海南岛中低纬冷暖系统相互作用下的非台暴雨分析

通过对1993年～2002年共10年的天气资料分析发现,在海南,中纬度的冷空气与低纬度在南海上活动的低压之间的相互作用,是秋季产生非台暴雨的非常重要的环流形势;同时发现,低空急流的存在与暴雨的产生有密切联系。并且对2000年10月13日～15日的暴雨过程利用T106物理量场诊断分析,说明暴雨形成的原因。     

冬春季格陵兰海冰变化与初夏中国气温/降水关系的初步分析

采用英国Hadley中心GISST海冰面积资料，NCEP／NCAR再分析资料以及中国地面降水和气温资料，运用EOF分解，小波分析和合成分析等方法，初步探讨了格陵兰岛两侧附近冬春季海冰面积变化特征及其与初夏6月中国气温和降水的关系，结果表明，格陵兰岛东西两侧海冰面积呈显著反相变化，并且具有明显的年际和年代际周期性振荡，冬春季格陵兰－寻威海海冰与初夏6月中国长江以北气温（降水）正相关（反相关），与长江以南气温（降水）反相关（正相关），而对于戴维斯海峡－拉布拉多海海冰则具有相反的相关型，大尺度500hPa环流合成分析初步表明，冬春季格陵兰附近海冰面积变化伴随着北极极涡环流和北半球阻塞高压的持续异常，海冰变化可能是影响初夏中国气温和降水的因子之一。     

A Case Study Of An On-Ice Air Flow Over The Arctic Marginal Sea-Ice Zone

A case study of warm air advection over the Arctic marginalsea-ice zone is presented, based on aircraft observations with direct flux measurements carriedout in early spring, 1998. A shallow atmospheric boundary layer (ABL) was observed, which wasgradually cooling with distance downwind of the ice edge. This process was mainly connected with astrong stable stratification and downward turbulent heat fluxes of about 10–20 W m^-2, but wasalso due to radiative cooling. Two mesoscale models, one hydrostatic and the other non-hydrostatic,having different turbulence closures, were applied. Despite these fundamental differences betweenthe models, the results of both agreed well with the observed data. Various closure assumptions had amore crucial influence on the results than the differences between the models.Such an assumption was, for example,the parameterization of the surface roughness for momentum (z₀) and heat (z_T). This stronglyaffected the wind and temperature fields not only close to the surface but also within and abovethe temperature inversion layer. The best results were achieved using a formulation for z₀ that took intoaccount the form drag effect of sea-ice ridges together withz_T = 0.1z₀. The stability within theelevated inversion strongly depended on the minimum eddy diffusivity K_min. A simple ad hocparameterization seems applicable, where K_min is calculated as 0.005 timesthe neutral eddy diffusivity. Although the longwave radiative cooling was largest within the ABL, theapplication of a radiation scheme was less important there than above the ABL. This was related to theinteraction of the turbulent and radiative fluxes. To reproduce the strong inversion, it wasnecessary to use vertical and horizontal resolutions higher than those applied in most regional andlarge-scale atmospheric models.     

本世纪昆明气温异常及突变的分析

根据昆明１９２１～１９９３年的年，夏季（６～８月），冬季（１２～２月）平均气温资料，分析研究了昆明的气温变化趋势，冷暖阶段，气温异常发生频率及气温突变点，结果表明：从本世纪２０年代开始，昆明气温呈上升趋势，至４０年代前后达最高，此后下降，７０年代降至最低，８０年代开始略有回升，１９２１～１９５４年为偏暖阶段，１９５５～１９９３年偏冷阶段，昆明高温异常主要出现在１９５０年以前，低温异常大多数出现在１     

水稻低温敏不育系培矮64s“冷灌繁种”适用技术研究

通过对低温敏不育系水稻培矮６４ｓ育性敏感期间冷水灌溉处理后的农田微气象要素和自交结实率的平行观测，分析研究了供试不育系的适宜灌水时段、灌水深度以及灌溉用水量等的“冷灌繁种”适用技术。     

