Journal of Climate最新文献_第10页

Revisiting the Relationship between the North Pacific High and Upwelling Winds along the West Coast of North America in the Present and Future Climate 北太平洋高压与北美西海岸上升风在现在和未来气候中的关系

IF 4.9 2区地球科学

Journal of Climate Pub Date : 2023-11-10 DOI: 10.1175/jcli-d-23-0238.1

Hui Ding, Michael A. Alexander, Mingfang Ting

{"title":"Revisiting the Relationship between the North Pacific High and Upwelling Winds along the West Coast of North America in the Present and Future Climate","authors":"Hui Ding, Michael A. Alexander, Mingfang Ting","doi":"10.1175/jcli-d-23-0238.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0238.1","url":null,"abstract":"Abstract The wind-driven circulation is an important driver of upwelling in the California Current System, a key factor in maintaining a productive ecosystem. In summer, the North Pacific high (NPH) dominates the atmospheric circulation, including the nearshore winds. The impact of the NPH on the surface winds along the North American west coast during summer is examined using the ECMWF Reanalysis v5 (ERA5) and the Community Earth System Model version 1 (CESM1) large ensemble of simulations. The strength, latitude, and longitude of the sea level pressure (SLP) and subsidence at 500 hPa are used to assess the NPH and its variability. While both the surface high pressure cell and subsidence are related to the interannual variability of the surface winds over the North Pacific, the strength of subsidence has a much larger effect on the coastal winds than the variability in SLP. Based on the mean of the 40 CESM simulations, future changes in upwelling also more strongly coincide with changes in subsidence than in SLP. Subsidence and southward upwelling-favorable winds increase off the Canadian coast, with the reverse occurring off the U.S. West Coast, by the end of the twenty-first century. In particular, the intermember correlation between the changes in the nearshore surface winds and the 500-hPa pressure vertical velocity reaches 0.75 and 0.87 in the southern and northern portions of the northeast Pacific, respectively. The effect of the subsidence on upwelling winds in the future is confirmed by the CESM2 large ensemble.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"509 35","pages":""},"PeriodicalIF":4.9,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138506171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Persistent Ocean Anomalies as a Response to Northern Hemisphere Heating Induced by Biomass Burning Variability 生物质燃烧变率引起的北半球升温对持续海洋异常的响应

IF 4.9 2区地球科学

Journal of Climate Pub Date : 2023-11-10 DOI: 10.1175/jcli-d-23-0090.1

Ryohei Yamaguchi, Ji-Eun Kim, Keith B. Rodgers, Karl Stein, Axel Timmermann, Sun-Seon Lee, Lei Huang, Malte F. Stuecker, John T. Fasullo, Gokhan Danabasoglu, Clara Deser, Jean-Francois Lamarque, Nan A. Rosenbloom, Jim Edwards

{"title":"Persistent Ocean Anomalies as a Response to Northern Hemisphere Heating Induced by Biomass Burning Variability","authors":"Ryohei Yamaguchi, Ji-Eun Kim, Keith B. Rodgers, Karl Stein, Axel Timmermann, Sun-Seon Lee, Lei Huang, Malte F. Stuecker, John T. Fasullo, Gokhan Danabasoglu, Clara Deser, Jean-Francois Lamarque, Nan A. Rosenbloom, Jim Edwards","doi":"10.1175/jcli-d-23-0090.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0090.1","url":null,"abstract":"Abstract Biomass burning aerosol (BBA) emissions in the Coupled Model Intercomparison Project phase 6 (CMIP6) historical forcing fields have enhanced temporal variability during the years 1997–2014 compared to earlier periods. Recent studies document that the corresponding inhomogeneous shortwave forcing over this period can cause changes in clouds, permafrost, and soil moisture, which contribute to a net terrestrial Northern Hemisphere warming relative to earlier periods. Here, we investigate the ocean response to the hemispherically asymmetric warming, using a 100-member ensemble of the Community Earth System Model version 2 Large Ensemble forced by two different BBA emissions (CMIP6 default and temporally smoothed over 1990–2020). Differences between the two subensemble means show that ocean temperature anomalies occur during periods of high BBA variability and subsequently persist over multiple decades. In the North Atlantic, surface warming is efficiently compensated for by decreased northward oceanic heat transport due to a slowdown of the Atlantic meridional overturning circulation. In the North Pacific, surface warming is compensated for by an anomalous cross-equatorial cell (CEC) that reduces northward oceanic heat transport. The heat that converges in the South Pacific through the anomalous CEC is shunted into the subsurface and contributes to formation of long-lasting ocean temperature anomalies. The anomalous CEC is maintained through latitude-dependent contributions from narrow western boundary currents and basinwide near-surface Ekman transport. These results indicate that interannual variability in forcing fields may significantly change the background climate state over long time scales, presenting a potential uncertainty in CMIP6-class climate projections forced without interannual variability.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"509 38","pages":""},"PeriodicalIF":4.9,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138506233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Important influence of North Atlantic Oscillation on interannual variability of the boreal autumn East Siberian-Beaufort Sea ice 北大西洋涛动对北方秋季东西伯利亚-波弗特海冰年际变化的重要影响

