Ana Barros1
Andrew Wood2
Francisco Munoz1
Julio-Cesar Rodriguez4
Dennis Lettenmaier2
Stephen S. Burges2
Ted Bohn2
Mekonnen Gebremichael1
Natalie Voisin2
Christopher Watts3
Monitoring the Diurnal Cycle ofLand-Atmosphere Interactions
During NAME/SMEX04
1Duke University2University of Washington3University of Sonora4IMADES
MotivationMotivation
Remote Sensing of Soil Moisture in Complex Terrain
Leverage on NAME data collection
Atmospheric Correction*
Explain Spatial Variability of Observed Soil Moisture
Understand Land-Atmosphere Interactions in Arid Regions
Exploratory Diagnostic Simulations with MM5 (@ 3km resolution)
June 5-7 2003
Surface Latent Heat
NW-SE
• Diurnal Cycle of Rainfall
Landform and organization of convective activity
Vegetation and the role of evapotranspiration
• Diurnal Cycle of Boundary Layer Winds
Relationship between organization of mountain-valley circulations and the diurnal cycle of rainfall
• Diurnal Cycle of Atmospheric Instability
Convective instability and the diurnal cycle of rainfall
ObjectivesObjectives
Vegetation Response to Rainfall
La Palma
0
510
15
2025
30
3540
45
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Tower
0
2
4
6
8
10
12
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
LOS CHINOS
0
10
20
30
40
50
1 3 5 7 9 11 13 15 17 19 21 23
Local Hour
Pre
cip
itat
ion
(m
m)
east
valley
slopes
Spatial VariabilityOf the Diurnal Cycle of Rainfall
SW- late afternoonEast- early afternoon
East- early afternoonNNW- early evening
NCAR/ATDTAOS system
a) Daytime
b) Evening/Nighttime
NAM diurnal cycle in the San Miguel
Moist anabatic upslope breezeTerrain induced asymmetry(Up) Valley windReturn Flow
(Downvalley) Mountain wind
Lateral Katabatic drainage breezeValley convergenceSouthward moving storms
Synoptic winds
Return flow
Surface FlowLocalwinds
S E N W 0 1 2 3 4 5 [m/s]
July 29, 2004
Low-level (downvalley) mountain wind
Mid-levelReturn Flow
AnabaticValley Winds
stable
stable
residual layer
mixed layersurface layer
Growthof the
Mixed layer
Stable
No RainConditions
La Palma
0
510
15
2025
30
3540
45
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Tower
0
2
4
6
8
10
12
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
LOS CHINOS
0
10
20
30
40
50
1 3 5 7 9 11 13 15 17 19 21 23
Local Hour
Pre
cip
itat
ion
(m
m)
east
valley
slopes
Spatial VariabilityOf the Diurnal Cycle of Rainfall
Synopticcontrols
LocalSurfacecontrols
a) Daytime
b) Evening/Nighttime
NAM diurnal cycle in the San Miguel
Moist anabatic upslope breezeTerrain induced asymmetry(Up) Valley windReturn Flow
(Downvalley) Mountain wind
Lateral Katabatic drainage breezeValley convergenceSouthward moving storms
Synoptic winds
Return flow
Surface FlowLocalwinds
*
drydrydry
*wet
wet wet wetwet wet
dry
S
Question: What is the Contribution of Evapotranspiration to Daytime Rainfall?
Discussion
“Exploratory” Field Experiment
Raingauge NetworkSoundings (radiosondes, profilers, rainy conditions)LightningHigh-maintenance Tower(s)
Unique evidence of strong space-time structuring of rainfall and low-level circulations in a semi-arid region of complex terrain
Insolation Patterns (surface energy budget)Landform and topographyLand-cover
“Definitive” Field Experiment
Acknowledgments