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Lenschow - ATD retreat - 23 Jan 04 GEOPHYSICAL TURBULENCE Scientific and observational needs Geophysics − The physics of the earth and its environment,

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Presentation on theme: "Lenschow - ATD retreat - 23 Jan 04 GEOPHYSICAL TURBULENCE Scientific and observational needs Geophysics − The physics of the earth and its environment,"— Presentation transcript:

1 Lenschow - ATD retreat - 23 Jan 04 GEOPHYSICAL TURBULENCE Scientific and observational needs Geophysics − The physics of the earth and its environment, that is, earth, air, and (by extension) space.

2 Lenschow - ATD retreat - 23 Jan 04 PHILOSOPHICAL CONSIDERATIONS Close collaboration is essential between numerical modelers, laboratory simulators and observers. Progress in one area depends on progress in the others.

3 Schematic of energy spectrum within a plant canopy showing energy from shear production feeding energy into the spectrum at the integral scale (Λ) and energy from wake and waving production feeding into smaller scales in the inertial subrange (Kaimal & Finnigan, 1994).

4 Lenschow - ATD retreat - 23 Jan 04 SCIENTIFIC PROBLEMS Improve sub-filter scale parameterizations in large- eddy simulation models Investigate complex flow regimes –heterogeneous terrain –stable planetary boundary layer –turbulent layers in stably-stratified regions from the PBL to the stratosphere –“wall” flow regimes Study structures in turbulent flow –vortices –microfronts –rolls and cells

5 Lenschow - ATD retreat - 23 Jan 04 Shallow Drainage Flows – Mahrt, Vickers, Nakamura, Soler, Sun, Burns, & Lenschow – BLM, 101, 2001. Schematic cross-section of prevailing southerly synoptic flow, northerly surface flow down The gully, and easterly flow likely drainage flow from Flint Hills. Numbers identify the Sonic anemometers on the E-W transect. E is to the right and N into the paper.

6 Lenschow - ATD retreat - 23 Jan 04 Two RHI lidar scans from HRDL in CASES-99 illustrating the time de- pendence of waves. (a) at 05:30:49 UTC; (b) at 05:34:24 UTC. Note that the vertical scale is 7.5 times the hori- Zontal scale. Lidar Resolution 30 m. (From Blumen et al., Dynamics of Atmospheres and Oceans, 2001, Fig. 4, p. 197).

7 Lenschow - ATD retreat - 23 Jan 04

8 NEW TECHNOLOGY REQUIREMENTS Better spatial and temporal resolution for both in situ and remote (e.g. lidar and radar) measurements, including both scalars and velocity components Greater coverage of observational domain (i.e. larger ratio of largest resolved scale to smallest resolved scale) and better integration of measurements from instrument arrays (e.g. Intelligent Sensor Array) More accurate measurements of flow structures - from smallest scales (e.g. surface-layer eddies of 10’s of cms) to largest scales (e.g. pockets of cells, or lines of rolls of 10’s of kms)

9 Lenschow - ATD retreat - 23 Jan 04 POSSIBLE SENSOR DEVELOPMENTS Ground-based in situ sensors –IR humidity –Tsinober turbulence probe – Larger instrument arrays for hetereogeneous terrain studies subfilter-scale parameterization studies –Faster, smaller, cheaper (and more robust) sensors –Laser Doppler anemometer (smaller scale & higher resolution?) –………….

10 Lenschow - ATD retreat - 23 Jan 04 Tsinober Probe Measures, 3 components of, 9 components of,, andand 3 components of

11 Lenschow - ATD retreat - 23 Jan 04 ARRAY-1 z s = 6.90m, dy s = 6.70m z d = 3.45m, dy d = 3.35m

12 Lenschow - ATD retreat - 23 Jan 04 ARRAY-4 z s = 5.15m dy s = 0.63m z d = 4.15m dy d = 0.50m

13 Lenschow - ATD retreat - 23 Jan 04 IMPORTANT SCIENCE ISSUES Reconstructing atmospheric data from laboratory templates Comparing remote (e.g. lidar or radar) measurements with in situ measurements (e.g. velocity or trace constituents) …...

14 Lenschow - ATD retreat - 23 Jan 04

15 POSSIBLE SENSOR DEVELOPMENTS Remote –trace constituent and air velocity lidars with fine-scale resolution for ground and mobile platforms –millimeter Doppler radar –portable VHF wind profiler –…..

16 Lenschow - ATD retreat - 23 Jan 04 POSSIBLE SENSOR DEVELOPMENTS Aircraft –fine-scale temperature in cloud –fine-scale humidity measurement –fine-scale trace constituent measurement –laser velocity measurement (3-D) –velocity difference measurements (via pressure differences) –fine-scale ocean waves via lidar or radar –…..

17 Lenschow - ATD retreat - 23 Jan 04 NEW PLATFORMS Unmanned Aerial Vehicles (UAV) TRAnsect Measurement (TRAM) Balloon- and kite-borne sensor packages …..


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