我国中高层大气观测研究的新进展

中高层大气是与人类生存环境关系极为密切、又易受太阳活动影响的层次，它的研究在日地物理研究中占有特殊的地位．近年来，我国在中高层大气行星波、重力波、光化过程和太阳活动与人类活动影响等方面取得了可喜的进展，获得一系列重要成果；在观测方面，VHF雷达、钠荧光激光雷达、中间层大气毫米波探测和倾斜滤光片光度计等一批新型观测设备投入使用，增强了对中高层大气的探测能力.本文重点介绍了近年来我国在高平流层、中间层和低热层大气方面的主要研究情况．     

热幔柱构造与地核热能

地核内部的压力和温度比以前人们的设想高得多。地核加热部分下地幔使之在地幔中升起形成热幔柱。有些热幔柱穿岩石圈在地表形成热点，其余热幔柱消溶在上地幔形成热室。这是上地幔在结构和温度上不均匀的原因，也是激发控制全球变化的头等重要因素。     

临震大气增温异常成因的初步认识

通过模拟对比试验，基本搞清了临震低空大气-地面增温异常的成因．初步认为，大气静电异常对大气的极化作用，是大气在太阳辐射下产生大面积、大幅度增温异常的主要因素；异常大气的增温效应也是其原因之一．      

地球物理场观测中的大气效应问题研究

作用在地表的大气质量不仅产生引力位的扰动，而且会引起各种地球物理场的附加效应，本文综述了近年来国内外同行在研究地表位移、重力、倾斜和应变固体潮观测中实施的大气效应改正问题，包括利用台站气压资料建立的实测模型，建立大气重力格林函数，利用全球和区域气象数据计算大气效应，建立大气改正的误差模型等，最后文章讨论了今后研究展望。     

我国干旱区深厚大气边界层与陆面热力过程的关系研究

大气边界层是地球大气重要物理特征之一.干旱气候背景下的大气边界层特征与人们以往对典型大气边界层的认识有很大不同,其形成机制也比较特殊.本文利用冬、夏两季典型时段在极端干旱区敦煌开展的大气边界层和陆面过程综合观测试验,对大气边界层厚度与净辐射、地-气温差和感热通量等陆面热力因素的日变化特征进行了对比分析,研究了大气边界层的发展和维持衰退过程与陆面热力和动力过程的关系,发现发展过程消耗的能量要比维持衰退过程高得多,而且进入残余层后对流边界层发展对陆面热力作用更敏感,发展也更迅速.风速的动力作用对大气边界层发展也有一定的影响,尤其对冬季稳定大气边界层影响较大.极强的陆面热力作用是我国干旱区形成深厚大气边界层的主导因素.     

北京首都机场的人工消雾及大气边界层特征的演变

在首都机场人工消雾作业过程中进行了大气边界层特征的观测,观测结果表明：用喷洒液氮进行人工消雾可以形成小面积降雪从而提高能见度,达到安全飞行的目的．人工消雾作业过程可影响小面积大气湍流特征,使湍流谱略偏离-5／3规律．人工消雾作业期间潜热通量明显大于作业期后．     

对高层大气模式的研究

本文根据最近关于大气热力学参数的知識,討論了現代大气結构的模式。用基本靜力学方程由上向下进行数值积分的方法,由大气密度的卫星观测资料計算了热大气层中的分子溫度随高度的分布。从大气分子溫度的誤差估算表明,积分根本不能由下而上进行,相反地,由上而下的数值积分法可以大大減小計算誤差。用由下而上的逐层逼近法,根据大气密度的卫星观測资料,計算了大气动力溫度随高度的分布,在这种运算中,并未对在热大气层中溫度随高度的垂直分布趋向做任何約束性的假定,只假設在120公里以上,大气处于扩散平衡状态,同时在小高度区間△z內,溫度和高度的关系是线性的。計算結果証明,在热大气层中并未出現等溫区,溫度随高度的加大有上升的趋势。     

