With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery ...With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery of the ozone layer is predicted in this century. However, strong volcanic activity can also cause ozone depletion that might be severe enough to threaten the existence of life on Earth. In this study, a transport model and a coupled chemistry–climate model were used to simulate the impacts of super volcanoes on ozone depletion. The volcanic eruptions in the experiments were the 1991 Mount Pinatubo eruption and a 100 × Pinatubo size eruption. The results show that the percentage of global mean total column ozone depletion in the 2050 RCP8.5 100 × Pinatubo scenario is approximately 6% compared to two years before the eruption and 6.4% in tropics. An identical simulation, 100 × Pinatubo eruption only with natural source ODSs, produces an ozone depletion of 2.5% compared to two years before the eruption, and with 4.4% loss in the tropics. Based on the model results,the reduced ODSs and stratospheric cooling lighten the ozone depletion after super volcanic eruption.展开更多
The hydrologic system in Jordan began its evolution with the regression of the Tethys during the Eocene and the rifting of Arabia from Africa. From that time onward Jordan lay on land. The rivers from Jordan and the S...The hydrologic system in Jordan began its evolution with the regression of the Tethys during the Eocene and the rifting of Arabia from Africa. From that time onward Jordan lay on land. The rivers from Jordan and the Sirhan east of it flew into the Rift. On the Jordan land volcanism developed and was on and off active until sub-recent times. Flows of magma covered large areas in north and central Jordan. The uppermost hard layers of the deep valleys of the Yarmouk and the Mujib present evidence for their later erosion. The land to the east of the rift was low and in depressions lakes formed on the Jordan plateau, which began to rise less than half a Million years ago. Especially the Jafr and the Azraq Lakes developed a belt of green vegetation that attracted numerous animals which were hunted by early men. Tools for hunting and food preparation were produced from flint and assembled next to the former lake shores with time. The shape of these flint tools allows a coarse dating and documents the arrival of humans hundred thousand years ago and of modern men between 50,000 and 80,000 years ago. Great changes in the shape of the eastern Rift margin had occurred before Lake Lisan evolved and its rising water flooded the mouths of canyons for example of Wadi Hasa, Wadi Mujib and Wadi Zerka Ma’in. On former gravel fans into Lake Lisan of the Tabaqat Fahl first agriculture still in Neolithic times evolved as well as in Amman where people from Ain Ghazal planted crops like barley and peas, beans, lentils and chickpeas and domesticated sheep, goats and pigs. The existence of the highland lakes seems to have been of utmost importance to human migrations from Africa. Such lakes provided water and food for those humans in the Arid area of Jordan.展开更多
This article presents a further development of the hypotheses concerning the possibility of predicting (“tectonic”) earthquakes [1]. Those hypotheses are based on the conversion of all types of released energy into ...This article presents a further development of the hypotheses concerning the possibility of predicting (“tectonic”) earthquakes [1]. Those hypotheses are based on the conversion of all types of released energy into heat and active chemical substances. One of the important sources of this phenomenon is the release of the latent energy trapped and stored during the Earth’s accretion. The latent energy of primordial hydrogen and helium escaping from the Earth’s core and lower mantle causes degassing processes [2] [3]. This latent energy converts into totally different types of chemical, electromagnetic and thermal energies of active compounds that are responsible for the major endogenic terrestrial processes. The dominating theories in seismology and volcanology are that an earthquake results from a sudden slip of a tectonic fault and that only magma and the gases contained in magma supply the volcanic energy resulting in the conclusions that earthquakes and eruptions are unpredictable. Volcanic eruption is considered herein to be a special case of the earthquake-process in which earthquake hypocenters rise to the Earth’s surface. A possible solution is proposed ([1] and herein) based on the analyses of the physicochemical processes as participants in earthquake and eruption preparations (foreshocks - major shock - aftershocks - volcanic eruptions) and on the characteristic rates of reflection of these processes on the Earth’s surface. Influences of Sun-Moon-tides and volcanic (“harmonic”) tremors are analyzed from physical-chemical point of view. The case of the 1980 eruption of Mount St. Helens and the proposed monitoring of the recommended additional data provides a way of selecting a complex of reliable earthquake and volcanic eruption precursors.展开更多
