12-5€¦ · Increased ability to resolve short lived intense precipitation events (thunderstorms,...
Transcript of 12-5€¦ · Increased ability to resolve short lived intense precipitation events (thunderstorms,...
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Olivier P. PratOlivier P. Prat 11, Brian R. Nelson, Brian R. Nelson 22, and Scott E. Stevens, and Scott E. Stevens 11
11Cooperative Institute for Climate and Satellites and NOAA/NCDC, Asheville, NC Cooperative Institute for Climate and Satellites and NOAA/NCDC, Asheville, NC 22Remote Sensing Applications Division, NOAA/NESDIS/NCDC, Asheville, NCRemote Sensing Applications Division, NOAA/NESDIS/NCDC, Asheville, NC
ERAD 2012 ERAD 2012 77thth European Conference on Radar in Meteorology and HydrologyEuropean Conference on Radar in Meteorology and Hydrology
June 25June 25--28, 201228, 2012
CHARACTERIZATION OF PRECIPITATION
FEATURES IN THE SOUTHEASTERN UNITED
STATES USING HIGH SPATIAL AND TEMPORAL
RESOLUTION QPE DERIVED FROM THE NATIONAL
MOSAIC AND MULTI-SENSOR QPE (NMQ/Q2)
• NMQ Reanalysis: 1998-2010 for a pilot domain (9 NEXRAD)
• Precipitation: Seasonal, daily, hourly, by event
• NMQ Comparison with:
• TRMM Satellite products (2A25, 3B42)
• Rain gauge data (70 RG in dense Network)
• Conclusion and Future work
ERAD 2012 25-29 June, Toulouse
Outline
• Developed at the National Severe Storms Laboratory (NSSL)
• Estimates of Precipitation
• Primary surface Radar based
• Incorporates RUC model data and gauge networks
• Represents significant step in resolution
• 1-km spatial resolution
• 5-min temporal resolution
ERAD 2012 25-29 June, Toulouse
National Mosaic and Multi-sensor QPE (NMQ/Q2)
ERAD 2012 25-29 June, Toulouse
NMQ
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• 9 Radar Sites over the Carolinas
• 13-yr of Level II data
ERAD 2012 25-29 June, Toulouse
NMQ Reanalysis Pilot Project (1998-2010)
• Collaboration CICS-
NC, NCDC, NSSL,
RENCI, NC State Univ.
• Data Management and
organization
• TBs of data
• CPUs
70 RGs
NMQ/Q2 : Seasonal Precipitation (1km)
Win
ter
Sum
mer
Spring
Fall
Blockage
Terrain
Blockage
Terrain
Blockage
Buildings
Blockage
Buildings
Gulf
Stream
Gulf
Stream
Side
Lobe
Side
Lobe
Sea
Breeze
Sea
Breeze
NMQ/Q2 : Maximum Daily Precipitation
Win
ter
Sum
mer
Spring
Fall
Winter
Storm/Snow
Winter
Storm/Snow
Tropical
Cyclones
Tropical
Cyclones
Floyd
(1999)
Floyd
(1999)
Isabel
(2003)
Isabel
(2003)
NMQ/Q2 : Maximum Hourly Precipitation
Win
ter
Sum
mer
Spring
Fall
Seasonal Distribution of
Storms
Seasonal Distribution of
Storms
Storm TracksStorm Tracks
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ERAD 2012 25-29 June, Toulouse
Precipitation Features : Warm Season Event
Hurricane Frances (2004/09/07 : 1235UTC)
1235UTC
1200UTC
3-hr
1235UTC
� Comparable patterns for rainfall distribution
� Local differences (beam blocking, rain-rate estimation algorithms, sensors, sites processed …)
5-min25
-km
1-km
5-km1-km
ERAD 2012 25-29 June, Toulouse
Precipitation Features : Cold Season Event
1200UTC
� Higher instant precipitation for NMQ than for TPR 2A25
� Higher 3-day Accumulation for NMQ with more detailed pattern at the ground
25-k
m1-
km
5-km1-km
0230UTC
�
�
�
�
�
�
�
�
�
�
�
�
2004 Christmas Eve Snowstorm (2004/12/26 : 0230UTC)
3-day 5-min
ERAD 2012 25-29 June, Toulouse
Seasonal differences TPR 2A25 and NMQ (5km)
2A25
Sum
mer
NM
Q S
umm
er
Diff. S
umm
er
