TITLE:
Meridional Distributions of Historical Zonal Averages and Their Use to Quantify the Global and Spheroidal Mean Near-Surface Temperature of the Terrestrial Atmosphere
AUTHORS:
Gerhard Kramm, Ralph Dlugi, Martina Berger, Nicole Mölders
KEYWORDS:
Global Mean Temperature, Spheroidal Mean Temperature, Climatological Mean Values for the Parallels of Latitude, Zonal Averages, Normal Temperature, Temperature Anomaly, Isothermal Charts, Solar Climate
JOURNAL NAME:
Natural Science,
Vol.12 No.3,
March
11,
2020
ABSTRACT: The zonal averages of temperature (the so-called
normal temperatures) for numerous parallels of latitude published between 1852
and 1913 by Dove, Forbes, Ferrel, Spitaler, Batchelder, Arrhenius, von Bezold,
Hopfner, von Hann, and Börnstein were used to quantify the global (spherical)
and spheroidal mean near-surface temperature of the terrestrial atmosphere.
Only the datasets of Dove and Forbes published in the 1850s provided global
averages below 〈T〉=14°C, mainly due to the poor coverage of the Southern Hemisphere
by observations during that time. The global averages derived from the
distributions of normal temperatures published between 1877 and 1913 ranged
from 〈T〉=14.0°C (Batchelder) to 〈T〉=15.1°C (Ferrel). The differences between
the global and the spheroidal mean near-surface air temperature are marginal.
To examine the uncertainty due to interannual variability and different years
considered in the historic zonal mean temperature distributions, the historical
normal temperatures were perturbed within ±2σ to obtain ensembles of 50
realizations for each dataset. Numerical integrations of the perturbed
distributions indicate uncertainties in the global averages in the range of
±0.3°C to ±0.6°C and depended on the number of available normal temperatures. Compared
to our results, the global mean temperature of 〈T〉=15.0°C published by von Hann
in 1897 and von Bezold in 1901 and 1906 is notably too high, while 〈T〉=14.4°C
published by von Hann in 1908 seems to be more adequate within the range of
uncertainty. The HadCRUT4 record provided 〈T〉≌13.7°C for 1851-1880 and 〈T〉=13.6°C
for 1881-1910. The Berkeley record provided 〈T〉=13.6°C and 〈T〉≌13.5°C for these
periods, respectively. The NASA GISS record yielded 〈T〉=13.6°C for 1881-1910 as
well. These results are notably lower than those based on the historic zonal
means. For 1991-2018, the HadCRUT4, Berkeley, and NASA GISS records provided 〈T〉=14.4°C, 〈T〉=14.5°C, and 〈T〉=14.5°C, respectively. The comparison of the 1991-2018
globally averaged near-surface temperature with those derived from
distributions of zonal temperature averages for numerous parallels of latitude
suggests no change for the past 100 years.