IHOP Workshop – Toulouse – June 2004 Multiscale Analyses of Moisture Transport by the Central Plains Low-Level Jet during IHOP Edward I. Tollerud 1, Brian

IHOP Workshop – Toulouse – June 2004

Multiscale Analyses of Moisture Transport by the Central Plains Low-Level Jet during IHOP

Edward I. Tollerud1, Brian D. Jamison2, Fernando Caracena1, Steven E. Koch1, Diana L. Bartels1,Randall S. Collander2

1NOAA Research - Forecast Systems Laboratory, Boulder, CO 2Cooperative Institute for Research in the Atmosphere – Colorado State University, Fort

Collins, CO

LIDAR DATA

R. Michael Hardesty3, Brandi J. McCarty4, Christoph Kiemle5, and Gerhard Ehret5

3NOAA Research - Environmental Technology Laboratory, Boulder, CO

4Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO

5German Aerospace Center (DLR), Germany


FSL/FRD IHOP Science Objectives

QPF Assessment

Design and Compare model runs for sensitivity to input data

LLJ Moisture Budget

Computations with LLJ research flight data

Scales of Moisture Transport by LLJ

Qualitative Comparison of Data Analyses


Flight Plans and Data Platforms


“Perfect storm” scenario

2004

(What we wanted…)


“Perfect storm” scenario(What we wanted…)


“Perfect storm” scenario(What we wanted…)


(What we got…)

LAPS Research Analysis

Isotachs (kt), 825 hpa

1300 UTC 9 June 2002


(What we got…)


Scales of Moisture Transport

Lidar-Scale

Dropsonde-Scale

Radiosonde-Scale



Lear Drop Times and Locations, Circuits 1 and 2



June 9 1200 UTC Radiosonde analysis along North Flight Leg – v x q, theta



June 9 1200 UTC Radiosonde analysis along South Flight Leg – v x q, theta


Falcon drops Circuit one North Leg v x q, theta



Lear drops Circuit two North Leg v x q, theta



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Flux Comparison - J une 9, 12:51 UTC

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Dropsonde V Dropsonde U HRDL & DIAL Radiosonde

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Platform Intercomparison: Meridional Moisture Flux


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Platform Intercomparison: Meridional Moisture Flux

Flux Comparison - J une 9, 14:14 UTC

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Dropsonde V Dropsonde U HRDL & DIAL Radiosonde


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Flux Comparison - J une 9 - Falcon 14:08, Lear 13:04

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Interplatform comparison: Co-located Falcon and Lear Profiles

dt ~ 1h


V x q profile comparison, circuit 1 to circuit 2

dt ~ 4h

Flux Comparison - J une 9 - Lear 13:17, Lear 17:22

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Average V Flux Differences, J une 9

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Drop Point (Falcon)

Falcon vs Lear Avg V flux difference

Lear 1st vs Lear 2nd Avg V fluxdifference

Temporal Vs. Interplatform Differences: Meridional Moisture Flux during Circuit 1


Average U Flux Differences, J une 9

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Drop Point (Falcon)

Falcon vs Lear Avg U flux difference

Lear 1st vs Lear 2nd Avg U fluxdifference

Temporal Vs. Interplatform Differences: Zonal Moisture Flux during Circuit 1


Moisture Budget for IHOP Domain

Objectives

•Determination of significant contributing mechanisms•Assessment of unresolved transports: comparison of LIDAR covariances and budget residuals

Issues

•Stationarity Assumption•Off-perimeter Budget Terms•Surface Fluxes


Moisture Budget for IHOP Domain

At a point:q/t + vq (q)/p R where R=(errors, P, surface flux,etc.)

Over a volume:q/t + vq (q)/p R

Term by term: vq = v q + v’q’

• Budget domain is 3D box enclosed by data “curtains” beneath flight track• Compute layer average horizontal flux as vq dl• Domain size and flight patterns are compromise chosen to legitimize assumption of stationarity


Figure: v and q Lear second circuit!

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Impact of Vertical Correlations

Circuit 2, South Leg, 17:56 UTC, 9 J une

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Impact of Within-layer Vertical Correlations

Circuit 2, South Leg, 17:56 UTC, 9 J une

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Impact of Horizontal Correlations on Layer-averaged Moisture Flux

Circuit 1

Circuit 1, v q vs vq

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Layer Flux (m/ s) (g/ kg)

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Change of Flux With Time

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Temporal Change of Layer Averaged Horizontal Moisture Flux


Computations from Falcon Dropsondes, Circuit 1

Vertically Integrated Moisture Fluxes on Budget Domain

Boundary

South

North


Full 3D Domain Net Moisture Flux, First Falcon Circuit

The answer is: -3.3 mm/day

What was the question?


QPF Sensitivity to High-Density Initialization Data

Objective 1: Determine impact of IHOP research data (primarily dropsondes) in initialization dataset on LLJ forecast intensity and placement

Procedure: Compare two WRF forecasts (with /IHOP research data in LAPS initialization, and without) for 3 June and 9 June LLJ cases)

LIDAR usage: Qualitative forecast assessment

Status: Operational runs in process; re-acquisition of LAPS initialization datasets required for research runs in process (eg., revised dropsonde data)

Objective 2: Assess importance of surface fluxes to LLJ development

LIDAR usage: Initialization dataset

Status: Questionable


Operational WRF Research WRF (w/dropsondes)

12 h Precipitation, 13:00 UTC 9 June - 01:00 UTC 10 June 2002


Operational LAPS Research LAPS (w/dropsondes)

Isotachs, north leg, 1700 UTC


RH, 825 hpa, 1700 UTC

Research LAPS (w/dropsondes) Research WRF (w/dropsondes)


Conclusions and Future Efforts

Multiscale Structure of the LLJ

1) Several Platforms provide similar picture of LLJ

2) Examine pervasiveness of laminar structures

3) Estimate effects of small (LIDAR-scale) horizontal correlations

4) More detailed determination of temporal development of LLJ


Conclusions and Future Efforts

1) Influence of drops on analyses and forecasts small

2) Confirm with June 3 case

3) Compute model-predicted fluxes, compare research to baseline

4) Compute fluxes through model-domain top

5) Examine model-generated precipitation fields

QPF Implications


Lear, Falcon Drop Times and Locations, Circuit 1


4h forecast

1700 UTC

9 June 2002


Analysis

1700 UTC

9 June 2002



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Circuit 2



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Data and observations

Documents

IHOP Workshop – Toulouse – June 2004 Multiscale Analyses of Moisture Transport by the Central Plains Low-Level Jet during IHOP Edward I. Tollerud 1, Brian