INTRODUCTION-MARINE AEROSOL

Roger J. CHENG, ASRC SUNY UALBANY

****大气中的微观世界 系列--4.海洋****

纽约州立大学,大气科学研究中心 郑均华研究员主持的科研项目

The generation of maritime cloud condensation nuclei (CCN) through the ejection of jet and film droplets from bursting whitecap-produced bubbles on the ocean surface has been well documented. The processes involved in the transformation (evaporation and crystallization) of these liquid droplets into their solid form under varying conditions, however, has not previously attracted much attention from researchers. A set of laboratory investigations and field observations of the characteristics, both physical and chemical, of sea water droplets during phase change in a controlled environment has revealed the following startling and very significant phenomena:
  • 1, Ejection of micro-size aerosols from the crystallizing droplet.
  • 2, Formation of hollow sphere of sea-salt particles.
  • 3, Shell structure of chlorides (MgCl/2 and KC1)on the surface
  • of the ejected aerosols and sea-salt particles.
海洋中云凝结核(CCN)的显微观察,测试研究报告
  • 1,附带硫化物(CaSO/4,MgSO/4)的气溶胶的测定。
• 2,海盐颗粒空心球体的发现。
• 3,氯化物(MgCl/2和KCl)在凝结核表面的证实。
纽约州立大学,大气科学研究中心 郑均华研究员主持的科研项目

 

  • The FORMATION of HOLLOW SEA-SALT PARTICLES

from the EVAPORATION of DROPS of SEAWATER

  • Roger J. Cheng, Duncan C. Blanchard and Ramon J. Ciprianoa
  • Atmospheric Sciences Research Center
  • State University of New York
Atmospheric Research
Volume 22, Issue 1, Pages 15-25,
June 1988

 

Abstract

Some non-volatile materials dissolved in water drops will, upon evaporation of the water, produce a hollow shell of the material. Though known for years in the chemical engineering literature, this fact was not appreciated by those working with the marine sea-salt aerosol. Our laboratory experiments show that a majority of seawater drops in free fall in air with a relative humidity less than about 60% evaporate, become salt-saturated, and change phase to produce hollow sea-salt particles. Some hollow salt particles have been found in marine air, though further investigation is required to show the extent of this phenomenon. Expressions have been derived from which both the size of the original drop of seawater and its salt supersaturation at the time of phase change can be calculated from the inner and outer radii of the salt shell. If hollow particles are common in the marine aerosol, then instruments that measure particle size -(TSP) cannot be used to obtain particle mass.

Résumé

Certaines substances non volatiles dissoutes dans les gouttes d'eau produisent, à l'évaporation de l'eau, des coquilles creuses. Ce processus est bien connu en génie chimique, et pourtant il n'en est pas tenu compte dans les travaux sur les aérosols salins océaniques. Nos expériences de laboratoire montrent que lorsque des gouttes du de mer tombent en chute libre dans de l'air à moins de 60% d'humidité relative, la plupart d'entre elles arrivent à saturation et changent de phase pour produire des particules salines creuses. On a d'ailleurs trouvé des particules creuses de sel dans de l'air marin, mais d'autres recherches sont nécessaires pour connaître l'étendue du phénomène. On présente des relations qui donnent la dimension de la goutte originale d'eau de mer, ainsi que la sursaturation au changement de phase, à partir des rayons intérieurs et extérieurs de la coquille de sel. S'il est prouvé que les particules creuses sont courantes dans l'aérosol marin, on ne pourra pas utiliser les appareils qui mesurent les dimensions des particules pour évaluer la masse de l'aérosol.

 

    Atmospheric Research
  • Volume 22, Issue 1, Pages 15-25, June 1988
  • Received 12 December 1986; accepted 31 July 1987.

 
 

CITATION by: DR. H.K. PRUPPACHER'S TEAM of GERMANY

 

  • The FORMATION of HOLLOW
  • SEA-SALT PARTICLES

from the EVAPORATION of DROPS of SEAWATER

Roger J. Cheng, Duncan C. Blanchard and Ramon J. Ciprianoa

  • Atmospheric Sciences Research Center
  • State University of New York at Albany
  • Received 12 December 1986; accepted 31 July 1987.
A, "A Wind Tunnel Study on the Drop-to-Particle Conversion"
JOURNAL of AEROSOL SCIENCES,
Vol.23, No.3, 1992.

by Dr. Pruppacher's term at Institute of Atmospheric Physics, Germany)

 

B, MICROPHYSICS OF CLOUDS AND PRECIPITATION ;
By Dr. Pruppacher and Dr. Klett,
Second Revised and Enlarged Edition.
Kluwer Academic Publishers, 1997
HOME
ATMOSPHERIC
SCIENCES
SNOW and ICE
CLOUD SEEDING
FREEZING
of A WATER DROP
FRAGMENTATION
of A FROZEN DROP
MELTING of
A FROZEN DROP
CHARGE within
An ICE CRYSTAL
PUBLICATION
and CITATION
 

 

  • SULFATE AEROSOL GENERATION
  • in the MARINE ATMOSPHERE

  • Roger J. CHENG
  • Atmospheric Sciences Research Center
  • State University of New York at Albany

The generation of maritime cloud condensation nuclei (CCN) through the ejection of jet and film droplets from bursting whitecap-produced bubbles on the ocean surface has been well documented. The processes involved in the transformation (evaporation and crystallization) of these liquid droplets into their solid form under varying conditions, however, has not previously attracted much attention from atmospheric researchers.

