国产遥感传感器大气层外波段平均太阳光谱辐照度计算

目前,我国大部分遥感传感器的大气层外波段平均太阳光谱辐照度(Mean solar exoatmospheric irradiances over band b,简称ESUN_b)尚未公布,这给遥感图像表观反射率的计算带来了不便,在一定程度上影响了数据资料的应用和推广。本文基于已有官方ESUN_b值的EO1/ALI、Terra/ASTER、QuickBird等多种中、高空间分辨率传感器,对9条常见的太阳光谱曲线进行比较分析。结果表明,WRC太阳光谱曲线最合适计算中分辨率传感器的ESUN_b,而Wehrli太阳光谱曲线最合适计算高分辨率传感器的ESUN_b。基于WRC太阳光谱曲线和Wehrli太阳光谱曲线计算,得到了ZY-1 02C/PMS相机、ZY-3/TLC相机和MUX相机,以及GF-1/WFV相机和PMS相机各波段ESUN_b值,并对ESUN_b值的不确定性进行了分析。结果显示,太阳光谱选取的不同,对ESUN_b的取值会产生-1.94%至1.48%的偏差。本文使用多种卫星传感器交叉比较的方式确定了最佳的太阳光谱,给出了ZY-1 02C、ZY-3和GF-1等卫星搭载的遥感传感器各波段的ESUN_b值,为这些国产卫星遥感数据的广泛应用提供便利。此外,本文所用方法简便易行,在其他新的遥感传感器上具有推广应用价值。     

VIRGO: Experiment for helioseismology and solar irradiance monitoring

The scientific objective of the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) is to determine the characteristics of pressure and internal gravity oscillations by observing irradiance and radiance variations, to measure the solar total and spectral irradiance and to quantify their variability over periods of days to the duration of the mission. With these data helioseismological methods can be used to probe the solar interior. Certain characteristics of convection and its interaction with magnetic fields, related to, for example, activity, will be studied from the results of the irradiance monitoring and from the comparison of amplitudes and phases of the oscillations as manifest in brightness from VIRGO, in velocity from GOLF, and in both velocity and continuum intensity from SOI/MDI. The VIRGO experiment contains two different active-cavity radiometers for monitoring the solar constant, two three-channel sunphotometers (SPM) for the measurement of the spectral irradiance at 402, 500 and 862 nm, and a low-resolution imager (LOI) with 12 pixels, for the measurement of the radiance distribution over the solar disk at 500 um. In this paper the scientific objectives of VIRGO are presented, the instruments and the data acquisition and control system are described in detail, and their measured performance is given.died 13 October 1994     

基于反射率的太湖典型湖区溶解性有机碳的反演

2004年4月基于野外水下辐照度的测定及实验室溶解性有机碳(DOC)的分析,通过研究典型湖区水体中DOC浓度与反射率之间的关系,选择DOC浓度反演的最佳波段,建立了DOC浓度的遥感定量反演模型。结果表明,DOC浓度在6.60～17.17 mg/L（均值为9.99 mg/L,方差为2.48 mg/L）之间;反射率的峰值出现在560～590 nm;红光波段与绿光波段反射率的对数值能较好的估计DOC浓度,其中又以lg(R670/R530)与lg(DOC)相关程度最高,决定系数为0.82;DOC浓度反演的经验模型为：lg(DOC)=0.654(±0.012)lg\[R(670)/R(530)\]+1.007(±0.086)。对模型进行检验,最小误差为6.7%、最大误差为20.3%,平均误差为12.3%。     

1991年冬季菲律宾以东海流特征和盐度结构

本文根据１９９１年１１月１５日～１２月２０日中国世界大洋环流实验（简称ＣＷＯＣＥ）首航ＡＤＣＰ测流资料并结合日本气象厅的ＡＣＭ次表层测流资料（１９９２年１月２０日～２月１５日），描述了菲律宾以东的海流特征。同时应用该航次ＣＴＰ资料计算了各观测断面的地转流流量，并用盐度跟踪讨论了北赤道逆流（ＮＥＣＣ）、黑潮和棉兰老海流的水源。计算和分析表明，本航次期间有３个强流区，即黑潮源头区、棉兰老沿岸区和北赤道逆流区。此外，本航次本区海流特征与１９８６／１９８７ＥＮＳＯ事件同期的海流特征基本相同。     

