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Outline for Today 26-8-2010

Outline for Today 26-8-2010. The long, slow, tedious road to winds for PBL study. Motivation Theory for Winds The Satellite Instruments The scatterometer, lidar , SAR The Results of Winds from Space The Consequences for surface wind analysis.

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Outline for Today 26-8-2010

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  1. Outline for Today26-8-2010 The long, slow, tedious road to winds for PBL study • Motivation • Theory for Winds • The Satellite Instruments • The scatterometer,lidar,SAR • The Results of Winds from Space • The Consequences for surface wind analysis

  2. What are the “Big Questions” as defined by NASA (lidar related)RAB • Earth Questions:How is the global earth system changing? (climate modeling) • What are the primary forcings of the Earth system?(Solar heating of the Atmosphere, hence PBL dynamics; weather/climate modeling) • How does the earth system respond to natural and human-induced changes? (climate models) • What are the consequences of change in the earth system for human civilization? • How will the Earth system change in the future? (climate modeling)

  3. Within the possibilities of GW…… • No GW; just the Milankovich cycle into the next glacial (ice) age in 100-5000 years. MOS 10-50. • Moderate GW; wards off ice age, affects sea level + 5-10 feet by 2100; ocean acidification eliminates many species, corals; redistribution of agriculture; strong storms, droughts, etc. • Maximum possible GW; land ice melts, seas rise 200 feet, ocean life nearly eliminated, most land species eliminated, including homo sap.

  4. The & of measuring from Space Science Politics Winds How do you measure the wind vector (speed & direction) in the atmosphere from hundreds of miles away in space ? The Winds are the basic parameter in the equations of motion for weather and climate  the state of knowing : knowledge as distinguished from ignorance or misunderstanding Hence based on Observations. Using the Navier Stokes equations (F = ma for fluid parcel) under certain conditions, Newtonian fluid; calculus definition, eddy size….. The Evolution of a Conspiracy theory over 20-years

  5. Theory • * In the beginning (1905) there was the Ekman solution: • Linear, 2nd order, a 10-page paper • In 1970 there was the nonlinear, 4th order (1972; 6th order) (1990; 8th order), a 176 page book. • Modelers preferred the Ekman solution (Oceanographers and many Atmos. Science Boundary Layer modelers still do.)

  6. Revelations from scatterometers • Ship or Buoy winds are not good surface truth in general. Hence the climate record is incorrect. * Data on storms and fronts is revolutionary. (Patoux, J., G.J. Hakim and R.A. Brown, 2004: Diagnosis of frontal instabilities over the Southern Ocean, Monthly Weather Review)

  7. Sources of Surface Wind Fields for Climate Studies • Over land: limited, accuracy varies, No. Hemi. • Over the ocean from Surface measurements • Ships • Buoys R.A. Brown, 2010

  8. The buoys in high winds, high seas 10-m wind Wave height ~ 10 m Buoy ~ 3 m Sheltering: The high waves place the buoy in shelter and/or turbulent wake of the waves yielding low winds Displacement height: When surrounding topography is rough, the sensor is ‘displaced’ downward to reflect its lower position in a more turbulent boundary layer =lower winds R. A. Brown 2003 U. ConcepciÓn R. A. Brown 03

  9. Sources of Surface Wind Fields for Climate Studies • From Surface Measurements • Ships • Buoys • From Models • GCM (with K-theory PBLs) • UW Similarity Model (with OLE) R.A. Brown, 2010

  10. Coherent Structures in the PBL • Organization within an otherwise turbulent field • Nonlinear • Finite perturbation theory • Vortex solution; Contains same parcels • In the PBL, Organized Large Eddies (OLE) • Nomenclature problem with ‘Chaos’ (coherent structure solution in chaotic turbulence) R. A. Brown 2010

  11. Taking measurements in the Rolls with Tower & Sondes 1-km Station A 2 - 5 km Station B R. A. Brown U. ConcepciÓn

  12. K-Theory Vs Similarityor Why RAB loves satellite data • 1970: OLE is just a complicated theory for cloud streets • 1974 “Single parameter Similarity Model w/OLE is just a theory” [so is gravity, evolution…..] • 1977 “OK. They also occur in numerical models and a few experiments. And, if the theory is correct, diffusion models (used in all GCMs) have wrong physics. But, how often are OLE present globally? Need data not just theory” • 1978. Seasat SAR shows OLE surface imprints, often. • 1980: OLE do occur. Analytically, Numerically, and Observations --- and they all look similar. • 1998: SAR (RADARSAT) shows OLE produce signature on ocean surface stats ~ 80% of the time R. A. Brown 2010

