Mike Freilich, Seawinds project scientist, was heard to say at my retirement party:

Bob keeps us abreast of PBL applications, and what the ‘real’ PBL looks like, and its latest revelations.

At times he gets impatient, as when he began one lecture with “Come on guys. Listen. Sometimes I feel like I’m casting pearls before swine.”

STOPSTOP• Using the Ekman solution Using the Ekman solution for Planetary Boundary Layer for Planetary Boundary Layer applicationsapplications

• Using K-theory in modeling Using K-theory in modeling PBL fluxesPBL fluxes

OK.OK.

The nonlinear PBL solution requires a book The nonlinear PBL solution requires a book (Brown, 1973) instead of a short paper (Brown, 1973) instead of a short paper (Ekman, 1905)(Ekman, 1905)

The nonlinear solution requires a quarter The nonlinear solution requires a quarter course instead of an hour lecturecourse instead of an hour lecture

The nonlinear solution requires a PBL The nonlinear solution requires a PBL measurement with at least an hour’s measurement with at least an hour’s average or a 60-km flight path instead of average or a 60-km flight path instead of a point measurement from a tower (point or a point measurement from a tower (point or short-time measurements often have short-time measurements often have significant errors) significant errors)

But:But:

The nonlinear solution is The nonlinear solution is complete (Foster, 1994, 2002).complete (Foster, 1994, 2002).

The nonlinear solution has The nonlinear solution has observational verification (SAR observational verification (SAR and scatterometer data, and scatterometer data, Brown Brown 20052005 Comments on the synergism between the analytic PBL Comments on the synergism between the analytic PBL model and remote sensing data, model and remote sensing data, Bound.-Layer Meteor.Bound.-Layer Meteor., , 116116:187-:187-199199 ) )

There is a version of the There is a version of the nonlinear solution ‘for nonlinear solution ‘for dummies’ (dummies’ (Brown, 2005, 2002,Brown, 2005, 2002, Scaling Scaling Effects in Remote Sensing Applications and the Case of Effects in Remote Sensing Applications and the Case of Organized Large Eddies, Organized Large Eddies, Canadian Jn. Remote SensingCanadian Jn. Remote Sensing, , 2828, 340-, 340-345, 2002345, 2002,),)

Station B

2 - 5 km

Hazards of taking measurements in the Rolls

Station A

1-km

RABrown 2004

U

V Mean Flow Hodograph

Z/ 1

2

3

The Mean Wind

The OLE winds

Hodographfrom center zone of rolls

Hodographfrom convergent zone of rolls

Station B

Station A

Principle of The Red Principle of The Red QueenQueen

Named after the chess piece in Named after the chess piece in Alice in Alice in Wonderland, -Wonderland, - she moves faster & faster, in she moves faster & faster, in more complicated ways, yet Nothing more complicated ways, yet Nothing Significant Changes.Significant Changes.

Used in Evolution and Biology, mainly to Used in Evolution and Biology, mainly to describe the predator-prey relationship.describe the predator-prey relationship.

I’m mentioning this because I note that the I’m mentioning this because I note that the principle seems to apply to modelling the principle seems to apply to modelling the turbulent PBL? (fantastically complicated turbulent PBL? (fantastically complicated turbulence models yet no better weather & turbulence models yet no better weather & climate models)climate models)

{6-06: This left a wonderful hole for {6-06: This left a wonderful hole for scatterometer winds to fill. Likewise for a scatterometer winds to fill. Likewise for a lidar to fill some day.}lidar to fill some day.}R. A. Brown 2005 EMS (from EGU 2005), LIDAR 1/06

R. A. Brown 2005 AGU

The nonlinear solution applied to satellite surface The nonlinear solution applied to satellite surface winds yields accurate surface pressure fields. These winds yields accurate surface pressure fields. These data show:data show:

* Agreement between satellite and ECMWF pressure fields. This indicates that both the Scatterometer winds and the nonlinear PBL model (VG/U10) are accurate within 2 m/s.

* A 3-month, zonally averaged offset angle <VG, U10> of 19° suggests the mean PBL state is near neutral (the angle predicted by the nonlinear PBL model).

* Swath deviation angle observations can be used to infer thermal wind and stratification.

* Higher winds are obtained from pressure gradients and used as surface truth (rather than from GCM or buoy winds).