海洋和大气对Chandler摆动激发的贡献

用1985～1995年期间海洋角动量变化序列和大气角动量变化序列,分析它们对Chandler摆动的激发能量以及它们与天文观测激发的相干性. 结果表明，在Chandler摆动频带内，海洋角动量变化提供的激发能量大约占观测激发的64髎，其中洋底压力变化起主导作用；NCEP/NCAR(美国国家环境预测中心/国家大气研究中心)和JMA(日本气象厅)大气角动量变化提供的激发能量分别为观测激发的23髎和214髎. 海洋激发与观测激发的相干系数约为0.52，接近99髎置信度下限(0.54)，海洋激发的相位滞后观测激发约19°；NCEP/NCAR和JMA的大气激发与观测激发的相干系数分别为0.32和0.37，大气激发的相位超前观测激发分别约47°和19°. 用更短期间(9年、6年)的海洋和大气角动量序列与更长期间(16、39年)的大气角动量序列作分析表明，在Chandler摆动频带内，无论是它们的激发能量，还是它们与观测激发之间的相干系数都呈现很大的变化，而且这些变化具有某种程度的随机性.     

平流层爆发性增温期间中高层大气行星波研究进展

极区平流层爆发性增温（SSW）是冬季半球最剧烈的大气扰动现象之一. SSW期间温度和风场的剧烈变化被认为是冬季半球中高层大气波动能量异常增强的主要原因.流星雷达是能够稳定连续探测中间层和低热层风场的重要地基探测设备.主要依托国家重大科技基础设施建设项目：“子午工程”,我国已建设了多个流星雷达观测台站,对中间层和低热层风场进行了长期稳定连续的监测,为揭示SSW期间中间层和低热层波动异常变化的物理机制提供了重要的观测资料.本文简述了近年来以我国“子午工程”流星雷达监测数据为核心,SSW期间中高层大气行星波的研究进展和成果;深入讨论了冬季半球中高层大气行星波发生异常变化的主要激发机制.随着“子午工程”二期十个流星雷达台站即将建成,本文对利用“子午工程”流星雷达监测台网进一步研究SSW期间中高层大气波动的变化特性进行了展望.     

大气吸引子的存在性

研究了无穷维Hilbert空间中,非定常外源强迫下大尺度大气方程组解的全局渐近行为.从算子的特性出发,给出能量不等式及解的唯一性定理.在外源强迫有界的假定下,证明了全局吸收集及大气吸引子的存在性,揭示出系统具有初始场作用衰减和向外源强迫适应的特征,并对结论的物理意义及由结论所引发的关于气候数值预报的几个想法进行了阐述.     

江淮地区旱涝灾害年份的水分气候研究

选取江淮地区夏季出现大面积洪涝年份（１９８０，１９９１年）与大面积干旱年份（１９７８，１９８５年），利用我国１２６个探空站每日两次的探空资料及江淮地区气象站的观测资料，计算了从地面到高空１００ｈＰａ共１１层的逐层和整层大气的水汽输送方向、水汽输送量和水汽通量散度，探讨了大气中的水分传输特征；同时计算了江淮地区地面的降水量、蒸发量和地面余水量，分析了地面的水分收支和水分盈亏。从而较全面地揭示了江淮地区干旱和洪涝灾害年份水分气候的特征与差异，对江淮地区旱涝灾害的致灾因子和成灾规律进行了物理分析。     

SPATIAL AND SEASONAL VARIABILITY IN THE COMPONENTS OF THE RIVER HEAT BUDGET

Detailed hydrometeorological measurements have been used to establish the components of the river heat budget for 495 days covering 18 study periods and 11 study reaches in the Exe Basin, Devon, UK. Averaging the results across the whole data-set indicates that net radiation, friction, sensible heat transfer, condensation and bed conduction contributed 56.0, 22.2, 13.2, 5.8 and 2.8%, respectively, to the non-advective energy gains, whereas net radiation, evaporation, sensible heat exchange and bed conduction accounted for 48.6, 30.4, 10.6 and 10.4%, respectively, of the non-advective heat losses. Precipitation falling on the river channel had little impact on the river heat budgets, but energy advected in groundwater accounted for an average 5% of the heat storage in the river. The magnitude and importance of the river heat budget components were found to be variable in space and time. The influence of channel morphology, valley topography, riparian vegetation, substratum nature and hydrological conditions, especially the effects of river regulation, promoted inter-reach variability in the make up of the heat budget and caused significant differences in energy fluxes at a local scale. Heat budget components also exhibited considerable differences between seasons and varied from day to day for individual reaches. © 1997 by John Wiley & Sons, Ltd.     