Large tropical volcanic eruptions can cause short-term global cooling. However, little is known whether large tropical volcanic eruptions, like the one in Tambora/Indonesia in 1815, cause regional hydroclimatic anomal...Large tropical volcanic eruptions can cause short-term global cooling. However, little is known whether large tropical volcanic eruptions, like the one in Tambora/Indonesia in 1815, cause regional hydroclimatic anomalies. Using a tree-ring network of precisely dated Himalayan birch in the central Himalayas, we reconstructed variations in the regional pre-monsoon precipitation back to 1650 CE. A superposed epoch analysis indicates that the pre-monsoon regional droughts are associated with large tropical volcanic eruptions, appearing to have a strong influence on hydroclimatic conditions in the central Himalayas. In fact, the most severe drought since 1650 CE occurred after the Tambora eruption. These results suggest that dry conditions prior to monsoon in the central Himalayas were associated with explosive tropical volcanism. Prolonged La Ni?a events also correspond with persistent pre-monsoon droughts in the central Himalayas. Our results provide evidence that large tropical volcanic eruptions most likely induced severe droughts prior to monsoon in the central Himalayas.展开更多
The responses of the East Asian summer monsoon(EASM)to large volcanic eruptions were analyzed using a millennial simulation with the FGOALS-gl climate system model.The model was driven by both natural(solar irradiance...The responses of the East Asian summer monsoon(EASM)to large volcanic eruptions were analyzed using a millennial simulation with the FGOALS-gl climate system model.The model was driven by both natural(solar irradiance,volcanic eruptions)and anthropogenic(greenhouse gases,sulfate aerosols)forcing agents.The results showed cooling anomalies after large volcanic eruptions almost on a global scale.The cooling over the continental region is stronger than that over the ocean.The precipitation generally decreases in the tropical and subtropical regions in the first summer after large volcanic eruptions.Cooling with amplitudes up to-0.3°C is seen over eastern China in the first summer after large volcanic eruptions.The East Asian continent is dominated by northeasterly wind anomalies and the corresponding summer rainfall exhibits a coherent reduction over the whole of eastern China.An analysis of the surface heat flux suggested the reduction in summer precipitation over eastern China can be attributed to a decrease of moisture vapor over the tropical oceans,and the weakening of the EASM may be attributed to the reduced land–sea thermal contrast after large volcanic eruptions.展开更多
In order to examine the response of the tropical Pacific Walker circulation（PWC） to strong tropical volcanic eruptions（SVEs）, we analyzed a three-member long-term simulation performed with Had CM3, and carried out...In order to examine the response of the tropical Pacific Walker circulation（PWC） to strong tropical volcanic eruptions（SVEs）, we analyzed a three-member long-term simulation performed with Had CM3, and carried out four additional CAM4 experiments. We found that the PWC shows a significant interannual weakening after SVEs. The cooling effect from SVEs is able to cool the entire tropics. However, cooling over the Maritime Continent is stronger than that over the central-eastern tropical Pacific. Thus, non-uniform zonal temperature anomalies can be seen following SVEs. As a result, the sea level pressure gradient between the tropical Pacific and the Maritime Continent is reduced, which weakens trade winds over the tropical Pacific. Therefore, the PWC is weakened during this period. At the same time, due to the cooling subtropical and midlatitude Pacific, the Intertropical Convergence Zone（ITCZ） and South Pacific convergence zone（SPCZ） are weakened and shift to the equator. These changes also contribute to the weakened PWC. Meanwhile, through the positive Bjerknes feedback, weakened trade winds cause El Nino-like SST anomalies over the tropical Pacific, which in turn further influence the PWC. Therefore, the PWC significantly weakens after SVEs. The CAM4 experiments further confirm the influences from surface cooling over the Maritime Continent and subtropical/midlatitude Pacific on the PWC. Moreover, they indicate that the stronger cooling over the Maritime Continent plays a dominant role in weakening the PWC after SVEs. In the observations,a weakened PWC and a related El Nino-like SST pattern can be found following SVEs.展开更多
为了探讨强火山喷发与横断山区干旱变化之间的关系,利用国际树轮库(International Tree-Ring Data Bank,ITRDB)资料集成区域年表,重建了横断山区过去1100多年的春季干旱变化序列,并通过时序叠加法分析了强火山喷发对其影响作用。结果表...为了探讨强火山喷发与横断山区干旱变化之间的关系,利用国际树轮库(International Tree-Ring Data Bank,ITRDB)资料集成区域年表,重建了横断山区过去1100多年的春季干旱变化序列,并通过时序叠加法分析了强火山喷发对其影响作用。结果表明:横断山区树木径向生长包含了干旱与火山信号,信号之间关联为强火山喷发后的4年间对该区域造成干旱影响,影响因素包括火山喷发强度、喷发位置纬度等。中纬度强火山喷发造成的影响更为显著,而低、高纬度强火山喷发影响较弱,影响差异的产生与横断山区干季降水形成的大气环流因素有关。展开更多
