本文通过耦合AFWA(Air Force Weather Agency)冻雨参数化方案的WRF模式,对2020年冬季因暖锋引发的中国北方严重冻雨灾害个例进行了模拟,结果显示模式能够很好地模拟此次冻雨过程中降水相态的空间分布。通过分析暖锋的演变、水成物云微...本文通过耦合AFWA(Air Force Weather Agency)冻雨参数化方案的WRF模式,对2020年冬季因暖锋引发的中国北方严重冻雨灾害个例进行了模拟,结果显示模式能够很好地模拟此次冻雨过程中降水相态的空间分布。通过分析暖锋的演变、水成物云微物理特征以及降水相态的变化,得到:在辽宁中北部—吉林中东部地区,暖锋导致中低空形成“冷—暖—冷”的温度层结,该区冻雨形成机制以“冰相机制”为主,即高空的雪花落入大于0℃暖层内融化、再降落到次冻结层后形成冻雨。同时,发现存在高空无固态水成物、逆温层内暖雨下落到次冻结层在地面形成冻雨的现象,这种新机制被定义为“暖雨机制”,更多水成物垂直剖面与同期地面观测降水相态的比对,验证了新机制的存在,并解释了该机制形成的可能原因。为更深入理解冻雨形成机理以及北方冻雨的预报、预警提供科学支撑。展开更多
The deposition of Asian dust aerosols during their trans-Pacific transport might cause significant marine phytoplankton biomass increases. However, the knowledge of the trans-Pacific dust transport, deposition, and sp...The deposition of Asian dust aerosols during their trans-Pacific transport might cause significant marine phytoplankton biomass increases. However, the knowledge of the trans-Pacific dust transport, deposition, and spatial distribution is still poor due to a lack of continuous and simultaneous observations in the Asian subcontinent, the north Pacific Ocean, and North America. The severe Asian dust storm during 6 to 9 April 2001 provided an opportunity to gain a better understanding of trans-Pacific dust transport and deposition, using a comprehensive set of observations from satellites, ground-based light detection and ranging, aircraft, and surface observation networks. The observations and model simulations outline the general pattern of dust transport, deposition, vertical profile, and spatial distribution. The following points were observed： （1） the surface dust concentrations decreased exponentially with the increasing dust transport distance from 80°E to 120°W along the transport pathway; （2） the altitude of the dust concentration peak increased with increasing transport distance in the north Pacific region; and （3） the spatial distribution of dust deposition mainly depended on the trans-Pacific transport route.展开更多
连云港市位于中国江苏省北部,该地滨海湿地位于东亚-澳大利西亚迁飞路线(East Asia-Australasian F lyway,EAAF)的中心。连云港是候鸟在迁飞途中的重要停歇点之一,也是一个人口密集且正在快速发展的滨海城市。2003—2018年间,27%的连云...连云港市位于中国江苏省北部,该地滨海湿地位于东亚-澳大利西亚迁飞路线(East Asia-Australasian F lyway,EAAF)的中心。连云港是候鸟在迁飞途中的重要停歇点之一,也是一个人口密集且正在快速发展的滨海城市。2003—2018年间,27%的连云港潮间带被围垦,并逐步转化为工业园区和水产养殖塘。然而,这些区域目前仍有重要的保护价值。在2008—2018年的调查期间,连云港共记录到鹬类43种,其中有20种超过了1%的EAAF种群总数。此前的调查仅由一名当地调查员执行展开,这意味着调查结果在时间和空间的维度上都十分局限。为了对这片区域的水鸟,尤其是鹬类有更深入的了解,2019年5月9—13日,笔者团队在连云港市的临洪河口、青口河口和兴庄河口开展了水鸟同步调查,以期推动更有效的水鸟及其栖息地的保育工作。展开更多
Whether climatic changes in high latitudes of the Northern Hemisphere since the last glaciation have effects on the Tibetan Plateau monsoon, and the variation characteristics of the Plateau monsoon itself are still no...Whether climatic changes in high latitudes of the Northern Hemisphere since the last glaciation have effects on the Tibetan Plateau monsoon, and the variation characteristics of the Plateau monsoon itself are still not solved but of great significance. The 22-m high-resolution Ioess-paleosol sequence in the Hezuo Basin on the northeastern Tibetan Plateau demonstrates that the Plateau winter monsoon experienced a millennial variation similar to high latitude Northern Hemisphere, with cold events clearly correlated with Heinrich events but less for the warm events (Dansgarrd-Oeschger events). It may indicate that the climate system at high latitudes in the Northern Hemisphere had played an important role in both the Plateau monsoon and the high-level westerlies. On 10^4 year scale, there are two distinct anomalous changes, which are not found in the records from high latitude northern hemisphere, revealed by the loess grain size in the Hezuo Basin. One is that there was a considerable grain size increase at -36 kaBP, suggesting an abrupt enhancement of the Plateau winter monsoon at that time; the other is that, during 43--36 kaBP, the grain size decreased distinctly, indicating a notable weakening of the Plateau winter monsoon around that period. Both of the two anomalies suggest that the Tibetan climate may have been controlled by some other factors, besides the high latitude climatic changes in the Northern Hemisphere.展开更多