A set of laboratory investigations and field observations of the characteristics, both physical and chemical, of seawater droplets during phase change in a controlled environment have revealed the following startling and very significant phenomena:

(1) The ejection of sulfate aerosols (CaSO4,MgSO4) with size range of 0.1mm to 10 mm. The concentration and chemical composition of the ejected aerosols, identified by the techniques of scanning electron microscopy and energy dispersive x-ray spectroscopy, were dependent on the rate of droplet evaporation. Sea-salt aerosols could be classified into three categories: (A) NaCI crystals, (B) Crystals of sulfates (CaSO4,MgSO4) and (C) Chloride droplets (MgCI2, KCI).

(2) The formation of hollow spherical sea-salt particles (>5 mm). A secondary ejection of aerosols was detected during melting by the busting of air bubbles, which were formed when the hollow particle was moved into a high-moisture environment or dissolved into a water droplet.

(3) A thin film of chlorides (MgCl2, KCI) observed on the surface of sea salt particles present a highly hygroscopic surface to initiate the condensation of water vapor in an environment with RH As low as 40%. Sodium Chloride (NaCI-75%RH) plays only a minor role for the formation of cloud droplets in the marine atmosphere.

Characterization of the ejected sulfate aerosols in comparison with field observation, chemical processes inside the evaporating seawater droplets and the mechanisms for the generation of secondary aerosols in the marine atmosphere are presented with illustrations.

 

 
 
           

 

    SHELL STRUCTURED MARINE AEROSOL:
    • A LABORATORY OBSERVATION
  • Roger J. CHENG
  • Atmospheric Sciences Research Center
  • State University of New York

 

Laboratory investigation revealed that a shell structure of chlorides (MgCl/2 and KC1) is always present on the surface of marine aerosol. Close examination by a polarizing microscope of an individual seawater droplet has resulted in the following observations: Evaporation of water increased the salt concentration. At first, a thin layer of brine formed at the surface of the evaporating droplet; this was followed by clearly sequential precipitations of numerous microcystals of sulfates (CaSO4MgSO4), and by a crust of many relatively larger cubic NaCI crystals correspondent with their individual solubility and concentrations.

During this process solution of chlorides (MgC12, KC1) mixed with microciystals of sulfates or NaCl were situated beneath the surface of the droplet. Finally, a seasalt particle with chloride film on the surface was formed. The shell structure of chlorides film present on the surface of the marine aerosol confirmed via optical and scanning electron microscopy is of extreme importance to understanding the fundamental nucleation processes in the atmosphere.

The chloride film presents a highly hygroscopic surface and was found to initiate the condensation of water vapor in an environment with RH as low as 40%. Sodium chloride (NaCI) crystals, on the other hand play only a minor role in initiating condensation (RH 75%) for cloud droplets formation in the atmosphere.

  • To be presented at:
  • the Annual Meeting of the American Associationfor Aerosol Research (AAAR),
  • Oak Brook, ILL. October 11-15, 1993
 

 

 

*****MARINE AEROSOL PROJECT*****
  • Roger J. CHENG, ASRC UALBANY SUNY

  • 纽约州立大学,大气科学研究中心 郑均华研究员主持的科研项目

  • A CRITICAL REVIEW-SEA SALT AEROSOL
  • by AMERICAN GEOPHYSICAL UNION-2004

 

The MICRO-WORLD in the ATMOSPHERE
  • MARINE AEROSOL PROJECT:
  • 纽约州立大学,大气科学研究中心 郑均华研究员主持的科研项目

