[en] The effects of the zonal mean circulation and planetary-wave winds on the distribution of nitric oxide in the 55-120 km height region is investigated. A time-dependent numerical model is used to investigate the interaction between planetary waves and the zonal mean circulation, and the effect of the circulation on the nitric oxide distribution is determined. The initial nitric oxide (NO) distribution is obtained by using a simple source/sink chemistry, vertical eddy diffusion, and advective transport by the zonal mean circulation. Changes in the initial NO distribution which result from the addition of planetary-wave winds are described. Planetary waves are found to induce a wave-like structure in the nitric oxide distribution which resembles the derived from observational data. Planetary waves can affect the nitric oxide concentration in two ways: first, through the wave-induced changes in the mean meridional circulation, and second, through the nitric oxide perturbation induced by wave winds themselves. The changes in total nitric oxide are due primarily to the zonal asymmetries in nitric oxide induced by the planetary waves. Implications of this result for explaining the winter anomaly are discussed

[en] Ultralong and long planetary waves are analyzed at the 500 mb level in terms of their amplitudes, phases and stationarity characteristics, the latter described in terms of a stationarity index SI/sub n/. This index consists of the ratio between planetary-wave amplitudes computed from time-average 500 mb height patterns, and the wave amplitudes computed on a daily basis and averaged for the same time interval irrespective of their phase angles. The index assumes the value 1 for completely stationary waves and 0 for randomly variable waves

[en] We have performed sensititivy tests on a one-dimensional physical-chemical model of the unperturbed stratospheric aerosols and have compared model calculations with observations. The sensitivity tests and comparisons with observations suggest that coagulation controls the particle number mixing ratio, although the number of condensation nuclei at the tropopause and the diffusion coefficient at high altitudes are also important. The sulfate mass and large particle number (r>0.15 μm) mixing ratios are controlled by growth, sedimentation, evaporation at high altitudes and washout below the tropopause. The sulfur gas source strength and the aerosol residence time are much more important than the supply of condensation nuclei in establishing mass and large particle concentrations. The particle size is also controlled mainly by gas supply and residence time. OCS diffusion (not SO₂ diffusion) dominates the production of stratospheric H₂SO₄ particles during unperturbed times, although direct injection of SO₂ into the stratosphere could be significant if it normally occurs regularly by some transport mechanism. We suggest a number of in-situ observations of the aerosols and laboratory measurements of aerosols parameters that can provide further information about the physics and chemistry of the stratosphere and the aerosols found there

[en] We have compared sensitivities of four different radiative-convective climate models. Although surface temperature sensitivities with respect to changes in solar constant and atmospheric, CO₂ concentration are almost the same in all models, sensitivity with respect to some other climate variables varies up to a factor of 2. We have found that the surface temperature sensitivity with respect to changes of the lapse rate is high in all models, and we emphasize the importance of a lapse rate--surface temperature feedback

[en] The time variation of the spring peak of stratospheric fallout is examined with surface air data of Cs-137 concentrations from about 30 stations in the zone 9 to 75⁰N and 80⁰W to 115⁰E. This study is likely to be more realistic than one derived from data confined to a particular meridian, such as the United States 80th meridian fallout sampling network. It is seen from an examination of the data that the spring peak of stratospheric fallout is progressively delayed with increasing latitude from 9 to 50⁰N. At latitudes beyond 50⁰N, no clear trend can be postulated due to limited data. The reason for this progressive delay in the appearance of the spring peak is likely to be due to changes in the circulation pattern, rather than variations in precipitation scavenging, as regions with different distribution of rainfall have the same progressive delay in the spring peak

[en] A method is described for analyzing the feedback and synergistic comtributions of temperature water vapor, cloud cover, surface albedo and CO₂ to the change in the radiation balance at the top of the atmosphere due to a perturbation in an annual-averaged zonal atmospheric climate model. The method is illustrated through analysis of a double CO₂ experiment with the Lawrence Livermore National Laboratory Statistical Dynamical Model (LLNL SDM). The method provides insight into the sensitivity of the model to feedback changes in individual parameters and how each parameter influences the effects of the others

[en] Stratospheric inventories of Sr-90 over the period 1963--75 yield T₁2asterisk/ = 6--7 months for the inventory difference between Northern and Southern Hemispheres, T₁2N/ = 9--10 months for the decay of the Northern Hemispheric inventory by transfer to the troposphere and Southern Hemisphere, T₁2T/ = 10--11 months for the decay of the total stratospheric inventory, and T₁2E/ = 2.5--3.5 years for the decay of the Northern Hemispheric inventory by transfer to the Southern Hemisphere alone

[en] The adjoint functions for an atmospheric model are the solution to a system of equations derived from a differential form of the model's equations. The adjoint functions can be used to calculate efficiently the sensitivity of the model's results to variations in any of the model's parameters. This paper shows that the adjoint functions themselves can be interpreted as the sensitivity of a result to instantaneous perturbations of the model's dependent variables. This interpretation is illustrated for a radiative convective model, although the interpretation holds equally well for general circulation models. The adjoint functions are used to reveal the three time scales associated with 1) convective adjustment, 2) heat transfer between the atmosphere and space and 3) heat transfer between the ground and atmosphere. Calculating the eigenvalues and eigenvectors of the matrix of derivatives occurring in the set of adjoint equations reveals similar physical information without actually solving for the adjoint functions

[en] The spectrum of sunlight reflected by Jupiter is analyzed by comparing observations of Woodman et al. (1979) with multiple-scattering computations. The analysis yields information on the vertical cloud structure at several latitudes and on the abundance of CH₄ and NH₃ in the atmosphere of Jupiter

[en] Precipitation surges in the equatorial Pacific ''dry zone'' (as delineated in a study by Doberitz) reveal statistically significant teleconnections with midlatitude tropospheric flow patterns during all seasons. These connections are strongest, however, during winter and agree with linear numerical model results. There is evidence that deep troughs in the central North Pacific antecede precipitation surges in the equatorial dry zone during that season, suggesting the possibility of triggering of such surges by middle latitude planetary-wave perturbations. Nonlinear numerical model results also indicate that the midlatitude planetary-wave response is strongest when North Pacific cold sea-surface temperature anomalies and equatorial East Pacific warm anomalies are present simultaneously