Table Of ContentA. Baklanov Æ B. Grisogono
Editors
Atmospheric Boundary Layers
Nature, Theory and Applications to
Environmental Modelling and Security
Introduction by A. Baklanov and B. Grisogono
PreviouslypublishedinjournalBoundary-LayerMeteorology,Volume125,No.2
123
AlexanderBaklanov BrankoGrisigono
DanishMeteorological Institute Departmentof Geophysics
Copenhagen,Denmark University ofZagreb
Zagreb, Croatia
Based upon papers presented at a NATO Advanced Research Workshop held in
Dubrovnik, Croatia, 18–22April, 2006.
Coverillustration: ThanksareduetoS.S.ZilitinkevichandI.N.EsaufortheuseofFigure3,from
‘Similaritytheoryandcalculationofturbulentfluxesatthesurfaceforthestablystratifiedatmospheric
boundarylayer’,p.43.
LibraryofCongressControlNumber:
ISBN-978-0-387-74318-9 e-ISBN 978-0-387-74321-9
Printedonacid-freepaper.
(cid:1)2007SpringerScience+BusinessMedia,LLC
Allrightsreserved.Thisworkmaynotbetranslatedorcopiedinwholeorinpartwithoutthewritten
permissionofthepublisher(SpringerScience+BusinessMedia,LLC.,233SpringStreet,NewYork,
NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in
connectionwithanyformofinformationstorageandretrieval,electronicadaptation,computersoftware,
orbysimilarordissimilarmethodologynowknownorhereafterdevelopedisforbidden.
Theuseinthispublicationoftradenames,trademarks,servicemarks,andsimilarterms,eveniftheyare
notidentifiedassuch,isnottobetakenasanexpressionofopinionastowhetherornottheyaresubject
toproprietaryrights.
9 8 7 6 5 4 3 2 1
springer.com
Contents
EDITORIAL
Atmospheric boundary layers: nature, theory and applications to environ-
mental modelling and security
A. Baklanov · B. Grisogono . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
ORIGINALPAPERS
Some modern features of boundary-layer meteorology: a birthday tribute
for Sergej Zilitinkevich
G.D. Djolov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Energy- and flux-budget (EFB) turbulence closure model for stably
stratified flows. Part I: steady-state, homogeneous regimes
S.S. Zilitinkevich · T. Elperin · N. Kleeorin · I. Rogachevskii . . . . . . . . . . . . . . . . . . . . . . . . 11
Similarity theory and calculation of turbulent fluxes at the surface for the
stably stratified atmospheric boundary layer
S.S. Zilitinkevich · I.N. Esau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Application of a large-eddy simulation database to optimisation of
first-order closures for neutral and stably stratified boundary layers
I.N. Esau · Ø. Byrkjedal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
The effect of mountainous topography on moisture exchange between the
“surface” and the free atmosphere
A.P. Weigel · F.K. Chow · M.W. Rotach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
The influence of nonstationarity on the turbulent flux—gradient
relationship for stable stratification
L. Mahrt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Chemical perturbations in the planetary boundary layer and their
relevance for chemistry transport modelling
A. Ebel · M. Memmesheimer · H.J. Jakobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Theoretical considerations of meandering winds in simplified conditions
A.G.O. Goulart · G.A. Degrazia · O.C. Acevedo · D. Anfossi . . . . . . . . . . . . . . . . . . . . . . . . 123
Aerodynamic roughness of the sea surface at high winds
V.N. Kudryavtsev · V.K. Makin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Modelling dust distributions in the atmospheric boundary layer on Mars
P.A. Taylor · P.-Y. Li · D.V. Michelangeli · J. Pathak · W. Weng . . . . . . . . . . . . . . . . . . . . . . 149
123
On the turbulent Prandtl number in the stable atmospheric boundary layer
