Abstract.A new interactive radiative-dynamical-chemical zonally averaged two-dimensional model has been developed at Goddard Space Flight Center. The model includes a linear planetary wave parameterization featuring wave-mean flow interaction and the direct calculation of eddy mixing from planetary wave dissipation. It utilizes family gas phase chemistry approximations and includes heterogeneous chemistry on the surfaces of both stratospheric sulfate aerosols and polar stratospheric clouds. This model has been used to study the effects of the sulfate aerosol cloud formed by the eruption of Mount Pinatubo in June 1991 on stratospheric temperatures, dynamics, and chemistry. Aerosol extinctions and surface area densities were constrained by satellite observations and were used to compute the aerosol effects on radiative heating rates, photolysis rates, and heterogeneous chemistry. The net predicted perturbations to the column ozone amount were low-latitude depletions of 2-3% and northern and southern high-latitude depletions of 10-12%, in good agreement with observations. In the low latitudes a depletion of roughly 1-2% was due to the altered circulation (increased upwelling) resulting from the perturbation of the heating rates, with the heterogeneous chemistry and photolysis rate perturbations contributing roughly 0.5% each. In the high latitudes the computed ozone column depletions were mainly a result of heterogeneous chemistry occurring on the surfaces of the volcanic aerosol. Temperature anomalies predicted were a low-latitude warming peaking at 2.5 K in mid-1992 and high-latitude coolings of 1-2 K which were associated with the high-latitude ozone reductions. The sensitivity of the predicted perturbations to changes in the specification of the planetary wave forcings was examined. The maximum globally averaged column ozone depletions ranged from 2 to 4% for the cases studied.

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[1] The Visible Infrared Imager Radiometer Suite (VIIRS) instrument was launched in October 2011 on the satellite now known as the Suomi National Polar-orbiting Partnership. VIIRS was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer and provide observation continuity with NASA's Earth Observing System's Moderate Resolution Imaging Spectroradiometer (MODIS). VIIRS snow and ice products include sea ice surface temperature, sea ice concentration, sea ice characterization, a binary snow map, and fractional snow cover. Validation results with these "provisional" level maturity products show that ice surface temperature has a root-mean-square error of 0.6-1.0 K when compared to aircraft data and a similar MODIS product, the measurement accuracy and precision of ice concentration are approximately 5% and 15% when compared to passive microwave retrievals, and the accuracy of the binary snow cover (snow/no-snow) maps is generally above 90% when compared to station data. The ice surface temperature and snow cover products meet their accuracy requirements with respect to the Joint Polar Satellite System Level 1 Requirements Document. Sea Ice Characterization, which consists of two age categories, has not been observed to meet the 70% accuracy requirements of ice classification. Given their current performance, the ice surface temperature, snow cover, and sea ice concentration products should be useful for both research and operational applications, while improvements to the sea ice characterization product are needed before it can be used for these applications.

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Daily average solar proton flux data for 1978 and 1979 have been used in a proton energy degradation scheme to derive ion pair production rates and, subsequently, atomic nitrogen production rates. These atomic nitrogen production rates are computed in a form suitable for inclusion in an atmospheric two‐dimensional time‐dependent photochemical model. Odd nitrogen (N, NO, NO2, NO3, HNO3, HO2NO2, N2O5, and ClONO2) distributions are computed from the model including the atomic nitrogen production from solar protons and are compared with baseline distributions. Comparisons show that the average effect of the solar protons in 1978 and 1979 was to cause changes in odd nitrogen only above 10 mbar and at latitudes only above about 50° in both hemispheres. The influence of the solar‐proton‐produced odd nitrogen on the local abundance of odd nitrogen depends primarily on the background odd nitrogen abundance as well as the altitude and season. The odd nitrogen change in the atmosphere due to solar protons during the solar proton events (SPEs) in 1978 and 1979 is important for 2–3 months, but it is generally negligible 6 months after the SPE. Inclusion of the SPEs' production of odd nitrogen does not produce a substantial change in the agreement between the model results and the Limb Infrared Monitor of the Stratosphere (LIMS) NO2 and HNO3 data.