The effects of floods on the temperature of riparian groundwater

The transition area between rivers and their adjacent riparian aquifers, which may comprise the hyporheic zone, hosts important biochemical reactions, which control water quality. The rates of these reactions and metabolic processes are temperature dependent. Yet the thermal dynamics of riparian aquifers, especially during flooding and dynamic groundwater flow conditions, has seldom been studied. Thus, we investigated heat transport in riparian aquifers during 3 flood events of different magnitudes at 2 sites along the same river. River and riparian aquifer temperature and water‐level data along the Lower Colorado River in Central Texas, USA, were monitored across 2‐dimensional vertical sections perpendicular to the bank. At the downstream site, preflood temperature penetration distance into the bank suggested that advective heat transport from lateral hyporheic exchange of river water into the riparian aquifer was occurring during relatively steady low‐flow river conditions. Although a small (20‐cm stage increase) dam‐controlled flood pulse had no observable influence on groundwater temperature, larger floods (40‐cm and >3‐m stage increases) caused lateral movement of distinct heat plumes away from the river during flood stage, which then retreated back towards the river after flood recession. These plumes result from advective heat transport caused by flood waters being forced into the riparian aquifer. These flood‐induced temperature responses were controlled by the size of the flood, river water temperature during the flood, and local factors at the study sites, such as topography and local ambient water table configuration. For the intermediate and large floods, the thermal disturbance in the riparian aquifer lasted days after flood waters receded. Large floods therefore have impacts on the temperature regime of riparian aquifers lasting long beyond the flood's timescale. These persistent thermal disturbances may have a significant impact on biochemical reaction rates, nutrient cycling, and ecological niches in the river corridor.     

OPTIMUM CHANNEL GEOMETRY AND MINIMUM ENERGY DISSIPATION RATE

1. INTRODUCTIONA natural river adjusts its roughness, channel geometry, slope I length, and Pattern to changing hydrologic, geologic, and manmade conditions. However, some sort of mean condition or quasi-equilibriumcondition appears to exist for natural streams. The earliest attempts to describe the quasi--equlibrium geometry of rivers were the empirical approaches, such as the regime approach proposed by Lacey (1929) andLeoPOld et al. (1953 ). Later, theoretical approaches based on the…     

中国大陆地区热流数据的分布及其初步分析

本文首次系统地收集整理了观测资料比较齐全、国内公开发表的热流数据167个,并对之进行了初步分析。这些数据的地理分布还很不均匀,热流值变化范围为25—245mWm-2,多种平均方法得到的结果表明,中国大陆区域代表性热流值范围为61—68mWm-2。作者所作的经纬度网格和条带统计还揭示,数据覆盖区内热流沿经、纬向的分布有明显的差异,纬向条带平均热流值看来具有波状起伏变化的规律。这一结果已经得到日本及其周围海域热流数据的初步印证,如果获得更广泛的证实,无疑具有深刻的地质和地球物理意义     

我国大陆地区大地热流与地壳厚度的变化

本文从我国大陆地区现有的热流观测和深部地球物理资料出发,对1°×1°网格平均热流值（q）与地壳厚度值（M）进行回归分析.结果表明,中国大陆地区作为一个整体,q-M之间存在良好的正相关关系;在111°E以东地区特别是在华北盆地,两者呈显著负相关关系.按地壳厚度分组和按热流值分组的统计结果具有相似的特征,在所有“一分为二”（即只分成小于和大于等于某一指定值）的分组系列中,高值范围的算例都呈显著正相关,回归直线斜率在0.4-2.8mW/（m²·km）的范围内,与国内外报道的地表岩石生热率值一致;而低值范围的算例均给不出清晰的相关关系.作者认为,上述统计结果是地壳岩石放射性生热贡献和来自深部的地幔热流在大地热流二元结构中所起的作用在不同情况下有所不同的体现.     

