沾化冬枣产地土壤元素分布特征及其对冬枣品质的影响

通过对沾化冬枣产地生态地球化学环境资料的系统整理,发现土壤中有益、有害元素的分布分配、迁移转化规律和赋存特征影响沾化冬枣的品质和食用安全性。对冬枣品质影响较大的元素有Mo、Cd、Co、Hg、S、N、Se等,其中Mo、Cd、Co、Hg、S含量过高时会降低冬枣果实的品质,尤以Hg、S、Cd影响最大,而N、Se可以提高冬枣的品质。结合基础研究成果,在土壤中增加Fe、K与水提取Se有效态含量或降低有效态B、Cu、P、N含量将有利于提高冬枣品质,该研究为冬枣统筹施肥和田间管理指明了方向。     

Detecting winter wheat phenology with SPOT-VEGETATION data in the North China Plain

Monitoring phenological change in agricultural land improves our understanding of the adaptation of crops to a warmer climate. Winter wheat–maize and winter wheat–cotton double-cropping are practised in most agricultural areas in the North China Plain. A curve-fitting method is presented to derive winter wheat phenology from SPOT-VEGETATION S10 normalized difference vegetation index (NDVI) data products. The method uses a double-Gaussian model to extract two phenological metrics, the start of season (SOS) and the time of maximum NDVI (MAXT). The results are compared with phenological records at local agrometeorological stations. The SOS and MAXT have close agreement with in situ observations of the jointing date and milk-in-kernel date respectively. The phenological metrics detected show spatial variations that are consistent with known phenological characteristics. This study indicates that time-series analysis with satellite data could be an effective tool for monitoring the phenology of crops and its spatial distribution in a large agricultural region.     

Symposium On Sediment Storage In Rivers And Estuaries

Book Reviewed in this article:

Geographical Aspects of Health and Disease in India. Rais Akhtarand A.T.A. Learmonth, eds.

Antarctic Treaty System: An Assessment. Proceedings of a Workshop at Beardmore South Field Camp, Antarctica.

American Electoral Mosaics. J. Clark Archerand Fred M. Shelley.

Kompas op Suidwes-Afrika/Namibie. W.S. Barnard, ed.

Jerusalem in the 19th Century: The Old City. Yehoshua Ben-Arieh.

The World as a Total System. Kenneth E. Boulding.

A Social History of Housing 1815–1985, Second Ed. John Burnett.

Human Migration. W.A.V. Clark.

Regional Population Projection Models. Andrei Rogers.

The State of Population Theory: Forward from Malthus. David Colemanand Roger Schofield, eds.

Imagining Tomorrow: History, Technology and the American Future. Joseph C. Corn, ed.

Swidden Agriculture in Indonesia: The Subsistence Strategies of the Kalimantan Kantú. Michael R. Dove.

Glacial Geologic Processes. David Drewry.

Physics of Desertification. Farouk El-Bazand M.H.A. Hassan, eds.

Housing the Homeless. Jon Ericksonand Charles Wilhelm, eds.

Settlement Patterns in Missouri: A Study of Population Origins, with a Wall Map. Russel L. Gerlach.

Desert Development: Man and Technology in Sparselands. Yehuda Gradus, ed.

Nuclear Winter. The Evidence and Risks. Owen Greene, Ian Percivaland Irene Ridge.

The Take-off of Suburbia and the Crisis of the Central City. Günter Heinritzand Elisabeth Lichtenberger, eds.

Regional Input-Output Analysis. Geoffrey J. D. Hewings.

Spatial Transportation Modeling. Christian Werner.

The Atlas of Georgia. Thomas W. Hodlerand Howard A. Schretter, eds.

Latin America. 5th ed. Preston E. Jamesand C.W. Minkel.

Applied Remote Sensing. C.P. Lo.

Localities, Class, and Gender. The Lancaster Regionalism Group.

Urban Social Movements: The City after Castells. Stuart Lowe.

Politics and Method. Doreen Masseyand Richard Meegan, eds.

Land Use. A. S. Mather.

The Kingdom of Coal. Donald L. Millerand Richard E. Sharpless.

The Presidio and Militia on the Northern Frontier of New Spain, A Documentary History, Vol. 1: 1570–1700. Thomas H. Naylorand Charles W. Polzer, S.J., comps. andeds.

Nuclear Power: Siting and Safety. Stan Openshaw.

The Central African Republic: The Continent's Hidden Heart. Thomas O'Toole.

Environmental and Dynamic Geomorphology. Márton Pécsi, ed.

Remote Sensing Principles and Interpretation. Floyd F. Sabins, Jr.