ENSO is an interannual mode which may be affected by external forcing, such as volcanic eruptions. Based on the reconstructed volcanic eruptions chronology and ENSO sequences, both 195 large volcanic eruptions (VEI≥4...ENSO is an interannual mode which may be affected by external forcing, such as volcanic eruptions. Based on the reconstructed volcanic eruptions chronology and ENSO sequences, both 195 large volcanic eruptions (VEI≥4) and 398 ENSO (El Niño and La Niña) events were extracted from 1525 to 2000. An analysis of the correspondence between the large volcanic eruptions and ENSO events was performed by matching the large volcanic eruptions with the types and magnitudes of ENSO events present in the 0-2 years after the eruptions. The results show the following: (1) The percentages of ENSO events within the 3 years after the large eruptions had increased to 68.3% from 31.7% compared with those with no-eruptions in the previous 0-2 years. In addition, the ratio of El Niño to La Niña events turned from 2:3 to 1:1, and more El Niño events occurred in the 0 year after eruptions in the low-latitudes of the Northern Hemisphere and in the tropics but more La Niña events occurred in the 0 year after in the high-latitudes of the Northern Hemisphere and the Southern Hemisphere. (2) After the eruptions, the weak (W) El Niño events had increased by 8 percentage points and the very strong (VS) El Niño events had decreased by 10 percentage points; conversely, there was a decrease by 15 percentage points of the weak La Niña events and an increase by 11.4 percentage points of the very strong La Niña events. Specifically, the percentages of strong La Niña events increased to a peak at 1 (+1) year after the eruptions. (3) The percentage of eruptions followed by single-year ENSO was the greatest. The percentage of ENSO events that occurred in the consecutive 2 years following an eruption was approximately equal to the percentage of events that occurred consecutively 3 years following an eruption, and both sets of ENSO magnitudes showed a decreasing trend.展开更多
基金supported by the National Key Research and Development Project of China (Grant No. 2016YFA0600604)the National Natural Science Foundation of China (Grant No. 41461144001 and No. 41861144016)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant No. 2014064)
文摘With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery of the ozone layer is predicted in this century. However, strong volcanic activity can also cause ozone depletion that might be severe enough to threaten the existence of life on Earth. In this study, a transport model and a coupled chemistry–climate model were used to simulate the impacts of super volcanoes on ozone depletion. The volcanic eruptions in the experiments were the 1991 Mount Pinatubo eruption and a 100 × Pinatubo size eruption. The results show that the percentage of global mean total column ozone depletion in the 2050 RCP8.5 100 × Pinatubo scenario is approximately 6% compared to two years before the eruption and 6.4% in tropics. An identical simulation, 100 × Pinatubo eruption only with natural source ODSs, produces an ozone depletion of 2.5% compared to two years before the eruption, and with 4.4% loss in the tropics. Based on the model results,the reduced ODSs and stratospheric cooling lighten the ozone depletion after super volcanic eruption.
文摘The hydrologic system in Jordan began its evolution with the regression of the Tethys during the Eocene and the rifting of Arabia from Africa. From that time onward Jordan lay on land. The rivers from Jordan and the Sirhan east of it flew into the Rift. On the Jordan land volcanism developed and was on and off active until sub-recent times. Flows of magma covered large areas in north and central Jordan. The uppermost hard layers of the deep valleys of the Yarmouk and the Mujib present evidence for their later erosion. The land to the east of the rift was low and in depressions lakes formed on the Jordan plateau, which began to rise less than half a Million years ago. Especially the Jafr and the Azraq Lakes developed a belt of green vegetation that attracted numerous animals which were hunted by early men. Tools for hunting and food preparation were produced from flint and assembled next to the former lake shores with time. The shape of these flint tools allows a coarse dating and documents the arrival of humans hundred thousand years ago and of modern men between 50,000 and 80,000 years ago. Great changes in the shape of the eastern Rift margin had occurred before Lake Lisan evolved and its rising water flooded the mouths of canyons for example of Wadi Hasa, Wadi Mujib and Wadi Zerka Ma’in. On former gravel fans into Lake Lisan of the Tabaqat Fahl first agriculture still in Neolithic times evolved as well as in Amman where people from Ain Ghazal planted crops like barley and peas, beans, lentils and chickpeas and domesticated sheep, goats and pigs. The existence of the highland lakes seems to have been of utmost importance to human migrations from Africa. Such lakes provided water and food for those humans in the Arid area of Jordan.
