagrasses while marine heatwaves and flooding could act synergistically to increase carbon demand of certain seagrasses and unfavourably change their biomass.These impacts are often aggravated by anthropogenic activities.This review calls for more studies and conservation efforts to understand the impacts of climate change on seagrass communities and future-proof them against the changing climate.
基金The National Natural Science Foundation of China under contract No.41706034the Basic Scientific Fund for National Public Research Institutes of China under contract No.2020Q05+7 种基金the Open Fund of the Key Laboratory of Ocean Circulation and WavesChinese Academy of Sciences under contract Nos KLOCW1803 and KLOCW1804the Open Fund of the Laboratory for Regional Oceanography and Numerical ModelingQingdao National Laboratory for Marine Science and Technology under contract No.2019A02the National Natural Science Foundation of China under contract Nos 91428206 and 41376038the National Science and Technology Major Project under contract No.2016ZX05057015the National Programme on Global Change and Air-Sea Interaction under contract Nos GASI-03-01-01-02 and GASI-IPOVAI-01-05the NSFC-Shandong Joint Fund for Marine Science Research Centers under contract No.U1606405。
文摘The spatial-temporal patterns of tropical cyclone(TC) intensity changes caused by the warm ocean mesoscale eddy(WOME) distribution are evaluated using two sets of idealized numerical experiments. The results show that the TC was intensified and weakened when a WOME was close to and far away from the TC center, respectively.The area where the WOME enhanced(weakened) TC intensity is called the inner(outer) area in this study.Amplitudes of the enhancement and weakening caused by the WOME in the inner and outer area decreased and increased over time, while the ranges of the inner and outer area diminished and expanded, respectively. The WOME in the inner area strengthened the secondary circulation of the TC, increased heat fluxes, strengthened the symmetry, and weakened the outer spiral rainband, which enhanced TC intensity. The effect was opposite if the WOME was in the outer area, and it weakened the TC intensity. The idealized simulation employed a stationary TC, and thus the results may only be applied to TCs with slow propagation. These findings can improve our understanding of the interactions between TC and the WOME and are helpful for improving TC intensity forecasting by considering the effect of the WOME in the outer areas.
文摘In the past decades, with the increasing frequency of extreme weather and climate events, the world has suffered huge losses. Based on NCEP/NCAR reanalysis data and China regional precipitation data provided by China Meteorological Administration, the extreme precipitation events in eastern China are defined by relative threshold method, and the temporal and spatial characteristics of summer extreme precipitation in eastern China from 1961 to 2016 are analyzed by empirical orthogonal function (EOF), and the reverse distribution of extreme precipitation in the middle and lower reaches of the Yangtze River and south China by Indian Ocean warm pool is revealed influence. The results show that the total amount and frequency of extreme precipitation in summer are concentrated in the Yangtze River Basin and south China. EOF1 decomposition of extreme precipitation reflects the interannual oscillation characteristics of reverse spatial distribution in the Yangtze River Basin and south China. The time series corresponding to EOF1 has significant interannual characteristics. The Pacific-Japan (PJ) teleconnection pattern is a circulation system that significantly affects the spatial-temporal pattern of extreme precipitation in southern China. When the PJ pattern is in the positive phase, the anticyclone controls the south China region, and restrains the convective activity, which results in the decrease of extreme precipitation. The anomalous southwest wind to the south of 30<span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">°</span></span>N and the anomalous northerly wind to the north of 30<span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">°</span></span>N converge in the middle and lower reaches of the Yangtze River. Combining with the sufficient water vapor carried by the anomalous southwest airflow at the edge of anticyclone, it is more conducive to the formation of extreme precipitation. The east propagating Kelvin wave in the warm pool of the Indian Ocean is an important reason for the formation of the PJ pattern and finally the formation of extreme precipitation anomalies in China.
