phys 622 - clouds spring ‘04 s. platnick (nasa gsfc/umbc phys adjunct faculty)
DESCRIPTION
PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty). Texts: Rogers, R.R., and M. K. Yau, A Short Course in Cloud Physics , Pergamon Press, 1989. Twomey, S., Atmospheric Aerosols , Elsevier Publishing, 1977. PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/1.jpg)
PHYS 622 - Cloudsspring ‘04
S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)
Texts:
Rogers, R.R., and M. K. Yau, A Short Course in Cloud Physics, Pergamon Press, 1989.Twomey, S., Atmospheric Aerosols, Elsevier Publishing, 1977.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 2: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/2.jpg)
Clouds - The “Wet” Aerosol
• “Wet” aerosol: much of the mathematics (e.g., size distribution, etc.) used for characterizing aerosol microphysics applies to clouds.
• A cloud definition: visible suspension of water and/or ice particles in the atmosphere.
– Key word is visible, but not quantitative. Example, “sub-visual cirrus” (observed through non-visible, non-passive sensors/imagers or lidars).
• Cloud physics: branch of physical meteorology, study of cloud formation (macrophysical & microphysical), lifecycles, precipitation, radiation, etc.
– Macrophysical: larger scale spatial information, total/column water amounts, etc.
– Microphysical: thermodynamic phase, size distribution, ice particle shape (habit), water content, etc.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 3: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/3.jpg)
Why Clouds?
• Weather – Dynamics: Latent heat and/or radiative effects impacting atmospheric
stability/instability, atmospheric heating/cooling– Radiation (e.g., surface heating)
• Chemical processes
• Climate– General circulation– Hydrological cycle– Radiation budget
Clouds are a critical component of climate models (for reasons cited above) and therefore also to climate change studies
• Not well-represented in climate models• Climate change: cloud-climate feedback, cloud-aerosol
interactions (to be discussed), etc.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 4: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/4.jpg)
1. Evaporation, transpiration (plants)
2. Atmospheric transport (vapor)
3. Condensation (liquid water, ice)
4. Precipitation
5. Surface transport (continental rivers, aquifers and ocean currents)
Earth’s Hydrological Cycle - Schematic
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 5: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/5.jpg)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
NASA TRMM (Tropical Rainfall Measurement Mission) Tropical cyclone Elita
Precipitation RadarPrecipitation Radar
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 6: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/6.jpg)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
TRMM 16 Feb 2004 weekly global rainfall accumulation
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 7: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/7.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 8: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/8.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 9: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/9.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Earth’s Radiation Budget - Schematic
![Page 10: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/10.jpg)
CERES (Clouds & Earth Radiant Energy System experiment) Radiation Budget Measurements - NASA Terra
(March 2000 - May 2001)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Record setting heat wave in CA, NV
Courtesy CERES Science Team, NASA LaRC
![Page 11: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/11.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Cloud-aerosol interactions ex.: ship tracks (27 Jan. 2003, N. Atlantic)
MODIS (MODerate resolution Imaging Spectroradiometer)
![Page 12: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/12.jpg)
Cold front - steep frontal slopes
Warm front - shallow frontal slopes
Convective development (mesoscale, local)
Synoptic development
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 13: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/13.jpg)
MODIS (MODerate resolution Imaging Spectroradiometer) true-color composite, NASA Terra, ~1030 LT
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 14: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/14.jpg)
Cloud Classifications (a nomenclature)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Genera
(main groups - high,
middle, low altitude
clouds, and clouds of
vertical extent)
Species
(shape, structure)
Variety
(special characteristics)
Cirrus uncinus, fibratus, …
Cirrocumulus Stratiformis, lenticularis
Cirrostratus fibratus
Altocumulus
Altostratus
high
leve
l m
id-le
vel
![Page 15: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/15.jpg)
Cloud Classifications, cont.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Genera Common Species Variety
Nimbostratus
Stratocumulus
Stratus
Cumulus humilus, congestus
Cumulonimbus
low
leve
l (ba
se)
vert
ical
ext
ent
(pot
entia
lly)
![Page 16: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/16.jpg)
cirrus
alto cumulus
cirrostratus: thin cirrus, note 22° halo => hexagonal crystals, parhelia (sundogs) => oriented crystals
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 17: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/17.jpg)
cumulus (fair weather) mammatus (implies sinking air)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
cumulus congestus (from NASA WB-57, July 13 2002)
![Page 18: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/18.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, PlatnickKelvin-Helmholtz waves
![Page 19: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/19.jpg)
Cumulonimbus (from NASA ER-2, July 19 2002)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 20: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/20.jpg)
Overview of Cloud Climatologies (statistics)- What do we know? How do we know it?
