Cloud microphysical structure analysis based on high-resolution insitu measurements

Konwar, Mahen; Prabhakaran, Thara; Khain, Alexander; Pinsky, Mark

doi:10.1175/jas-d-20-0229.1

Title: Cloud microphysical structure analysis based on high-resolution insitu measurements

Full Record
Other Related Research

Abstract

This study investigates the microphysical parameters and shapes of droplet size distributions (DSDs) along three aircraft traverses of developing convective clouds during Cloud Aerosol Interactions and Precipitation Enhancement Experiment (CAIPEEX) Phase III 2015 at a sampling frequency of 25 Hz. The droplet number concentration (Nc, cm^-3), and liquid water content (LWC, g m^-3) present steep gradients within zones of a few tens of meters near the cloud edges and relatively gentle gradients in the strong updraft zones. Sometimes, the horizontal LWC distribution resembles a trapezoidal shape with steep LWC and Nc gradients near the cloud edges. The LWC maximums (LWC_max) are lower than the adiabatic LWCs, but the high adiabatic fractions in the cloud core indicate low dilution. High LWC/LWC_max, largest droplets, and narrow and similarly shaped DSDs are found in the regions of high updrafts. Zones of low LWC/LWC_max are found close to the cloud edges, where DSDs are highly diverse, containing both large and small droplets. Finally, we analyze the mixing diagrams. Significant in-phase turbulent fluctuations in LWC and N_c were found. The effective radii change slightly across cloud updraft zones but decrease at the zone of low LWC/LWC_max ratio close to cloud edges. The spectra of LWCmore »« less

Authors:

Konwar, Mahen ^[1]; Prabhakaran, Thara ^[1]; Khain, Alexander ^[2]; Pinsky, Mark ^[2]

Indian Inst. of Tropical Meteorology, Pune (India). Ministry of Earth Sciences
Hebrew Univ. of Jerusalem (Israel)

Publication Date:: Thu May 20 00:00:00 EDT 2021

Research Org.:: Univ. of Oklahoma, Norman, OK (United States)

Sponsoring Org.:: USDOE Office of Science (SC); Israel Science Foundation

OSTI Identifier:: 1851157

Grant/Contract Number:: SC0008811; 2027/17; 2635/20

Resource Type:: Accepted Manuscript

Journal Name:: Journal of the Atmospheric Sciences

Additional Journal Information:: Journal Volume: 78; Journal Issue: 7; Journal ID: ISSN 0022-4928

Publisher:: American Meteorological Society

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; Meteorology & Atmospheric Sciences; Entrainment; Mixing; Updrafts/downdrafts; Convective clouds; Cloud microphysics; Drop size distribution

Citation Formats


                    Konwar, Mahen, Prabhakaran, Thara, Khain, Alexander, and Pinsky, Mark. Cloud microphysical structure analysis based on high-resolution insitu measurements.  United States: N. p., 2021. 
Web.  doi:10.1175/jas-d-20-0229.1.

Copy to clipboard


                    Konwar, Mahen, Prabhakaran, Thara, Khain, Alexander, & Pinsky, Mark. Cloud microphysical structure analysis based on high-resolution insitu measurements.  United States.  https://doi.org/10.1175/jas-d-20-0229.1

Copy to clipboard


                    Konwar, Mahen, Prabhakaran, Thara, Khain, Alexander, and Pinsky, Mark. Thu .  
"Cloud microphysical structure analysis based on high-resolution insitu measurements".  United States.  https://doi.org/10.1175/jas-d-20-0229.1.  https://www.osti.gov/servlets/purl/1851157.

Copy to clipboard


                    
@article{osti_1851157,

  title        = {Cloud microphysical structure analysis based on high-resolution insitu measurements},

  author       = {Konwar, Mahen and Prabhakaran, Thara and Khain, Alexander and Pinsky, Mark},

  abstractNote = {This study investigates the microphysical parameters and shapes of droplet size distributions (DSDs) along three aircraft traverses of developing convective clouds during Cloud Aerosol Interactions and Precipitation Enhancement Experiment (CAIPEEX) Phase III 2015 at a sampling frequency of 25 Hz. The droplet number concentration (Nc, cm-3), and liquid water content (LWC, g m-3) present steep gradients within zones of a few tens of meters near the cloud edges and relatively gentle gradients in the strong updraft zones. Sometimes, the horizontal LWC distribution resembles a trapezoidal shape with steep LWC and Nc gradients near the cloud edges. The LWC maximums (LWCmax) are lower than the adiabatic LWCs, but the high adiabatic fractions in the cloud core indicate low dilution. High LWC/LWCmax, largest droplets, and narrow and similarly shaped DSDs are found in the regions of high updrafts. Zones of low LWC/LWCmax are found close to the cloud edges, where DSDs are highly diverse, containing both large and small droplets. Finally, we analyze the mixing diagrams. Significant in-phase turbulent fluctuations in LWC and Nc were found. The effective radii change slightly across cloud updraft zones but decrease at the zone of low LWC/LWCmax ratio close to cloud edges. The spectra of LWC and Nc obey Kolmogorov -5/3 turbulence law. The radii of the correlation of LWC and Nc in updraft zones are of several tens of meters. Filaments up to 120–175 m in size are also noticed.},

  doi          = {10.1175/jas-d-20-0229.1},

  journal      = {Journal of the Atmospheric Sciences},

  number       = 7,

  volume       = 78,

  place        = {United States},

  year         = {Thu May 20 00:00:00 EDT 2021},

  month        = {Thu May 20 00:00:00 EDT 2021}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1175/jas-d-20-0229.1

