The source area influencing a measurement in the Planetary Boundary Layer: The ``footprint'' and the ``distribution of contact distance''

Details The source area influencing a measurement in the Planetary Boundary Layer: The ``footprint'' and the ``distribution of contact distance'' The source area influencing a measurement in the Planetary Boundary Layer: The ``footprint'' and the ``distribution of contact distance''

Apr 1991

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991bolme..55...25w&link_type=abstract

Boundary-Layer Meteorology, Volume 55, Issue 1-2, pp. 25-46

Other

8

Scientific paper

This paper considers the ground area which affects the properties of fluid parcels observed at a given spot in the Planetary Boundary Layer (PBL). We examine two source-area functions; the “footprint,” giving the source area for a measurement of vertical flux: and the distribution of “contact distance”, the distance since a particle observed aloft last made contact with the surface. We explain why the distribution of contact distance extends vastly farther upwind than the footprint, and suggest for the extent of the footprint the inequalities: [begin{array}{l} Uh/{σ _W (h)} < x < Uleft\{ {_{h/dot z,{{ }}otherwise}^{T_L (h){{, h }}above{{ }}surface - layer} } right. \ \ |y| < σ _v (h)x/U \ ] where U is the mean streamwise ( x) velocity, h is the observation height, ΤL is the Lagrangian timescale, Σ v and Σ w are the standard deviations of the cross-stream horizontal ( y) and vertical ( z) velocity fluctuations, and ż is the Lagrangian Similarity prediction for the rate of rise of the centre of gravity of a puff released at ground. Simple analytical solutions for the contact-time and the footprint are derived, by treating the PBL as consisting of two sub-layers. The contact-time solutions agree very well with the predictions of a Lagrangian stochastic model, which we adopt in the absence of measurements as our best estimate of reality, but the footprint solution offers no improvement over the above inequality.

Affiliated with

Also associated with

No associations

Rating

The source area influencing a measurement in the Planetary Boundary Layer: The ``footprint'' and the ``distribution of contact distance'' 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 The source area influencing a measurement in the Planetary Boundary Layer: The ``footprint'' and the ``distribution of contact distance'', we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The source area influencing a measurement in the Planetary Boundary Layer: The ``footprint'' and the ``distribution of contact distance'' will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1790772