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
• Quantities of interest – Cloud frequency (fraction), cloud-top height, cloud phase (ice vs.
liquid water), optical properties (optical thickness), microphysics (particle size), column water amount (aka, “water path”), solar and IR radiative impact
• Historic data sets– Ground observations
• e.g.: Warren, S. G., et al. 1988: Global distribution of total cloud over and cloud type amounts over the ocean. NCAR/TN-317+STR [Available from the National Center for Atmospheric Research, Boulder, CO, 80307]
– Satellite observations• ISCCP (International Satellite Cloud Climatology Project), solar reflective
& IR techniques– amount, temperature, optical thickness, water path
• HIRS (High Resolution Infrared Radiation Sounder - on NOAA polar orbiters), GOES VAS (VISSR [Vis-Ir Spin-Scan Sounder] Atmospheric Sounder)
– amount, effective emissivity, and pressure heights with “CO2 slicing” technique
![Page 21: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/21.jpg)
Overview of Cloud Climatologies (statistics), cont.
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
• SSM/I () - microwave passive remote sensing– liquid water path
• ERBE (Earth Radiation Budget Experiment) - mid-80’s, instruments flown on the Earth Radiation Budget Satellite (ERBS), and NOAA -9, -10
• Recent/new data sets– Satellite observations
• Solar IR imager: MODIS, flown on Terra, Aqua• Microwave: AMSR (Japanese ADEOS-II), AMSR-E (Aqua)• Radiation Budget: CERES (Clouds and the Earth’s Radiant Energy
System) - next generation of radiation budget measurements, flown on TRMM, Terra, Aqua
![Page 22: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/22.jpg)
HIRS cloud frequency vs. month[Wylie et al., Journal of Climate, Vol. 7, No. 12, December, 1994]
![Page 23: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/23.jpg)
HIRS cloud frequency vs. altitude (September)
![Page 24: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/24.jpg)
HIRS cloud frequency vs. month for “thicker” clouds (opt thickness >6)
![Page 25: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/25.jpg)
ISCCP climatology exampleslow-level cloud amount (%)
![Page 26: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/26.jpg)
ISCCP climatology examplesmid-level cloud amount (%)
![Page 27: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/27.jpg)
ISCCP climatology exampleshigh-level cloud amount (%)
![Page 28: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/28.jpg)
AMSR-E cloud liquid water pathSept 2003
(from F. Wentz, http://www.ssmi.com/)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 29: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/29.jpg)
Cloud Microphysics
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 30: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/30.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Clouds Particle Scales
![Page 31: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/31.jpg)
Cloud Microphysical Quantities
• Size distribution [n(r)] - droplet size pdf
• Thermodynamic phase (liquid water, ice)
• Number concentration [N] - e.g., cm-3; range: 10’s cm-3 - 100’s cm-3 for liquid water droplets, 10 liter-1 for ice particles
• Water Content [LWC, IWC] - mass density, e.g., g-m-3
• Water Path [W] - vertical integration of water content, e.g., g-m-2
• Particle Size Moments
– Mean
– Effective radius [re] - radiatively relevant moment
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 32: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/32.jpg)
Cloud Microphysical Quantitiesschematic of vertically inhomogeneous cloud (horizontally homogeneous)
N(z) n0
(r,z)dr
LWC(z) l4
3 r3(z) N(z)
liquid water path : W LWCzbase
ztop
(z)dz
re (z) r3(z)
r2(z)one def. for nonspherical ice particles
3
4
V (z)
Ac (z)
size distribution, n(r,z)
z, p
surface
zztop, pptop
zzbase, ppbase
![Page 33: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/33.jpg)
MODIS monthly cloud fraction - Sept. 2003
Ice cloud fraction
Liquid water cloud fraction
Sc regimes
ITCZ (climatological feature)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 34: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/34.jpg)
MODIS monthly cloud particle size retrievals - Sept. 2003
Ice cloud particle effective radius
Liquid water cloud particle effective radius (QA)
Sc regimes
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
![Page 35: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/35.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Clouds are difficult, in part, by the natureof the relevant spatial scales and interdisciplinary fields
Scale Relevant Physics
synoptic ~1000s km
(large scale dynamics/thermodynamics, vapor fields)
mesoscale ~100s km
local (cloud scale) <1-10 km
(dynamics/thermodynamics, turbulence, mixing)
particle µm - mm
(nucleation, surface effects, coagulation,
turbulence, stat-mech)
molecular
![Page 36: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/36.jpg)
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Co
ld C
lou
d P
roce
sses
War
m C
lou
d
Pro
cess
es
![Page 37: PHYS 622 - Clouds spring ‘04 S. Platnick (NASA GSFC/UMBC PHYS Adjunct Faculty)](https://reader036.vdocument.in/reader036/viewer/2022062519/56814d05550346895dba346d/html5/thumbnails/37.jpg)
PHYS 622 Clouds
Emphasis on cloud microphysics: cloud particle nucleation, growth
• Water Clouds – Formation concepts– Water path for adiabatic cloud parcel– Nucleation theory for water droplets
• Ice Clouds
• Precipitation mechanisms
PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick
Next 2,3 lectures}