文摘This article presents a further development of the hypotheses concerning the possibility of predicting (“tectonic”) earthquakes [1]. Those hypotheses are based on the conversion of all types of released energy into heat and active chemical substances. One of the important sources of this phenomenon is the release of the latent energy trapped and stored during the Earth’s accretion. The latent energy of primordial hydrogen and helium escaping from the Earth’s core and lower mantle causes degassing processes [2] [3]. This latent energy converts into totally different types of chemical, electromagnetic and thermal energies of active compounds that are responsible for the major endogenic terrestrial processes. The dominating theories in seismology and volcanology are that an earthquake results from a sudden slip of a tectonic fault and that only magma and the gases contained in magma supply the volcanic energy resulting in the conclusions that earthquakes and eruptions are unpredictable. Volcanic eruption is considered herein to be a special case of the earthquake-process in which earthquake hypocenters rise to the Earth’s surface. A possible solution is proposed ([1] and herein) based on the analyses of the physicochemical processes as participants in earthquake and eruption preparations (foreshocks - major shock - aftershocks - volcanic eruptions) and on the characteristic rates of reflection of these processes on the Earth’s surface. Influences of Sun-Moon-tides and volcanic (“harmonic”) tremors are analyzed from physical-chemical point of view. The case of the 1980 eruption of Mount St. Helens and the proposed monitoring of the recommended additional data provides a way of selecting a complex of reliable earthquake and volcanic eruption precursors.
基金supported by the National Natural Science Foundation of China (41661144040)the Strategic Priority Research Program of Chinese Academy of Sciences (XDA20050101, XDA2006040103)+1 种基金Youth Innovation Promotion Association of Chinese Academy of Sciences, and the Open Research Fund of Key Laboratory of Tibetan Environmental Changes and Land Surface Processes, Chinese Academy of Sciencessupported by the Chinese Academy of Sciences President’s International Fellowship Initiative (2018PC0040)
文摘Large tropical volcanic eruptions can cause short-term global cooling. However, little is known whether large tropical volcanic eruptions, like the one in Tambora/Indonesia in 1815, cause regional hydroclimatic anomalies. Using a tree-ring network of precisely dated Himalayan birch in the central Himalayas, we reconstructed variations in the regional pre-monsoon precipitation back to 1650 CE. A superposed epoch analysis indicates that the pre-monsoon regional droughts are associated with large tropical volcanic eruptions, appearing to have a strong influence on hydroclimatic conditions in the central Himalayas. In fact, the most severe drought since 1650 CE occurred after the Tambora eruption. These results suggest that dry conditions prior to monsoon in the central Himalayas were associated with explosive tropical volcanism. Prolonged La Ni?a events also correspond with persistent pre-monsoon droughts in the central Himalayas. Our results provide evidence that large tropical volcanic eruptions most likely induced severe droughts prior to monsoon in the central Himalayas.
基金supported by the National Natural Science Foundation of China(41305069)the Open Project Program of the Key Laboratory of Meteorological Disaster of Ministry of Education,Nanjing University of Information Science and Technology,China R&D Special Fund for Public Welfare Industry(meteorology)(GYHY201406020)the National Basic Research Program of China(2010CB951904)
文摘The responses of the East Asian summer monsoon(EASM)to large volcanic eruptions were analyzed using a millennial simulation with the FGOALS-gl climate system model.The model was driven by both natural(solar irradiance,volcanic eruptions)and anthropogenic(greenhouse gases,sulfate aerosols)forcing agents.The results showed cooling anomalies after large volcanic eruptions almost on a global scale.The cooling over the continental region is stronger than that over the ocean.The precipitation generally decreases in the tropical and subtropical regions in the first summer after large volcanic eruptions.Cooling with amplitudes up to-0.3°C is seen over eastern China in the first summer after large volcanic eruptions.The East Asian continent is dominated by northeasterly wind anomalies and the corresponding summer rainfall exhibits a coherent reduction over the whole of eastern China.An analysis of the surface heat flux suggested the reduction in summer precipitation over eastern China can be attributed to a decrease of moisture vapor over the tropical oceans,and the weakening of the EASM may be attributed to the reduced land–sea thermal contrast after large volcanic eruptions.