Whether the Tibetan Plateau is a significant dust source area is of great importance, because this is re-lated to the understanding of sources, accumulation and environmental effects of dusts on the Tibetan Plateau an...Whether the Tibetan Plateau is a significant dust source area is of great importance, because this is re-lated to the understanding of sources, accumulation and environmental effects of dusts on the Tibetan Plateau and in the Far East-Pacific Ocean regions as well as to the evolution of coupling of the Tibetan Plateau and atmosphere-ocean- continent exchange. Synoptic dynamics and remote sensing tracing of a dust storm on 3 to 5 March, 2003 in Lhasa on South Tibet demonstrate that the Tibetan Plateau possesses all factors and conditions of generating dust storms. Accom-panied with this dust storm is a strong ascending stream on the Plateau which has raised various sizes of dust particles into different levels. The lifted coarse particles were largely fallen down and accumulated as loess on the eastern Tibetan Plateau, and the fine particles were translated by the west-erly jet and subsided in the northern Pacific Ocean. The spa-tial-temporal distribution of dust-storms between years 1961 and 2000 on the Plateau shows that dust-storms mainly occur in winter and early spring with high frequency, and the path of dust storm moves gradually from south to north, which is closely coupled with the northward moving of the westerly jet from winter to spring over the Tibetan Plateau. Com-pared with other twelve dust source areas in China, the Ti-betan Plateau is one of the key dust source areas for the long-distance transport because its high occurring frequency and elevation cause fine particles easily to be lifted into the zone of the westerly jet.展开更多
Testing the effects of iron fertilization in booming metabolism of microbes in North Pacific Ocean has become an important hot topic in current global climate change study. The first supportive evidence with natural i...Testing the effects of iron fertilization in booming metabolism of microbes in North Pacific Ocean has become an important hot topic in current global climate change study. The first supportive evidence with natural iron inputs to ocean was ob-tained by Bishop and his colleagues at the PAPA re-gion in North Pacific Ocean. They found a rapid in-crease of marine phytoplankton over North Pacific Ocean after a strong dust storm in April 2001. We demonstrate that the dust deposition flux during this dust storm period decreases exponentially with in-creasing distance from the dust source regions along the dust transport pathway, through integration of synoptic dynamics, changes of TOMS-AI (aerosol index) and surface PM10 values along the dust pathway and changes of particulate organic carbon and chlorophyll in surface oceans. This strong dust storm may result in deposition of about 3.1—5.8 μg/m3 eolian iron into the PAPA region in North Pa-cific Ocean, thus causing a rapid increase of marine phytoplankton productivity observed by Bishop and his colleagues. This work supplies more direct and detailed evidence, from continental dust process, to support the iron hypothesis with natural iron inputs to the surface oceans through dust storms.展开更多
文摘本文通过耦合AFWA(Air Force Weather Agency)冻雨参数化方案的WRF模式,对2020年冬季因暖锋引发的中国北方严重冻雨灾害个例进行了模拟,结果显示模式能够很好地模拟此次冻雨过程中降水相态的空间分布。通过分析暖锋的演变、水成物云微物理特征以及降水相态的变化,得到:在辽宁中北部—吉林中东部地区,暖锋导致中低空形成“冷—暖—冷”的温度层结,该区冻雨形成机制以“冰相机制”为主,即高空的雪花落入大于0℃暖层内融化、再降落到次冻结层后形成冻雨。同时,发现存在高空无固态水成物、逆温层内暖雨下落到次冻结层在地面形成冻雨的现象,这种新机制被定义为“暖雨机制”,更多水成物垂直剖面与同期地面观测降水相态的比对,验证了新机制的存在,并解释了该机制形成的可能原因。为更深入理解冻雨形成机理以及北方冻雨的预报、预警提供科学支撑。
文摘The deposition of Asian dust aerosols during their trans-Pacific transport might cause significant marine phytoplankton biomass increases. However, the knowledge of the trans-Pacific dust transport, deposition, and spatial distribution is still poor due to a lack of continuous and simultaneous observations in the Asian subcontinent, the north Pacific Ocean, and North America. The severe Asian dust storm during 6 to 9 April 2001 provided an opportunity to gain a better understanding of trans-Pacific dust transport and deposition, using a comprehensive set of observations from satellites, ground-based light detection and ranging, aircraft, and surface observation networks. The observations and model simulations outline the general pattern of dust transport, deposition, vertical profile, and spatial distribution. The following points were observed： （1） the surface dust concentrations decreased exponentially with the increasing dust transport distance from 80°E to 120°W along the transport pathway; （2） the altitude of the dust concentration peak increased with increasing transport distance in the north Pacific region; and （3） the spatial distribution of dust deposition mainly depended on the trans-Pacific transport route.