辐射增温效应对水稻叶片温度及光合速率的影响

根据人工气候箱试验资料，分析了水稻叶片温度随环境温度、辐射强度的变化规律及辐射增温效应对单叶光—光合曲线的影响；由直角双曲型光合模型模拟了辐射增温效应对叶片光合特征的影响。结果表明，环境温度低于光合的生理适宜温度时，辐射增温效应将使叶片温度升高，从而有利于光合能力的提高；反之则相反。     

Facular excess radiation and the energy balance of solar active regions

Plage areas and intensities derived from CaII K spectroheliograms are used as a proxy for the facular irradiance excess of solar active regions for the period 19 August to 4 September 1980. Using a calibration method proposed by Vrnak et al. (1991), the photospheric facular index (PFI) with constant facular contrastC _p = 0.018 is replaced by a variableC _p , depending on the plage brightness. A sgnificant increase ofC _p from 0.015 to 0.025 is found for plage areas varying from a few to approx. 6 · 10³ millionths hemispheres.Combining the facular irradiance excess with sunspot deficits (as determined for the same period by Steinegger et al. 1990) yields good aggrement with the irradiance variations measured by ACRIM I, using a center-to-limb variation ofC _p according to Chapman and Meyer (1986). The ratio of facular excess to sunspot deficit (integrated over solid angle 2) decreases from values of 1.5 to 2 for regions with sunspot areas below 100 millionths hemispheres to 0.2 for sunspots of areas > 1000 millionths hemispheres,     

青藏高原晴天太阳直接辐射的计算和分析

本文根据1979年5～8月青藏高原气象科学实验资料,研究了利用卡斯特洛夫公式计算青藏高原晴天太阳直接辐射的有关问题。首先从原始资料中挑选出晴天太阳直接辐射并计算其日平均辐照度,然后以此为标准,利用迭代法反求可能太阳直接辐射日平均辐照度理论公式中的系数C,建立该系数与平均水汽压的经验公式,再利用经验式反演晴天太阳直接辐射。本文还比较了由乌克兰英采夫法确定的可能太阳直接辐射与实际晴天太阳直接辐射的差异,证实前者要比后者偏大,其偏离程度随站点拔海高度增加而缩小。文中最后讨论了青藏高原晴天太阳直接辐射日平均辐照度的地理分布,并分析了其随拔海高度的变化。     

香河地区冬季NO2光解速率的变化特征及其估算方法的建立

NO₂的光解速率j(NO₂)是对流层化学研究中的一个重要的参数，它是对流层臭氧（O₃）和OH自由基的形成关键影响因子之一。本文利用香河站2017年11月至2018年1月的观测资料对NO₂的光解速率j(NO₂)、太阳辐射的变化特征，及光解速率与分波段辐射相关性进行分析，在此基础上建立了一套适合于构建香河地区j(NO₂)的参数化方案。结果表明，香河地区的j(NO₂)与太阳辐射的变化趋势基本一致，日变化均呈正午高、早晚低的单峰型。香河地区冬季j(NO₂)的变化范围是0.00046～0.0044 s-1，平均值为0.0029 s-1。j(NO₂)与晴空指数（K_S）和定义的紫外辐射晴空指数（K_UV）存在很好的相关性，因此，利用j(NO₂)与大气质量数和晴空指数的相互依赖关系，基于K_UV构建了适合于香河地区j(NO₂) 的估算方程。由于总辐射是气象站的常规观测要素，晴空指数K_S更容易获取，继而建立了通过K_S参数化计算j(NO₂)的估算方程。利用K_UV和K_S建立的j(NO₂)估算方程的瞬时估算值与观测值的平均相对误差分别为6.5%和13.9%，均方根误差分别为0.00029和0.00051。