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Introduction 12 August 15 July
Initiation and microphysical development ofconvective clouds observed over the Black
Forest mountains during COPS
Alan Blyth, Lindsay Bennett, and Yahui Huang
NCAS, U. Leeds
March 17, 2010
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July
Collaborators
Philip R.A. Brown, MO
Richard Cotton, MO
Jonathan Crosier, U Manchester
Keith N. Bower, U Manchester
Martin W. Gallagher, U Manchester
Hazel Jones, U Manchester
Alan M. Gadian, NCAS, U Leeds
Ralph Burton, NCAS, U Leeds
Tom W. Choularton, U Manchester
John Cardwell, U Manchester
Hugh Coe, U Manchester
Stephen D. Mobbs, NCAS, U Leeds
Martin Hagen, DLR
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July
Motivation
Low skill in forecasting convective precipitation; particularlytiming, location and amount
Major field campaigns to address summer-time convection:
International H20 Project (IHOP) in USA 2002Convective Storm Initiation Project (CSIP) in UK 2004/5Convective and Orographically-Induced Precipitation Study(COPS) in SW Germany/SE France 2007
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July
The Convective and Orographically-induced Precipitation Study (COPS)
Improve understanding of initiation and development ofconvection over complex terrain,Understand microphysics of the clouds and role ofaerosols on the development of precipitationTwo case studies: 12 August (initiation); and 15 July(microphysics and aerosols) 2007.
Comparison between Doppler on Wheels (DoWs) radardata with high-resolution simulations from the WeatherResearch and Forecasting (WRF) model on 12 AugustObservations of aerosols (ground-based and airborne) andcloud particles during penetrations of ascending cloud on15 July; MAC3 model runs and sensitivity studies
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July
COPS map
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
IOP 15a: 12 August, 2007
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Synoptic Conditions
Well-defined trough over the UK and surface low centred overnorthwest Scotland
Weak upper level ridge positioned over central Europe and weaksurface high
Diffluent flow at 500mb over E France and SW Germany
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Satellite Observations
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Satellite Observations
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Doppler on Wheels (DoW) Radar Observations
Location of 1st precip (11-14 UTC)
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
WRF Model Setup
Version 3.1121 vertical levelsInitialised by GFSanalyses at 0000 UTCused as boundaryconditions on outerdomainModel output every5mins for d3, 60mins ford1 and d2
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
WRF Results and Comparison with Obs
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
WRF Cross-Sections
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Cross-Section A
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Cross-Section B
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Cross-Section D
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Observations WRF / DoWs WRF X-Sects Summary
Summary of this case
DOW radar observations showed that precipitating clouds onlydeveloped between the north-south orientated Murg and NagoldValleys
WRF model used to investigate processes responsible forinitiating convection
Simulated thermodynamics, clouds and precipitation comparedwell with observations
Physical processes
elevated heating formed warm and moist coresconvergence lines controlled location of convection withincorescold-pool outflows generated secondary convection
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
IOP 8a: 15 July, 2007
Microphysical Development and Role of Aerosols
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Synoptic Conditions
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
IMK Radar showing N and S clouds
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Track of a/c; position of clouds
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Vertical velocity and conc from CPC
020
0040
0060
00
Time (UTC)
Con
cent
ratio
n(cm
−3)
134233 134253 134313 134333 134353 134413 134433 134453
−4
−2
01
23
45
Ver
tical
Vel
ocity
(ms−1
)
400
600
800
Top
ogra
phy
(m)
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Aerosol lidar backscatter: Murg Valley
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Aerodyne Time-of-Flight Aerosol Mass Spectrometer, Hornisgrinde
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Coarse-mode aerosol: Grimm OPC behind 4µm filter
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Aircraft penetrations: VW, LWC, SID-2 (d > 50µm)
−5
05
10
Time (UTC)
W (
m s
−1)
