The Modular Earth Submodel System (MESSy) is an open, multi-institutional project providing a strategy for developing comprehensive Earth System Models (ESMs) with highly flexible complexity. The ...first version of the MESSy infrastructure and process submodels, mainly focusing on atmospheric chemistry, has been successfully coupled to an atmospheric General Circulation Model (GCM) expanding it into an Atmospheric Chemistry GCM (AC-GCM) for nudged simulations and into a Chemistry Climate Model (CCM) for climate simulations. Here, we present the second development cycle of MESSy, which comprises (1) an improved and extended infrastructure for the basemodel independent coupling of process-submodels, (2) new, highly valuable diagnostic capabilities for the evaluation with observational data and (3) an improved atmospheric chemistry setup. With the infrastructural changes, we place the headstone for further model extensions from a CCM towards a comprehensive ESM. The new diagnostic submodels will be used for regular re-evaluations of the continuously further developing model system. The updates of the chemistry setup are briefly evaluated.
Abstract
The atmospheric oxidation of biogenic volatile organic compounds (BVOC) by OH radicals over tropical rainforests impacts local particle production and the lifetime of globally distributed ...chemically and radiatively active gases. For the pristine Amazon rainforest during the dry season, we empirically determined the diurnal OH radical variability at the forest-atmosphere interface region between 80 and 325 m from 07:00 to 15:00 LT using BVOC measurements. A dynamic time warping approach was applied showing that median averaged mixing times between 80 to 325 m decrease from 105 to 15 min over this time period. The inferred OH concentrations show evidence for an early morning OH peak (07:00–08:00 LT) and an OH maximum (14:00 LT) reaching 2.2 (0.2, 3.8) × 10
6
molecules cm
−3
controlled by the coupling between BVOC emission fluxes, nocturnal NO
x
accumulation, convective turbulence, air chemistry and photolysis rates. The results were evaluated with a turbulence resolving transport (DALES), a regional scale (WRF-Chem) and a global (EMAC) atmospheric chemistry model.
Technologies aimed at reducing the consumption of reagents and the environmental impact resulting from the operation of water-treatment equipment in the domestic power industry are analyzed. ...Attention is focused on the specifics of the reagents' application in membrane-separation technologies. It is noted that the membrane technologies used for water treatment frequently involve the necessity of applying chemical reagents, the ingress of which into the sewage makes the utilization of the latter more difficult and increases the environmental impacts. A conclusion about the impossibility of completely abandoning reagents for water treatment has been made. A method for the environmentally friendly, reagent-free operation of membrane-separation plants has been devised and its viability has been proven by an example of a pilot nanofiltration water-treatment unit for the heat-supply system operating with a water of the potable quality. Approaches have been outlined that allow a reduction in the water-treatment costs of thermal power plants using integrated membrane technologies and/or their combinations with ion exchange. Despite the fact that there is no possibility of completely abandoning reagents for water treatment in common cases, membrane-separation technologies currently constitute the basis for engineering solutions that allow a reduction in the water-treatment costs and even the implementation of reagent-free techniques in particular cases.
The features of the geomagnetic effect of the approach of an interplanetary magnetic cloud to the Earth’s magnetosphere during the recovery phase of a strong magnetic storm (June 21–26, 2015) are ...studied. On the Earth’s surface, the greatest geomagnetic effects were recorded when the leading edge of the magnetic cloud approached the Earth’s magnetosphere, where large alternating variations in the
Bz
and
By
components of the IMF were observed. Large (up to 1000 nT), bay-like magnetic disturbances were observed in the near-noon sector of the circumpolar latitudes, presumably in the region of the projection of the daytime polar cusp. It is shown that the sign of the high-latitude magnetic bay was controlled by the sign of the
By
component of the IMF and did not depend on the direction of the
Bz
component of the IMF. The planetary, high-latitude geomagnetic activity and the distribution of large-scale, field aligned electric currents calculated from magnetic observations were studied based on simultaneous magnetic registration on 66 ionospheric communication satellites (project AMPERE). It was found that, in the case of the development of a negative magnetic bay (the western electrojet), the downward field aligned electric currents in the midday sector were observed to be more polar than the upward currents. For a positive bay (the eastern electrojet), the upward currents were more polar than the downward ones. It is shown that an abrupt change in the sign of the
By
components of the IMF led not only to a sharp change in the direction of the ionospheric current, but also to its movement in latitude.
The development of two supersubstorms (i.e., very intense substorms with an amplitude of more than 2000 nT) recorded in the main phase of two consecutive strong magnetic storms with maxima at ~0100 ...UT (
Dst
~ –150 nT) and ~1300 UT (
Dst
~ –115 nT) on September 8, 2017, is analyzed. Data from the SuperMAG global magnetometers network and the Scandinavian profile of IMAGE stations are used. Analysis of spatial distribution maps of ionospheric equivalent electric currents on the Scandinavian meridian derived according to the MIRACLE model and global maps of magnetic field vectors obtained from SuperMAG observations makes it possible to obtain the spatial distribution of planetary-scale disturbances. Both supersubstorms were characterized not only by strong nighttime disturbances at auroral latitudes (~–3600 nT and ~–2600 nT) but also by the simultaneous development of daytime magnetic bays at polar latitudes with amplitudes of ~–1000 nT and ~–400 nT, respectively. We assume that the daytime polar disturbances observed simultaneously with the supersubstorms can result from the pull of the westward ionospheric current to the dayside. Our observations support the assumption that the westward electrojet during the supersubstorm develops on a global scale from the evening to the dayside.
The article presents the results of a studying detection of the sudden commencement (SC) and main impulse (MI) of a magnetic storm as a function of the geographic coordinates of magnetic ...observatories and Universal Time, using modern data with second time resolution. The analysis was carried out for two events in which an interplanetary shock wave impacting the magnetosphere was associated with interplanetary coronal mass ejections (CMEs) with sources in different hemispheres of the Sun. The authors propose an approach to determine the time points of SC and MI detection. It is concluded that the SC and MI detection times may differ by several seconds to more than a minute at magnetic observatories located at different geographic latitudes and longitudes. For the studied events, the graphs of SC and MI detection as functions of the geographic coordinates of magnetic observatories and Universal Time revealed trends according to which, on average, the higher station the latitude, the later SC and MI are detected at the station.
Photophysical processes and photochemical reactions of a 15-crown-5-containing styryl dye of the pyridine series and its complexes with barium perchlorate in water in the absence and in the presence ...of cucurbit7,8urils were studied using absorption, luminescence, and laser kinetic spectroscopy. The
trans—cis
-photoisomerization, interconversion of the dye to the triplet state, and charge transfer were concluded to occur. The formation of a dye inclusion complex with cucurbit7,8urils was established.
We present version 3.0 of the atmospheric chemistry box model CAABA/MECCA. In addition to a complete update of the rate coefficients to the most recent recommendations, a number of new features have ...been added: chemistry in multiple aerosol size bins; automatic multiple simulations reaching steady-state conditions; Monte-Carlo simulations with randomly varied rate coefficients within their experimental uncertainties; calculations along Lagrangian trajectories; mercury chemistry; more detailed isoprene chemistry; tagging of isotopically labeled species. Further changes have been implemented to make the code more user-friendly and to facilitate the analysis of the model results. Like earlier versions, CAABA/MECCA-3.0 is a community model published under the GNU General Public License.
Among various directions in the science of photoactive organic compounds, the design, creation, and study of multichromophore supramolecular devices and machines attract special attention, since this ...way can open up new approaches to the construction of complex hierarchical “smart” materials.
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