1996年全球重大气候事件概述

１９９６年，全球平均气温低于１９９５年，但从总体上来讲，气候仍比常年偏暖，是８０年代以来连续出现的第１１个暖年。１９９５／１９９６年冬季，中高纬度地区经向环流旺盛，欧洲、北美东部出现异常冷冬，许多地区遇到数十年未见的风雪严寒；前几年的大范围持久干旱已大大减弱或完全解除，高温热浪的强度与范围也明显少于上年。而洪涝却十分频繁，各洲洪水不断，亚洲尤为严重。北大西洋飓风继去年达５０年来最多之后，今年仍十分活跃。这些气候特点，可能与１９９５／１９９６年赤道太平洋大气状况由长达５年之久的暖位相特征转变为冷位相有关。     

培矮64S冷灌繁种技术研究

通过对低温敏核不育系培矮６４Ｓ育性敏感期间冷水处理后温度场分布特征和自交结实率的资料分析，得出培矮６４Ｓ的灌水始期是冷灌后的见穗期往前推１８天，终止期为见穗期往前推３天，灌水深度前１０天为１５ｃｍ，，后５天为２０ｃｍ，，为“冷繁”技术在生产上应用提供了理论依据。     

Roll Vortices and Boundary-Layer Development during a Cold Air Outbreak

The development of the boundary layer during a cold air outbreak in the FramStrait is documented by aircraft measurements. The convection was organisedinto roll vortices with aspect ratios increasing from 2.9 near the ice edgeto more than 6 at 100 km further downstream. This increase coincides with anincrease of the latent heat release in the cloud layer. The stability parameter-zi/L varies from about zero at the ice edge to 30 at a distance of 200 kmdownstream over open water where the satellite picture still shows cloudstreets. The increase is mainly due to the deepening of the boundary layer.The turbulent vertical sensible and latent heat fluxes near the surface amountto 400 W m^-2 within a 300 km off-ice zone. 25% of the upward heat fluxin the subcloud layer is carried out by organised roll motions. Experimentswith a 2-dimensional non-hydrostatic model show a similar roll aspect ratio inthe first 50 km, but further downstream where condensational heating is moreimportant the modelled roll wavelengths are distinctly smaller than the observedones.     

粗糙冷岛宽度与布局对局地气候影响的数值研究

利用一个二维大气模式，研究粗糙冷岛宽度与布局对局地气候的影响问题。结果表明：粗糙冷岛激发的局地环流随其宽度的变化表现出３种流型－单环流型，双上升单下沉型，双环流型。存在４０－５０ｋｍ左右的临界宽度ｄｃ，当粗糙冷岛宽度ｄ〈ｄｃ时，粗糙冷岛激发的局地环流随ｄ的增加而明显增强；而ｄ〉ｄｃ时，局地环流随ｄ的增国变化不大，甚至趋向准定常。     

Assessment of Lichen Vitality During a Transplantation Experiment to a Polluted Site

The present work evaluates the stress effects in two epiphytic lichen species with different thallus morphology, the foliose Parmelia caperata and the fruticose Evernia prunastri, as resulting from transplanting from an unpolluted to an air-polluted area. Lichen samples were collected in Portugal in a clean area, during the spring 2003, and transplanted (1) to the same zone nearby and (2) to a polluted area as affected by an industrial complex. Transplant samples were taken periodically during four months in both places. At the same time lichen samples from the clean-air site native (in-situ) populations were also collected. For each sample were measured the chlorophyll content, the chlorophyll degradation and the cell membrane damage, the latter represented by leacheate conductivity. During the experiment the meteorological conditions were registered. The results indicate the absence of stress effects of transplanting as such, and suggest that leachate conductivity may be the more sensitive indicator of general lichen vitality.