A Review on Impact of Anthropogenic Sulphur Dioxide Pollution on Health and Environment

The explosive global change in the emissions of Sulphur dioxide (SO2) over the decades have brought about tremendous effects in the regional as well as global scale in the composition and quality of air that we breathe. The global SO2 emission peaked in the 1970s, decreased until 2000 and has risen to peak again mainly as the result of increased globalization in developing countries. The global estimation is surprisingly low but the regional output of SO2 is high. The main hotspots being in East Asia Countries. The Sulphur aerosols not only impacts the animals’ health, but those of the ecosystems at large. SO2 contributes to global warming, ozone depletion, acid rain, smog etc. that has brought disastrous environmental conditions. WHO recommends a maximum exposure of not more than 0.5 ppm for around 24 hours’ span. SO2 reacts with other gases to form sulphate particles, constituent of particulate matters i.e. PM 2.5 concentrations, the exposure to which causes skin, respiratory, reproductive failures and cardiovascular ailments. This study, as such, is meant to bring into light the sources of SO2 and its harmful effects on health and environment at large. Air pollution is a major issue with adverse effects prevailing over the globe at present.

Global Estimation and Assessment of Monthly Lake/Reservoir Water Level Changes Using ICESat-2 ATL13 Products

Accurate and detailed information on lake/reservoir water levels and temporal changes around the globe is urgently required for water resource management and related studies. The traditional satellite radar altimeters normally monitor water level changes of large lakes and reservoirs (i.e., greater than 1 km2) around the world. Fortunately, the recent Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) makes it possible to monitor water level changes for some small lakes and reservoirs (i.e., less than 1 km2). ICESat-2 ATL13 products provide observations of inland water surface heights, which are suitable for water level estimation at a global scale. In this study, ICESat-2 ATL13 products were used to conduct a global estimation and assessment of lake/reservoir water level changes. We produced monthly water levels for 13,843 lakes and reservoirs with areas greater than 0.1 km2 and all-season ATL13 products across the globe, in which 2257 targets are smaller than 1 km2. In total, the average valid number of months covered by ICESat-2 is 5.41 months and only 204 of 13,843 lakes and reservoirs have water levels in all the months in 2019. In situ water level data from 21 gauge stations across the United States and 12 gauge stations across Australia were collected to assess the monthly lake/reservoir water levels, which exhibited a high accuracy (RMSE = 0.08 m, r = 0.999). According to comparisons between the monthly water levels and changes from ATL08 products in another study and ATL13 products in this study, we found that both products can accurately estimate the monthly water level of lakes and reservoirs, but water levels derived from ATL13 products exhibited a higher accuracy compared with water levels derived from ATL08 products (RMSE = 0.28 m, r = 0.999). In general, the ATL13 product is more convenient because the HydroLAKES mask of inland water bodies, the orthometric height (with respect to the EGM2008 geoid) of water surfaces, and several data quality parameters specific to water surfaces were involved in the ATL13 product.

PERBANDINGAN TIGA PENDEKATAN GEOSTATISTIK UNTUK MEMODELKAN KETIDAKPASTIAN DALAM ESTIMASI SUMBERDAYA TIMAH DAN MINERAL IKUTAN TIMAH PADA ENDAPAN ALUVIAL

Blok C merupakan salah satu blok endapan aluvial di Pulau Bangka yang memiliki prospek timah dan mineral ikutan timah seperti ilmenite, rutile, anatase, zircon, dan monazite. Endapan aluvial umumnya memiliki variabilitas yang tinggi sehingga faktor ketidakpastian akan sumberdaya timah dan mineral ikutan timah juga tinggi. Pada penelitian ini dilakukan perbandingan antara 3 (tiga) pendekatan geostatistik untuk memodelkan ketidakpastian sumberdaya dengan studi kasus pada endapan aluvial di Blok C di Pulau Bangka. Untuk mengetahui variabilitas global di daerah penelitian dilakukan dengan menggunakan metode Global Estimation Variance (GEV), sedangkan untuk mengetahui variabilitas lokal dilakukan menggunakan Sequential Gaussian Simulation (SGS) dan Discrete Gaussian Model (DGM). Hasil dari metode GEV dibandingkan dengan metode SGS dan hasil dari metode SGS juga akan dibandingkan dengan metode DGM. Dari hasil perbandingan GEV dan SGS menunjukkan bahwa hasil GEV cenderung less confidence jika dibandingkan dengan hasil SGS. Less confidence pada hasil GEV disebabkan oleh efek proporsional di daerah penelitian. Hasil perbandingan SGS dan DGM menunjukkan pola yang hampir sama untuk Sn (timah) dan ilmenite+rutile+anatase serta pola yang cukup berbeda untuk zircon. Perbedaan ini disebabkan oleh pemusatan data yang merupakan bagian dari metode DGM. Selain itu, mayoritas nilai minimum hasil DGM lebih besar daripada nilai minimum hasil SGS dan nilai maksimum hasil DGM lebih kecil daripada nilai maksimum hasil SGS. Hal ini disebabkan oleh change of support coefficient (r) yang mempengaruhi fungsi dari transformasi

