【作者】 姜朝阳；

【导师】 王天铎；

【作者基本信息】 中国科学院研究生院（上海生命科学研究院） ， 植物学， 2003， 博士

【摘要】 近地层大气与植被间的相互作用紧密联系着农业、气象和自然生态过程。植物通过光合作用形成有机物以建构自身,把光能转化为化学能形成生物量和农作物的产量,又通过蒸腾作用散失水分。植被通过光合作用吸收大气中的CO2并释放氧气到大气中,又通过蒸腾作用与大气环境之间交换水汽、热量,这一过程直接受到诸如太阳辐射、温度、大气湍流等环境因素的影响。植物排放到大气中的水汽等也影响着局地的或全球的气候模式。热量、水汽和物质等的交换与输送被不同形式的传输阻力制约着,通量的时间序列具有非线性、非平稳的特征。本文从谱分析的角度研究陆面通量的时间序列的性质,并探讨利用红外成像观测叶片表面温度的方法估算传输过程中的阻力。一陆面通量与大气稳定度变化的小波分析采用中国科学院地理科学与资源研究所2001 年3 月30 日至4 月24 日对北京顺义5 号干小麦田返青期冬小麦进行涡度相关观测的显热(H)、潜热(LE)、CO2(F-CO2)通量数据,计算得到大气稳定度? (? = z/L)以及反映温度、湿度和CO2 浓度变化的无量纲参数(T/T*、q/q*、c/c*)。本文采用小波变换方法分析这些通量以及大气稳定度和无量纲参数的时间序列,以揭示这些量的变化在数小时到数天的时间尺度上的特征。主要结果有: 1,显热、潜热和CO2 通量、净辐射(Rn)、温度(T)以及大气稳定度(? )数据的连续小波变换把混叠的周期分量分解展开在时间—周期平面上,结果显示,1d 和0.5d 是这些数据所包含的主要周期分量,各量的数据序列都包含丰富的低于0.5d 的短周期分量,大于1d 的长周期分量则彼此不同;2,对连续小波变换系数的统计分析得到小波变换谱,概括了这些量的数据序列所包含的周期分量以及这些周期分量的时间变异性;3,离散多分辨率小波分析把数据序列中的能量方差集中表现为数目较少的小波变换系数,并以相对能量方差分布刻画了这些量所包含的周期分量的平均特征;4,对应于不同的大气条件,更多还原

【Abstract】 The changes in speed of agriculture, meteorological and ecological processes arethe results of the interactions between vegetation and atmosphere. Photosynthesisand transpiration are processes in which heat, water vapor and mass are beingtransported between vegetation and atmosphere. The processes are driven or affectedby meteorological and environmental factors like solar radiation and wind, the ratesof transport of heat, water vapor and CO2 absorbed by plant change the regional orglobal climatic mode. Since the resistance to transport is highly variable, and isaffected by physiological and water conditions in different ways in different parts,the quantitative estimation of it is needed in predicting the rates of photosynthesisand transpiration, and the ratio between them, the water use efficiency. Land surfacefluxes are non-linear and non-stationary stochastic variables. The analysis of thespectral properties of time series of land surface fluxes and the estimation of transferresistance are the main content of this thesis.1. Continuous wavelet transform and discrete multi-resolution analysis of surface fluxes and atmosphericstabilityVariations of land surface fluxes of sensible heat (H), latent heat (LE), and CO2(F-CO2) obtained from the eddy-covariance measurements above a winter wheatfield from March 30 to April 24, 2001 were studied at scales ranging from 10 minutesto days. Atmospheric stability ? (? = z/L) and three non-dimentional coefficients(T/T*, q/q* and c/c*) were also calculated from the eddy covariance measurements.Wavelet transform was used in the analysis of land surface fluxes and atmosphericstability, to reveal the changes in land surface fluxes at hours to days scales. Themain results are: (1) Concise and compact information about the fluxes, net radiation(Rn), temperature (T) and ? in the scale-time domain were extracted from the data bycontinuous wavelet analysis, and 1d, 0.5d and short-period (less than 0.5d)components were revealed. Continuous wavelet coefficients were used tocharacterize periodic components of changes in fluxes and ? . (2) Discrete-timemulti-resolution analysis was used to concentrate total energy variance of time seriesof the measurements to a small number of coefficients, plotting the relative energydistribution to get several meaningful characteristics of the data. (3) Under neutralatmospheric conditions, the relative energy distributions of the Haar multi-resolutionanalysis of the three non-dimensional coefficients (T/T*, q/q* and c/c*) displayedclear similarities.2. The use of infrared thermometry in the estimations ofleaf surface effective wind speed and boundary layerresistance within a maize canopy Infrared thermometric observations of leaf surfaces and measurements ofmicroclimatic variables were made at three heights within a maize canopy every 2hin daytime in summer. Infrared photographs of leaves at different heights in a maizecanopy were taken from which surface temperature distributions over the leaveswere obtained. By reversing the relation between wind speed, boundary layerresistance over leaf surface, and partition of radiation energy into sensible and latentheat obtained in wind tunnel experiments under laminar flow, the vertical更多还原