A.A. Grachev · E.L. Andreas · C.W. Fairall · P.S. Guest · P.O.G. Persson . . . . . . . . . . . . . . 173
Micrometeorological observations of a microburst in southern Finland
L. Järvi · A.-J. Punkka · D.M. Schultz · T. Petäjä · H. Hohti · J. Rinne ·
T. Pohja · M. Kulmala · P. Hari · T. Vesala . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Role of land-surface temperature feedback on model performance for the
stable boundary layer
A.A.M. Holtslag · G.J. Steeneveld · B.J.H. van de Wiel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Katabatic flow with Coriolis effect and gradually varying eddy diffusivity
I. Kavc(cid:1)ic(cid:1)· B. Grisogono . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Parameterisation of the planetary boundary layer for diagnostic wind models
M. Burlando · E. Georgieva · C.F. Ratto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
123
Dedicated to Sergej S. Zilitinkevich
on the occasion of his 70th birthday
(cid:1)belokouroffalexander2007
Professor Sergej S. Zilitinkevich
Atmospheric boundary layers: nature, theory and
applications to environmental modelling and security
AlexanderBaklanov · BrankoGrisogono
This special issue presents a set of peer-reviewed papers from the NATO Advanced
ResearchWorkshop(ARW)“AtmosphericBoundaryLayers:ModellingandApplicationsto
EnvironmentalSecurity”,heldinDubrovnik,Croatia,18–22April2006;57researchersfrom
21countriesand4continentsparticipated(seetheARWweb-sitehttp://pbl-nato-arw.dmi.dk).
TheprincipalgoalsoftheARWwere
(cid:127) tosummariseandassesscurrentknowledgeonplanetaryboundary-layer(PBL)physics
andparameterization,
(cid:127) topromotetheexchangeofideasandknowledgebetweenphysicists,meteorologists,and
environmentalmodellers,
(cid:127) tosetacourseforimprovingPBLparameterisationsinclimate,numericalweatherpre-
diction,air-quality,andemergencypreparednessmodels.
ApleasantreasontoarrangethiseventinApril2006wasthe70thbirthdayofProfessor
SergejZilitinkevich(bornon13April1936inSt.Petersburg,Russia).Amostappropriate
tribute to him is the fact that a major part of the presentations at this ARW are based on
orlinkedwithhisfundamentalworks.HisscientificbiographicalnotebyGeorgeDjolovis
includedinthisissue.Heisinperfectform,sprinklingwithnewideas,andveryproductive
scientifically.
The scientific organisation of the ARW was performed by the Organising Commit-
tee consisting of the NATO-country ARW director Alexander Baklanov (Meteorological
Research Division, Danish Meteorological Institute, Copenhagen, Denmark); the Partner-
countryARWdirectorBrankoGrisogono(DepartmentofGeophysics,UniversityofZagreb,
Croatia);AdolfEbel(PhenishInstituteforEnvironmentalResearch,UniversityofCologne,
Germany); Sylvain M. Joffre (Finnish Meteorological Institute) and Sergej Zilitinkevich
(DivisionofAtmosphericSciences,UniversityofHelsinki,Finland)—withvaluablecontri-
B
A.Baklanov( )
MeteorologicalResearch,DanishMeteorologicalInstitute,Lyngbyvej100,Copenhagen,2100Denmark
e-mail: [email protected]
B.Grisogono
GeophysicalInstitute,FacultyofScience,UniversityofZagreb,Horvatovacbb,10000Zagreb,Croatia
Atmospheric Boundary Layers.A. Baklanov & B. Grisogono (eds.), 1
doi: 10.1007/978-0-387-74321-9_1, © Springer Science+Business Media B.V. 2007
22 AA.. BBaakkllaannoovv,, BB.. GGrriissooggoonnoo
butionsfromthelocalorganisers:IvaKavcicandIvaGrisogono(DepartmentofGeophysics,
UniversityofZagreb).
Theprogrammeincludedthreeintroductorytalks,ninekeylectures,and27regularpre-
sentationsdividedintoseveralthematicsessions.Itisonlynaturalthatthisissuedoesnot
cover all presentations; some of them were based on already published, submitted or still
uncompletedpapers.
