一条具有宽阔尾随层状云区的中纬度飑线的中尺度结构

1985年6月11日,一条具有宽阔的尾随层状云区的强飑线经过美国堪萨斯—俄克拉荷马州的PRE-STORM中尺度网。本文应用由14个探空站得到的53个探空资料,对这条飑线在成熟价段和消亡阶展的运动学和热力学结构分别作了合成分析。分析表明,飑线系统有稳定的中尺度环流,一股由前向后的入流及一股由后向前的入流构成了环流框架。在对流区,高层辐散、低层辐合,整层上升。在层状云区,中层福合,高、低层分别为上升和下沉运动。雷达次级强回波区与层状云区高层的上升运动区相对应。在层状云区中低层有一气旋性涡旋。     

C_N~2剖面的声雷达探测与直接测量

本文简要叙述了C_N~2的声雷达探测方法和直接测量的计算方法,给出在稳定和不稳定条件下用单点声雷达推得C_(N,a)~2剖面。 在80和140米两个高度的C_(N,a)~2与C_(N,d)~2进行比较,结果指出,C_(N,a)~2/C_(N,d)~2的比值与声折射率谱的斜率差异有关.最后还对谱形及其对C_(N,a)~2/C_(N,d)~2比值的影响作了初步讨论.     

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, we report on the first year-round observations available for any site in Taylor Valley. This dataset augments the year-round data obtained at Lake Vanda (Wright Valley) by winter-over crews during the late 1960s and early 1970s. The mean annual solar flux at Lake Hoare was 92 W m-2 during 1986, the mean air temperature -17.3 degrees C, and the mean 3-m wind speed 3.3 m s-1. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year. Temperature increases of 20 degrees-30 degrees C are frequently observed during the winter due to strong f?hn winds descending from the Polar Plateau. A model incorporating nonsteady molecular diffusion into Kolmogorov-scale eddies in the interfacial layer and similarity-theory flux-profiles in the surface sublayer, is used to determine the rate of ice sublimation from the acquired meteorological data. Despite the frequent occurrence of strong winter f?hns, the bulk of the annual ablation occurs during the summer due to elevated temperatures and persistent moderate winds. The annual ablation from Lake Hoare is estimated to have been 35.0 +/- 6.3 cm for 1986.