GQZ—Z1型称重式蒸渗计的研制及标定     

党选发  杨兴国  张旭东  孔令旺  李晓峰  杨启国 《干旱气象》2013,(4):835-839

在土壤水分蒸散量测量仪器研制中,首次在蒸渗计的原状土柱与反滤层接触部分安装了自动补（抽）水设备,使土桶内原状土柱与大田内的土壤水分保持一致。提出了传感器的参数选用原则和蒸渗计标定方法。经过安装和标定使用,GQZ—Z1蒸渗计的精度达到设计和观测0．1mm的要求,能够有效提高农田蒸散量的观测精度,其测定值能很好地反映植物在短时段内的蒸散变化。  相似文献   

亚洲区域海—陆—气相互作用对全球和亚洲气候变化的作用研究进展   总被引：13，自引：4，他引：9  

李建平  任荣彩  齐义泉  王法明  陆日宇  张培群  江志红  段晚锁  于非  杨永增 《大气科学》2013,37(2):518-538

围绕全球变化研究国家重大研究计划项目“亚洲区域海—陆—气相互作用机理及其在全球变化中的作用”预定的总体研究内容和科学目标,项目执行两年多以来,取得了一系列阶段性科研成果.关于气候动力学方面,项目揭示了热带印度洋—西太平洋暖池的海温变化是全球热带气候年代际变化的重要驱动力,是全球尺度副热带干旱的重要调控器;发现热带东太平洋海温存在冷舌模态,它是一个海气耦合模态,阐明在全球变暖背景下其对ENSO型态变异的作用及影响东亚气候的机理;揭示了青藏高原热力强迫的异常特征及其气候效应;提出了水平非均匀基流中行星波传播的理论,研究了其在不同东亚夏季风背景下的传播特征.关于气候预测方法方面,提出了若干有物理基础的气候预测方法,如尺度分离的降尺度预测新方法、基于北大西洋涛动(NAO)-ENSO的东亚夏季风预测模型、基于南半球环状模的东亚气候预测模型等,为业务部门提供了重要参考.关于观测方面,项目在亚洲区域海气补充观测和海洋资料同化方面也取得突出进展,成功进行了南海18°N断面海洋综合观测,为形成我国第一条南海断面长期海气观测打下了基础.在国际合作方面,项目还继续推动和领导了“亚洲季风年”(AMY2007-2012)与“东亚气候模拟”国际计划,提升了我国在该领域的国际地位.  相似文献   

大理州潜在蒸散量的计算及应用   总被引：1，自引：0，他引：1  

周明昆  张健东  高月忠 《气象与减灾研究》2013,(4):55-59

利用云南大理州12个气象站1961—2010年气温、日照、风速、蒸发量等观测资料,运用彭曼—蒙蒂斯公式计算大理州潜在蒸散量及湿润度指数,并对大理州潜在蒸散量的时空分布特征进行分析,对干旱情况进行评价。结果表明,大理州潜在蒸散量东部大,南部次之,北部最小。月潜在蒸散量5月最大,12月最小,1—5月递增,5—12月递减。1994—2010的平均潜在蒸散量明显大于1961—1993年。大理州潜在蒸散量与降水量、水汽压、气温、净辐射呈显著正相关关系,与风速没有明显的相关关系。正常年份大理州11月至次年5月都存在不同程度的干旱。  相似文献   

Detection of large color variation in the potentially hazardousasteroid （297274） 1996 SK     

Chien-Hsien Lin  Wing-Huen Ip  Zhong-Yi Lin  Fumi Yoshida  Yu-Chi Cheng 《中国天文和天体物理学报》2014,(3):311-318

Low-inclination near-earth asteroid(NEA)(297274) 1996 SK,which is also classified as a potentially hazardous asteroid,has a highly eccentric orbit.It was studied by multi-wavelength photometry within the framework of an NEA color survey at Lulin Observatory.Here,we report the finding of large color variation across the surface of(297274) 1996 SK within one asteroidal rotation period of4.656 ± 0.122 hours and classify it as an S-type asteroid according to its average colors of B- V = 0.767 ± 0.033,V- R = 0.482 ± 0.021,V- I = 0.801 ± 0.025and the corresponding relative reflectance spectrum.These results might be indicative of differential space weathering or compositional inhomogeneity in the surface materials.  相似文献   

Comparison of some properties of star forming galaxies and active galactic nuclei between two BOSS galaxy samples from SDSS DR9     

Xin-Fa Deng 《中国天文和天体物理学报》2014,(4):401-410

Using the LOWZ and CMASS samples of the ninth data release(DR9)from the SDSS-III Baryon Oscillation Spectroscopic Survey(BOSS), I investigate properties of star forming galaxies and active galactic nuclei(AGNs). The CMASS sample seriously suffers from the radial selection effect, even within the redshift0.44 ≤ z ≤ 0.6, which will likely lead to statistical conclusions in the CMASS sample being less robust. In the LOWZ sample, the fraction of star-forming galaxies is nearly constant from the least dense regime to the densest regime; the AGN fraction is also insensitive to the local environment. In addition, I note that in the LOWZ sample, the distributions of stellar mass and stellar velocity dispersion for star forming galaxies and AGNs are nearly the same.  相似文献   

A new lunar absolute control point: established by images from the landing camera on Chang'e-3     

