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Planetary boundary layer energetics simulated from a regional climate model over Europe for present climate and climate change conditions
Author(s) -
Sánchez E.,
Yagüe C.,
Gaertner M. A.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl028340
Subject(s) - energetics , climate model , climatology , environmental science , atmospheric sciences , planetary boundary layer , troposphere , climate change , boundary layer , convection , energy budget , diurnal cycle , meteorology , geology , physics , mechanics , thermodynamics , oceanography
This paper presents a description of the planetary boundary layer (PBL) for current (1960–1990) and future (2070–2100) climate periods as obtained from a regional climate model (RCM) centered on the Mediterranean basin. Vertically integrated turbulent kinetic energy (TKEZ) and boundary layer height ( z i ) are used to describe PBL energetics. Present climate shows a TKEZ annual cycle with a clear summer maximum for southern regions, while northern regions of Europe exhibit a smoother or even a lack of cycle. Future climate conditions exhibit a similar behaviour, with an increase in the summer maximum peaks. A detailed analysis of summer surface climate change energetics over land shows an increased Bowen ratio and decreases in the evaporative fraction. The enhanced sensible heat flux responsible for these results causes an energy surplus inside the PBL, resulting in increased convective activity and corresponding TKEZ. These results are consistent with temperature increases obtained by several other model simulations, and also indicate that changes in the turbulent transport from the PBL to the free troposphere can affect atmospheric circulations.