Statistics – Applications
Scientific paper
Sep 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009ems..confe.603z&link_type=abstract
"9th EMS Annual Meeting, 9th European Conference on Applications of Meteorology (ECAM) Abstracts, held Sept. 28 - Oct. 2, 2009 i
Statistics
Applications
Scientific paper
A remarkable feature of the ongoing global warming is the asymmetry in trends of the daily minima, ?min, and maxima, ?max, of the surface air temperature (SAT): ?min increases faster than ?max, so that the daily temperature range (DTR), ?max-?min, basically decreases. The state of the art general circulation and climate models (GCMs) do not reproduce it and predict approximately the same change rates for ?min and ?max. We propose that the difference in trends of ?min and ?max is caused by the strong stability dependence of the height, h, of the planetary boundary layer (PBL). Indeed, the daytime warming is associated with deep convective (C) PBLs (with the heights hC ~ 103m), in contrast to the nocturnal and/or wintertime cooling associated with shallower mid-latitudinal nocturnal stable (NS) PBLs (with hNS ~ 200m) and even shallower high-latitudinal long-lived stable (LS) PBLs (with hLS ~ 30-50m) developing during longer than night periods of the persistent surface cooling. As a result, one and the same increment, δQ0, in the surface heat flux leads to only minor increment in ?max in deep C PBLs, but essential increments in ?min in shallow NS and especially NS PBLs. The latter type of the PBL has been discovered only recently and is not yet accounted for in modern GCMs. In the present paper, we derive theoretical estimates of the variations, δ?min and δ?max, in the SAT minima and maxima associated with the stable and convective PBLs, respectively, and by this means explain the observed asymmetry in the growth rates of ?min and ?max. To characterise the role of PBLs in the climate system, we introduce the concepts of local and general PBL feedbacks. Besides the strengths of feedbacks, we propose to take into account the reaction times of different mechanisms. The proposed concepts could be applied to different climate-change problems from global (as in this paper) to local, in particular, to those caused by the land-use modification.
Esau Igor
Zilitinkevich Sergej S.
No associations
LandOfFree
Planetary boundary layer feedbacks in climate system does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Planetary boundary layer feedbacks in climate system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Planetary boundary layer feedbacks in climate system will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1185325