Description: Large volumes of seawater are used in different industrial sectors such as power plants and ships. Chemical disinfection of this seawater prevents bio-fouling, but also produces halogenated disinfection by-products (DBPs). One major DBP is bromoform whose anthropogenic input to the environment is highly uncertain. Halocarbons such as bromoform impact the oxidation of trace gases and ozone chemistry in the atmosphere. We quantify the contribution of DBPs from industrial waste water to oceanic halocarbon concentrations and their impact on atmospheric chemistry. Based on industrial water discharge and DBP estimates, we simulate oceanic pathways of halocarbons along NEMO-ORCA12 driven Lagrangian trajectories. Anthropogenic halocarbon concentration are strongly enhanced along the coasts in Southeast Asia, but also allow for transport into the open ocean. We highlight bromoform showing that its anthropogenic sources can explain much of observed shelf water concentrations. We show how anthropogenic marine bromine impacts tropospheric and stratospheric ozone chemistry compared to natural background emissions.

Description: It is an open question how localized elevated emissions of bromoform (CHBr3) and other very short-lived halocarbons (VSLHs), found in coastal and upwelling regions, and low background emissions, typically found over the open ocean, impact the atmospheric VSLH distribution. In this study, we use the Lagrangian dispersion model FLEXPART to simulate atmospheric CHBr3 resulting from assumed uniform background emissions, and from elevated emissions consistent with those derived during three tropical cruise campaigns. The simulations demonstrate that the atmospheric CHBr3 distributions in the uniform background emissions scenario are highly variable with high mixing ratios appearing in regions of convergence or low wind speed. This relation holds on regional and global scales. The impact of localized elevated emissions on the atmospheric CHBr3 distribution varies significantly from campaign to campaign. The estimated impact depends on the strength of the emissions and the meteorological conditions. In the open waters of the western Pacific and Indian oceans, localized elevated emissions only slightly increase the background concentrations of atmospheric CHBr3, even when 1∘ wide source regions along the cruise tracks are assumed. Near the coast, elevated emissions, including hot spots up to 100 times larger than the uniform background emissions, can be strong enough to be distinguished from the atmospheric background. However, it is not necessarily the highest hot spot emission that produces the largest enhancement, since the tug-of-war between fast advective transport and local accumulation at the time of emission is also important. Our results demonstrate that transport variations in the atmosphere itself are sufficient to produce highly variable VSLH distributions, and elevated VSLHs in the atmosphere do not always reflect a strong localized source. Localized elevated emissions can be obliterated by the highly variable atmospheric background, even if they are orders of magnitude larger than the average open ocean emissions.

Description: Carbon dioxide measurements made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument between 2002 and 2014 were analyzed to reveal the rate of increase of CO 2 in the mesosphere and lower thermosphere. The CO 2 data show a trend of ~5% per decade at ~80 km and below, in good agreement with the tropospheric trend observed at Mauna Loa. Above 80 km, the SABER CO 2 trend is larger than in the lower atmosphere, reaching ~12% per decade at 110 km. The large relative trend in the upper atmosphere is consistent with results from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). On the other hand, the CO 2 trend deduced from the Whole Atmosphere Community Climate Model (WACCM) remains close to 5% everywhere. The spatial coverage of the SABER instrument allows us to analyze the CO 2 trend as a function of latitude for the first time. The trend is larger in the northern hemisphere than in the southern hemisphere mesopause above 80 km. The agreement between SABER and ACE-FTS suggests that the rate of increase of CO 2 in the upper atmosphere over the past 13 years is considerably larger than can be explained by chemistry-climate models.

Description: In this paper, we present near-simultaneous observations of a gravity wave (GW) event in the stratosphere, mesosphere, and ionosphere over the South-Central United States and track it from its convective source region in the troposphere to the ionosphere, where it appears as a traveling ionospheric disturbance (TID). On April 4, 2014 concentric GW ring patterns were seen at stratospheric heights in close-proximity to a convective storm over North Texas in the Atmospheric Infrared Sounder (AIRS) data on board the NASA Aqua satellite. Concentric GWs of similar orientation and epicenter were also observed in mesospheric nightglow measurements of the Day/Night Band (DNB) of the Visible/Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (NPP) satellite. Concentric TIDs were seen in Total Electron Content data derived from ground-based GPS receivers distributed throughout the U.S. These new multi-sensor observations of TIDs and AGWs can provide a unique perspective on ionosphere-atmosphere coupling.

Description: The first no-gap OH airglow all-sky imager network was established in northern China in February 2012. The network is composed of 6 all-sky airglow imagers that make observations of OH airglow gravity waves and cover an area of about 2000 km east and west and about 1400 km south and north. An unusual outbreak of Concentric Gravity Wave (CGW) events were observed by the network nearly every night during the first half of August 2013. These events were coincidentally observed by satellite sensors from FY-2, AIRS/Aqua, and VIIRS/Suomi NPP. Combination of the ground imager network with satellites provides multi-level observations of the CGWs from the stratosphere to the mesopause region. In this paper, two representative CGW events in August 2013 are studied in detail. First, is the CGW on the night of 13 August 2013, likely launched by a single thunderstorm. The temporal and spatial analyses indicate that the CGW horizontal wavelengths follow freely propagating waves based on a GW dispersion relation within 300 km from the storm center. In contrast, the more distant observed gravity wave field exhibits a smaller horizontal wavelength of ~20 km and our analysis strongly suggest this wave field represents a ducted wave. A second event, exhibiting multiple CGWs, was induced by two very strong thunderstorms on 09 August 2013. Multi-scale waves with horizontal wavelengths ranging from less than 10 km to 200 km were observed.

