Analysis Of The Wind Field And Temperature In Near Space Based On Rocket Sounding Data And The Study On Turbopause

Main contents for this study can be separated into three parts,i.e.,the first part is the characteristics of wind field in stratosphere were analyzed based on rocket sounding data;the second part is the statistical characteristics of temperature data detected by sounding rocket were analyzed;the third part is that a new method was come up with to calculate the turbopause altitude and its variation characteristics were presented.Main tasks we have done and the interesting findings are list as follows:(1)About 65 sets of rocket sounding experiments conducted at Jiuquan(41.18 N,100.28E),China,from 1967 to 2004 are presented to study horizontal wind fields in the stratosphere.At a fixed height,wind speed obeys the lognormal distribution.The monthly zonal mean winds have an annual cycle period with large amplitudes at high altitudes.Seasonal mean winds are westerly in winter and easterly in summer.In spring and autumn,zonal wind directions change from the upper to the lower stratosphere.The correlation coefficients for zonal winds between observations and the Horizontal Wind Model(HWM)with all datasets are 0.7.The MERRA reanal ysis is in good agreement with rocketsonde data according to the zonal winds comparison with a coefficient of 0.98.Both the model and the reanalysis show dramatic meridional wind differences with the observation data.The sudden stratospheric warming is an important contribution to biases in the HWM,because it changes the zonal wind direction in the midlatitudes.(2)The data accuracy and variable characteristics of upper atmosphere temperature data,gathered at heights of 20–60 km over Jiuquan,China,during 1974–2014,were analyzed.The relative accuracy of sounding rocket temperature data was determined by comparing the data with Mass Spectrometer and Incoherent Scatter(MSIS)model data by season,and with Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)from the Thermosphere,Ionosphere,Mesosphere Energetics and Dynamics(TIMED)satellite by year.The sounding rocket temperature data showed differences from MSIS in every season,with the minimum difference occurring in summer,the next smallest difference in winter,and the maximum difference occurring in autumn.The sounding rocket data showed smaller differences from the SABER data,although the deviation still fluctuated depending on the date and hour of the observations.In addition,the temperature distributions of the temperature profiles were examined at different times at the same heights.By linearly fitting the mean temperature profiles of each season,the statistical characteristics of the temperature changes with height were explored.(3)Below the turbopause,turbulent dissipation and the atmospheric density have import effect on the increase of atmospheric wave energy as the altitude rises.A new method is come up with to calculate the turbopause altitude based on the influence process of turbulent dissipation.The SABER V2.0 temperature data is used to calculate the atmospheric background temperature and temperature variance.Then the gradient of temperature variance is calculated using a sliding window and the gradi ent curve is obtained.The turbulent dissipation will nearly have no suppression to the increase of atmospheric wave energy at turbopause altitude,the gradient should reach a maximum.Some rules are set to determine the maximum which indicates the turbopause and then the turbopause altitude can be found.The variation of turbopause altitude during 2010-2013 is analyzed and the calculation result based on the new method is compared with the achievements of some predecessors.