This paper utilizes the SOCATv2 data product to calculate surface ocean pH. The pH data are divided into 17 biomes, and a linear regression is used to derive the long-term trend of pH in each biome. The results are consistent with the trends observed at time series stations. The uncertainties are too large for a mechanistic understanding of the driving forces behind the trend, but there are indications that concurrent changes in chemistry create spatial variability.

Production of calcium carbonate by coral reefs is important in the global carbon cycle. Using a global framework we evaluate four models of reef calcification against observed values. The temperature-only model showed significant skill in reproducing coral calcification rates. The absence of any predictive power for whole reef systems highlights the importance of coral cover and the need for an ecosystem modelling approach accounting for population dynamics in terms of mortality and recruitment.

We link the mineralogy of soils affected by erosion and deposition to the distribution of soil carbon fractions, their turnover and microbial activity. We show that the weathering status of soils and their history are controlling the stabilization of carbon with minerals. After burial, aggregated C is preserved more efficiently while non-aggregated C can be released and younger C re-sequestered more easily. Weathering changes the effectiveness of stabilization mechanism limiting this C sink.

The increase in anthropogenic atmospheric carbon dioxide is mitigated by uptake by the world ocean, which alters the pH of the water. In the South Atlantic we find the highest rates of acidification relative to increase in anthropogenic carbon (Cant) found in Subantarctic Mode Water and Antarctic Intermediate Water. The moderate rates of increase in Cant combined with low buffering capacities, due to low salinity and alkalinity values, have caused rapid acidification in the Subantarctic Zone.

Agricultural intensification has contributed to sustained Chinese food supply since 1980s and also influenced soil organic carbon (SOC) stock. The study, conducted in Huantai county - a typical intensive farming region in northern China, found that from 1982 to 2011, farmland SOC stock (0-20cm) of the entire county increased by 59% which can be well explained by the increasing crop residues input. More technologies must be developed for enhancement of SOC and reduction of non-CO2 GHG emissions.

We investigated the origin and mechanisms of the natural iron fertilization that sustains a phytoplankton bloom downstream of the Kerguelen Islands. We used radium isotopes to trace the fate of shelf waters that may transport iron and other micronutrients towards offshore waters. We show that shelf waters are rapidly transferred offshore and may be transported across the polar front (PF). The PF may thus not be a strong physical barrier for chemical elements released by the shelf sediments.

This study quantifies the exchange of carbon dioxide (CO2) between the atmosphere and the land-ocean aquatic continuum (LOAC) of the northeast North American coast, which consists of rivers, estuaries, and the coastal ocean. Our analysis reveals significant variations of the flux intensity both in time and space across the study area. Ice cover, snowmelt, and the intensity of the estuarine filter are identified as important control factors of the CO2 exchange along the LOAC.

We investigated the nitrate N, O isotopic composition for the Southern Ocean Kerguelen Plateau area, aiming at understanding the N-cycling in this naturally iron fertilized area characterized by large recurrent phytoplankton blooms. The system is characterized by moderate consumption of nitrate over the season while silicic acid, on the contrary, becomes depleted, suggesting significant recycling of N. Mixed layer nitrate isotopic signatures corroborate this.

Basic marine carbonate system variables such as pH are often computed from others. Such calculations are made with many public software packages, but their results have never been compared. A new study compares 10 of these packages, quantifying differences, isolating causes, and making recommendations to reduce future discrepancies. This comparison effort has led to more than a 10-fold reduction in differences between packages for some computed variables.

This study looks at the combined impacts of hypoxia and acidification, two major environmental stressors affecting coastal systems, in a seasonally stratified basin. Here, the surface water experiences less seasonality in pH than the bottom water despite higher process rates. This is due to a substantial reduction in the acid-base buffering capacity of the bottom water as it turns hypoxic in summer. This highlights the crucial role of the buffering capacity as a modulating factor in pH dynamics.

The spatial variability of N2O fluxes measured at the field scale were investigated using a high-precision closed loop dynamic chamber. The results highlight the large and often unpredictable variation in N2O flux magnitude measured from agricultural soils at a relatively small scale. Available nitrogen content of the soils accounts for some of the variability in N2O emissions. The study suggests animal waste is an important source of N2O emissions released from livestock farms.

The Smithian--Spathian boundary was a key event in the recovery of marine environments and ecosystems following the end-Permian mass extinction ~1.5 million years earlier. Our analysis of the Shitouzhai section in South China reveals major changes in oceanographic conditions at the SSB intensification of oceanic circulation leading to enhanced upwelling of nutrient- and sulfide-rich deep waters and coinciding with an abrupt cooling that terminated the Early Triassic hothouse climate.

Here we investigate how ecosystem carbon stocks vary with elevation shifting from the closed forest to open alpine tundra, in the mountains of southern Norway. Above-ground carbon stocks decreased with elevation, with a clear breakpoint at the forest line, while the organic horizon soil carbon stocks increased linearly with elevation. Overall, ecosystem carbon stocks increased with elevation above the treeline and decreased with elevation below, demonstrating the importance of the treeline.

A hyperspectral lidar produces point clouds with multiple spectral channels (colours) for each point. We measured a pine and used the spectral content to estimate chlorophyll content. We validated these results using chemical laboratory analysis of needles taken from the pine. Our prototype has limitations, but still shows the great potential of coloured point clouds. Potential applications include forestry, security, archaeology and city modelling.