Study Of Stratosphere Gravity Waves Based On Rayleigh Doppler Lidar

The temperature,density and wind field play an important role in atmosphere dynamics,thermodynamics,atmosphere modelling and space weather forecast.The Rayleigh Doppler Lidar system developed by USTC(University of Science and Technology of China),can provide continuous and high-temporal-and-spatial resolution wind,temperature measurements with high accuracy in 15-60km.The system employed double edges technique,by using a three-channel FPI(Fabry-Perot Interferometer)for identifying Doppler shifts and locking center frequency.Between 2013 and 2016,the system obtained more than 100 nights of valid data.Meanwhile,the comparison with radiosonde,MERRA and ECMWF shows satisfied results.In the process of wind retrieval,the broadening of Rayleigh backscatter at different altitudes is dependent on the atmosphere temperature there.This dissertation introduce a detailed method of using the measured atmosphere temperature profiles to calculate the broadening of Rayleigh backscatters and substituting it into the Response functions which are used in the wind retrieving process.Besides,a HSRL temperature measuring method,which use the cavity-tunable FPI to scan the spectrum of atmosphere backscatters,is showed in details.This method has an advantage of not being limited by the existence of aerosols below 30km,compared with the conventional integration method.Gravity waves are one of the most important ways of momentum and energy transporting in the atmosphere.The perturbations of the temperature or density profiles can’t show a whole picture of the characteristics and properties of gravity waves.Simultaneous wind and temperature measurements can show the two variables’ polarization relations of gravity waves.Using the polarization relation of wind components and temperature,the intrinsic frequency,direction of propagation and horizontal wavelengths can be derived from it.We applied 2D Fourier transform and inverse Fourier transform to find the dominant wave patterns and filter the quasi-single mode out from the perturbations.This work demonstrate the ability of the Rayleigh Doppler lidar to study the mesoscale perturbations that are generated by atmosphere gravity waves.CALIPSO is a satellite on the A-train carrying a lidar named CALIOP,which has two polarized receiving channels of 532nm and one non-polarized channel in 1064nm.This lidar has already obtained more than 10 years of global aerosol and clouds data.It has been proved that the subsurface signal of CALIOP can also be used to retrieve parameters and properties of the ocean.At the same time,a multi-layer neuro network is applied to the MODIS retrieving process of water-leaving radiance and aerosol optical depth of the atmosphere,in a base of training data coming from the simulation of a radiation transfer model.At last,wave patterns with a horizontal wavelength of about 1000 and 3000km and period of 4-6 days were found in the AOD map measured by both CALIOP and MODIS.