利用地基GPS水汽层析技术对成都平原不同天气背景下的水汽演变特征研究

The water vapor plays a significant role in atmosphere although it is rare in it. It is not only a key factor contributing to global hydrological cycle and heat change, but also a major driving force in meso-and micro-scale disastrous weathers. By comparing with traditional vapor detection methods, ground-based GPS technology has been developed into a novel vapor detection method due to its favorable characteristics including high precision, high temporal and spatial resolution, and all-weather etc., The three-dimensional (3-D) distribution and evolution trend of vapor are the key factors of understanding the weather and climate change. To solve the instability and low precision of the chromatography results of vapor in 3-D using GPS, this research established the horizontal and vertical restraint equations by neural network technology，and using matrix perturbation and numerical analysis to obtain the precise and stable results. Based on the chromatography results, warning and forecasting indicator system was established by qualitative and quantitative analysis of vapor evolution in Chengdu Plain with various weather conditions; moreover, underlying physical mechanisms were illustrated by considering the comprehensive effects of dynamic and heat in the particular topography; Finally, the rotation mode and velocity change of the earth were applied to further revealed the causes of water vapor change and its influencing mechanism on upstream and downstream.

水汽尽管在大气中的含量很少，但是其在大气演变中的作用却十分显著。它不仅是全球水文循环与热量变化的重要因子，也是中小尺度灾害性天气发生发展的主要驱动力。与传统的水汽探测手段相比，地基GPS技术具有高精度、高时空分辨率、全天候等特点，目前已逐渐成为一种新型的水汽探测方法。由于水汽的三维空间分布及演变趋势是深入了解天气气候演变的关键所在，针对当前GPS三维水汽层析过程中存在的精度较低及层析结果不稳定的问题本研究将通过神经网络技术建立水平和垂直约束方程，利用矩阵扰动分析和数值分析的平衡技术获得较为精确稳定的层析结果。在此基础上重点对成都平原各种天气背景下的水汽演变特征进行定性与定量的分析，提出相应的预警预报指标体系，并综合考虑殊地形下涉及的动力和热力作用，阐释水汽变化的内在物理机制，最后通过研究地球转动方式与速度变化同水汽时空变化间存在的相关性，进一步揭示水汽变化的深层次缘由及对上下游的影响机制。

水汽尽管在大气中的含量很少，但是其在大气演变中的作用却十分显著。它不仅是全球水文循环与热量变化的重要因子，也是中小尺度灾害性天气发生发展的主要驱动力。与传统的水汽探测手段相比，地基GPS技术具有高精度、高时空分辨率、全天候等特点，目前已逐渐成为一种新型的水汽探测方法。由于水汽的三维空间分布及演变趋势是深入了解天气气候演变的关键所在，针对当前GPS三维水汽层析过程中存在的精度较低及层析结果不稳定的问题，利用矩阵扰动分析和数值分析的平衡技术获得较为精确稳定的层析结果。在此基础上重点对多种天气背景下的水汽演变特征进行定性与定量的分析，提出相应的预警预报指标体系，并综合考虑殊地形下涉及的动力和热力作用，阐释水汽变化的内在物理机制，最后通过研究大气可降水量与实际降水间存在的相关性，进一步揭示水汽变化的深层次缘由及对降水的影响效应。该研究深化及拓展了GPS资料的气象应用，揭示了大气可降水量与实际降水量之间存在的相互影响机制，为大气水汽变化的预警预报研究提供了必要的科学参考。