144447 144507 144527 144547 144607
01
23
45
67
8
Alti
tude
(km
)
(a)
0.0
0.4
0.8
1.2
Time (UTC)
LWC
from
JW
(gK
g−1)
144447 144507 144527 144547 144607
020
4060
Nic
e fr
om S
ID2
for
d >
50µ
m (
L−1)
1445 UTC, 4.6 km MSL; T ≈ -4◦C
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Aircraft penetrations: VW, LWC, SID-2 (d > 50µm)
−5
05
10
Time (UTC)
W (
m s
−1)
145707 145717 145727 145737 145747 145757
01
23
45
67
8
Alti
tude
(km
)
(b)
0.0
0.4
0.8
1.2
Time (UTC)
LWC
from
JW
(gK
g−1)
145707 145717 145727 145737 145747 145757
020
6010
014
0
Nic
e fr
om S
ID2
for
d >
50µ
m (
L−1)
1457 UTC, 5 km MSL, T ≈ -7◦C
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Aircraft penetrations: VW, LWC, SID-2 (d > 50µm)
−10
−8
−6
−4
−2
02
Time (UTC)
W (
m s
−1)
150920 150930 150940 150950
03
69
1317
2125
Alti
tude
(km
)
(c)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Time (UTC)
LWC
from
JW
(gK
g−1)
150920 150930 150940 150950
050
100
200
300
Nic
e fr
om S
ID2
for
d >
50µ
m (
L−1)
1509 UTC, 5.3 km MSL, T ≈ -9◦C
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(a) T=15 min
10m/s
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(b) T=20 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(c) T=25 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(d) T=30 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(e) T=35 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(f) T=40 min
MAC3 model: reference run
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(cm−3)(a) Max Nd= 558.2
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(L−1)(b) Max Ni= 3.918
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(L−1)(c) Max Ng= 0.0918
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(m−3)(d) Max Nr= 146.3
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(ms−1)(e) Max W= 12.79
Time (min)
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(a) T=15 min
10m/s
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(b) T=20 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(c) T=25 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(d) T=30 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(e) T=35 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(f) T=40 min
Biological ice nuclei
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(cm−3)(a) Max Nd= 558.2
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(L−1)(b) Max Ni= 704
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(L−1)(c) Max Ng= 5.673
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(m−3)(d) Max Nr= 1.922
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(ms−1)(e) Max W= 12.79
Time (min)
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(a) T=15 min
10m/s
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(b) T=20 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(c) T=25 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(d) T=30 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(e) T=35 min
Radial Distance (km)
Alti
tude
(km
)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
02
46
8
(f) T=40 min
Low aerosol
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(cm−3)(a) Max Nd= 126.4
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(L−1)(b) Max Ni= 24.18
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(L−1)(c) Max Ng= 0.7419
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(m−3)(d) Max Nr= 1226
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(ms−1)(e) Max W= 15.25
Time (min)
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Reflectivity from: Reference; biological IN; low aerosol
Alti
tude
(km
)
10 20 30 40 50 600
24
68
(a) Max Ref= 43.4 (dBZ)
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(b) Max Ref= 37.04 (dBZ)
Alti
tude
(km
)
10 20 30 40 50 60
02
46
8
(c) Max Ref= 65.8 (dBZ)
Time (min)
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
Introduction 12 August 15 July Overview Aerosols Cloud obs Model runs Summary
Summary of this case
High concentrations of relatively small ice particles
Conditions not suitable for HM
Biological nuclei, oxidised aerosol particles in vented polluted air anddesert dust – all possible candidates.
Model results: standard Meyers – hardly any ice particles; biological icenucleus scheme – high concentration of ice particles.
Increased emissions of biogenic VOC oxidation products from the trees
Venting of pollutants from valleys in BF mts can influence microphysicsand dynamics:
oxidised aerosol particles – more efficient ice nuclei?greater number of CCN causes cloud to be shallower andproduce less rain – cleaner cloud was more vigorous
Convection initiated by orographically-influenced flows may be modifiedby differences in aerosol loadings that are generated within the flows.
Alan Blyth, Lindsay Bennett, and Yahui Huang Convection observed during COPS