* VG (pressure gradients) rather than U10 could be used to initialize GCMs

R. A. Brown 2006 AMS

NCEP real time forecasts use NCEP real time forecasts use PBL modelPBL model

Even the best NCEP analysis, Even the best NCEP analysis, used as the first guess in the used as the first guess in the real time forecasts, is real time forecasts, is improved with the QuikScat improved with the QuikScat surface pressure analyses.surface pressure analyses.

This is the actual slp output from the uwpbl model using the 0543 UTC QuikSCAT pass

This is the actual output of the uwpbl model slp using the 0648 UTC QuikSCAT pass

This is a cut and paste of the previous two slides.

This is a composite of two runs of the model using the 0549 QuikSCAT pass and the 0648 QuikSCAT pass.

This is the 0600 UTC Ocean Prediction Center hand drawn surface analysis superimposed over the GOES12 0615UTC Image.

This is the composite of three consecutive runs of the uwpbl model using the 0543, 0648 and 0834 QuikSCAT passes superimposed on the GOES 12 image from 0645 UTC

This is the Ocean Prediction Center hand drawn surface analysis 0526 0600 UTC with the surface vorticity field from the uwpbl model overlaid. The vorticity field is a composite of three passes (0543, 0648 and 0834 UTC); it shows the locations of the frontal zones well.

OPC Sfc Analysis and IR Satellite Image 10 Jan 2005 0600 UTC UWPBL 10 Jan 2005 0600 UTC

a b

c d

QuikSCAT 10 Jan 2005 0709 UTC

991

982

996

996

999

984

This example is from 10 January 2005 0600UTC. Numerical guidance from the 0600UTC GFS model run (a) indicated a 999 hPa low at 43N, 162E. QuikScat winds (b) suggested strong lows --- OPC analysis uses 996. UW-PBL analysis indicates 982.

GFS Sfc Analysis 10 Jan 2005 0600 UTC

Improved 6/06

Programs and Fields available onPrograms and Fields available onhttp://pbl.atmos.washington.ehttp://pbl.atmos.washington.e

dudu QuestionsQuestions to rabrown, Ralph to rabrown, Ralph

oror jerome jerome @atmos.washington.edu@atmos.washington.edu Direct PBL modelDirect PBL model: PBL_LIB. (’75 -’05) An analytic : PBL_LIB. (’75 -’05) An analytic solution for the PBL flow with rolls, U(z) = f( solution for the PBL flow with rolls, U(z) = f( P, P, TTo o , , TTaa , , ) )

The The Inverse PBL modelInverse PBL model: Takes U: Takes U10 10 field and calculates field and calculates surface pressure field surface pressure field P (UP (U1010 , , TTo o , , TTaa , , ) ) (1986 - 2005)(1986 - 2005)

Pressure fields directly from the Pressure fields directly from the PMFPMF: : P (P (oo) along all ) along all swaths swaths (exclude 0 - (exclude 0 - 5° lat.?) (2001) (dropped in 5° lat.?) (2001) (dropped in favor of I-PBL)favor of I-PBL)

Global swath pressure fields for QuikScat swaths (with Global swath pressure fields for QuikScat swaths (with global I-PBL model) (2005)global I-PBL model) (2005)

Surface stressSurface stress fields from PBL_LIB corrected for fields from PBL_LIB corrected for stratification effects along all swaths (2006)stratification effects along all swaths (2006)

R. A. Brown 2006

1980 – 2005: Using surface 1980 – 2005: Using surface wind as a lower boundary wind as a lower boundary condition on a PBL model, condition on a PBL model, considerable information about considerable information about the atmosphere and the PBL has the atmosphere and the PBL has been inferred. been inferred. The symbiotic relation between surface backscatter The symbiotic relation between surface backscatter data and the PBL model has been beneficial to both.data and the PBL model has been beneficial to both.

The PBL model has established superior ‘surface The PBL model has established superior ‘surface truth’ winds (or pressures) for the satellite model truth’ winds (or pressures) for the satellite model functions.functions.

Satellite data have proven that the nonlinear PBL Satellite data have proven that the nonlinear PBL solution with OLE is observed most of the time.solution with OLE is observed most of the time.

R. A. Brown 2006 AMS