2区地球科学

Journal of Climate Pub Date : 2023-11-10 DOI: 10.1175/jcli-d-23-0341.1

Li Liu, Wenjun Zhang, Chao Liu, Feng Jiang

{"title":"Important influence of North Atlantic Oscillation on interannual variability of the boreal autumn East Siberian-Beaufort Sea ice","authors":"Li Liu, Wenjun Zhang, Chao Liu, Feng Jiang","doi":"10.1175/jcli-d-23-0341.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0341.1","url":null,"abstract":"Abstract The East Siberia-Beaufort (EsCB) sea ice during boreal autumn has recently been reported to play important roles in the climate over Eurasia and North America. The EsCB sea ice exhibits remarkable year-to-year fluctuations in autumn (August-September-October), the season in which its minimum extent usually occurs. However, the physical driver of the autumn EsCB sea ice interannual variability remains unclear, impeding the seasonal prediction of local sea ice. Here we find that the autumn EsCB sea ice variability is largely driven by the preceding summer (May-June-July) dipolar atmospheric anomalies over the North Atlantic, resembling the North Atlantic Oscillation (NAO) pattern. During the negative NAO-like phase, the circumpolar anticyclonic anomalies tend to transport the warm air from Greenland towards the EsCB region, which triggers rapid sea ice melt there. The associated EsCB sea ice anomalies can be maintained or even intensified by the local sea ice-albedo positive feedback until autumn. Therefore, the abnormal signals of Arctic sea ice tend to show significant persistence in summer and autumn. The influence of the summer NAO-like atmospheric circulation on the ensuing autumn EsCB sea ice can be realistically reproduced in the historical simulation of the E3SM-1-0 model, supporting our findings based on the observation. This lagged relationship provides a promising pathway for skillful seasonal prediction of the EsCB sea ice and its related climatic impacts.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"121 14","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135136348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of Sea Surface Temperature in the Extratropical Southern Indian Ocean on Antarctic Sea Ice in Austral Spring 南印度洋温带海表温度对南部春季南极海冰的影响

IF 4.9 2区地球科学

Journal of Climate Pub Date : 2023-11-10 DOI: 10.1175/jcli-d-22-0655.1

Juan Dou, Renhe Zhang

{"title":"Impact of Sea Surface Temperature in the Extratropical Southern Indian Ocean on Antarctic Sea Ice in Austral Spring","authors":"Juan Dou, Renhe Zhang","doi":"10.1175/jcli-d-22-0655.1","DOIUrl":"https://doi.org/10.1175/jcli-d-22-0655.1","url":null,"abstract":"Abstract The relationship between the seasonal Antarctic sea ice concentration (SIC) variability and the extratropical southern Indian Ocean (SIO) sea surface temperature (SST) is explored in this study. It is found that the Antarctic SIC in a wide band of the SIO, Ross Sea, and Weddell Sea is significantly related to an SIO dipole (SIOD) SST anomaly on the interannual time scale during austral spring. This relationship is linearly independent of the effects of El Niño–Southern Oscillation, the Indian Ocean dipole, and the Southern Hemisphere annular mode. The positive phase of the SIOD, with warm SST anomalies off of western Australia and cold SST anomalies centered around 60°E in high latitudes, stimulates a downstream wave train that induces large-scale cyclonic circulations over the SIO and the Ross and Weddell Seas. Subsequently, anomalous horizontal moisture advection causes water vapor divergence, changes the surface energy budget, and cools the underlying ocean, which leads to the increased SIC over the region in the SIO, Ross Sea, and Weddell Sea. This SIOD SST anomaly reached a record low during the austral spring of 2016 and promoted the prominent wave pattern at high latitudes, contributing to the dramatic decline of sea ice in the 2016 spring. In addition, the proportion of the SIC trend that is linearly congruent with the SIOD SST trend during austral spring is quantified. The results indicate that the trend in the SIOD SST may account for a significant component of the 1979–2014 SIC trend in the Ross Sea with the congruency peaking at 60%.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"543 ","pages":""},"PeriodicalIF":4.9,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138506206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The significance of the melt-pond scheme in a CMIP6 global climate model 融化池方案在CMIP6全球气候模式中的意义

