高原航线飞机颠簸出现规律的对比分析——以青藏高原与云贵高原为例

不同的高原产生大气湍流的条件不尽相同,因此航线上飞机颠簸的出现规律也不一样。分析青藏高原和云贵高原的地形差异和气候区别,并根据四川航空公司的机载QAR数据,对青藏高原和云贵高原的飞机颠簸出现次数、出现概率和颠簸强度进行统计,对比分析了青藏高原和云贵高原航线上飞机颠簸的出现和分布规律,为高原航线飞机颠簸的预报和航行签派工作提供重要参考。     

Soil moisture mapping over the Chinese Loess Plateau using ENVISAT/ASAR data

In this paper, we used the available algorithm for soil moisture estimation over LOPEX05 (the Loess Plateau land surface process Experiment (2005)) area. The available algorithm used ENVISAT/ASAR AP mode VV polarization observational data at a low incidence angle and ground measured soil moistures. The ground measurements were performed in the summer of the 2005 during the LOPEX05 field campaign. The validated results indicate that an average difference between the soil moistures estimated from the microwave remote sensing and ground measurements is less than 0.02 cm³/cm³, with a RMS error of 2.0%, and a maximum less than 0.04 cm³/cm³. The algorithm was applied to the surface soil moisture mapping later. The results show that this algorithm is suitable for monitoring soil moisture information of the agricultural fields over the Chinese Loess Plateau, when ground land cover situation and the resolution of imagery data are taken into account. However, we also find that there are large differences over the steep slope region, the edge of mesa. The results are not acceptable for surface soil moisture estimation in these regions. Thus, the surface soil moisture retrieval in the steep slope region of the Loess Plateau need to be further investigated in the future.     

Interseismic slip rate of the Garze–Yushu fault belt in the Tibetan Plateau from C-band InSAR observations between 2003 and 2010

InSAR time series techniques can provide high-spatial resolution deformation fields across an active fault belt, even for zones with heavy vegetation coverage. An interseismic deformation map across the Garze–Yushu fault belt in the Tibetan Plateau, ∼300 km by ∼100 km, is derived from C-band Envisat/ASAR imagery collected between 2003 and 2010. Unlike previous research, we obtain a lookup figure which relates the slip rate with the fault locking depth, the dip angle and the rake angle. The estimated slip rate changes significantly with the locking depth and the rake angle, but relatively little with the dip angle. When considering the focal mechanism solutions of historical earthquake along the Garze–Yushu fault, the interseismic slip rate of the Garze–Yushu fault is close to a value of 6.4 mm/yr, which is between the highest (18.2 mm/yr) and the lowest (3.1 mm/yr) slip rate from GPS estimations, but slightly less than the minimum value (∼ 7 mm/yr) from the geological estimations. The earthquake recurrence interval on the Yushu part of Garze–Yushu fault equals 272 yr, and the April 14, 2010 Mw 6.9 earthquake has not completely released the accumulated strain energy between 1738 and 2010.     

GFS数值产品对高原机场地面阵性大风的预报检验

利用全球预报系统GFS(Global Forecast System)数值预报资料对2012年11月21日西南地区高原机场一次地面阵性大风天气过程进行预报和分析。对比预报和实况,结果表明:GFS数值预报产品对云南地区高原机场的阵风发生区域、影响时段和持续时间有较好的预报效果;对藏区的拉萨和康定机场强阵风发生情况也有一定的预报效果;但对阵风的极大值有着不同程度的误差。     

Preliminary study on migration pattern of the Tibetan antelope (Pantholops hodgsonii) based on satellite tracking

The spatial and temporal patterns of the endangered Tibetan antelope or chiru (Pantholops hodgsonii) have been studied using satellite-based ARGOS platform transmitter terminal (PTT) tracking data. The data was obtained from the satellite tracking of two female Tibetan antelopes that were collared with satellite transmitters and have been tracked from August 2007 to April 2009.     