Description: A (6, 14)-connected metal-organic framework (MOF), namely [Co 9 (μ 3 -OH) 2 (CPT) 10 (HCOO) 6 ] n ( 1 ) [HCPT = 4-(4-carboxyphenyl)-1, 2,4-triazole], was synthesized using custom-designed bifunctional triazolate-carboxylate organic linkers and Co II salts. The framework exhibits two types of highly connected Co3 and Co6 cluster moieties with distinct arrangement, which were generated in situ . The combination of these building units results in an unusual (6, 14)-connected structure, which has been rarely observed in MOF chemistry. This MOF was characterized by single X-ray diffraction, PXRD, and TGA. Furthermore, its magnetic properties were investigated.

Description: The Cloud Imaging and Particle Size (CIPS) instrument on the Aeronomy of Ice in the Mesosphere (AIM) satellite provides an opportunity to study the longitudinal variation in polar mesospheric cloud (PMC). We examined the longitudinal variation in PMC albedo using 8 years (2007-2014) of observations from the CIPS instrument. The results show that the PMC albedo in the Southern Hemisphere (SH), especially in the latitude band of 80°S-85°S, is persistently low (~65% relative to the rest of the hemisphere) within 60°W to 150°W longitude. In the Northern Hemisphere (NH), however, PMC albedo is found to be relatively zonally asymmetry. Harmonic analyses shows that the persistent longitudinal variation in the SH PMC albedo is due to zonal wavenumbers 1 through 4 (WN1-WN4) processes with minima in the longitude range of 60°W-150°W. The influence of temperature and H 2 O on the longitudinal variation of the PMC albedo is discussed based on results obtained using a simple 0-D PMC model and temperature from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere with Broadband Emission Radiometry (SABER) and H 2 O from MLS. The modeled region of low ice mass in the SH is generally consistent with that of low PMC albedo seen in CIPS. Tidal analyses using the SABER temperatures indicate that the non-migrating semidiurnal tides with modes of S0, W1 and E1 might be the main drivers of the persistent longitudinal variations of PMC albedo in the SH. Non-migrating tides are much weaker in the NH and consistent with the observed lack of longitudinal variability in PMC albedo.

Description: To further explore the coordination possibilities of the flexible tripodal ligand, 4,4′,4′′-(benzene-1,3,5-triyl-tris(oxy))tribenzoic acid (H 3 BTTB), two solvent-controlled three-dimensional (3D) manganese(II) coordination polymers, [Mn 3 (BTTB) 2 (H 2 O) 4 ](H 2 O) 2 ( 1 ) and [Mn 3 (BTTB) 2 (DMF) 2 ](DMF) 2 ( 2 ), were synthesized and characterized. Single crystal X-ray diffraction analysis indicates that in the Mn II complexes the BTTB ligands exhibit two coordination modes, which have not been reported previously. Complexes 1 and 2 involve different one-dimensional (1D) rod-shaped metal–carboxylate secondary building units (SBUs). The 1D SBUs are further extended to afford two different three-dimensional (3D) frameworks with similar flu topology via linkage of the BTTB ligands. The results demonstrate that the reaction solvent as well as conformation and coordination mode of BTTB ligands play key roles on the formation of the final framework structures. Additionally, their luminescent properties were investigated.

Description: The Thermosphere-Ionosphere-Mesosphere Electrodynamics General Circulation Model (TIME-GCM) is used to theoretically study the 6-day wave effects on the ionosphere. By introducing a 6-day perturbation with zonal wavenumber 1 at the model lower boundary, the TIME-GCM reasonably reproduces the 6-day wave in temperature and horizontal winds in the mesosphere and lower thermosphere (MLT) region during the vernal equinox. The E-region wind dynamo exhibits a prominent 6-day oscillation that is directly modulated by the 6-day wave. Meanwhile, significant local time variability (diurnal and semi-diurnal) is also seen in wind dynamo as a result of altered tides due to the nonlinear interaction between the 6-day wave and migrating tides. More importantly, the perturbations in the E-region neutral winds (both the 6-day oscillation and tidal-induced short-term variability) modulate the polarization electric fields, thus leading to the perturbations in vertical ion drifts and ionospheric F 2 -region peak electron density (NmF2). Our modeling work shows that the 6-day wave couples with the ionosphere via both the direct neutral wind modulation and the interaction with atmospheric tides.

Description: The quasi 2-day wave (QTDW) can effectively interact with atmospheric tides in the mesosphere and lower thermosphere (MLT). We study the effect of this QTDW-tidal interaction on the ionosphere and thermosphere using the Thermosphere-Ionosphere-Mesosphere Electrodynamics General Circulation Model (TIME-GCM). This interaction reduces the amplitude of the migrating diurnal tide in the lower thermosphere by ~10 m/s in neutral winds and also generates sum and difference secondary waves in the lower thermosphere and E-region ionosphere. As a result of the changed migrating diurnal tide and sum/difference secondary wave, vertical ion drift varies with local time at different longitudes by ~5 m/s. In addition, the changed migrating diurnal tide also modulates the thermospheric composition (O/N 2 ). During a QTDW event, the ionosphere F 2 -region peak electron density (NmF2) is reduced due to the mixing effect of the QTDW dissipation; NmF2 also shows changes in local time variation due to the QTDW-tidal interaction. The sum and difference secondary waves can cause additional oscillations in vertical ion drift and ionospheric electron densities. The QTDW-tidal interaction is another mechanism by which the QTDW impacts the ionosphere and thermosphere, along with other mechanisms: QTDW modulation of the E-region wind dynamo with a period of quasi 2 days and QTDW dissipation induced mixing in the thermosphere.