文摘Subject Code:D05Under support of the National Natural Science Foundation of China,a concerted study by Dr.Huang Gang(黄刚)from the Institute of Atmospheric Physics,Chinese Academy of Sciences,climate scientist Jing-Jia Luo from the Australian Bureau of Meteorology,Dr.Yao Shuailei(姚帅磊)from the Institute
基金supported by the APEC Climate Centersupported by the UNIST research fund (Grant No. 1.09006.01)provided by a grant (Grant No. 14AWMP-B082564-01) from the Advanced Water Management Research Program funded by the Ministry of Land, Infrastructure and Transport of the Korean government
文摘Using 32 CMIP5(Coupled Model Intercomparison Project Phase 5) models, this study examines the veracity in the simulation of cloud amount and their radiative effects(CREs) in the historical run driven by observed external radiative forcing for 1850-2005, and their future changes in the RCP(Representative Concentration Pathway) 4.5 scenario runs for2006-2100. Validation metrics for the historical run are designed to examine the accuracy in the representation of spatial patterns for climatological mean, and annual and interannual variations of clouds and CREs. The models show large spread in the simulation of cloud amounts, specifically in the low cloud amount. The observed relationship between cloud amount and the controlling large-scale environment are also reproduced diversely by various models. Based on the validation metrics,four models-ACCESS1.0, ACCESS1.3, Had GEM2-CC, and Had GEM2-ES-are selected as best models, and the average of the four models performs more skillfully than the multimodel ensemble average.All models project global-mean SST warming at the increase of the greenhouse gases, but the magnitude varies across the simulations between 1 and 2 K, which is largely attributable to the difference in the change of cloud amount and distribution. The models that simulate more SST warming show a greater increase in the net CRE due to reduced low cloud and increased incoming shortwave radiation, particularly over the regions of marine boundary layer in the subtropics. Selected best-performing models project a significant reduction in global-mean cloud amount of about-0.99% K^-1and net radiative warming of 0.46 W m^-2K^-1, suggesting a role of positive feedback to global warming.
基金supported by the Opening Project of Guangxi Laboratory on the Study of Coral Reefs in the South China Sea,Nanning 530004,China(GXLSCRSCS2019003)Natural Science Foundation of Guang Dong(2022A1515010521)+2 种基金the National Natural Science Foundation of China(31971501)The CAS Pioneer Hundred Talents Program(Y8SL031001,Y9YB021001)Science and Technology Program of Guangzhou,China(202002030345).
文摘Coral fluorescence phenotypes have been suggested as an adaptation to a broad range of environmental conditions,yet the mechanisms linking thermal bleaching tolerance in reef-building coral populations,associated with fluorescence phenotypes due to GFP-like proteins,remains unclear.In this study,the relationship between the thermal sensitivity and phenotypic plasticity of corals was investigated using two phenotypes of Galaxea fascicularis,green and brown.The results reveal that brown G.fascicularis was more susceptible to bleaching than green G.fascicularis when exposed to a higher growth temperature of 32℃.Both phenotypes of G.fascicularis were associated with the thermotolerant Symbiodiniaceae symbiont,Durusdinium trenchii.However,the brown G.fascicularis showed a significant decrease in Symbiodiniaceae cell density and a significant increase in pathogenic bacteria abundance when the growth temperature was raised from 29 to 32℃.The physiological traits and transcriptomic profiles of Symbiodiniaceae were not notably affected,but there were differences in the transcriptional levels of certain genes between the two phenotype hosts of G.fascicularis.Under heat stress of 32℃,the gene encoding green fluorescent protein(GFP)-like and chromosome-associated proteins,as well as genes related to oxidative phosphorylation,cell growth and death showed lower transcriptional levels in the brown G.fascicularis compared to the green G.fascicularis.Overall,the results demonstrate that the green form of G.fascicularis is better able to tolerate ocean warming and defend against pathogenic bacteria,likely due to higher gene transcription levels and defense ability.
基金This study was supported by the National Natural Science Foundation of China(Nos 41720104005,41721005,31872587)the Joint Project of National Natural Science Foundation of China and Shandong Province(No.U1606404)+1 种基金the Shanghai Pujiang Talent Program(18PJ1404000)Shanghai Municipal Natural Science Foundation(17ZR1412900).
文摘The oceans are taking up over one million tons of fossil CO_(2) per hour,resulting in increased/ρCO_(2) and declining pH,leading to ocean acidification(OA).At the same time,accumulation of CO_(2) and other greenhouse gases is causing ocean warming,which enhances stratification with thinned upper mixed layers,exposing planktonic organisms to increasing levels of daytime integrated UV radiation.Ocean warming also reduces dissolved oxygen in seawater,resulting in ocean deoxygenation.All these ocean global changes are impacting marine ecosystems and effects are well documented for each individual driver(pH,oxygen,temperature,UV).However,combined effects are still poorly understood,strongly limiting our ability to project impacts at regional or local levels.Different regions are often exposed(and often adapted)to contrastingly different physical and chemical environmental conditions and organisms,and ecosystems from different parts of the world will be exposed to unique combinations of stressors in the future.Understanding the modulating role of adaptation,species niche and stressors’interaction is key.This review,being a non-exhaustively explored one.aims to provide an overview on understandings of ecophysiological effects of OA and its combination with covarying drivers,mainly warming,deoxygenation and solar UV radiation.We propose a testable hypothetical model as well as future research perspectives.