A historical monthly upper-air humidity dataset for Australia

Monthly humidity (represented as dew point temperature, DWPT) data from 22 land and 5 island Australian upper-air sites were analysed, with trends estimated over the 1965–2017 period at four pressure levels. Humidity selected to ensure that collected under consistent sampling conditions used (‘modified data’). The quality control process involved examining station metadata applying an objective statistical test detected discontinuities in series. At each level, modified series adjusted (homogenised) on a monthly timescale when identified. Analysis of homogenised (adjusted) DWPT indicates that, period, linear are mostly positive smaller compared unadjusted data. all-Australian time-series show 850–400-hPa total increases since 1965 850-, 700-, 500- 400-hPa levels ~0.5, ~1.2, ~1.3 ~0.8°C respectively. increase lower middle troposphere is accordance expectation warms, amount moisture it should (at differential rate ~7%°C–1 low altitudes globally, following Clausius–Clapeyron scaling) due increasing surface evaporation moisture-holding capacity air. However, changes atmospheric dynamics also influence magnitude distribution trends. radiosonde for 850-hPa level this increased ~8.8%°C–1 during 1965–2015