Acid Rain and Friendly Neighbors: The Policy Dispute between Canada and the United States. Jurgen Schmandtand Hilliard Roderick, eds.

Earth's Changing Surface: An Introduction to Geomorphology. M.J. Selby.

International Migration: The Female Experience. Rita J. Simonand Caroline B. Brettell, eds.

On Geography and Its History. D.R. Stoddart.

Transportation Networks: A Quantitative Approach. D. Teodorovic.

Processes in Physical Geography. R.D. Thompson, A.M. Mannion, C.W. Mitchell, M. Parry, J.R.G. Townshend.

Imaging Radar for Resources Surveys. J.W. Trevett.

Dominance and Affection: The Making of Pets. Yi-Fu Tuan.

Capturing the Horizon. The Historical Geography of Transportation since the Transportation Revolution of the Sixteenth Century. James E. Vance, Jr.

Nations at Risk: The Impact of the Computer Revolution. Edward Yourdon.     

Can Eurasia Experience a Cold Winter under a Third-Year La Ni?a in 2022/23?

The Northern Hemisphere(NH) often experiences frequent cold air outbreaks and heavy snowfalls during La Ni?a winters. In 2022, a third-year La Ni?a event has exceeded both the oceanic and atmospheric thresholds since spring and is predicted to reach its mature phase in December 2022. Under such a significant global climate signal, whether the Eurasian Continent will experience a tough cold winter should not be assumed, despite the direct influence of mid-to high-latitude,large-scale atmospheric ...     

华南冬末春初降水变异关联主模态及机理

基于1951—2018年再分析资料和观测的降水量资料,采用联合经验正交函数分解的方法,分析了华南冬末春初(2、3月)降水年际变异特征,并讨论了相应的环流背景及物理机制。华南2、3月降水变异的第一关联主模态反映出全区2、3月同相变化,第二模态呈现反相变化。第一模态的降水异常与ENSO关联的热带海温异常分布有关,其导致的西太平洋异常反气旋的维持使得2、3月的降水持续出现同相异常。第二模态的降水异常与中高纬度的大气环流异常有关：2月表现为欧亚遥相关型,3月则表现为北极涛动型。第二模态2、3月位势高度异常型的转变分别与北大西洋的热通量的异常变化及平流层极涡信号的下传有关：当2月北大西洋热通量正异常显著时,500 hPa高度场呈现欧亚遥相关(EU)负位相的分布;平流层极涡异常信号在3月下传达到对流层低层,使得3月对流层极涡增强,有利于北极涛动(AO)正位相的形成。2、3月欧亚大陆上空分别在EU遥相关型和AO型环流异常的影响下,导致了华南地区上空的大气环流的辐合辐散异常,并最终造成2、3月华南的降水量反相异常的出现。     

冬季欧亚大陆反气旋活动特征及其与中国气温的关系

本文基于拉格朗日观点,利用NCEP/NCAR再分析资料追踪了1979—2012年冬季欧亚大陆的反气旋活动,定义了冬季欧亚大陆反气旋强度指数,并据此分析了近30多年来欧亚大陆反气旋的活动特征及其与中国冬季气温的关系。结果表明,近30多年来冬季欧亚大陆反气旋强度有明显的年际、年代际变化,近10 a来其活动处于较强的位相;反气旋强度指数序列与中国大部分地区的冬季气温存在显著的负相关关系,当冬季欧亚大陆反气旋活动增强(减弱)时,中国大部分地区的冬季气温偏低(高);影响我国气温的反气旋生命期主要为1~3 d;蒙古高原是欧亚大陆反气旋活动的关键区域,每年有超过40%的反气旋经过该区域。这些反气旋多具有较强的移动性,其主要源地为斯堪的纳维亚半岛、地中海—黑海—里海—咸海附近以及中西伯利亚地区。     

Simple metrics for representing East Asian winter monsoon variability: Urals blocking and western Pacific teleconnection patterns

Instead of conventional East Asian winter monsoon indices(EAWMIs), we simply use two large-scale teleconnection patterns to represent long-term variations in the EAWM. First, the Urals blocking pattern index(UBI) is closely related to cold air advection from the high latitudes towards western Siberia, such that it shows an implicit linkage with the Siberian high intensity and the surface air temperature(SAT) variations north of 40?N in the EAWM region. Second, the well-known western Pacific teleconnection index(WPI) is connected with the meridional displacement of the East Asian jet stream and the East Asian trough. This is strongly related to the SAT variations in the coastal area south of 40?N in the EAWM region.The temperature variation in the EAWM region is also represented by the two dominant temperature modes, which are called the northern temperature mode(NTM) and the southern temperature mode(STM). Compared to 19 existing EAWMIs and other well-known teleconnection patterns, the UBI shows the strongest correlation with the NTM, while the WPI shows an equally strong correlation with the STM as four EAWMIs. The UBI–NTM and WPI–STM relationships are robust when the correlation analysis is repeated by(1) the 31-year running correlation and(2) the 8-year high-pass and low-pass filter. Hence,these results are useful for analyzing the large-scale teleconnections of the EAWM and for evaluating this issue in climate models. In particular, more studies should focus on the teleconnection patterns over extratropical Eurasia.     