� Important differences over the mountains (beam blocking)
� WINTER & SPRING : TPR 2A25 > NMQ
� SUMMER & FALL : NMQ > TPR 2A25
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
DJF MAM JJA SON YEAR
ΣΣ ΣΣ [2
A25
- Q
2]/2
A25
(-)
ERAD 2012 25-29 June, Toulouse
Seasonal differences TMPA 3B42 and NMQ (25km)
Win
ter
Sum
mer
Spring
Fall
� Important differences over the mountains (beam blocking)
� Important differences along the coasts (sea breeze)
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ERAD 2012 25-29 June, Toulouse
Seasonal PDFs (1998-2010)
0.00
0.05
0.10
0.15
0.1 1 10 100
Rel
ativ
e R
ain
Vol
ume
(%)
Rain Rate (mm/h)
TRMM TMPA 3B42
DJF
MAM
JJA
SON
0.00
0.05
0.10
0.15
0.1 1 10 100
Rel
ativ
e R
ain
Vol
ume
(%)
Rain Rate (mm/h)
NMQ/Q2
DJF
MAM
JJA
SON
� Higher seasonal variability for NMQ/Q2 PDFs
� Summer NMQ/Q2 PDF indicates higher rain rates (convective events)
� Winter NMQ/Q2 PDF indicates a more widespread rain rate contribution
(cold precipitation: snow, mixed phase …)
TRMM 3B42 NMQ
� Lower Avg. Rain Rate (-11%) for NMQ during the cold season (DJF-SON)� Higher Avg. Rain Rate (+17%) for NMQ during the warm season (MAM-
JJA)� Higher Annual Rain Rate for NMQ (+8%)
0
1
2
3
4
DJF MAM JJA SON YEAR
Aver
age
Rai
n R
ate
(mm
/h)
NMQ/Q2 TRMM 3B42
ERAD 2012 25-29 June, Toulouse
Low/High Rain Rate ContributionTRMM 3B42 NMQ
� Higher contribution for Q2 in the low rain intensity domain(RR<1mm/h)
���� Higher sensitivity for low rain-rate detection
0%
20%
40%
60%
80%
100%
DJF MAM JJA SON YEAR
Rai
n R
ate
Con
trib
utio
n (%
)
TRMM 3B42 RR>10mm/h 1<RR<10mm/h RR<1mm/h
0%
20%
40%
60%
80%
100%
DJF MAM JJA SON YEAR
Rai
n R
ate
Con
trib
utio
n (%
)
NMQ/Q2 RR>10mm/h 1<RR<10mm/h RR<1mm/h
� Higher contribution for Q2 in the high intensity domain (RR> 10mm/h)���� Increased ability to resolve short lived intense precipita tion
events (thunderstorms, convective events …)
ERAD 2012 25-29 June, Toulouse
Diurnal Cycle : RG and NMQ
Win
ter
Sum
mer
0.00
0.04
0.08
0.12
0.16
0.20
0 6 12 18 24
Aver
age
RR
(m
m/h
)
Time (LST)
RG : DJF
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 6 12 18 24
Aver
age
RR
(m
m/h
)
Time (LST)
RG : JJA
0.00
0.04
0.08
0.12
0.16
0.20
0 6 12 18 24
Aver
age
RR
(m
m/h
)
Time (LST)
NMQ : DJF
RG_DJF=2.21 mm/day NMQ_DJF=2.11 mm/day
RG_JJA=3.78 mm/day NMQ_JJA=3.66 mm/day
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 6 12 18 24
Aver
age
RR
(m
m/h
)
Time (LST)
NMQ : JJA
NMQ_JJA=3.66 mm/day
ERAD 2012 25-29 June, Toulouse
Conclusion and Future WorkPRECIPITATION FEATURES AT HIGH RESOLUTION (NMQ/Q2) :
1. Good agreement between average RR derived from Q2 and 3B42 (+8% yearly)
2. Higher inter-seasonal differences for the PDFs derived from NMQ than 3B42.
3. Important local differences due to beam blockage over the mountains. Necessity of a
global MULTI-SENSOR approach to assess reliable precipitation estimates
FUTURE WORK: REANALYSIS
1.Extend the current domain of study to
32 radars and the entire CONUS
2.Improve artifact identification/removal
(Beam Blockage, AP, …)
3.Incorporate rain gauge measurements
to adjust Q2 rain accumulation (RG
adjusted products)
FUTURE WORK: COMPARISON
1. Impact of T/S resolution on
precipitation features
2. Diurnal Cycle at fine scale
3. Precipitation Types (Stra/Conv)
4. Precipitation Phases (Liquid/Frozen)
5. PDFs (low/extremes RR)
This work is supported by the Cooperative
Agreement NOAA Grant NA09NES4400006