Besides presentations, the programme included three general discussions: “Stability
dependenceoftheturbulentPrandtlnumberandthecriticalRichardsonnumberproblem”,
“Turbulenceclosureproblem”,“TowardsimprovementofPBLschemesinoperationalmod-
els”;andspecificdiscussionsinworkinggroups:(WG1)Boundary-layerphysics(L.Mahrt);
(WG2)Turbulenceclosure(S.S.Zilitinkevich);(WG3)Complexandmesoscaleboundary-
layer flows (P.A. Taylor); (WG4) Air-sea-ice interaction (S.E. Larsen); (WG5) Air flows
withinandaboveurbanandvegetationcanopies(R.Bornstein);(WG6)PBLsinoperational
models(M.W.Rotach);(WG7)Environmentalsecurityissuesanddemandsfromendusers
(H.J.S. Fernando). The WG chairmen (see their names in brackets) have summarised and
forwardedtoustheconclusionsandrecommendationsoftheirgroups.Belowwebrieflyskim
throughworking-groupandgeneralinert-groupconclusions.
WG1recommended(i)creationofacatalogueofthemoreextensivePBLdatasets,(ii)
analysingdifferentsiteswiththesameanalysismethod,and(iii)maintenanceofarespon-
sivedata-basecentrethatcanaccommodatecontinualupgradesofdatasets.Moreattention
should be concentrated on spatial averaging of turbulent fluxes. Tower measurements can
provide spatial averages, such as over a grid area, only with weak heterogeneity and the
precariousassumptionofTaylor’shypothesis.Mostpracticalapplicationsinvolvecomplex
surfaces, which require more attention. The degree of failure of existing similarity theory
overcommoncomplexsurfacesneedstobedeterminedtoestablishthelikelymagnitudeof
errors.Evenmodestimprovementsoftheformulationoftheflux-gradientrelationshipsover
heterogeneoussurfaceswouldbeofconsiderablepracticaluse.
WG2emphasisedthattraditionaltreatmentoftheturbulenceenergeticsusingsolelythe
turbulentkineticenergy(TKE)budgetequationisinsufficientandcausesdifficultiesinoper-
ationalturbulenceclosuremodels.TheTKEequationincombinationwiththedown-gradi-
entformulationfortheturbulentfluxesandKolmogorov’sclosurehypothesisfortheeddy
exchange coefficients leads to unrealistic degeneration of turbulence at Richardson num-
bers,Ri,exceedingsomecriticalvalue,Ri .ToRi ,Ri-dependent“correctioncoefficients”
c c
are introduced in the above formulation without physical explanation of the maintenance
ofturbulenceinstronglystablestratification.AsdemonstratedattheARWtheabovediffi-
cultiesarecausedbyoverlookingtheturbulentpotentialenergy(TPE)proportionaltothe
meansquaredtemperaturefluctuations.TogetherTKEandTPEcomprisetheturbulenttotal
energy(TTE),whosebudgetequationdoesnotincludetheverticalfluxofbuoyancyandhas
theformofaconservationequationsecuringpositiveTTEinanystratification.Theconcepts
ofTPEandTTEeliminateRi fromtheturbulenceclosureproblemandopenaconstructive
c
way to create a hierarchy of energetically consistent closure schemes for operational use.
ThenatureoforganisedstructuresintheconvectivePBL,namelycellsandrollsintheshear-
freeandshearedregimes,respectively,remainnotfullyunderstood.Thesurfaceheat/mass
transferlawsfortheshear-freeconvectionareobtained,buttoextendthetheorytosheared
convectionandtoverticaltransportswithintheconvectivezone,furtherobservationaland
numericalsimulationstudiesareneeded.
