MOSAiC drift expedition from October 2019 to July 2020: sea ice conditions from space and comparison with previous years

We combine satellite data products to provide a first and general overview of the physical sea ice conditions along the drift of the international Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition and a comparison with previous years (2005–2006 to 2018–2019). We find that the MOSAiC drift was around 20 % faster than the climatological mean drift, as a consequence of large-scale low-pressure anomalies prevailing around the Barents–Kara–Laptev sea region between January and March. In winter (October–April), satellite observations show that the sea ice in the vicinity of the Central Observatory (CO; 50 km radius) was rather thin compared to the previous years along the same trajectory. Unlike ice thickness, satellite-derived sea ice concentration, lead frequency and snow thickness during winter months were close to the long-term mean with little variability. With the onset of spring and decreasing distance to the Fram Strait, variability in ice concentration and lead activity increased. In addition, the frequency and strength of deformation events (divergence, convergence and shear) were higher during summer than during winter. Overall, we find that sea ice conditions observed within 5 km distance of the CO are representative for the wider (50 and 100 km) surroundings. An exception is the ice thickness; here we find that sea ice within 50 km radius of the CO was thinner than sea ice within a 100 km radius by a small but consistent factor (4 %) for successive monthly averages. Moreover, satellite acquisitions indicate that the formation of large melt ponds began earlier on the MOSAiC floe than on neighbouring floes.

The MOSAiC Drift: Ice conditions from space and comparison with previous years

We combine satellite data products to provide a first and general overview of the sea-ice conditions along the MOSAiC drift and a comparison with previous years. We find that the MOSAiC drift was around 25 % faster than the climatological mean drift, as a consequence of large-scale low-pressure anomalies prevailing around the Barents-Kara-Laptev Sea region between January and March. In winter (October–April), satellite observations show that the sea-ice in the vicinity of the Central Observatory (CO) was rather thin compared to the previous years along the same trajectory. Unlike ice thickness, satellite-derived sea-ice concentration, lead frequency, and snow thickness during winter month were close to the long-term mean with little variability. With the onset of spring and decreasing distance to Fram Strait, variability in ice concentration and lead activity increased. In addition, frequency and strength of deformation events (divergence and shear) were higher during summer than during winter. Overall, we find that sea-ice conditions observed close (~ 5 km) to the CO are representative for the wider (50 km and 100 km) surroundings. An exception is the ice thickness: Here we find that sea-ice near the CO (50 km radius) was 4 % thinner than sea-ice within a 100 km radius. Moreover, satellite acquisitions indicate that the formation of large melt ponds began earlier on the MOSAiC floe than on neighbouring floes.

Efficiency and mechanism of lead stabilization in soil of lead-acid battery contaminated site with phosphorus-based materials

<p>Lead contaminated soils occurred at lead-acid battery manufacturing and recycling sites are of great concern. Bench-scale batch experiments of stabilization treatment were conducted using twelve materials and three phosphorus-based materials, KH<sub>2</sub>PO<sub>4</sub>(KP), KH<sub>2</sub>PO<sub>4</sub>:oyster shell power = 1:1 (by mass ratio; KSP), and KH2PO4:sintered magnesia = 1:1(by mass ratio; KPM), were screened out for lead contaminated soil in an abandoned lead-acid battery factory site. The three materials had higher remediation efficiencies that led to a 92% reduction in leachable Pb and 12% reduction in bioaccessible Pb with the addition of 5% material, while the acid soluble fraction of lead decreased by 41–46%. The lead activity in the soil solution sharply decreased treated by three materials. Pb<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>Cl was the primary mineral controlling lead solubility in soil treated by KP and KSP and lead activity was related to Pb<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>OH and Pb<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>Cl in soil amended with KPM.</p>

HEAVY METALS INFLUENCE ON THE CTENOPHORES MNEMIOPSIS LEIDYI AND BEROE OVATA BIOLUMINESCENCE

Investigations were conducted in the Department of biophysical ecology of Kovalevsky IMBR of RAS in September - October of 2013 and 2015. The body length of the gathered for experiments ctenophores was 35 – 40 mm. Characteristics of the ctenophores light emission were studied under the mechanical and chemical stimulations, with the usage of laboratory complex “Svet”. The following HM salts: Cu2S04, ZnCl2, PbCl2 and HgCl2 in different concentrations were used in our experiments. The just-caught samples, contained in the clean marine water were used as a control. The exposition time was 1, 3 and 24 hours under the temperature of 21 ± 2°C. The investigations results have shown considerable variability of the ctenophore luminosity characteristics in dependence of metal concentration and exposition duration. It was stated that minimal concentrations of cooper, zinc and mercury stimulates ctenophores bioluminescence and the high ones inhibit. The alien ctenophore luminescence inhibition was registered under the lead activity under all investigated concentrations. We can place investigated metals as following: Zn < Cu < Hg < Pb, according to the force of the toxic influence on the ctenophore bioluminescence. Thus, alien ctenophore bioluminescence parameters can serve as a sensitive express-indicator of the resistance degree to the heavy metals impact and be the expressive index of the marine environment regional pollution.

Neurons of the anterior mesial cortex related to faciovocal activity in the awake monkey

1. The anterior mesial cortex, including the cingulate region, is thought to be involved in the voluntary control of vocalization. Previous recording studies have demonstrated that anterior mesial neurons discharge before conditioned and spontaneous vocalizations, but questions remain regarding the location and functional properties of these neurons. The present study was performed to provide a more complete description of the location and discharge properties of anterior mesial neurons involved in faciovocal behaviors. 2. Single-unit activity was recorded from neurons in the anterior mesial cortex of monkeys during performance of self-paced vocalizations and jaw openings. Cells were also tested for responsiveness to acoustic stimulation, and attempts were made to elicit vocalization through stimulation of the cortex surrounding related cells. Discharge properties of the cells were statistically analyzed, and correlation analysis was performed between measure of cell discharge and vocalization. 3. A total of 145 neurons were observed to modulate their discharge in association with vocalization or jaw opening. Four general classes of neurons were observed: neurons related only to vocalization, neurons related only to jaw opening, neurons related to both vocalization and jaw opening, and neurons related to other oromotor activities such as lip movements or reinforcement consumption. 4. Vocalization-related cells typically discharged tonically at a low frequency (mean 22 Hz), and many instances of long-lead activity (lead time > 500 ms) were noted. No neurons responded to acoustic stimulation, and electrical stimulation failed to elicit vocalization. Neural activity was not correlated with any measure of vocalization. 5. Neurons related to faciovocal behavior were located in the anterior cingulate sulcus and adjacent cortex of the mesial wall at a level just rostral to the genu of the arcuate sulcus. This region roughly corresponds to the rostral cingulate motor area and is located caudal to the traditionally described cingulate vocalization region. 6. In the present study we demonstrate the existence of an additional region in the medial wall that is involved in a variety of faciovocal behaviors such as vocalization, jaw opening, lip movements, and reinforcement consumption. The neurons do not appear to be strongly coupled to the execution of these acts. These results suggest that the activity of neurons in the anterior mesial cortex may relate to faciovocal behavior in a more global way than the activity of neurons in other motor areas.