2区地球科学

Journal of Climate Pub Date : 2023-11-08 DOI: 10.1175/jcli-d-22-0902.1

Rachel Diamond, David Schroeder, Louise C. Sime, Jeff Ridley, Danny Feltham

{"title":"The significance of the melt-pond scheme in a CMIP6 global climate model","authors":"Rachel Diamond, David Schroeder, Louise C. Sime, Jeff Ridley, Danny Feltham","doi":"10.1175/jcli-d-22-0902.1","DOIUrl":"https://doi.org/10.1175/jcli-d-22-0902.1","url":null,"abstract":"Abstract The impact of melt ponds on sea-ice albedo has been observed and documented. In general circulation models, ponds are now accounted for through indirect diagnostic treatments (‘implicit’ schemes), or prognostic melt-pond parametrisations (‘explicit’ schemes). However, there has been a lack of studies showing the impacts of these schemes on simulated Arctic climate. We focus here on rectifying this using the general circulation model HadGEM3, one of the few models with a detailed explicit pond-scheme. We identify the impact of melt ponds on the sea ice and climate, and associated ice-ocean-atmosphere interactions. We run a set of constant forcing simulations for three different periods and show, for the first time, using mechanistically different pond-schemes can lead to very significantly different sea-ice and climate states. Under near-future conditions, an implicit scheme never yields an ice-free summer Arctic, whilst an explicit scheme yields an ice-free Arctic 35% of years and raises autumn Arctic air temperatures by 5 to 8 °C. We find that impacts on climate and sea ice depend on the ice state: under near-future and Last Interglacial conditions, the thin sea ice is very sensitive to pond formation and parametrisation, whilst during the Pre-Industrial, the thicker sea ice is less sensitive to the pond-scheme choice. Both of these two commonly-used parametrisations of sea-ice albedo yield similar results under pre-industrial conditions, but in warmer climates, lead to very different Arctic sea ice and ocean and atmospheric temperatures. Thus changes to physical parametrisations in the sea-ice model can have large impacts on simulated sea ice, ocean and atmosphere.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"32 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135390995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seasonal Variations and Spatial Patterns of Arctic Cloud Changes in Association with Sea-Ice Loss during 1950-2019 in ERA5 1950-2019年与海冰损失相关的北极云变化的季节变化和空间格局

2区地球科学

Journal of Climate Pub Date : 2023-11-08 DOI: 10.1175/jcli-d-23-0117.1

Matthew T. Jenkins, Aiguo Dai, Clara Deser

{"title":"Seasonal Variations and Spatial Patterns of Arctic Cloud Changes in Association with Sea-Ice Loss during 1950-2019 in ERA5","authors":"Matthew T. Jenkins, Aiguo Dai, Clara Deser","doi":"10.1175/jcli-d-23-0117.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0117.1","url":null,"abstract":"Abstract The dynamic and thermodynamic mechanisms that link retreating sea ice to increased Arctic cloud amount and cloud water content are unclear. Using the fifth generation of the ECMWF Reanalysis (ERA5), the long-term changes between years 1950-1979 and 1990-2019 in Arctic clouds are estimated along with their relationship to sea-ice loss. A comparison of ERA5 to CERES satellite cloud fractions reveals that ERA5 simulates the seasonal cycle, variations, and changes of cloud fraction well over water surfaces during 2001-2020. This suggests that ERA5 may reliably represent the cloud response to sea-ice loss because melting sea ice exposes more water surfaces in the Arctic. Increases in ERA5 Arctic cloud fraction and water content are largest during October-March from ~950-700 hPa over areas with significant (≥15%) sea-ice loss. Further, regions with significant sea-ice loss experience higher convective available potential energy (~2-2.75 J kg −1 ), planetary boundary layer height (~120-200 m) and near-surface specific humidity (~0.25-0.40 g kg −1 ) and a greater reduction of the lower tropospheric temperature inversion (~3-4 °C) than regions with small (<15%) sea-ice loss in autumn and winter. Areas with significant sea-ice loss also show strengthened upward motion between 1000-700 hPa, enhanced horizontal convergence (divergence) of air, and decreased (increased) relative humidity from 1000-950 hPa (950-700 hPa) during the cold season. Analyses of moisture divergence, evaporation minus precipitation, and meridional moisture flux fields suggest that increased local surface water fluxes, rather than atmospheric motions, provide a key source of moisture for increased Arctic clouds over newly exposed water surfaces from October-March.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"72 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135342594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