WG3identifiedthefollowingmesoscaleboundary-layerflowsthatstronglyaffectregional
climate, weather and air quality: internal boundary layers caused by the roughness and/or
thermalheterogeneity;flowsovertopography,suchasslopewinds;thermallydrivenfeatures:
Atmospheric boundary layers 3
surface-inducedconvectionandthunderstorms,seaandlakebreezes,mountain-valleywinds,
urbanandotherheatislands,convectivecirculationsoverleadsandpolynias;mechanically
drivenflows:orographicgravitywaves,downslopewindstorms,retardationoffrontalpas-
sages by orography or roughness; and features combing thermal and mechanical driving
mechanisms,suchasbora,chinookandfoehn.Herethetraditionalcomputationaltechniques
areReynolds-averagedNavier–Stokesequation(RANS)modelswithvaryinglevelsofclo-
sure.TTEclosuresopennewopportunitiestoimproveRANSmodels,firstofall,addressing
airqualityissues.Large-eddysimulation(LES)hasjuststartedtoaddressidealisedcomplex-
terrainflows(e.g.,Arcticleads,simplycomposedslopes,urbancanopies)utilisingperiodic
lateralboundaryconditions.Inviewoftheincreasingpowerofsupercomputersthistechnique
willbecomesuitableforoperationalmodellingintheverynearfuture.
WG4focusedonthemarineatmosphericplanetaryboundarylayer(MPBL).Thesmaller
roughness and larger heat capacity of the ocean result in more organised convective flow
patterns,suchascloudstreets.Parameterizationofthesurfaceturbulentfluxesofmomen-
tum,heatandwatervapouroverthesearemainsthekeyproblembecauseofdifficultiesin
obtaininghighqualitydatainstrongwinds.Severalstudiesrevealeddecreasingoftheeffec-
tiveroughnesslengthinverystrongwindscausedbytheinputoftheseasprayintothelower
surfacelayer.Constrainedwaters,coastalareasandlakesrepresentanevenmorecomplex
problemrequiringknowledgeofthewindfetchandthebasindepth.Modellingofthegasand
particleexchangebetweentheatmosphereandoceanstillsuffersfrommanyuncertaintiesof
boththeoreticalandexperimentalnature.Forgases,animportantuncertaintyfollowsfrom
theempiricalnatureofthesurfaceexchangecoefficientallowingnosimplerulestoaccount
fornon-stationaryandheterogeneousfeaturesoftenfoundinaqueousconcentrationpatterns
andwindspeeds.Themixedice-seasurfaceisoftenhighlyheterogeneouswithrespectto
theheatflux,duetotheoften-extremedifferenceintemperaturebetweentheicesurfaceand
underlyingwaters.Alsothedragmaychangestronglyduetoridgedbordersoftheicefloes.
A quite successful effort has been made to understand and model the flow and fluxes for
individualwater openings,andalsofromice-coveredsurfaces.However,aggregationinto
averagesurfacefluxesremainsstronglyuncertain.Passingcloudschangetheradiationheat
fluxandthusconstituteanimportantnon-stationaryeffectontheMPBL.Thestrongwind
MPBLtraditionallyconsideredasasimpleneutrallystratifiedboundarylayerexhibitsnovel
features and, as recognised recently, should be treated as “conventionally neutral” (near-
neutralclosetothesurfacebutstronglyaffectedbythefree-flowstabilityandstablystrati-
fiedinitsupperportion).
WG5emphasisedthekeyroleoftheurbanboundarylayerinairqualityproblems.Urban
features essentially influence atmospheric flow and microclimate, strongly enhance atmo-
sphericturbulence,andmodifyturbulenttransports,dispersionanddepositionofatmospheric
pollutants. Considerably increased resolution in numerical weather prediction models has
allowedformorerealisticallyreproducingurbanairflowsandairpollutionprocesses.This
hastriggerednewinterestinmodellingandinvestigatingexperimentallyspecificprocesses
essential for urban areas. Recent developments performed within the EU-funded project
FUMAPEXonintegratedsystemsforforecastingurbanmeteorologyandairpollutionand
otherrelevantstudiesshowedmanyopportunitiesin“urbanisation”ofweatherprediction,
airpollutionandemergencypreparednessmodels.
WG6andWG3agreedthathigh-resolutionmesoscaleRANSmodelsandLESarecom-
plementaryprovidingbasicinformationonfine-scalefeaturesofairflowovercomplexterrain.