不可忽视的汶川大震前奇热奇旱奇涝特异背景剖析

通过对汶川大震前的21个月和10个月,在川渝地区出现的较长期高温热浪,严重干旱和暴洪（简称奇热奇旱奇涝“三奇”）并使下垫面生态气象出现奇差等大气物理现象的空前异常的分析,发现汶川大震恰处“三奇”中心西部边缘,大震发生在“三奇”后21个月和10个月。在此基础上探讨了他们之间的物理机制,并提出孕震地球物理过程和“三奇”大气物理过程可能存在某种“能”和“力”的交织影响假设。     

A TEST OF THE RADIATIVE ENERGY BALANCE OF THE SHAW MODEL FOR SNOWCOVER

Snow and ice present interesting challenges to hydrologists. Simulating the radiative balance over snow, which is an important part of surface–atmosphere interactions, is particularly challenging because of the decay in albedo over time and the difficulty in estimating surface temperature and incoming long-wave radiation fluxes. Few models are available that include a comprehensive energy and water balance for cold season conditions. The simultaneous heat and water model (SHAW) is a detailed, physical process model of a vertical, one-dimensional canopy–snow–residue–soil system which integrates the detailed physics of heat and water transfer through a plant canopy, snow, residue and soil into one simultaneous solution. Detailed provisions for metamorphosis of the snowpack are included. The SHAW model was applied to data for one winter/spring season (November to May) on a ploughed field in Minnesota without prior calibration to test the performance of the radiation components. Maximum snow depth during this period was 30 cm. For the nearly 100 days of snowcover, the model accounted for 69% of the variation in net solar radiation, 66% of the variation in incoming long-wave radiation, 87% of the variation in emitted long-wave radiation, 26% of the variation in net long-wave radiation and 55% of the variation in net radiation balance. Mean absolute error in simulated values ranged from 10 W m⁻² for emitted long-wave radiation to 27 W m⁻² for the entire net radiation balance. Mean bias error ranged from 8 W m⁻² for emitted long-wave radiation to −16 W m⁻² for the entire net radiation balance. When the entire 170 days of simulation, which included periods without snowcover, were included in the analysis, the variation in observed values increased greatly. As a result, the variation in observed values accounted for by the model increased to 97, 71, 93, 56 and 94%, respectively, while the mean absolute and mean bias errors in simulated values remained nearly the same. Model modifications and parameter adjustments necessary to improve winter-time simulation were investigated. Simulation results suggest that the SHAW model may be a useful tool in simulating the interactive influences of radiative transfer at the surface–atmosphere interface.     

A preliminary study on the heat storage fluxes of a tropical seasonal rain forest in Xishuangbanna

In order to discuss the values and daily variation characteristics of heat storage fluxes in a tropical seasonal rain forest in Xishuangbanna, the sensible and latent heat storage flux within air column, canopy heat storage flux, energy storage by photosynthesis and ground heat storage above the soil heat flux plate, as well as the ratios of these heat storage fluxes to the net radiation in the cool-dry, hot-dry and rainy season were compared and analyzed based on the observation data of carbon fluxes, meteorological factors and biomass within this tropical seasonal rain forest from January 2003 to December 2004. The findings showed that heat storage terms ranged significantly in the daytime and weakly in the nighttime, and the absolute values of sensible and latent heat storage fluxes were obviously greater than other heat storage terms in all seasons. In addition, the absolute values of total heat storage fluxes reached the peak in the hot-dry season, then were higher in the rainy season, and reached the minimum in the cool-dry season. The ratios of heat storage fluxes to net radiation generally decreased with time in the daytime, moreover, the sensible and latent heat storage dominated a considerable fraction of net radiation, while other heat storage contents occupied a smaller fraction of the net radiation and the peak value was not above 3.5%. In the daytime, the ratios of the total heat storage to net radiation were greater and differences in these ratios were distinct among seasons before 12:00, and then they became lower and differences were small among seasons after 12:00. The energy closure was improved when the storage terms were considered in the energy balance, which indicated that heat storage terms should not been neglected. The energy closure of tropical seasonal rain forest was not very well due to effects of many factors. The results would help us to further understand energy transfer and mass exchange between tropical forest and atmosphere. Moreover, they would supply a research basis for studying energy closure at other places.     

磁层系统的能量输入、输出与日地耦合

用１９７８年和１９８２年３６个磁暴期间的太阳风、行星际磁场（ＩＭＦ）和地磁资料，分析和检验已有的两类太阳风－磁层能量耦合函数．结果表明：Ａｋａｓｏｆｕ提出的耦合函数ε能大致地预报亚暴和磁暴的发生。ε开始起重要作用时即出现亚暴；电离层能耗达到饱和值是发生磁暴的标志。ε与磁层体系能耗之间有接近于对数量的线性关系．用１９７８－１９８６年的资料，分析环电流和极光区电离层能耗在１２１个太阳自转周内的分布表明，日面上可能存在相对持久的活动区域