MJO-induced Warm Pool Eastward Extension Prior to the Onset of El Niño: Observations from 1998-2019 厄尔尼诺Niño开始前mjo引起的暖池向东延伸:1998-2019年的观测

2区地球科学

Journal of Climate Pub Date : 2023-11-06 DOI: 10.1175/jcli-d-23-0234.1

Yakelyn R. Jauregui, Shuyi S. Chen

{"title":"MJO-induced Warm Pool Eastward Extension Prior to the Onset of El Niño: Observations from 1998-2019","authors":"Yakelyn R. Jauregui, Shuyi S. Chen","doi":"10.1175/jcli-d-23-0234.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0234.1","url":null,"abstract":"Abstract The Madden-Julian Oscillation (MJO) and El Niño Southern Oscillation (ENSO) are the two most important tropical phenomena that affect global weather and climate on intraseasonal and interannual timescales. Although they occur on different timescales, the MJO-induced sea surface temperature (SST) anomalies over the equatorial Pacific have spatial scales similar to SST anomalies prior to El Niño. This study aims to address the question of whether the MJO plays an important role in the warm pool eastward extension (WPEE) leading up to El Niño. We use over 20 years of satellite observations, including optimum interpolated SST, TRMM-GPM precipitation, and the cross-calibrated multi-platform (CCMP) surface winds from 1998-2019, to quantify the spatial structure and duration of the MJO-induced warm SST anomalies over the equatorial Pacific (130°E-180°E, 10°S–10°N). The intensity of the MJO is measured by the total rain volume and average surface westerly wind speed throughout its convectively active phase. Results show that 1) 61% of the MJO events induced a WPEE over 1000-3000 km along the equator, which can last beyond 15 days; 2) the MJO events prior to El Niño are generally stronger and produce significant WPEE far beyond its annual cycle and increasing SST warming in the Niño 3.4 region; 3) consecutive MJO events can produce much stronger WPEE prior to El Niño, which are observed in all El Niño events from 1998-2019; and 4) more frequent and stronger MJO-induced WPEE occur in March-May than other seasons. These results can help better understand the MJO-ENSO interaction and, ultimately, improve the prediction of El Niño onset.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"4 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135635164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Responses of the Madden-Julian Oscillation to Global Warming: Impacts from Tropical Sea Surface Temperature Changes Madden-Julian涛动对全球变暖的响应:来自热带海面温度变化的影响

2区地球科学

Journal of Climate Pub Date : 2023-11-06 DOI: 10.1175/jcli-d-23-0213.1

Hien X. Bui, Yi-Xian Li, Wenyu Zhou, Peter van Rensch

{"title":"Responses of the Madden-Julian Oscillation to Global Warming: Impacts from Tropical Sea Surface Temperature Changes","authors":"Hien X. Bui, Yi-Xian Li, Wenyu Zhou, Peter van Rensch","doi":"10.1175/jcli-d-23-0213.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0213.1","url":null,"abstract":"Abstract The impacts of tropical sea surface temperature (SST) changes on the Madden-Julian oscillation (MJO) are investigated using the large ensemble simulation from the Community Earth System Model version 2 (CESM2-LE) under the shared socioeconomic pathway (SSP370 scenario). Three SST change patterns are featured, distinguished by the zonal gradient of the change in the equatorial Pacific warming. MJO characteristics and its teleconnections responses are composited for the clusters, and their relationships to the zonal SST gradient changes are examined. Results show that the anomalously strong El Niño-like SST change pattern significantly intensifies the MJO amplitude and enhances its eastward extension compared to the anomalously weak El Niño-like SST change pattern. These changes in MJO amplitude are further interpreted through the α framework. We also found no statistically different extratropical geopotential height responses to MJO between the three SST warming patterns, possibly due to strong internal climate variability. Changes in Rossby wave source between clusters also show a weak relationship with the MJO teleconnections. Our results highlight the importance of Indo-Pacific zonal SST gradient changes on the changes of MJO but limited impacts on MJO teleconnections to the mid-latitudes.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135636228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

