Interactive Stratospheric Aerosol models response to different sulfur injection amount and altitude distribution during volcanic eruption

<p>Large magnitude tropical volcanic eruptions emit sulphur dioxide and other gases directly into the stratosphere, creating a long-lived volcanic aerosol cloud which scatter incoming solar radiation, absorbs outgoing terrestrial radiation, and can strongly affect the composition of the stratosphere.</p><p>Such major volcanic enhancements of the stratospheric aerosol layer have strong “direct effects” on climate via these influences on radiative transfer, primarily surface cooling via the reduced insolation, but also have a range of indirect effects, due to the volcanic aerosol cloud’s effects on stratospheric circulation, dynamics and chemistry.</p><p>In this study, we investigate the 3 largest volcanic enhancements to the stratospheric aerosol layer in the last 100 years (Mt Agung 1963; Mt El Chichón 1982; Mt Pinatubo 1991), comparing co-ordinated simulations within the so-called HErSEA experiments (Historical Eruptions SO2 Emission Assessment) several national climate modelling centres carried out for the model intercomparison project ISA-MIP.</p><p>The HErSEA experiment saw participating models performing interactive stratospheric aerosol simulations of each of the volcanic aerosol clouds with common upper-, mid- and lower-estimate amounts and injection heights of sulfur dioxide, in order to better understand known differences among modelling studies for which initial emission gives best agreement with observations. </p><p>First, we compare results of several models HErSEA simulations with a range of observations, with the aim to find where there is agreement between the models and where there are differences, at the different initial sulfur injection amount and altitude distribution.</p><p>In this way, we could understand the differences and limitations in the mechanisms that controls the dynamical, microphysical and chemical processes of stratospheric aerosol layer.</p>

3D Reconstruction of Typhoon and Thunderstorm Cloud Top Using Airborne Camera

<p>Typhoons are extreme weather phenomena that inflict damages and casualties around globe. These phenomena are difficult to study because of their chaotic behaviour but the capacity to measure their intensity can help mitigate the hazards that they bring. In the past, several attempts have been done to relate typhoon's intensity with the structural evolution of its eye. This suggests the possible relation between the typhoon intensity with typhoon eye altitude. In this research, we visualize Typhoon Trami’s structure by reconstructing the three-dimensional model inside its eye and analyze the information of its cloud top altitude. An experiment was conducted under the SATREPS/ULAT project (SATREPS: Science and Technology Research Partnership for Sustainable Development, ULAT: Understanding Lightning and Thunderstorm) where images of Typhoon Trami were taken from an aircraft last September 26, 2018. Aircraft images were used to reconstruct the 3D model inside the typhoon eye because they provide closer views of the typhoon than that of geostationary satellite images, making it easier to reconstruct a 3D model. The 3D reconstruction generated covers 43 km region of the typhoon eye at 20.2 m/pixel spatial resolution. Three cross-sections of the 3D model were analyzed, and the resulting altitude distribution was compared with the cloud-top altitude estimated by mapping the brightness temperature of the Himawari Thermal Infrared Band 13 with cloud-top height as measured by NOAA sonde data. From the 3D model, the altitude distribution ranges from 5.3 km to 14.3 km which corresponds with the altitude estimated from the brightness temperature of 6.5 km to 14.3 km. However, regions of altitude difference can also be observed between the two methods. This study shows that a three-dimensional model could be a good mode of typhoon visualization as it shows a more detailed typhoon structure such as the stairstep structures that was detected at some regions within the typhoon eye. This research was supported by SATREPS, funded by Japan Science and Technology Agency (JST) / Japan International Cooperation Agency (JICA).</p>

System analysis of mathematical modeling of the thermal conductivity of the neutral gas of the upper atmosphere of the earth

Данная статья является продолжением [1]. В представленной работе приведена постановка задачи математического моделирования теплопроводности на основе основных законов сохранения (плотности, импульса энергии). В уравнении энергии учтены основные динамические и фотохимические источники и стоки тепла в верхней атмосфере Земли. Приведены результаты численного расчета высотного распределения температуры и ее источников и стоков для условий средних широт(45ºN), и средней солнечной активности(F10.7150) нейтрального газа. Эти результаты получены на основе решения нелинейных, связанных, «жестких», алгебраических систем. Написан алгоритм и программа на языке Фортран90 адаптированная для использования на любой вычислительной системе. Расчеты проводятся самосогласованно с другими параметрами нейтрального и ионного состава. Показана возможность применения одинакового высотного распределения коэффициента турбулентного перемешивания системы нейтрального газа верхней атмосферы Земли. This article is a continuation of [1]. In the presented work, the formulation of the problem of mathematical modeling of thermal conductivity based on the basic conservation laws (density, energy momentum) is given. The energy equation considers the main dynamic and photochemical sources and sinks of heat in the Earth's upper atmosphere. The results of a numerical calculation of the altitude distribution of temperature and its sources and sinks for conditions of middle latitudes (45ºN), and average solar activity (F10.7150) of neutral gas are presented. These results are obtained on the basis of solving nonlinear, coupled, "rigid" algebraic systems. An algorithm and a program have been written in Fortran90 adapted for use on any computing system. The calculations are carried out in a self-consistent manner with other parameters of the neutral and ionic composition. The possibility of using the same altitude distribution of the turbulent mixing coefficient of the neutral gas system of the Earth's upper atmosphere is shown.

Mesostratospheric Lidar for the Heliogeophysical Complex

The Heliogeophysical Complex of RAS, which is developing at the Institute of Solar-Terrestrial Physics SB RAS in the Irkutsk region, includes instruments for studying the Sun, the upper atmosphere and the mesostratospheric lidar system (MS lidar) for analyzing the neutral part of the atmosphere from Earth’s surface to the thermosphere (100–110 km altitude). More specifically, the objective of the MS lidar is to measure profiles of thermodynamic parameters of the atmosphere and the altitude distribution of the aerosol-gas composition. To solve these problems, the MS lidar ensures the use of several laser sensing methods at a number of specially selected laser wavelengths in the total range 0.35–1.1 μm. In this case, the following types of scattering are used: molecular, aerosol, Raman, resonance, as well as differential absorption, Doppler broadening and shift of the spectrum of scattered radiation. The article describes the methods used in the MS lidar and the measured atmospheric characteristics.

Mesostratospheric Lidar for the Heliogeophysical Complex

The Heliogeophysical Complex of RAS, which is developing at the Institute of Solar-Terrestrial Physics SB RAS in the Irkutsk region, includes instruments for studying the Sun, the upper atmosphere and the mesostratospheric lidar system (MS lidar) for analyzing the neutral part of the atmosphere from Earth’s surface to the thermosphere (100–110 km altitude). More specifically, the objective of the MS lidar is to measure profiles of thermodynamic parameters of the atmosphere and the altitude distribution of the aerosol-gas composition. To solve these problems, the MS lidar ensures the use of several laser sensing methods at a number of specially selected laser wavelengths in the total range 0.35–1.1 μm. In this case, the following types of scattering are used: molecular, aerosol, Raman, resonance, as well as differential absorption, Doppler broadening and shift of the spectrum of scattered radiation. The article describes the methods used in the MS lidar and the measured atmospheric characteristics.