Sea surface temperature and salinity reconstruction based on stable isotopes and Mg/Ca of planktonic foraminifera in the western Pacific Warm Pool during the last 155 ka

Changes in sea surface temperature(SST), seawater oxygen isotope(δ 18 O sw), and local salinity proxy(δ 18 O sw-ss) in the past 155 ka were studied using a sediment core(MD06-3052) from the northern edge of the western Pacifi c Warm Pool(WPWP), within the fl ow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ 18 O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO 2 profi le showed a close connection between the WPWP and the Antarctic. Values of δ 18 O sw exhibited very similar variations to those of mean ocean δ 18 O sw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ 18 O sw-ss refl ect a more saline condition during high local summer insolation(SI) periods. Such correspondence between δ 18 O sw-ss and local SI in the WPWP may refl ect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their infl uence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP.     

东海西部陆架海域水团的季节特征分析

On the basis of the CTD data and the modeling results in the winter and summer of 2009, the seasonal characteristics of the water masses in the western East China Sea shelf area were analyzed using a cluster analysis method. The results show that the distributions and temperature-salinity characteristics of the water masses in the study area are of distinct seasonal difference. In the western East China Sea shelf area, there are three water masses during winter, i.e., continental coastal water（CCW）, Taiwan Warm Current surface water（TWCSW） and Yellow Sea mixing water（YSMW）, but four ones during summer, i.e., the CCW, the TWCSW, Taiwan Warm Current deep water（TWCDW） and the YSMW. Of all, the CCW, the TWCSW and the TWCDW are all dominant water masses. The CCW, primarily characterized by a low salinity, has lower temperature, higher salinity and smaller spatial extent in winter than in summer. The TWCSW is warmer, fresher and smaller in summer than in winter, and it originates mostly from the Kuroshio surface water（KSW） northeast of Taiwan, China and less from the Taiwan Strait water during winter, but it consists of the strait water and the KSW during summer. The TWCDW is characterized by a low temperature and a high salinity, and originates completely in the Kuroshio subsurface water northeast of Taiwan.     

内蒙古正镶白旗宝力根套海井田构造地质特征与找煤方向

内蒙古正镶白旗宝力根套海井田为一个新发现的全隐蔽井田,井田含煤地层为侏罗系中、下统阿拉坦合力群,是一套典型的内陆湖泊、河流、三角洲陆相含煤建造。井田为四条正断层所围限的矩形断块,含煤地层的形成严格受构造因素控制,与其所处特殊构造地理位置有关。含煤区处于隆起带的凹陷内,西北及西南为古隆起带,呈直角包围宝力根套海井田,形成有利的聚煤场所—交角构造区。井田与邻区实例对比分析表明:地台内隆起带的凹陷区聚煤的构造控煤模式是该区域的普遍成煤规律,煤易在盆地次边缘沉积,交角构造区更有利于聚煤。通过区域构造特征分析,提出了找煤方向。     

A 2000-yr reconstruction of air temperature in the Great Basin of the United States with specific reference to the Medieval Climatic Anomaly

A sediment core representing the past two millennia was recovered from Stella Lake in the Snake Range of the central Great Basin in Nevada. The core was analyzed for sub-fossil chironomids and sediment organic content. A quantitative reconstruction of mean July air temperature (MJAT) was developed using a regional training set and a chironomid-based WA-PLS inference model (r²_jack = 0.55, RMSEP = 0.9°C). The chironomid-based MJAT reconstruction suggests that the interval between AD 900 and AD 1300, corresponding to the Medieval Climate Anomaly (MCA), was characterized by MJAT elevated 1.0°C above the subsequent Little Ice Age (LIA), but likely not as warm as recent conditions. Comparison of the Stella Lake temperature reconstruction to previously published paleoclimate records from this region indicates that the temperature fluctuations inferred to have occurred at Stella Lake between AD 900 and AD 1300 correspond to regional records documenting hydroclimate variability during the MCA interval. The Stella Lake record provides evidence that elevated summer temperature contributed to the increased aridity that characterized the western United States during the MCA.     

海进体系域碳氧同位素地球化学响应——以黔西南地区三叠系为例

层序地层研究表明,位于扬子地块西南缘的黔西南地区在中三叠世末期(相当于Ladinian-Carnian期)出现了一次与全球同步的大规模海侵,形成了一个向上变深的碳酸盐岩台地淹没沉积层序。垄头组顶部和竹竿坡组分别是海进体系域(TST)的下、上部分。碳、氧同位素研究表明,垄头组顶部自下而上δ(18O)持续增大,而δ(13C)先逐渐增大,后在顶部界面附近快速下降,反映了垄头组顶部在暴露环境下氧化作用的结果。竹竿坡组δ(13C)自下而上逐渐增大,δ(18O)总体呈现逐渐减小趋势,反映了海平面变化特征。研究认为,海进体系域的δ(13C)和δ(18O)演化不但反映了海平面和沉积环境变化,同时对密集段(CS)、层序界面和古暴露面等也有很好的识别作用,在层序地层研究中具有重要的意义。     

Dynamics of warm inflation with gauge fields in Bianchi type I universe model

In this paper, we study the dynamics of warm inflation in which slow-roll inflation is driven by non-Abelian gauge fields. To this end, we use the geometry of locally rotationally symmetric Bianchi type I universe model. We construct dynamical equations, i.e., first model field equation, energy conservation equations and equation of motion under slow-roll approximation. In order to discuss inflationary perturbations, we evaluate parameters like scalar and tensor power spectra as well as scalar and tensor spectral indices. We also evaluate inflaton, directional Hubble parameter, slow-roll and perturbation parameters as well as tensor-scalar ratio as a function of inflaton during intermediate and logamediate inflationary eras. It is concluded that anisotropic inflationary universe model with non-Abelian gauge fields remains compatible with WMAP7.     