ENSO Disrupts Boreal Winter CRE Feedback ENSO干扰北方冬季CRE反馈

2区地球科学

Journal of Climate Pub Date : 2023-11-03 DOI: 10.1175/jcli-d-23-0282.1

Daeho Jin, Ryan J. Kramer, Lazaros Oreopoulos, Dongmin Lee

{"title":"ENSO Disrupts Boreal Winter CRE Feedback","authors":"Daeho Jin, Ryan J. Kramer, Lazaros Oreopoulos, Dongmin Lee","doi":"10.1175/jcli-d-23-0282.1","DOIUrl":"https://doi.org/10.1175/jcli-d-23-0282.1","url":null,"abstract":"Abstract Twenty years of satellite-based cloud and radiation observations allow us to examine the observed cloud radiative effect (CRE) feedback (i.e., CRE change per unit change in global mean surface temperature). By employing a decomposition method to separate the contribution of “internal changes” and “relative-frequency-of-occurrence (RFO) changes” of distinct cloud regime (CR) groups, notable seasonal contrasts of CRE feedback characteristics emerge. Boreal winter CRE feedback is dominated by the positive shortwave CRE (SWCRE) feedback of oceanic low-thick clouds, due to their decreasing RFO as temperature rises. This signal is most likely due to El Niño-Southern Oscillation (ENSO) activity. When ENSO signals are excluded, boreal winter CRE feedback becomes qualitatively similar to the boreal summer feedback, where several CR groups contribute to the total CRE feedback more evenly. Most CR groups’ CRE feedbacks largely come from changing RFO: e.g., the predominant transition from oceanic cumulus to broken clouds and more occurrences of higher convective clouds with warming temperature. At the same time, low-thick and broken clouds experience optical thinning and decreasing cloud fraction, and these features are more prominent in boreal summer than winter. Overall, the seasonally asymmetric patterns of CRE feedback, primarily due to ENSO, introduce complexity in assessments of CRE feedback.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"37 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135820054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seasonal variations in eddy-induced atmospheric perturbations in the South China Sea 南海涡旋引起的大气扰动的季节变化

2区地球科学

Journal of Climate Pub Date : 2023-11-02 DOI: 10.1175/jcli-d-22-0921.1

Ningning Zhang, Jian Lan, Yi Yu, Youguang Zhang, Yijun He

{"title":"Seasonal variations in eddy-induced atmospheric perturbations in the South China Sea","authors":"Ningning Zhang, Jian Lan, Yi Yu, Youguang Zhang, Yijun He","doi":"10.1175/jcli-d-22-0921.1","DOIUrl":"https://doi.org/10.1175/jcli-d-22-0921.1","url":null,"abstract":"Abstract This study investigates the impact of eddy-induced sea surface temperature (SST) anomalies on the overlying atmosphere in the South China Sea, utilizing observational and reanalysis datasets. The results reveal that SST anomalies caused by anticyclonic/cyclonic eddies have a significant impact on the acceleration/deceleration of surface winds, with a stronger response in summer compared to winter. Moreover, atmospheric responses, such as heat flux, precipitation and marine atmospheric boundary layer (MABL) depth above anticyclonic (cyclonic) eddies, exhibit in-phase seasonal variations as surface winds. The study also explores the mechanisms leading to atmospheric response, pointing towards the vertical mixing mechanism as the dominant cause, supported by both the in-phase relationship between SST and surface wind anomalies and the linear relationship between the wind stress divergence anomaly and downwind SST gradient anomaly. Seasonal variations in coupling intensity are attributed to varying background atmospheric conditions, with more effective vertical turbulence mixing and stronger coupling intensity caused by more unstable MABL and enhanced large-scale vertical wind shear during summer than winter. Besides, the atmosphere above eddies is under quasi-equilibrium condition, in which the surface wind stress increases monotonically with the depth of MABL. Given that the MABL depth response to eddy-induced SST anomaly is stronger in summer than in winter, it is reasonable to expect more intense wind response during this season. Thus the MABL depth coupling works together with the vertical mixing mechanism to explain the proportional relationship between SST and wind anomalies, and why the atmospheric response is stronger in summer than in winter.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"1 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135973684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0