Deliquesence and freezing of stratospheric aerosol observed by balloonborne backscattersondes
- Danish Meterological Institute, Copenhagen (Denmark)
- Univ. of Wyoming, Laramie, WY (United States); and others
Stratospheric sulfate aerosols, originating from the Mt. Pinatubo volcanic eruption, have been observed during three winters in the Arctic by balloonborne backscattersondes. A measured color index, defined as the quotient between the aerosol backscatter ratios at wavelengths 940 and 480 nm, provides information of the size of the observed particles. The effects of liquid particle growth, by water vapor uptake, clearly show up as changes in the color index, whereas measurements on other days indicate the particles to be frozen. Air parcel trajectories have been calculated, providing the temperature history of the observed particles. Evidences appear of a temperature hysteresis in the freezing and melting cycle of the aerosol, indicating melting temperatures around 215-220 K in good agreement with laboratory measurements, and freezing of the particles within less than 5 K above the ice frost point. The changes in color index of the liquid particles are in good agreement with predictions from theoretical model calculations of growth by water vapor uptake. 13 refs., 5 figs., 1 tab.
- OSTI ID:
- 175778
- Journal Information:
- Geophysical Research Letters, Vol. 22, Issue 10; Other Information: PBD: 15 May 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Simultaneous ozone and polar stratospheric cloud observations at South Pole Station during winter and spring 1991
The lifetime of leewave-induced ice particles in the Arctic stratosphere: I. Balloonborne observations