High-resolution RCM simulation of Kansas convective storms: Preliminary results William J. Gutowski,...

High-resolution RCM simulation High-resolution RCM simulation of of

Kansas convective storms: Kansas convective storms: Preliminary resultsPreliminary results

William J. Gutowski, Jr., & David FloryWilliam J. Gutowski, Jr., & David Flory

Dept. Geol. & Atmospheric SciencesDept. Geol. & Atmospheric SciencesDept. of AgronomyDept. of Agronomy

Iowa State UniversityIowa State University

MotivationMotivation

Study Basin-Scale Land-Atmosphere Water CycleStudy Basin-Scale Land-Atmosphere Water Cycle

Focus: Walnut River Basin (Kansas, USA)Focus: Walnut River Basin (Kansas, USA)

GCIP Large-Scale GCIP Large-Scale Area - SouthwestArea - Southwest

Observations:Observations:

CASESCASES

ABLEABLE

ARMARM


Flat TerrainFlat Terrain

Convective Convective SystemsSystems

Study Basin-Scale Land-Atmosphere Water CycleStudy Basin-Scale Land-Atmosphere Water Cycle

Focus: Walnut River Basin (Kansas, USA)Focus: Walnut River Basin (Kansas, USA)


10-6

10-4

10-2

100

0 2 4 6 8 10

Daily Precip. Intensity: Apr - Sep

OBS-1d

MOD-1d

frac

tion

[cm/d]

Model & SimulationModel & Simulation

NCAR/Penn State Non-hydrostatic MM5 (V3.3)NCAR/Penn State Non-hydrostatic MM5 (V3.3) Modified Grell cumulus convectionModified Grell cumulus convection Mixed-phase microphysicsMixed-phase microphysics RRTM & Dudhia radiationRRTM & Dudhia radiation Burk-Thompson PBLBurk-Thompson PBL Smirnova et al. land surface modelSmirnova et al. land surface model

Parallel Code Parallel Code Cluster computation Cluster computation

20-km grid (120 x 150)

Grell & Pagowski

1994 - 1999 1999



5-km grid (121 x 165)

May - August 1997 (after spin-up)

20-km grid (120 x 150)

Grell & Pagowski

1994 - 1999

Results - PrecipitationResults - Precipitation

0

100

200

300

400

500

120 140 160 180 200 220 240

Domain Averaged Precipitation

CDC Obs

Model

Cum

ulat

ive

Pre

cip

[mm

/d]

Day of 1997


0

2

4

6

8

0 4 8 12 16 20 24

Precipitation Diurnal Cycle

EastWestWhole Domain

[mm

/d]

Time [Local ST]

Precipitation & Vertical WindPrecipitation & Vertical Wind

20 LST - 20 June20 LST - 20 June

ContoursContours

Precip: Precip: last hour last hour 5 mm/d 5 mm/d (filled)(filled)

Vert. Motion: Vert. Motion: 300 hPa 300 hPa instantaneousinstantaneous 2 m/s 2 m/s (lines)(lines)


10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

0 5 10 15 20 25 30 35

Precipitation Histogram

CDC5-km model

Fra

ctio

nal C

ount

[cm/d]


10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

0 5 10 15 20 25 30 35


CDC5-km model20-km aggregate

Fra

ctio

nal C

ount

[cm/d]


10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

0 5 10 15 20 25 30 35


Aggregate (20 km)

20-km model

Fra

ctio

nal C

ount

[cm/d]


10-3

10-2

10-1

0 1 2 3 4


CDC5-km model20-km model

Fra

ctio

nal C

ount

[cm/d]

Results - Vertical MotionResults - Vertical Motion

10-9

10-7

10-5

10-3

10-1

-10 0 10 20 30 40

Vertical Motion Frequency

5-km20-km

Fre

quen

cy

[m/s]

Results - Vertical MotionResults - Vertical Motion

10-9

10-7

10-5

10-3

10-1

-10 0 10 20 30 40

Vertical Motion Frequency

5-km20-kmAggregate

Fre

quen

cy

[m/s]

Need More FromNeed More From Convection Parameterization?Convection Parameterization?

Grid % Convective Param Precipitation

5 km 29%

20 km 30%

ConclusionConclusion

1.1. Credible simulation of precipitationCredible simulation of precipitation Cumulative amountCumulative amount Diurnal cycleDiurnal cycle Somewhat organized evolutionSomewhat organized evolution

2.2. But … excessive single-grid vertical But … excessive single-grid vertical motion?motion? Strong motion, generally at single pointsStrong motion, generally at single points Excessive high-intensity precip. on 20-om Excessive high-intensity precip. on 20-om

grid?grid?

ConclusionConclusion

Thanks to: Thanks to: Georg Grell & Mariusz Pagowski (FSL)Georg Grell & Mariusz Pagowski (FSL)John Taylor (Argonne NL)John Taylor (Argonne NL)Martyn Clark (CIRES)Martyn Clark (CIRES)

Acknowledgement: U.S. NOAA GAPPAcknowledgement: U.S. NOAA GAPP

ProgramProgram

http://www.ogp.noaa.gov/mpe/gapp/gapp/abstracts/clark.htm














0

5

10

15

20

25

120 140 160 180 200 220 240

Daily Precipitation

CDC OBS

Model

[mm

/d]

Day of 1997

Station Distribution - CDC AnalysisStation Distribution - CDC Analysis

Precip. Diurnal Cycle Precip. Diurnal Cycle Upper Ms. RiverUpper Ms. River

QuickTime™ and a GIF decompressor are needed to see this picture.


ResultsResults

0

20

40

60

80

100

120

0 20 40 60 80 100 120 140

Scaling

Code

Perfect ScalingSim

ula

ted

Ho

urs

per

Ho

ur

# Nodes

High-resolution RCM simulation of Kansas convective storms: Preliminary results William J. Gutowski,...

Documents

Transcript of High-resolution RCM simulation of Kansas convective storms: Preliminary results William J. Gutowski,...