ENSO冷暖位相影响东亚冬季风与东亚夏季风联系的非对称性

东亚冬季风（East Asian Winter Monsoon,简称EAWM）和东亚夏季风（East Asian Summer Monsoon,简称EASM）作为东亚季风系统的两个组成部分,他们之间存在显著的转换关系。前人的研究表明EAWM与次年EASM的转换关系只有在ENSO事件发生时才显著,然而这些研究都是基于ENSO对大气环流的影响是对称的这一假设下进行的。本文的研究表明EAWM和次年EASM的转换关系在ENSO冷暖事件中存在着明显的不对称性。通过将EAWM分为与ENSO有关的部分（EAWM_EN）和与ENSO无关的部分（EAWM_RES）,我们发现在强EAWM_EN年（即La Ni?a年）,在西北太平洋会存在一个从冬季维持到次年夏季的气旋性环流异常（the anomalous western North Pacific Cyclone,WNPC）,从而造成EASM偏弱;而在弱EAWM_EN年（即El Ni?o年时）,在西北太平洋会存在一个从冬季维持到次年夏季的反气旋性环流异常（the anomalous western North Pacific anticyclone,WNPAC）,从而引起次年EASM偏强。比较而言,WNPAC的位置比WNPC的位置偏南,且强度更强,因而在El Ni?o年能够引起次年EASM更大幅度的增强。造成这一不对称联系的主要原因是热带太平洋和印度洋异常海温的演变差异。在强EAWM_EN年,热带太平洋的负海温异常衰减地较慢,使得在次年夏季仍然维持着显著的负异常海温;相反,在弱EAWM_EN年,热带太平洋的正海温异常衰减地较快,以至于在次年夏季的异常海温信号已经基本消失,但此时印度洋却有着显著的暖海温异常。海温演变的差异进一步造成了大气环流的差异,从而导致EAWM与次年EASM联系的不对称性。     

干旱与灌溉处理对冬小麦冠层内光分布的影响

为探讨北方冬麦区节水灌溉的关键时期,借助干旱和灌溉对冬小麦冠层光分布,获取本地化参数,为华北农业干旱预报模型的修正提供依据。采用美国CID公司生产的CI-110型植物冠层分析仪,对干旱和灌溉条件下冬小麦冠层内光分布进行直接测定。结果表明,干旱和灌溉条件下,无论是高氮还是低氮、中氮,平均叶面倾角(MLA)都随生育期的延长呈现出先下降再上升的趋势。高氮和低氮时,随着生育期的延长,干旱处理和灌溉处理的冬小麦散射辐射透过系数(TCDP)都呈现先下降再上升的变化趋势;中氮时,干旱处理和灌溉处理的冬小麦TCDP在开花期和灌浆期都呈现一直上升的趋势。无论高氮还是中氮、低氮,冬小麦直接辐射透过系数(TCRP)的值都随着天顶角角度的增大而减小,冬小麦TCRP的值随着冬小麦生育期的推进,都呈现出先下降、后上升的变化趋势。高、中、低氮3种情况下,干旱和灌溉处理的冬小麦每个生育期均呈现随着天顶角角度的增加,消光系数K也增大;高氮时,多数情况下,冬小麦冠层的消光系数K干旱的大于灌溉的;中氮、低氮时,多数情况下,冬小麦冠层的消光系数K干旱的小于灌溉的。干旱和灌溉对冬小麦冠层光分布的影响:灌溉增加了冬小麦的平均叶面倾角(MLA);干旱和灌溉处理条件下冬小麦的TCDP差异较小,TCDP与MLA变化趋势相似,也都呈现出先下降、再上升的变化规律;干旱和灌溉处理冬小麦TCRP,无论高氮还是中氮、低氮,都随着天顶角角度的增大而减小,在7.5°、22.5°时干旱和灌溉对冬小麦TCRP的影响较大,而在37.5°、52.5°、67.5°时对冬小麦TCRP的值影响很小;每个生育期消光系数K均随着天顶角角度的增加而增大。