The role of ammoniated aerosols in cirrus cloud nucleation

被引:71
作者
Tabazadeh, A
Toon, OB
机构
[1] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA
[2] Univ Colorado, LASP, Boulder, CO 80309 USA
[3] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA
关键词
D O I
10.1029/97GL03585
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Recent results obtained during the SUCCESS experiment show that aerosols containing ammonium ion are commonly found in the upper troposphere and therefore it is of great importance to investigate the ice freezing properties of such aerosols. For this purpose we present mathematical expressions, derived from recent model calculations and laboratory data, for calculating the deliquescence relative humidity of (NH4)(2)SO4, NH4HSO4 and NH4NO3 under upper tropospheric conditions. Using these functions we define the temperature and relative humidity requirements for the deliquescence of dry particles in the upper troposphere. Further using a thermodynamic model of the H2SO4/HNO3/NH3/H2O system, we calculate the variation in the supercooled aerosol composition and saturation ratios of various ionic salts in solution as a function of temperature and relative humidity. Using these values we show salt crystallization in the upper troposphere may occur in two distinct type of ammoniated aerosol solutions. First (NH4)(3)H(SO4)(2) (letovicite) may crystallize in acidic solutions of (NH4)(2)SO4. Second double salts of (NH4)(2)SO4 and NH4NO3 may crystallize in nearly neutralized solutions of (NH4)(2)SO4 and NH4NO3. Finally we discuss how the presence of crystalline salt surfaces in aqueous solutions may alter the mode of cirrus cloud formation from homogeneous to heterogeneous freezing nucleation.
引用
收藏
页码:1379 / 1382
页数:4
相关论文
共 16 条
[1]  
CLEGG SL, UNPUB J PHYS CHEM
[2]  
Heymsfield AJ, 1995, J ATMOS SCI, V52, P4302, DOI 10.1175/1520-0469(1995)052<4302:RHATIO>2.0.CO
[3]  
2
[4]   Phase transformations in sulfuric acid aerosols: Implications for stratospheric ozone depletion [J].
Imre, DG ;
Xu, J ;
Tridico, AC .
GEOPHYSICAL RESEARCH LETTERS, 1997, 24 (01) :69-72
[5]   Ammonium bisulfate water equilibrium and metastability phase diagrams [J].
Imre, DG ;
Xu, J ;
Tang, IN ;
McGraw, R .
JOURNAL OF PHYSICAL CHEMISTRY A, 1997, 101 (23) :4191-4195
[6]   The potential impact of soot particles from aircraft exhaust on cirrus clouds [J].
Jensen, EJ ;
Toon, OB .
GEOPHYSICAL RESEARCH LETTERS, 1997, 24 (03) :249-252
[7]   MICROPHYSICAL MODELING OF CIRRUS .1. COMPARISON WITH 1986 FIRE IFO MEASUREMENTS [J].
JENSEN, EJ ;
TOON, OB ;
WESTPHAL, DL ;
KINNE, S ;
HEYSMFIELD, AJ .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1994, 99 (D5) :10421-10442
[8]   HEAT CAPACITIES AND THERMODYNAMIC PROPERTIES OF AMMONIUM NITRATE CRYSTAL - PHASE TRANSITIONS BETWEEN STABLE AND METASTABLE PHASES [J].
NAGATANI, M ;
SEIYAMA, T ;
SAKIYAMA, M ;
SUGA, H ;
SEKI, S .
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 1967, 40 (08) :1833-+
[9]  
SASSEN K, 1989, J ATMOS SCI, V46, P3005, DOI 10.1175/1520-0469(1989)046<3005:HPNSIC>2.0.CO
[10]  
2