NDLI: Equilibrium Evaporation and the Convective Boundary Layer

Content Provider	Springer Nature Link
Author	Raupach, M. R.
Copyright Year	2000
Abstract	A theory is developed for surface energy exchanges in well-mixed, partlyopen systems, embracing fully open and fully closed systems as limits.Conservation equations for entropy and water vapour are converted intoan exact rate equation for the potential saturation deficit D in a well-mixed, partly open region. The main contributions to changes in D arise from (1) the flux of D at the surface, dependent on a conductance gq that is a weighted sum of the bulk aerodynamic and surface conductances; and (2) the ‘exchange’ flux of D with the external environment by entrainment or advection, dependent on a conductance ge that is identifiable with the entrainment velocity when the partly open region is a growing convective boundary layer (CBL). The system is fully open when ge/gq → ∞, and fully closed when ge/gq → 0. The equations determine the steady state surface energy balance (SEB) in a partly open system, the associated steady-state deficit, and the settling time scale needed to reach the steady state. The general result for the steady-state SEB corresponds to the equations of conventional combination theory for the SEB of a vegetated surface, with the surface-layer deficit replaced by the external deficit and with gq replaced by the series sum (gq -1 + ge -1)-1. In the fully open limit D is entirely externally prescribed, while in the fully closed limit, D is internally determined and the SEB approaches thermodynamic equilibrium energy partition. In the case of the CBL, the conductances gq and ge are themselves functions of D through short-term feedbacks, induced by entrainment in the case of ge and by both physiological and aerodynamic (thermal stability) processes in the case of gq. The effects of these feedbacks are evaluated. It is found that a steady-state CBL is physically achievable only over surfaces with at least moderate moisture availability; that entrainment has a significant accelerating effect on equilibration; that the settling time scale is well approximated by h/(gq + ge), where h is the CBL depth; and that this scale is short enough to allow a steady state to evolve within a semi-diurnal time scale only when h is around 500 m or less.
Starting Page	107
Ending Page	142
Page Count	36
File Format	PDF
ISSN	00068314
Journal	Boundary-Layer Meteorology
Volume Number	96
Issue Number	1-2
e-ISSN	15731472
Language	English
Publisher	Kluwer Academic Publishers
Publisher Date	2000-01-01
Publisher Place	Dordrecht
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Meteorology/Climatology Atmospheric Protection/Air Quality Control/Air Pollution
Content Type	Text
Resource Type	Article
Subject	Atmospheric Science

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Fluid Modelling Of Atmospheric Dispersion In The Convective Boundary Layer

Boundary-Layer Meteorology

Observations Of The Morning Transition Of The Convective Boundary Layer

Non-local mixing of momentum in the convective boundary layer

Turbulent mixing of reactive gases in the convective boundary layer

Growth Of The Summer Daytime Convective Boundary Layer At Anand

A Lagrangian Decorrelation Time Scale in the Convective Boundary Layer

Convective Boundary-Layer Entrainment: Short Review and Progress using Doppler Lidar

Observations of the Relation Between Upslope Flows and the Convective Boundary Layer in Steep Terrain

Equilibrium Evaporation and the Convective Boundary Layer

Similar Documents

Fluid Modelling Of Atmospheric Dispersion In The Convective Boundary Layer

Boundary-Layer Meteorology

Observations Of The Morning Transition Of The Convective Boundary Layer

Non-local mixing of momentum in the convective boundary layer

Turbulent mixing of reactive gases in the convective boundary layer

Growth Of The Summer Daytime Convective Boundary Layer At Anand

A Lagrangian Decorrelation Time Scale in the Convective Boundary Layer

Convective Boundary-Layer Entrainment: Short Review and Progress using Doppler Lidar

Observations of the Relation Between Upslope Flows and the Convective Boundary Layer in Steep Terrain

Equilibrium Evaporation and the Convective Boundary Layer