Global estimation of ionospheric drivers during extreme storms

<p>During geomagnetic storms, the space environment can be drastically altered as the plasma in the upper atmosphere, or ionosphere, moves globally. This plasma redistribution is mainly caused by storm-time electric fields, but another important driver of the velocity of the ions in the plasma is the neutral winds. These winds refer to the movement of the neutral particles that are part of the thermospheric layer of the atmosphere, that can drag the plasma. Geomagnetic storms increase the neutral winds, due to the heating of the thermosphere that comes from the storm. In this study we want to understand how these ionospheric drivers affect the ionosphere behavior because, among other reasons, during geomagnetic storms the plasma can refract and diffract trans-ionospheric signals and, consequently, can cause problems in the navigation systems such as GNSS (Global Navigation Satellite System)/GPS (Global Positioning System) that use the information from the signals.</p><p>In this work, our objective is to estimate the electric fields and neutral winds globally during a geomagnetic storm. Global GNSS TEC (total electron content) measurements are ingested by the Ionospheric Data Assimilation 4-Dimensional (IDA4D) algorithm [1], whose output is the electron density rate over a grid at different time steps during a geomagnetic storm. The density rates are treated as “observations” in EMPIRE (Estimating Model Parameters from Ionospheric Reverse Engineering), which is a data assimilation algorithm based on the plasma continuity equation [2,3,4]. Then, the EMPIRE “observations” are used to estimate corrections to the electric field and neutral winds by solving a Kalman filter. To study these drivers with EMPIRE, basis functions are used to describe them. For the global potential field, spherical harmonics are used.</p><p>To have a global estimation of the neutral winds, we introduce vector spherical harmonics as the basis function for the first time in EMPIRE. The vector spherical harmonics are used to model orthogonal components of neutral wind in the zonal (east-west) and meridional (north-south) directions. EMPIRE’s Kalman filter needs the error covariance of the vector spherical harmonics decomposition. To calculate it, the basis function is fitted to the model HWM14 (Horizonal Wind Model) values of the neutral winds and the error between the fitting and the model is studied. Later, we study the global potential field and global neutral winds over time to understand how much each driver contributes to the plasma redistribution during the geomagnetic storm on October 25<sup>th</sup> 2011. We compare the results to FPI (Fabry-Perot Interferometer) neutral winds measurements to validate the results.   </p><p>[1] G.S.Bust, G.Crowley, T.W.Garner, T.L.G.II, R.W.Meggs, C.N.Mitchell, P.S.J.Spencer, P.Yin, and B.Zapfe, Four-dimensional gps imaging of space weather storms, Space Weather, 5 (2007),  doi:10.1029/2006SW000237.</p><p>[2] D.S.Miladinovich, S.Datta-Barua, G.S.Bust, and J.J.Makela, Assimilation of thermospheric measurements for ionosphere-thermosphere state estimation, Radio Science, 51 (2016).</p><p>[3] D.S.Miladinovich, S.Datta-Barua, A.Lopez, S. Zhang, and G.S.Bust, Assimilation of gnss measurements for estimation of high-latitude convection processes, Space Weather, 18 (2020).</p><p>[4] G.S.Bust and S.Datta-Barua, Scientific investigations using ida4d and empire, in Modeling the Ionosphere-Thermosphere System, J. Huba, R. Schunk, and G. Khazanov, eds., John Wiley & Sons, Ltd, 1 ed., 2014.</p>