Leontiev Anton, Reuveni Yuval
Department of Electrical Engineering, Ariel University, Ariel, Israel.
Department of Physics, Ariel University, Ariel, Israel.
Sci Rep. 2018 Oct 3;8(1):14785. doi: 10.1038/s41598-018-33163-x.
Water vapor (WV) is the most variable greenhouse gas in the troposphere, therefore investigation of its spatio-temporal distribution and motion is of great importance in meteorology and climatology studies. Here, we suggest a new strategy for augmenting integrated water vapor (IWV) estimations using both remote sensing satellites and global positioning system (GPS) tropospheric path delays. The strategy is based first on the ability to estimate METEOSAT-10 7.3 µm WV pixel values by extracting the mathematical dependency between the IWV amount calculated from GPS zenith wet delays (ZWD) and the METEOSAT-10 data. We then use the surface temperature differences between ground station measurements and METEOSAT-10 10.8 µm infra-red (IR) channel to identify spatio-temporal cloud distribution structures. As a last stage, the identified cloud features are mapped into the GPS-IWV distribution map when preforming the interpolation between adjusted GPS station inside the network. The suggested approach improves the accuracy of estimated regional IWV maps, in comparison with radiosonde data, thus enables to obtain the total water amount at the atmosphere, both in the form of clouds and vapor. Mean and root mean square (RMS) difference between the GPS-IWV estimations, using the spatio-temporal clouds distribution, and radiosonde data are reduced from 1.77 and 2.81 kg/m to 0.74 and 2.04 kg/m, respectively. Furthermore, by improving the accuracy of the estimated regional IWV maps distribution it is possible to increase the accuracy of regional Numerical Weather Prediction (NWP) platforms.
水汽(WV)是对流层中变化最大的温室气体,因此研究其时空分布和运动在气象学和气候学研究中具有重要意义。在此,我们提出一种新策略,利用遥感卫星和全球定位系统(GPS)对流层路径延迟来增强综合水汽(IWV)估计。该策略首先基于通过提取由GPS天顶湿延迟(ZWD)计算得到的IWV量与METEOSAT - 10数据之间的数学相关性来估计METEOSAT - 10 7.3μm水汽像素值的能力。然后,我们利用地面站测量值与METEOSAT - 10 10.8μm红外(IR)通道之间的地表温度差异来识别时空云分布结构。在最后阶段,在对网络内调整后的GPS站进行插值时,将识别出的云特征映射到GPS - IWV分布图中。与探空仪数据相比,所提出的方法提高了估计区域IWV图的精度,从而能够获取大气中以云和气态形式存在的总水量。利用时空云分布的GPS - IWV估计值与探空仪数据之间的平均差异和均方根(RMS)差异分别从1.77和2.81 kg/m²降至0.74和2.04 kg/m²。此外,通过提高估计区域IWV图分布的精度,有可能提高区域数值天气预报(NWP)平台的精度。