Ground Based Measurements of
Aerosols and Precipitation
Douglas B. Collins
Prather Research Group
University of California, San Diego
CalWater2 Planning Workshop – 23 April 2014
UCSD/SIO Mobile Laboratory
Field-Deployable Platform
20’ x 7’ Double Axle Box Trailer
GVWR: 7000 lbs.
Power: 100 A (220 V) Max
Aerosols
Composition (d = 0.1 – 3 μm): Aerosol Time-of-Flight Mass Spectrometers (ATOFMS, x2)
Size Distributions (d = 0.01 – 20 μm): Scanning Mobility Particle Sizer, Aerodynamic Particle Sizer
Light Absorption/Black Carbon: 7-wavelength Aethalometer
Cloud Condensation Nuclei (CCN): Single Column CCN Counter, Condensation Particle Counter
PM2.5 Mass: Beta Attenuation Monitor (BAM)
Others: Continuous Flow Diffusion Chamber (Ice Nuclei; DeMott, Colo. State. Univ.)
Aerosol Ion Chromatography, Aerosol and CCN Capillary Electrophoresis (Roberts, SIO)
Trace Gases
Carbon Monoxide (CO), Nitrogen Oxides (NOx), Ozone (O3), Sulfur Dioxide (SO2)
CalWater Field Sites
UCSD/SIO Mobile Aerosol Laboratory
Precipitation Sampling (USGS)
Surface Met & Radar (HMT West/NOAA ESRL)
Sugar Pine Dam (SPD): 2009, 2010, 2011
Mariposa (MPI): 2010
Bodega Bay (BBY): 2014
STA
SPD
CZC
LHM
Precipitation Sampling (USGS)
Cazadero (CZC): 2011
Shasta Dam (STA): 2011
BBY
MPI
[Google Maps]
Aerosol Size Distributions & CCN Concentrations
Precipitation Sampling (USGS)
Lincoln (LHM): 2011
Yosemite Snow Sampling (NPS)
Crane Flat (CFT), Badger Pass (BPS),
Tuolumne Meadows (TMD): 2011
Sugar Pine Dam
Foresthill Backcountry, Tahoe National Forest
[Late January – Mid March]
STA
SPD
CZD
LHM
BBY
MPI
[Google Maps]
Elevation: 1066 m MSL
Locale: Remote, Rural (>10 km from I-80)
Access: 20 min drive from nearest lodging;
¼ mile hike from road (snow only)
Communications: Satellite Internet (HughesNet)
[No cellular or satellite phone reception]
Notable features:
1. Low aerosol concentrations (esp. coarse mode)
2. Sierra Barrier Jet/Aerosol interactions
3. New Particle Formation after precipitation
4. Snow and Rain both possible at ground level
Sugar Pine Dam
Foresthill Backcountry, Tahoe National Forest
[Late January – Mid March]
Ambient Particle Sources
Elevation: 1066 m MSL
Locale: Remote, Rural (>10 km from I-80)
Access: 20 min drive from nearest lodging;
¼ mile hike from road (snow only)
Communications: Satellite Internet (HughesNet)
[No cellular or satellite phone reception]
Notable features:
1. Low aerosol concentrations (esp. coarse mode)
2. Sierra Barrier Jet/Aerosol interactions
3. New Particle Formation after precipitation
4. Snow and Rain both possible at ground level
Bodega Bay
UC Davis Bodega Marine Laboratory
[February – March]
STA
SPD
CZD
LHM
Elevation: <10 m MSL
Locale: Coastal, active laboratory
Access: Lodging onsite
Communications: via Bodega Marine Lab
BBY
MPI
[Google Maps]
Notable features:
1. Strong contribution from marine aerosol
2. Central Valley influence via Petaluma Gap
3. Coastal barrier jet formation
4. Local burning (campfires), especially on
weekends can complicate regional scale signal
Bodega Bay
UC Davis Bodega Marine Laboratory
[February – March]
Ambient Particle Sources
Elevation: <10 m MSL
Locale: Coastal, active laboratory
Access: Lodging onsite
Communications: via Bodega Marine Lab
Notable features:
1. Strong contribution from marine aerosol
2. Central Valley influence via Petaluma Gap
3. Coastal barrier jet formation
4. Local burning (campfires), especially on
weekends can complicate regional scale signal
Bodega Bay
UC Davis Bodega Marine Laboratory
[February – March]
Elevation: <10 m MSL
Locale: Coastal, active laboratory
Access: Lodging onsite
Communications: via Bodega Marine Lab
Bodega Bay vs. Sugar Pine Dam
BBY has larger coarse mode,
which consists of mostly sea
spray aerosol
Notable features:
1. Strong contribution from marine aerosol
2. Central Valley influence via Petaluma Gap
3. Coastal barrier jet formation
4. Local burning (campfires), especially on
weekends can complicate regional scale signal
Comparative Analysis
Sugar Pine Dam (Tahoe National Forest)
Bodega Bay (Bodega Marine Lab)
Pros
• Established aerosol dataset (3 years)
• Possibility for various phases of precip
• Receptor site for SNR Orographic Precip
• Clean, remote site
Pros
• Access to supplies, bio lab, office space
• Housing is on-site  data consistency
• Often receives clean marine air
• Petaluma gap flow, coastal jet, new particle
formation
• Backup power is provided (although it
pollutes the air heavily)
Cons
• Poor communication, very remote
• Access can be blocked for >24 hrs (snow)
[Can require heavy equipment]
• Power can be lost for >24 hrs (snow)
• Limited relationship to cloud chemistry
Cons
• Salty air can be problematic for electronics
• Conditions (and sources) can change very
quickly, real-time forecasting necessary
• Occasional local pollution (easy to filter)
Adding Value with Co-Location
Sugar Pine Dam, 2011
Aerosol
S-PROF
Precip
Thoughts for Future:
• LIDAR, Cloud Radar
DRUM
• Snow Pillow and SWE
Precip
Aerosol
Bodega Bay, 2014
449 MHz
+ RASS
• Hydrometeor Size
Distributions
Logistical Considerations
UCSD/SIO Mobile Lab needs
near-constant attention
Influence of local particle
sources can overshadow
regional-scale trends
Access and communications must
be reliable
C. McCluskey, Colo. State
Thank You!
MariposaYosemite Airport
Mariposa, CA
STA
SPD
CZD
LHM
BBY
MPI
[Google Maps]
Elevation: 670 m MSL
Locale: Rural, active road and air traffic
Access: Short drive to lodging
Communications: Generally available
Notable features:
1. Airport and truck traffic influenced signal
2. SBJ appeared to influence aerosol (like SPD)
3. Not strongly coupled to Central Valley
Strong local sources of particles make this site not
a good option for CalWater