The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cyc...The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cycle.During 2015-2016,a super El Nino event occurred in the equatorial Pacific.Suspended particulate matter(SPM)data and related environmental observations in the tropical Western Pacific were obtained during two cruses in Dec.2014 and 2015,which coincided with the early and peak stages of this super El Nino event.Compared with the marine environments in the tropical Western Pacific in Dec.2014,an obviously enhanced upwelling occurred in the Mindanao Dome region;the nitrate concentration in the euphotic zone almo st tripled;and the size,mass concentration,and volume concentration of SPM obviously increased in Dec.2015.The enhanced upwelling in the Mindanao Dome region carried cold but eutrophic water upward from the deep ocean to shallow depths,even into the euphotic zone,which disrupted the previously N-limited conditions and induced a remarkable increase in phytoplankton blooms in the euphotic zone.The se results reveal the mechanism of how nutrient-limited ecosystems in the tropical Western Pacific respond to super El Nino events.In the context of the ENSO cycle,if predicted changes in biogenic particles occur,the proportion of carbon storage in the tropical Western Pacific is estimated to be increased by more than 52%,ultimately affecting the regional and possibly even global carbon cycle.This paper highlights the prospect for long-term prediction of the impact of a super El Nino event on the global carbon cycle and has profound implications for understanding El Nino events.展开更多
The mechanism of the locking of the E1 Nino event onset phase to boreal spring （from April to June） in an intermediate coupled ocean-atmosphere model is investigated. The results show that the seasonal variation of ...The mechanism of the locking of the E1 Nino event onset phase to boreal spring （from April to June） in an intermediate coupled ocean-atmosphere model is investigated. The results show that the seasonal variation of the zonal wind anomaly over the equatorial Pacific associated with the seasonal variation of the ITCZ is the mechanism of the locking in the model. From January to March of the E1 Nino year, the western wind anomaly over the western equatorial Pacific can excite the downwelling Kelvin wave that propagates eastward to the eastern and middle Pacific by April to June. From April to December of the year before the E1 Nifio year, the eastern wind anomaly over the equatorial Pacific forces the downwelling Rossby waves that modulate the ENSO cycle. The modulation and the reflection at the western boundary modulate the time of the transition from the cool to the warm phase to September of the year before the E1 Nifio year and cause the strongest downwelling Kelvin wave from the reflected Rossby waves at the western boundary to arrive in the middle and eastern equatorial Pacific by April to June of the E1 Nino year. The superposition of these two kinds of downwelling Kelvin waves causes the El Nino event to tend to occur from April to June.展开更多
根据1951-1999年完整可靠的海表温度(SST)资料,利用墨西哥帽小波和Morlet小波变换分析近50 a SST的突变点以及多时间尺度结构．结果表明,两种小波都十分明显,并有效地揭示了近50 a SST的不同层次的奇异点及其多时间尺度精细结构．Nino...根据1951-1999年完整可靠的海表温度(SST)资料,利用墨西哥帽小波和Morlet小波变换分析近50 a SST的突变点以及多时间尺度结构．结果表明,两种小波都十分明显,并有效地揭示了近50 a SST的不同层次的奇异点及其多时间尺度精细结构．Nino各海区的海温距平(△TSS)序列具有多层次的时间尺度结构,存在着准4 a,4-10 a和20 a左右尺度的周期变化,24 a左右的较大时间尺度和8个月以下的小时间尺度周期信号较弱．Nino各海区的SST变化表现为多层次多时间尺度的冷暖结构特征; 近50 a海温总的变化趋势变暖．展开更多
On the basis of large amount of historical and measured data, this paper analyzed the regional, periodic, frequency, continuing, and response characteristics of droughts and floods in Zhejiang and proposed the concept...On the basis of large amount of historical and measured data, this paper analyzed the regional, periodic, frequency, continuing, and response characteristics of droughts and floods in Zhejiang and proposed the conception of ratio of peak runoff. Main characteristics of droughts and floods in Zhejiang are as follows： 1） The western Zhejiang region is plum rain major control area, and the eastern coastal region of Zhejiang is typhoon major control area. 2） Within a long period in the future, Zhejiang will be in the long period that features droughts. 3） In Zhejiang the 17th century was frequent drought and flood period, the 16th, 19th, and 20th centuries were normal periods, while the 18th century was spasmodic drought and flood period. 4） The severe and medium floods in Zhejiang were all centered around the M-or m-year of the 11-year sunspot activity period. 5） There are biggish years of annual runoff occurred in E1 Nifio year （E） or the following year （E＋1） in Zhejiang. The near future evolution trend of droughts and floods in Zhejiang is as follows： 1） Within a relatively long period in the future, Zhejiang Province will be in the long period of mostly drought years. 2） Between 1999 and 2009 this area will feature drought years mainly, while the period of 2010-2020 will feature flood years mostly. 3） Zhejiang has a good response to the sunspot activities, and the years around 2009, 2015, and 2020 must be given due attention, especially around 2020 there might be an extremely severe flood year in Zhejiang. 4） Floods in Zhejiang have good response to El Nifio events, in El Nifio year or the following year much attention must be paid to. And 5） In the future, the first, second, and third severe typhoon years in Zhejiang will be 2009. 2012. and 2015. resnectivelv.展开更多