  13. Revelations from scatterometers • Ship or Buoy winds are not good surface truth in general. Hence the climate record is incorrect. • * Weather & climate PBL models have the wrong physics. * Data on storms and fronts is revolutionary. (Patoux, J., G.J. Hakim and R.A. Brown, 2004: Diagnosis of frontal instabilities over the Southern Ocean, Monthly Weather Review)

  14. Sources of Surface Wind Fields for Climate Studies • From Surface Measurements • Ships • Buoys • From Models • GCM (with K-theory PBLs) • UW Similarity Model (with OLE) • From Satellites • Scatterometer (ESU ASCAT) • SARs, radiometers …. • (Lidar) R.A. Brown, 2010

  15. Revelations from scatterometers • Ship or Buoy winds are not good surface truth in general. Hence the climate record is incorrect. • * Weather & climate PBL models have the wrong physics. • * The winds are higher, the low pressures are lower & more frequent, heat fluxes are greater and stress much greater than climatology states. Climate modelers take note. * Data on storms and fronts is revolutionary. (Patoux, J., G.J. Hakim and R.A. Brown, 2004: Diagnosis of frontal instabilities over the Southern Ocean, Monthly Weather Review)

  16. The Newest satellites:6-20-2014 New scatterometers; One K-band and one C-band dedicated to hurricane analyses. A scatterometertamden with a SAR (100-meter resolution) for global surface winds. In the meantime……

  17. Lidar PBL possibilities Initialization for Weather & Climate Models Roll details Aerosol statistics PBL (Inversion) height PBL turbulence spectrum Surface characteristics R. A. Brown 2010

  18. Geostrophic Wind or the scatterometer 1-km wind VG=P / ( f ) 30-meters Mid- PBL V = P / ( f) - Fviscous Lidar average wind in PBL 1-3 KM Geostrophic Wind direction 25° (Stable strat.) 18° (neutral stratification) Surface wind 5° (Unstable strat.) -10° to 40° (Thermal Wind Effect) R. A. Brown U. ConcepciÓn

  19. Practical Aspects of Wind Measurements available for parameterization: Surface ‘Truth’ Limits Ship winds: Sparse and inaccurate (except some Met. Ships). Buoy winds: Sparse; a point. They tilt; have variable height - miss high winds and low wind directions. GCM winds: Inaccurate physics in PBL Models; Toolow high winds, too high low winds. Resolution coarse (getting better). 5/10 RAB

  20. Practical Aspects of a Geostrophic Wind Model Function ̶̶ (implied Surface Pressure fields) ------------------------------------- Surface ‘Truth’ Limits (pressure fields) Buoy and ship pressures: Sparce but accurate in low and high wind regimes. GCM: Good verification; compatible scale 11-99, ’08 RAB

  21. Revelations from scatterometers • * Ship or Buoy winds are not good surface truth in general. Hence the climate record is incorrect. • Weather & climate PBL models have the wrong physics. • Satellite PBL wind data can be used to improve weather forecasts and climate data * Data on storms and fronts is revolutionary. (Patoux, J., G.J. Hakim and R.A. Brown, 2004: Diagnosis of frontal instabilities over the Southern Ocean, Monthly Weather Review)

  22. CROSS-VALIDATION of scatterometer winds via sea-level pressure retrieval JérômePatoux Ralph C. Foster Robert A. Brown May 19, 2010

  23. Original winds New winds (SLP_u10) Derive a new set of winds from the SLP field

  24. The scatterometer-derived SLP fields compare well with NCEP and ECMWF SLP analyses.

  25. Comparison of QS- and ASCAT-derived SLP fields

  26. Surface Pressures QuikScat analysis ECMWF analysis

  27. Applications: Midlatitude cyclone intensification, tracking, and climatology of air-sea fluxes. Patoux J., X. Yuan and C. Li, 2009: Satellite-based midlatitude cyclone statistics over the Southern Ocean. Part I: Scatterometer-derived pressure fields and storm tracking, J. of Geophys. Res., D04105, doi:10.1029/2008JD010873 . Yuan X., J. Patoux and C. Li, 2009: Satellite-based midlatitude cyclone statistics over the Southern Ocean. Part II: Tracks and surface fluxes, J. of Geophys. Res., D04106, doi:10.1029/2008JD010874.

  28. Programs and Fields available onhttp://pbl.atmos.washington.eduQuestionsto rabrown, neal or jerome@atmos.washington.edu • Direct PBL model: PBL_LIB. (’75 -’00) An analytic solution for the PBL flow with rolls, U(z) = f( P, To , Ta , ) • The Inverse PBL model: Takes U10 field and calculates surface pressure field P (U10 , To , Ta , ) (1986 - 2000) • Pressure fields directly from the PMF: P (o) along all swaths (exclude 0 -  5° lat.?) (2001) • Surface stress fields from PBL_LIB corrected for stratification effects along all swaths (2001) http://blog.seattlepi.com/robertbrown/ R.A. Brown 2010

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