Other availability

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Combined Effect of the Wegener–Bergeron–Findeisen Mechanism and Large Eddies on Microphysics of Mixed-Phase Stratiform Clouds

Journal Article Khain, Alexander ; Pinsky, M. ; Korolev, A. - Journal of the Atmospheric Sciences

Abstract The process of glaciation in mixed-phase stratiform clouds was investigated by a novel Lagrangian–Eulerian model (LEM) in which thousands of adjoining Lagrangian parcels moved within a turbulent-like velocity field with statistical parameters typical of the Arctic boundary layer. We used detailed bin microphysics to describe the condensation/evaporation processes in each parcel, in which droplets, aerosols, and ice particles were described using size distributions of 500 mass bins. The model also calculated aerosol mass inside droplets and ice particles. Gravitational sedimentation of droplets and ice particles was also accounted for. Assuming that droplet freezing is the primary source of icemore »« less
https://doi.org/10.1175/JAS-D-20-0269.1
Theoretical analysis of mixing in liquid clouds – Part IV: DSD evolution and mixing diagrams

Journal Article Pinsky, Mark ; Khain, Alexander - Atmospheric Chemistry and Physics (Online)

Evolution of droplet size distribution (DSD) due to mixing between cloudy and dry volumes is investigated for different values of the cloud fraction and for different initial DSD shapes. The analysis is performed using a diffusion–evaporation model which describes time-dependent processes of turbulent diffusion and droplet evaporation within a mixing volume. Time evolution of the DSD characteristics such as droplet concentration, LWC and mean volume radii is analyzed. The mixing diagrams are plotted for the final mixing stages. It is shown that the difference between the mixing diagrams for homogeneous and inhomogeneous mixing is insignificant and decreases with an increasemore »« less
Cited by 10
https://doi.org/10.5194/acp-18-3659-2018

Full Text Available
A cloud-evaporation parameterization for general ciculation models

Journal Article Schlesinger, M E ; Oh, J H - Monthly Weather Review; (United States)

An evaporation-zone (EZ) model for cloud evaporation is developed. In this model a cloud consists of I [open quotes]cloudlets,[close quotes] each comprising cloud droplets with radii from zero to r[sub max], the latter value depending on the drop size distribution (DSD). Evaporation occurs only within the EZ comprised of J[le]I cloudlets. When the cloudlet at cloud edge evaporates, the EZ progresses one cloudlet into the cloud's interior. This eventually results in evaporation of the cloud in time t[sub E] = K(H/h)r[sup 2][sub max](1[minus]S[sub e])[sup [minus]1] where H is the cloud thickness, h the EZ thickness, S[sub e] the environmental saturationmore »« less
https://doi.org/10.1175/1520-0493(1993)121<1239:ACEPFG>2.0.CO;2
Convective and Turbulent Motions in Nonprecipitating Cu. Part II: LES Simulated Cloud Represented by a Starting Plume

Journal Article Pinsky, Mark ; Eytan, Eshkol ; Koren, Ilan ; ... - Journal of the Atmospheric Sciences

The dynamic structure of a small trade wind cumulus (Cu) is analyzed using a novel approach. Cu developing in a shear-free environment is simulated by 10-m-resolution LES model with spectral bin microphysics. The aim is to clarify the dynamical nature of cloud updraft zone (CUZ) including entrainment and mixing in growing Cu. The validity of concept stating that a cloud at developing state can be represented by a parcel or a jet is tested. To investigate dynamical entrainment in CUZ performed by motions with scales larger than the turbulence scales, the modeled fields of air velocity were filtered by waveletmore »« less
https://doi.org/10.1175/jas-d-21-0137.1

Full Text Available
Theoretical Analysis of the Entrainment–Mixing Process at Cloud Boundaries. Part II: Motion of Cloud Interface

Journal Article Pinsky, Mark ; Khain, Alexander - Journal of the Atmospheric Sciences

The entrainment–mixing process leads to formation of a cloud–environment interface zone, consisting of the cloud dilution zone, where the liquid water content decreases as the distance from the cloud interior increases, and a humid shell with higher humidity in comparison with the dry environment. The time evolution of the location and width of these zones is analyzed by solving the diffusion–evaporation equation for the open region in the vicinity of the cloud–dry air interface. Upon normalization, the problem is reduced to a one-parametric one, the governing parameter being the potential evaporation parameter R < 0, which is proportional to themore »« less
Cited by 9
https://doi.org/10.1175/JAS-D-18-0314.1

Similar Records