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB42010203,XDA19060401,XDA23050503)the Science&Technology Basic Resources Investigation Program of China(No.2017FY100802)+1 种基金the Open Fund for Key Laboratory of Mar.Geol.and Environment,Institute of Oceanology,Chinese Academy of Sciences(No.MGE2019KG03)the Qingdao(Laoshan)Postdoctoral Applied Research Proj ect in 2019(No.Y9KY161)。
文摘The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cycle.During 2015-2016,a super El Nino event occurred in the equatorial Pacific.Suspended particulate matter(SPM)data and related environmental observations in the tropical Western Pacific were obtained during two cruses in Dec.2014 and 2015,which coincided with the early and peak stages of this super El Nino event.Compared with the marine environments in the tropical Western Pacific in Dec.2014,an obviously enhanced upwelling occurred in the Mindanao Dome region;the nitrate concentration in the euphotic zone almo st tripled;and the size,mass concentration,and volume concentration of SPM obviously increased in Dec.2015.The enhanced upwelling in the Mindanao Dome region carried cold but eutrophic water upward from the deep ocean to shallow depths,even into the euphotic zone,which disrupted the previously N-limited conditions and induced a remarkable increase in phytoplankton blooms in the euphotic zone.The se results reveal the mechanism of how nutrient-limited ecosystems in the tropical Western Pacific respond to super El Nino events.In the context of the ENSO cycle,if predicted changes in biogenic particles occur,the proportion of carbon storage in the tropical Western Pacific is estimated to be increased by more than 52%,ultimately affecting the regional and possibly even global carbon cycle.This paper highlights the prospect for long-term prediction of the impact of a super El Nino event on the global carbon cycle and has profound implications for understanding El Nino events.
基金This work was supported by The National Key Basic Reserch and Development Project of China(2004CB418303)Project 4023100 of the Major Research Program for Global Change and Regional ResponseNational Natural Science Foundation of China(Grant No.40231005).
文摘The mechanism of the locking of the E1 Nino event onset phase to boreal spring （from April to June） in an intermediate coupled ocean-atmosphere model is investigated. The results show that the seasonal variation of the zonal wind anomaly over the equatorial Pacific associated with the seasonal variation of the ITCZ is the mechanism of the locking in the model. From January to March of the E1 Nino year, the western wind anomaly over the western equatorial Pacific can excite the downwelling Kelvin wave that propagates eastward to the eastern and middle Pacific by April to June. From April to December of the year before the E1 Nifio year, the eastern wind anomaly over the equatorial Pacific forces the downwelling Rossby waves that modulate the ENSO cycle. The modulation and the reflection at the western boundary modulate the time of the transition from the cool to the warm phase to September of the year before the E1 Nifio year and cause the strongest downwelling Kelvin wave from the reflected Rossby waves at the western boundary to arrive in the middle and eastern equatorial Pacific by April to June of the E1 Nino year. The superposition of these two kinds of downwelling Kelvin waves causes the El Nino event to tend to occur from April to June.
基金Under the auspices of Zhejiang Provincial ScienceTechnology Foundation of China(No.2006C23066)
文摘On the basis of large amount of historical and measured data, this paper analyzed the regional, periodic, frequency, continuing, and response characteristics of droughts and floods in Zhejiang and proposed the conception of ratio of peak runoff. Main characteristics of droughts and floods in Zhejiang are as follows： 1） The western Zhejiang region is plum rain major control area, and the eastern coastal region of Zhejiang is typhoon major control area. 2） Within a long period in the future, Zhejiang will be in the long period that features droughts. 3） In Zhejiang the 17th century was frequent drought and flood period, the 16th, 19th, and 20th centuries were normal periods, while the 18th century was spasmodic drought and flood period. 4） The severe and medium floods in Zhejiang were all centered around the M-or m-year of the 11-year sunspot activity period. 5） There are biggish years of annual runoff occurred in E1 Nifio year （E） or the following year （E＋1） in Zhejiang. The near future evolution trend of droughts and floods in Zhejiang is as follows： 1） Within a relatively long period in the future, Zhejiang Province will be in the long period of mostly drought years. 2） Between 1999 and 2009 this area will feature drought years mainly, while the period of 2010-2020 will feature flood years mostly. 3） Zhejiang has a good response to the sunspot activities, and the years around 2009, 2015, and 2020 must be given due attention, especially around 2020 there might be an extremely severe flood year in Zhejiang. 4） Floods in Zhejiang have good response to El Nifio events, in El Nifio year or the following year much attention must be paid to. And 5） In the future, the first, second, and third severe typhoon years in Zhejiang will be 2009. 2012. and 2015. resnectivelv.
