Range of monthly mean hourly land surface air temperature diurnal cycle over high northern latitudes

Aihui Wang, Xubin Zeng

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Daily maximum and minimum temperatures over global land are fundamental climate variables, and their difference represents the diurnal temperature range (DTR). While the differences between the monthly averaged DTR (MDTR) and the range of monthly averaged hourly temperature diurnal cycle (RMDT) are easy to understand qualitatively, their differences have not been quantified over global land areas. Based on our newly developed in situ data (Climatic Research Unit) reanalysis (Modern-Era Retrospective analysis for Research and Applications) merged hourly temperature data from 1979 to 2009, RMDT in January is found to be much smaller than that in July over high northern latitudes, as it is much more affected by the diurnal radiative forcing than by the horizontal advection of temperature. In contrast, MDTR in January is comparable to that in July over high northern latitudes, but it is much larger than January RMDT, as it primarily reflects the movement of lower frequency synoptic weather systems. The area-averaged RMDT trends north of 40°N are near zero in November, December, and January, while the trends of MDTR are negative. These results suggest the need to use both the traditional MDTR and RMDT suggested here in future observational and modeling studies. Furthermore, MDTR and its trend are more sensitive to the starting hour of a 24 h day used in the calculations than those for RMDT, and this factor also needs to be considered in model evaluations using observational data. Key Points Introduce the range of monthly averaged hourly land temperature diurnal cycle It differs substantially from monthly mean diurnal temperature range Their trends also differ significantly in winter over high northern latitudes

Original languageEnglish (US)
Pages (from-to)5836-5844
Number of pages9
JournalJournal of Geophysical Research: Space Physics
Volume119
Issue number10
DOIs
StatePublished - May 27 2014

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land surface
surface temperature
air temperature
cycles
air
Air
temperature
trends
Temperature
radiative forcing
Advection
advection
weather
winter
climate
low frequencies
trend
evaluation
modeling
land

Keywords

  • diurnal temperature range
  • land surface air temperature

ASJC Scopus subject areas

  • Atmospheric Science
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Cite this

Range of monthly mean hourly land surface air temperature diurnal cycle over high northern latitudes. / Wang, Aihui; Zeng, Xubin.

In: Journal of Geophysical Research: Space Physics, Vol. 119, No. 10, 27.05.2014, p. 5836-5844.

Research output: Contribution to journalArticle

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