Thelatterarenotresolvedinlargerscaleclimateandweatherpredictionmodelsandareto
be parameterized through appropriate spatial averaging of turbulent fluxes (flux aggrega-
tion).Thisappliesinparticularto“hydrologicalheterogeneity”associatedwithareaswith
4 AA.. BBaakkllaannoovv,, BB.. GGrriissooggoonnoo
manysmalllakes.Currently-usedflux-profilerelationshipsdeterminingthelowerboundary
conditions in both mesoscale and larger scale models need to be refined. The background
Monin–Obukhov similarity theory is not applicable over complex terrain (see WG1) and
doesnotrealisticallyreproducestronglystableandstronglyunstablestratificationregimes.
Recentlyithasbeengeneralisedaccountingforthenon-localeffectsofthefree-flowstabil-
ityinstablestratificationandlarge-scale,organisededdiesinshear-freeconvection.Further
workisneededtoextendsurface-layertheorytoshearedconvectionandalsotocomplexand
slopingterrain.
WG7consideredenvironmentalsecurityissuesanddemandsfromendusers.Withgrow-
ingspectraofchemical,biologicalandradiological(CBR)terrorism,ithasbecomeincreas-
inglynecessarytoprotectourecosystemsagainstdeleteriousactivitiesofhumans.Therapid
rise of population in cities has created concentrated human centres that are vulnerable to
extensivedestructionthroughterrorismorbynaturalcausessuchashurricanes,asevidenced
withincreasingfrequencyinrecentdecades.Increaseofairpollutionisanotherissuethatis
closelyrelatedtothequalityoflife.Giventhatthebulkoflivingentitiesareembeddedinthe
PBL,itisopportunetodiscusstherolethatboundary-layermeteorologyplaysinsecuring
ourenvironment.OneofthekeyissuesisthepredictionofthepathwaysofCBRreleases.
Firstandforemost,suitablesensorsareneededforthedetectionoftoxins,andinthepost-
9/11erasuchsensortechnologiesarerapidlyadvancing.Whatfollowsareinthearenaof
PBLmodelling:optimalplacementofsensoranddesignofsensornetworks,environmental
cyber-infrastructure, prediction of transport, diffusion and distribution of contaminants in
thePBL,especiallyfastforecastmodels,monitoringofcontaminantpaths,includingsensor
modelfusionwork,longrangetransportanddilution,indoorairquality(airseepagethrough
building accessories), environmental remediation, informing the authorities and providing
helpinemergencyresponse.
We hope that the principal goals of the ARW will be achieved and this issue will help
readerstoassessthepotentialofrecentachievementsandnovelwaysinPBLphysicsand
itsapplications.ItwastheunanimousopinionofallparticipantsthattheARWhasindeed
made a step towards these goals, and that similar meetings, say, once in 2–3years would
stronglyfacilitatefurtherprogressinboundary-layermeteorologyandoperationalenviron-
mentalmodelling,includingthesecurityissues.
Acknowledgements ThisARWhasbeensponsoredbytheNATOProgrammeNo.982062“Securitythrough
Science”.AdditionalsupportshavecomefromCroatianMeteorologicalandHydrologicalService(CMHS),
DanishMeteorologicalInstitute(DMI),FinnishMeteorologicalInstitute(FMI),theEUMarieCurieChairPro-
jectMEXC-CT-2003–509742“Theory,ModellingandRoleinEarthSystems”andtheNORDPLUSNEIGH-
BOURProject177039/VII.WethanktheNATOAdministration,theCMHSDirectorGeneralIvanCˇacˇic´
andtheFMIDirectorGeneralPekkaPlathanformakingthismeetingpossible,productiveandavailableto
manyparticipants.WealsothanktheworkinggroupleadersLarryMahrt,SergejZilitinkevich,PeterTaylor,
SørenLarsen,RobertBornstein,MathiasRotachandJoeFernandoforprovidinguswithrecommendations
summarisedherein.
9July2007