基金supported by the National Key R&D Program of China(Grant No.2016YFA0600701)the National Natural Science Foundation of China(Grant Nos.41661144005,41575086 and 41320104007)the CAS–PKU Joint Research Program
文摘In order to examine the response of the tropical Pacific Walker circulation（PWC） to strong tropical volcanic eruptions（SVEs）, we analyzed a three-member long-term simulation performed with Had CM3, and carried out four additional CAM4 experiments. We found that the PWC shows a significant interannual weakening after SVEs. The cooling effect from SVEs is able to cool the entire tropics. However, cooling over the Maritime Continent is stronger than that over the central-eastern tropical Pacific. Thus, non-uniform zonal temperature anomalies can be seen following SVEs. As a result, the sea level pressure gradient between the tropical Pacific and the Maritime Continent is reduced, which weakens trade winds over the tropical Pacific. Therefore, the PWC is weakened during this period. At the same time, due to the cooling subtropical and midlatitude Pacific, the Intertropical Convergence Zone（ITCZ） and South Pacific convergence zone（SPCZ） are weakened and shift to the equator. These changes also contribute to the weakened PWC. Meanwhile, through the positive Bjerknes feedback, weakened trade winds cause El Nino-like SST anomalies over the tropical Pacific, which in turn further influence the PWC. Therefore, the PWC significantly weakens after SVEs. The CAM4 experiments further confirm the influences from surface cooling over the Maritime Continent and subtropical/midlatitude Pacific on the PWC. Moreover, they indicate that the stronger cooling over the Maritime Continent plays a dominant role in weakening the PWC after SVEs. In the observations,a weakened PWC and a related El Nino-like SST pattern can be found following SVEs.
文摘为了探讨强火山喷发与横断山区干旱变化之间的关系,利用国际树轮库(International Tree-Ring Data Bank,ITRDB)资料集成区域年表,重建了横断山区过去1100多年的春季干旱变化序列,并通过时序叠加法分析了强火山喷发对其影响作用。结果表明:横断山区树木径向生长包含了干旱与火山信号,信号之间关联为强火山喷发后的4年间对该区域造成干旱影响,影响因素包括火山喷发强度、喷发位置纬度等。中纬度强火山喷发造成的影响更为显著,而低、高纬度强火山喷发影响较弱,影响差异的产生与横断山区干季降水形成的大气环流因素有关。
基金National Natural Science Foundation of China,No.41430528。
文摘ENSO is an interannual mode which may be affected by external forcing, such as volcanic eruptions. Based on the reconstructed volcanic eruptions chronology and ENSO sequences, both 195 large volcanic eruptions (VEI≥4) and 398 ENSO (El Niño and La Niña) events were extracted from 1525 to 2000. An analysis of the correspondence between the large volcanic eruptions and ENSO events was performed by matching the large volcanic eruptions with the types and magnitudes of ENSO events present in the 0-2 years after the eruptions. The results show the following: (1) The percentages of ENSO events within the 3 years after the large eruptions had increased to 68.3% from 31.7% compared with those with no-eruptions in the previous 0-2 years. In addition, the ratio of El Niño to La Niña events turned from 2:3 to 1:1, and more El Niño events occurred in the 0 year after eruptions in the low-latitudes of the Northern Hemisphere and in the tropics but more La Niña events occurred in the 0 year after in the high-latitudes of the Northern Hemisphere and the Southern Hemisphere. (2) After the eruptions, the weak (W) El Niño events had increased by 8 percentage points and the very strong (VS) El Niño events had decreased by 10 percentage points; conversely, there was a decrease by 15 percentage points of the weak La Niña events and an increase by 11.4 percentage points of the very strong La Niña events. Specifically, the percentages of strong La Niña events increased to a peak at 1 (+1) year after the eruptions. (3) The percentage of eruptions followed by single-year ENSO was the greatest. The percentage of ENSO events that occurred in the consecutive 2 years following an eruption was approximately equal to the percentage of events that occurred consecutively 3 years following an eruption, and both sets of ENSO magnitudes showed a decreasing trend.
