Volume 12 Issue 8, August 2019

The climate of South and East Asia is affected by anthropogenic aerosols, but the magnitude of the aerosol imprint is not well known. As regional emissions are rapidly changing, potential related climate risks must be quantified.

Social media is increasingly being used to share near-real-time analysis of emergent and sometimes hazardous geological events. Such open discussion can drive new research directions and collaborations for geoscientists.

Ocean-floor plateaus are not voluminous lava flows from central volcanoes as thought, but anomalously thick oceanic crust, suggest magnetic anomaly patterns from the Shatsky Rise, in the northwestern Pacific Ocean.

African savannah grasslands initially proliferated in the late Miocene due to declining atmospheric CO₂, rather than previously proposed regional climate drying. Supplanting previous woodland vegetation due to photosynthetic adaptations, these grasslands set the stage for subsequent mammalian evolutionary trends on the continent.

Recovery of the stratospheric ozone layer above Antarctica has not been straightforward, as a result of human activities and climate change. The recovery process might be delayed by up to decades if further mitigation actions are not taken.

Ice deposits up to around 50 m thick infill some craters near the Moon’s south pole and Mercury’s north pole, as inferred from the poleward shallowing of simple craters.

Polluted continental aerosols contain a considerable fraction of ice nucleating particles, suggest analyses of satellite observations and simulations with cloud-resolving models.

Solid ammonium nitrate particles are formed in the upper troposphere during the Asian monsoons, which bring large amounts of ground ammonia to this altitude, according to integrated analyses of measurements on ammoniated aerosol, together with model simulations.

Decadal averages of March precipitation in western Europe can be predicted by exploiting links with the jet stream and ocean along with skilful predictions of sea surface temperatures, according to an analysis of observations and reanalysis products.

Droughts in South America and marine heatwaves in the South Atlantic have a common remote cause, convection in the tropical oceans that triggers atmospheric blocking, suggest analyses of observations.

Permafrost loses carbon at a faster rate than previously thought as climate warms, according to direct soil carbon observations over five years in the field in Alaska’s tundra ecosystem.

Deep soil drying, caused by high evaporation, can explain California forest die-off in the droughts during 2012–2015, according to analyses of patterns of die-off and moisture deficit.

Controls on the ecological success of marine calcifiers changed from abiotic to biotic in the mid-Jurassic, according an environmental forcing model compared with skeletal taxa.

Multidecadal global-mean temperature fluctuations over the past 2,000 years are consistent in comprehensive climate reconstructions and model simulations, and volcanic eruptions had the most important influence at that timescale between 1300 and 1800 CE.

Large volcanic eruptions in the first half of the nineteenth century blurred the transition from the Little Ice Age to anthropogenic warming, and led to sustained cooling, drought in Africa and weakened monsoons, suggests a combination of observations and model simulations.

Aridification did not cause the expansion of ecosystems using the C₄ photosynthetic pathway in parts of Africa 10 million years ago, according to leaf-wax analyses in deep-sea drill cores, leaving declining atmospheric carbon dioxide levels as the most plausible cause.

The Shatsky Rise oceanic plateau formed by spreading ridge volcanism, according to analyses of linear magnetic anomalies over the Tamu Massif submarine volcano.

Oxidation of arc magmas may be a secondary feature, acquired as hydrogen from magmatic water is incorporated into anhydrous minerals in the mantle wedge, according to analyses of orthopyroxenes in mantle xenoliths from an arc setting.

Deep mantle heterogeneity and large-scale deep mantle convection has been operating since the Palaeoarchaean, according to enriched plume signatures found in a 3.45-billion-year-old ultramafic–mafic suite from the North China Craton.