文摘连云港市位于中国江苏省北部,该地滨海湿地位于东亚-澳大利西亚迁飞路线(East Asia-Australasian F lyway,EAAF)的中心。连云港是候鸟在迁飞途中的重要停歇点之一,也是一个人口密集且正在快速发展的滨海城市。2003—2018年间,27%的连云港潮间带被围垦,并逐步转化为工业园区和水产养殖塘。然而,这些区域目前仍有重要的保护价值。在2008—2018年的调查期间,连云港共记录到鹬类43种,其中有20种超过了1%的EAAF种群总数。此前的调查仅由一名当地调查员执行展开,这意味着调查结果在时间和空间的维度上都十分局限。为了对这片区域的水鸟,尤其是鹬类有更深入的了解,2019年5月9—13日,笔者团队在连云港市的临洪河口、青口河口和兴庄河口开展了水鸟同步调查,以期推动更有效的水鸟及其栖息地的保育工作。
文摘Whether climatic changes in high latitudes of the Northern Hemisphere since the last glaciation have effects on the Tibetan Plateau monsoon, and the variation characteristics of the Plateau monsoon itself are still not solved but of great significance. The 22-m high-resolution Ioess-paleosol sequence in the Hezuo Basin on the northeastern Tibetan Plateau demonstrates that the Plateau winter monsoon experienced a millennial variation similar to high latitude Northern Hemisphere, with cold events clearly correlated with Heinrich events but less for the warm events (Dansgarrd-Oeschger events). It may indicate that the climate system at high latitudes in the Northern Hemisphere had played an important role in both the Plateau monsoon and the high-level westerlies. On 10^4 year scale, there are two distinct anomalous changes, which are not found in the records from high latitude northern hemisphere, revealed by the loess grain size in the Hezuo Basin. One is that there was a considerable grain size increase at -36 kaBP, suggesting an abrupt enhancement of the Plateau winter monsoon at that time; the other is that, during 43--36 kaBP, the grain size decreased distinctly, indicating a notable weakening of the Plateau winter monsoon around that period. Both of the two anomalies suggest that the Tibetan climate may have been controlled by some other factors, besides the high latitude climatic changes in the Northern Hemisphere.
文摘Whether the Tibetan Plateau is a significant dust source area is of great importance, because this is re-lated to the understanding of sources, accumulation and environmental effects of dusts on the Tibetan Plateau and in the Far East-Pacific Ocean regions as well as to the evolution of coupling of the Tibetan Plateau and atmosphere-ocean- continent exchange. Synoptic dynamics and remote sensing tracing of a dust storm on 3 to 5 March, 2003 in Lhasa on South Tibet demonstrate that the Tibetan Plateau possesses all factors and conditions of generating dust storms. Accom-panied with this dust storm is a strong ascending stream on the Plateau which has raised various sizes of dust particles into different levels. The lifted coarse particles were largely fallen down and accumulated as loess on the eastern Tibetan Plateau, and the fine particles were translated by the west-erly jet and subsided in the northern Pacific Ocean. The spa-tial-temporal distribution of dust-storms between years 1961 and 2000 on the Plateau shows that dust-storms mainly occur in winter and early spring with high frequency, and the path of dust storm moves gradually from south to north, which is closely coupled with the northward moving of the westerly jet from winter to spring over the Tibetan Plateau. Com-pared with other twelve dust source areas in China, the Ti-betan Plateau is one of the key dust source areas for the long-distance transport because its high occurring frequency and elevation cause fine particles easily to be lifted into the zone of the westerly jet.
文摘Testing the effects of iron fertilization in booming metabolism of microbes in North Pacific Ocean has become an important hot topic in current global climate change study. The first supportive evidence with natural iron inputs to ocean was ob-tained by Bishop and his colleagues at the PAPA re-gion in North Pacific Ocean. They found a rapid in-crease of marine phytoplankton over North Pacific Ocean after a strong dust storm in April 2001. We demonstrate that the dust deposition flux during this dust storm period decreases exponentially with in-creasing distance from the dust source regions along the dust transport pathway, through integration of synoptic dynamics, changes of TOMS-AI (aerosol index) and surface PM10 values along the dust pathway and changes of particulate organic carbon and chlorophyll in surface oceans. This strong dust storm may result in deposition of about 3.1—5.8 μg/m3 eolian iron into the PAPA region in North Pa-cific Ocean, thus causing a rapid increase of marine phytoplankton productivity observed by Bishop and his colleagues. This work supplies more direct and detailed evidence, from continental dust process, to support the iron hypothesis with natural iron inputs to the surface oceans through dust storms.
