Spatial–Temporal Distribution of Tropospheric Specific Humidity in the Arid Region of Northwest China

Based on the atmospheric temperature and dew point difference series of mandatory levels in arid region northwest China, we calculated specific humidity stations at 200, 300, 400, 500, 700, 850 hPa analyzed spatial temporal distribution. The radiosonde is compared with two sets reanalysis data (ERA-interim from European Centre for Medium Range Weather Forecasts Modern Era Retrospective Analysis Research Applications: MERRA-2). annual summer show a positive trend vertical during period 1958–2018. Taking middle 1980s 2002 as boundaries, selected “declining-gentle rising-fluctuation rising”. maximum observed level 850–700 warm months year, most expansion July. In terms distribution, greatly influenced by topography underlying surface lower levels. characteristics distribution are well described upper levels, but there some deficiencies depicting