Fen-Fei Wang  Jian-Jun Liu  Chun-Lai Li  Xin Ren  Ling-Li Mu  Wei Yan  Wen-Rui Wang  Jing-Tao Xiao  Xu Tan  Xiao-Xia Zhang  Xiao-Duan Zou  Xing-Ye Gao 《中国天文和天体物理学报》2014,(12)

The establishment of a lunar control network is one of the core tasks in selenodesy, in which defining an absolute control point on the Moon is the most important step. However, up to now, the number of absolute control points has been very sparse. These absolute control points have mainly been lunar laser ranging retroreflectors, whose geographical location can be observed by observations on Earth and also identified in high resolution lunar satellite images. The Chang'e-3(CE-3) probe successfully landed on the Moon, and its geographical location has been monitored by an observing station on Earth. Since its positional accuracy is expected to reach the meter level, the CE-3 landing site can become a new high precision absolute control point. We use a sequence of images taken from the landing camera, as well as satellite images taken by CE-1 and CE-2, to identify the location of the CE-3 lander. With its geographical location known, the CE-3 landing site can be established as a new absolute control point, which will effectively expand the current area of the lunar absolute control network by 22%, and can greatly facilitate future research in the field of lunar surveying and mapping, as well as selenodesy.  相似文献   

Data processing and initial results from the CE-3 Extreme Ultraviolet Camera     

Jian-Qing Feng  Jian-Jun Liu  Fei He  Wei Yan  Xin Ren  Xu Tan  Ling-Ping He  Bo Chen  Wei Zuo  Wei-Bin Wen  Yan Su  Yong-Liao Zou  Chun-Lai Li 《中国天文和天体物理学报》2014,(12)

The Extreme Ultraviolet Camera(EUVC) onboard the Chang'e-3(CE-3)lander is used to observe the structure and dynamics of Earth's plasmasphere from the Moon. By detecting the resonance line emission of helium ions(He+) at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius(RE) in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plasmasphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies.  相似文献   

Disappearance of a coronal hole induced by a filament activation     

Lin Ma  Zhong-Quan Qu  Xiao-Li Yan  Zhi-Ke Xue 《中国天文和天体物理学报》2014,(11)

We present a rare observation of direct magnetic interaction between an activating filament and a coronal hole(CH). The filament was a quiescent one located at the northwest of the CH. It underwent a nonradial activation, during which filament material constantly fell and intruded into the CH. As a result, the CH was clearly destroyed by the intrusion. Brightenings appeared at the boundaries and in the interior of the CH, meanwhile, its west boundaries began to retreat and the area gradually shrank. It is noted that the CH went on shrinking after the end of the intrusion and finally disappeared entirely. Following the filament activation, three coronal dimmings(D1–D3) were formed, among which D1 and D2 persisted throughout the complete disappearance of the CH. The derived coronal magnetic configuration shows that the filament was located below an extended loop system, which obviously linked D1 to D2. By extrapolating this result, our observations imply that the interaction between the filament and the CH involved direct intrusion of the filament material to the CH and the disappearance of the CH might be due to interchange reconnection between the expanding loop system and the CH's open field.  相似文献   

Improvement in the performance of solar adaptive optics     

Xiao-Fang Zhang  Lian-Qi Wang 《中国天文和天体物理学报》2014,(4):471-484

Adaptive optics （AO）, which provides diffraction limited imaging over a field-of-view （FOV）, is a powerful technique for solar observation. In the tomographic approach, each wavefront sensor （WFS） is looking at a single reference that acts as a guide star. This allows a 3D reconstruction of the distorted wavefront to be made. The correction is applied by one or more deformable mirrors （DMs）. This technique benefits from information about atmospheric turbulence at different layers, which can be used to reconstruct the wavefront extremely well. With the assistance of the MAOS software package, we consider the tomography errors and WFS aliasing errors, and focus on how the performance of a solar telescope （pointing toward zenith） is related to atmospheric anisoplanatism. We theoretically quantify the performance of the to- mographic solar AO system. The results indicate that the tomographic AO system can improve the average Strehl ratio of a solar telescope in a 10＂ - 80＂ diameter FOV by only employing one DM conjugated to the telescope pupil. Furthermore, we discuss the effects of DM conjugate altitude on the correction achievable by the AO system by selecting two atmospheric models that differ mainly in terms of atmospheric prop- erties at ground level, and present the optimum DM conjugate altitudes for different observation sites.  相似文献   

Low-dimensional chaos and fractal properties of long-term sunspot activity     

Shuang Zhou  Yong Feng  Wen-Yuan Wu  Yi Li  Jiang Liu 《天文和天体物理学研究(英文版)》2014,(1):104-112

Two primary solar-activity indicators sunspot numbers(SNs)and sunspot areas(SAs)in the time interval from November 1874 to December 2012 are used to determine the chaotic and fractal properties of solar activity.The results show that(1)the long-term solar activity is governed by a low-dimensional chaotic strange attractor,and its fractal motion shows a long-term persistence on large scales;(2)both the fractal dimension and maximal Lyapunov exponent of SAs are larger than those of SNs,implying that the dynamical system of SAs is more chaotic and complex than SNs;(3)the predictions of solar activity should only be done for short-to mid-term behaviors due to its intrinsic complexity;moreover,the predictability time of SAs is obviously smaller than that of SNs and previous results.  相似文献