REFERENCES and CITATIONS

Roger J. CHENG

  • 1. "The Formation of Hollow Sea-Salt Particles from the Evaporation of Drops of Seawater"
  • ATMOSPHERIC RESEARCH,
  • Vol. 22, No. 1. June 1988 (Cheng, Blanchard & Cipriano).
  • 2. "The Generation of Secondary Marine Aerosols: The Crystallization of Seawater Droplets"
  • A. LECTURE NOTES IN PHYSICS, 309, Atmospheric Aerosols and Nucleation,
  • Ed: P.E Wagner and G. Vail, Springer-Verlag. 1988.
  • B. International Conference on Atmospheric Aerosols and Nucleation,
  • Vienna, Austria. August 22-27, 1988
  • 3. "Sulfate Aerosols Generation in the Marine Atmosphere:
  • The Evaporation of SeawaterDroplets"
  • International Conference on Global and Regional Environmental Atmospheric Chemistry,
  • Beijing, China. May 1989.
  • 4. "A New Mechanism for the Generation of High Sulfate Enriched Aerosols
  • in the Marine Atmosphere"
  • 9th World Clean Air Congress, Montreal, Quebec, Canada. 1992.
  • 5. "Shell Structured Marine Aerosol: A Laboratory Observation"
  • Annual Meeting of American Association for Aerosol Research,
  • Oak Brook, Illinois. October 11-15, 1993.
  • 6. "On the Phenomenon of Nuclei Enhancement During the Evaporative Stage of a Cloud"
  • ATMOSPHERIC RESEARCH, Vol. 47, No. 48, 1998. ( DeFelice and Cheng )
  • CITATIONS:
  • A. AN INTRODUCTION TO METEOROLOGICAL INSTRUMENTATION
  • AND MEASUREMENT
  • By Dr.Thomas P. DeFelice, Prentice Hall, 1998.
  • B. "A Wind Tunnel Study on the Drop-to-Particle Conversion"
  • JOURNAL of AEROSOL SCIENCES, Vol.23, No.3, 1992.
  • (Confirmationby Dr. Pruppacher's term at Institute of Atmospheric Physics, Germany)
  • C. MICROPHYSICS OF CLOUDS AND PRECIPITATION ;
  • By Dr. Pruppacher and Dr. Klett, Second Revised and Enlarged Edition.
  • Kluwer Academic Publishers, 1997
  • .
  • D. " Microscopic Investigation of Marine Aerosol "
  • ALBANY-Fall 1996-University at Albany Magazine.

 

 

HOME
EXHIBIT
ATMOSPHERE
OCEAN
ENVIRONMENT
LET IT SNOW
SCIENCE
EDUCATION
COMMUNITY
SERVICE
CHINA
CONNECTION
CHENG'S
HAVING FUN
 

 

 

Roger J. CHENG ASRC SUNY
****大气中的微观世界 系列****

  科学教育 网站介绍
  1.大气 2.雷雨 3.环境 4.海洋
纽约州立大学,大气科学研究中心 郑均华研究员主持的科学教育项目
WHO want to KNOW MORE the SECRETS of the ATMOSPHERE and
WHO wish to SEE the LIFE CYCLE of A WATER DROP in A THUNDERCLOUD
SCIENCE EDUCATION and GENERAL PUBLIC EDITION
 
1, The MICRO-WORLD in the ATMOSPHERE
SCIENTIFIC and PROFESSIONAL EDITION
 
2, The MICRO-WORLD in the THUNDERSTORM
  • www.RogerCheng.com
  • "The STORY of The LIFE CYCLE of A WATER DROP in a THUNDERCLOUD"
  • NEWLY PUBLISHED: FEB.2011--under TESTING and REVISION
3, The MICRO-WORLD in our ENVIRONMENT
  • A, CHARACTERIZATION of POWER PLANT EMISSION--OIL and COAL
  • B, ACID RAIN FORMATION-CATALYTIC SO/2 OXIDATION in A WATER DROP
  • C, ECOLOGICAL EFFECTS- MARBLE DETERIORATION and PLANT DAMAGE
  • in preparation

4, The MICRO-WORLD in the MARINE ATMOSPHERE

  • A, DISCOVERY of HOLLOW SEA SALT PARTICLES
  • B, TRANSFER of MARINE SULFATE from OCEAN into the ATMOSPHERE
  • C, SHELLED (CHLORIDES) MIRINE-CCN(CLOUD CONDENSATION NUCLEI
  • in preparation
  • FOR BEST RESULT: please log-on GOOGLE SEARCH-
  • (WEB and IMAGES)
 
 
NEWLY PUBLISHED WEB SITE
by Roger J. CHENG-ASRC-UALBANY
The MICRO-WORLD in the THUNDERSTORM
FEBRUARY 2011
The MICRO-WORLD in our ENVIRONMENT
JULY 2011

AS MY BOSS DR. VINCENT J. SCHAEFER ALWAYS SAID:

" PLEASE HAVING FUN and ENJOY IT!"

  • "I didn't solve the problem
  • I just opened another way to look at something"
  • ***Roger J. CHENG***
  • ASRC SUNY UALBANY

 

SEARCH INDEX-The MICRO-WORLD in the ATMOSPHERE series

Roger J. CHENG, ASRC UALBANY SUNY

纽约州立大学,大气科学研究中心 郑均华研究员主持的科研项目

HOME
EXHIBIT
ATMOSPHERE
OCEAN
ENVIRONMENT
LET IT SNOW
SCIENCE
EDUCATION
COMMUNITY
SERVICE
CHINA
CONNECTION
CHENG'S
HAVING FUN
 
 
ATMOSPHERIC
SCIENCES
SNOW and ICE
CLOUD SEEDING
FREEZING
of A WATER DROP
FRAGMENTATION
of A FROZEN DROP
MELTING of
A FROZEN DROP
CHARGE within
An ICE CRYSTAL
PUBLICATION
and CITATION
POWER PLANT EMISSION
ACID RAIN FORMATION
ECOLOGICAL EFFECT
ALBEDO of CLOUDS
BUILDING EROSION
ATMOSPHERIC PTS
CARBONACEOUS PTS
AIR POLLUTION CONTROL