藏传密宗对死亡的认知

中国传统文化中对死亡的讨论很少,在雪域高原的宗教里,死亡却是一种艺术,一种通过死而认知生的艺术。在这一生一死间,对生命的珍惜、敬重感油然而出。从藏传密宗上师密勒日巴尊者的入灭启示,影响西藏宗教很深的"中阴"密法及其意义等方面论述,以期更多地了解雪域高原的这种死亡艺术。     

浅议邦达至拉萨航线的放行工作

高原机场由于其特殊的地理环境导致了特殊的恶劣的气象环境,使得航空公司对此类航线的运行控制难度很大。本文通过对邦达-拉萨航线上天气、跑道道面、航行通告等方面的分析,阐述邦达-拉萨这条特殊的高原-高原航线的运行特点和运行控制的难点。     

北京地区重力波活动及其波谱的季节分布特性研究

利用激光雷达对北京地区上空Na层进行持续观测,通过连续三年累积的夜间观测数据对北京地区重力波活动及其波谱进行研究.根据重力波的线性理论计算,得到北京地区上空的大气密度扰动规律、空间功率谱和时间频率谱.通过选择重力波波长在1~8 km,具有特定波长以及特定周期为60,45,25 min的重力波活动辅助研究重力波的季节变化规律,结果表明北京地区重力波大气密度扰动具有夏季大、冬季小的活动规律.结合波源与背景风场的季节性变化规律,分析得出北京上空重力波活动季节性变化的主要原因为青藏高原地形和对流因素与我国北方地区季节性背景风场共同作用的结果.     

Evaluation and utilization of CloudSat and CALIPSO data to analyze the impact of dust aerosol on the microphysical properties of cirrus over the Tibetan Plateau

The present study elucidates on the evaluation of two versions (V3 and V4.10) of vertical feature mask (VFM) and aerosol sub-types data derived from the Cloud-Aerosol LiDAR and Infrared Pathfinder Satellite Observations (CALIPSO), and its utilization to analyze the impact of dust aerosol on the microphysical properties of cirrus over the Tibetan Plateau (TP). In conjunction to the CALIPSO, we have also used the CloudSat data to study the same during the summer season for the years 2007–2010 over the study area 25–40°N and 75–100°E. Compared to V3 of CALIPSO, V4.10 was found to have undergone substantial changes in the code, algorithm, and data products. Intercomparison of both versions of data products in the selected grid between 30–31°N and 83–84°E within the study area during 2007–2017 revealed that the VFM and aerosol sub-types are in good agreement of ～95.27% and ～82.80%, respectively. Dusty cirrus is defined as the clouds mixed with dust aerosols or existing in dust aerosol conditions, while the pure cirrus is that in a dust-free environment. The obtained results illustrated that the various microphysical properties of cirrus, namely ice water content (IWC), ice water path (IWP), ice distribution width (IDW), ice effective radius (IER), and ice number concentration (INC) noticed a decrease of 17%, 18%, 4%, 19%, and 10%, respectively due to the existence of dust aerosol, consistent with the classical “Twomey effect” for liquid clouds. Moreover, the aerosol optical depth (AOD) showed moderate negative correlations between ?0.4 and ?0.6 with the microphysical characteristics of cirrus. As our future studies, in addition to the present work undertaken, we planned to gain knowledge and interested to explore the impact of a variety of aerosols apart from the dust aerosol on the microphysical properties of cirrus in different regions of China.     

我国高原重要航线飞机颠簸分布规律分析

根据2006年1-12月四川航空公司 A320和 A319飞机的机载 QAR数据,对我国高原重要航线上飞机颠簸次数、强度和出现的概率进行了统计,分析了我国高原重要航线上飞机颠簸的出现规律.研究指出,在我国高原航线上,飞机颠簸主要出现在冬春季节,以成都为中心,以九黄、丽江、大理、昆明为弧线的扇形区域,是高原航线飞机颠簸主...