Stained Glass and Climate Change: How are they Connected?

As expressions of regional architecture, sacred (Christian) Gothic structures often possess several adaptations to their prevailing climate regime. The late medieval (Gothic) period in northern Europe is also, according to the evidence presented here, marked by a transition from warm and sunny to cooler and cloudier conditions. It is within the context of this climate change that we consider one of the most important features in Gothic churches—interior daylighting—during the transitional period (the thirteenth to the end of the fifteenth centuries) between the Medieval Warm Period (MWP) and the Little Ice Age (LIA). This paper seeks to determine whether increasingly cloudy conditions over northern continental Europe, in part due to a shift in North Atlantic Oscillation (NAO) phase, may have influenced the use of more white glass in the fourteenth century. To the best of our knowledge, this is the first time an extensive daylighting dataset has been collected in medieval sacred interiors. From an analysis of these illuminance and luminance data collected in European churches and cathedrals, we find that high-translucency glazing is associated with limited lighting gains compared to full-colour programs under sunny conditions but substantial lighting improvements (up to an order of magnitude) for cloudy conditions. Additionally, we find that backlighting from direct sunlight produces significant obscuration of some of the iconographical glass when interiors are dominated by high-translucency glazing, further suggesting that these interiors are not ideal for sunny conditions.

[Traduit par la rédaction] Étant donné que les cathédrales gothiques (chrétiennes) sont des expressions de l'architecture régionale, plusieurs adaptations au climat de l’époque y ont souvent été apportées. À la fin du Moyen Âge (période du gothique), le climat chaud et ensoleillé en Europe du nord continentale a fait place à un climat plus froid et plus nuageux, d'après les preuves que nous présentons ici. C'est donc dans la perspective de ce changement climatique que nous nous penchons sur l'un des éléments les plus importants de l'architecture des églises gothique, l’éclairage naturel intérieur, durant la transition (du XIII^e siècle à la fin du XV^e siècle) entre la période chaude médiévale (MWP) et le petit âge glaciaire (LIA). Dans le présent article, nous voulons notamment évaluer si l'utilisation de plus en plus fréquente du vitrail blanc au XIV^e siècle s'expliquerait par les conditions plus nuageuses en Europe du nord continentale, attribuables en partie à un changement dans l'indice d‘oscillation nord-atlantique (NAO). À notre connaissance, c'est la première fois qu'une série élaborée de données a été recueillie sur l’éclairage à l'intérieur des cathédrales gothiques. L'analyse des données sur l’éclairement lumineux et la luminance lumineuse dans les églises et les cathédrales d'Europe nous permet de constater que le verre très translucide présente peu d'avantages comparativement au verre plein coloré dans des conditions ensoleillées, mais qu'il améliore considérablement l’éclairage dans des conditions nuageuses (jusqu’à 10 fois). De plus, nous constatons que l’éclairage en contre-jour produit par l'ensoleillement direct obscurcit une partie des pièces de verre ornées d'icônes lorsque le verre très translucide domine à l'intérieur, ce qui confirme une fois de plus qu'il ne s'agit pas d'un aménagement idéal pour les conditions ensoleillées.     

Light-Time Effect in the Eclipsing Binaries GO Cyg, GW Cep, AR Aur and V505 Sgr

Orbital period changes of the eclipsing binaries GO Cyg and GW Cep are explained by the light-time effect for the first time. New minima of the eclipsing binary AR Aur improve the predicted light-time orbit. The light-time orbit with the quadratic ephemeris of the binary matches the new observations of V505 Sgr better than the linear one. As the light-time effect fits in corresponding O − C diagrams of all four systems have been reaching extreme values, the observations of minima times in forthcoming years are highly desirable.     

The period variation of DY Hercules

In this paper the researchers collected 28 times of maximum light including 4 times of those observed at the Xinglong station, the National Astronomical Observation of China between May 27, 2004 and June 1, 2004 and 1 time of maximum light from a 60 cm telescope on May 4, 1984. It found that the O-C point distribution was more completely compared than in any papers published before. The period is decreasing at the rate of about (1.4±0.1)×10⁻⁸ per year, which should not be caused by stellar evolution. It might be only part of a binary orbital light-time variation or other unknown reason. The time scale is longer than Pocs and Szeidl’s suggestion; the star needs more observations before we can be certain of the exact light-time variation.     

Medieval Warming, Little Ice Age, and European impact on the environment during the last millennium in the lower Hudson Valley, New York, USA

Establishing natural climate variability becomes particularly important in large urban areas in anticipation of droughts. We present a well-dated bi-decadal record of vegetation, climate, land use, and fire frequency from a tidal marsh in the Hudson River Estuary. The classic Medieval Warm Period is evident through striking increases in charcoal and Pinus dominance from 800–1300 A.D., paralleling paleorecords southward along the Atlantic seaboard. Higher inputs of inorganic sediment during this interval suggest increased watershed erosion during drought conditions. The presence of the Little Ice Age ensues with increases in Picea and Tsuga, coupled with increasing organic percentages due to cooler, moister conditions. European impact is manifested by a decline in arboreal pollen due to land clearance, increased weedy plant cover (i.e., Ambrosia, Plantago, and Rumex), and an increase in inorganic particles to the watershed.