摘要:

Atmospheric circulation leads to an accumulation of debris from meteors in the Antarctic stratosphere at the beginning of austral spring. The major component of meteoric material is alkaline, comprised predominantly of the oxides of magnesium and iron. These metals may neutralize the natural acidity of stratospheric aerosols, remove nitric acid from the gas phase, and bond it as metal nitrates in the aerosol phase. Removal of nitric acid vapor has been previously shown to be a critical link in the photochemical depletion of ozone in the Antarctic spring, by allowing for increased catalytic loss from chlorine and bromine.

ISSN:0094-8276    

DOI:10.1029/GL015i001p00001

年代:1988

数据来源: WILEY

摘要:

Total ozone amounts derived from the NOAA operational sounder (TOVS) are compared to measurements from Nimbus‐7 SBUV and ground‐based Dobson spectrophotometer observations over a seven‐year period. The global trends of the data, in terms of deviations from long‐term averages, derived from measurements by each satellite instrument show qualitative agreement until mid‐1984 when the data diverge with the TOVS‐derived data showing higher values. Additionally, more significant differences appear in both the north and south temperate zones' records. The trends derived from the satellite systems' measurements also show differences from that of the Dobson instrument measurements with the trend of the TOVS measurements showing generally better overall agreement with the Dobson

ISSN:0094-8276    

DOI:10.1029/GL015i001p00005

年代:1988

数据来源: WILEY

摘要:

The oxygen isotopic fractionation, which occurs during ozone decomposition, has been determined, complementing earlier studies on the fractionation during ozone formation. Oxygen produced in the decomposition is depleted in heavy isotopes in a mass‐independent fashion. The mechanism for the mass‐independent effect is unknown, though the fractionation magnitude information is required for modelling the steady‐state isotopic composition of stratospheric

ISSN:0094-8276    

DOI:10.1029/GL015i001p00009

年代:1988

数据来源: WILEY

摘要:

The formation of ozone by the termolecular association of atomic and molecular oxygen is discussed. On taking the relevant symmetry numbers into account it is inferred that there is an enhancement that depends on τ(R)/τ(D) where τ(R) is the energy randomization time and τ(D) is the lifetime of the activated complex. To explain the observed enhancement τ(R)/τ(D) would have to be about a third which is within the rather wide range that the uncertainties in τ(R) and τ(D

ISSN:0094-8276    

DOI:10.1029/GL015i001p00013

年代:1988

数据来源: WILEY

摘要:

Laboratory studies of sticking coefficients of H2O, HCl, Cl2and HNO3on ice and heterogeneous reactions of ClONO2with ice or HCl/ice have been performed in a fast flow reactor. A quadrupole mass spectrometer with electron impact ionization was used as a detector. Measured sticking coefficients are: 0.3 (+0.7. −0.1) for H2O, 0.4 (+0.6, −0.2) for HCl,<1.0 × 10−4for Cl2, and 0.3 (+0.7, −0.1) for HNO3at 200 K. The reaction probability of ClONO2on ice was found to be 0.06 (±0.03) while HOCl was observed as a sole product in the gas phase. With HCl present in ice, the reaction probability of ClONO2is greatly enhanced, approaching 0.27 (+0.73, −0.13) while molecular chlorine was found to be the major product in the gas phase. Another reaction product was nitric acid which remained in the solid phase. Since the polar stratospheric clouds contain ice particles or possibly HCl/ice particles on the surface, the present results should be a major factor in producing the observed springtime ozone depletion in the Antarctic s

ISSN:0094-8276    

DOI:10.1029/GL015i001p00017

年代:1988

数据来源: WILEY

摘要:

Airborne lidar observations of Arctic polar stratospheric clouds (PSCs) during January 1984 and January 1986 show constrast suggestive of two distinct PSC growth stages delineated by the frost‐point temperature. Results obtained at temperatures 2–6K above the frost point indicate a stage of significant, but limited, particle growth such as proposed in recent models of PSC formation by co‐deposition of HNO3and H2O vapors. Results obtained at a temperature near the frost point indicate the formation of somewhat larger crystalline part

ISSN:0094-8276    

DOI:10.1029/GL015i001p00021

年代:1988

数据来源: WILEY

摘要:

A 9‐year time series of multispectral radiometric observations taken at Rattlesnake Mountain Observatory (46.4 N, 119.6 W) is analyzed to determine the long‐term behavior of the El Chichon‐induced perturbation to the stratospheric aerosol layer. A technique for determining the volcanic enhancement is described. Time series data for the volcanic enhancement in stratospheric optical depth at wavelengths of 1010, 785, 535, 486, and 428 nm are presented. The main features of the results, slight wavelength dependence and a seasonal oscillation superimposed on the expected exponential decay at all wavelengths, are disc

ISSN:0094-8276    

DOI:10.1029/GL015i001p00024

年代:1988

数据来源: WILEY

摘要:

Exceptionally strong echoes from the mesopause region have been observed with the EISCAT 224 MHz radar during the summer of 1987. The echoes are so strong that they cannot be explained by incoherent scatter theory but may instead be associated with neutral air turbulence. We discuss the variability of these echoes in terms of time and height distribution, and outline some characteristics of vertical velocity oscillations observed at the echo height.

ISSN:0094-8276    

DOI:10.1029/GL015i001p00028

年代:1988

数据来源: WILEY

摘要:

Using the sun as an infrared source, we determined the total atmospheric column absorbance of methane and carbon dioxide spectral lines in the 8‐ to 10‐µm infrared region. At our laboratory located in an urban region, these absorbances showed fluctuations larger than can be accounted for by known variabilities in the background atmosphere. We interpret these observations in terms of large changes in concentration of methane and carbon dioxide within the urban boundary layer. These increases could affect the radiative balance in urban locations and contribute to the urban heat is

ISSN:0094-8276    

DOI:10.1029/GL015i001p00032

年代:1988

数据来源: WILEY

摘要:

Sea ice is an important factor in controlling the exchange of energy between the ocean and atmosphere in the polar regions and has an important impact on climate. A climate model has been developed which enables analysis of the effect of changes in sea ice on the ocean‐atmosphere energy exchange and atmospheric temperature. The model results described here show that opening small areas of open ocean (leads) within the winter ice pack has a large impact on the atmospheric temperature of the polar regions. This effect is due to changes in the sensible heat flux between the surface and atmosphere resulting from leads. Thus leads within the ice pack may have significant impact on short and long term climatic variation

ISSN:0094-8276    

DOI:10.1029/GL015i001p00036

年代:1988

数据来源: WILEY