New estimates of tropical mean temperature trend profiles from zonal mean historical radiosonde and pilot balloon wind shear observations

Autor(en)
Lorenzo Ramella Pralungo, Leopold Haimberger
Abstrakt

Estimation of global scale trends and low-frequency variability directly from radiosonde temperature records is challenging particularly in the Tropics due to large biases in the earlier parts of the records that need to be adjusted. Zonal mean zonal winds and wind shear observations are less prone to time varying biases. Together with a zonal mean reference temperature trend profile in the extratropics, the wind data can be used to estimate zonal mean temperature trends in the tropics using the thermal wind relationship. Earlier estimates using this approach for the periods 1970-2005 and 1979-2005 showed strong trend amplification in the tropical upper troposphere but also very large uncertainties because the latitude for the reference profile was chosen very far north and due to a lack of data in the tropics. Both sources of uncertainties have been addressed by (i) using reference temperature profiles from homogenized radiosonde temperature data sets, (ii) using the new Global historical Radiosondes and Tracked Balloons Archive on standard pressure levels (GRASP) as data source that includes not only radiosondes but also pilot balloons, and (iii) more accurate vertical discretization and sampling of wind data. The new trend estimates are extended back to 1958 and are considerably less noisy. Trend amplification factors between 1.3 and 2.6 were found in the intervals 1979-2005 and 1958-2010, respectively, when using wind shear information. The best estimates for the warming maxima in the upper tropical troposphere agree well with those directly from temperatures but tend to be located at higher altitudes.

Organisation(en)
Institut für Meteorologie und Geophysik
Journal
Journal of Geophysical Research: Atmospheres
Band
120
Seiten
3700-3713
Anzahl der Seiten
14
ISSN
2169-897X
DOI
https://doi.org/10.1002/2014JD022664
Publikationsdatum
2015
Peer-reviewed
Ja
ÖFOS 2012
105205 Klimawandel, 105201 Aeronomie, 105206 Meteorologie
ASJC Scopus Sachgebiete
Forestry, Aquatic Science, Soil Science, Water Science and Technology, Earth-Surface Processes, Geochemistry and Petrology, Geophysics, Oceanography, Palaeontology, Ecology, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), Atmospheric Science
Sustainable Development Goals
SDG 13 – Maßnahmen zum Klimaschutz
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/new-estimates-of-tropical-mean-temperature-trend-profiles-from-zonal-mean-historical-radiosonde-and-pilot-balloon-wind-shear-observations(df34733d-780f-4e91-94a1-66e8e74a4d01).html