Analysis of observations on six continents reveals a global preference for afternoon rain to fall on locally drier soils—contrary to the predictions of large-scale climate models, and suggesting that such models may exaggerate the occurrence of droughts.

Tropical cyclones over the Arabian Sea in the pre-monsoon season (May–June) have intensified since 1997 owing to significant reductions in storm-ambient vertical wind shear (VWS) in the troposphere; these reductions have decreased on average by about 3 m s−1 from the pre-1997 epoch (1979–1997) to the recent epoch (1998–2010)1. The authors attribute the reduction of pre-monsoon VWS to the dimming effects of increased anthropogenic black carbon and sulphate emissions.

Biomass burning (BB) contributes large amounts of black carbon (BC) and particulate organic matter (POM) to the atmosphere and contributes significantly to the earth’s radiation balance. BB particles can be a complicated optical system, with scattering and absorption contributions from BC, internal mixtures of BC and POM, and wavelength-dependent absorption of POM. Large amounts of POM can also be externally mixed.

The Indian summer monsoon rainfall (ISMR) has remained remarkably stable during the last 140 years. The ISMR has varied between 70% and 120% of the long-term average of about 85 cm. Monsoon seasons with ISMR of less than 90% of the average are considered to be droughts, whereas those with more than 110% rainfall are considered as excess rainfall seasons. Although the variation is not large (Figure 1), it has a substantive impact on our agriculture and gross domestic product (GDP).

South of Africa, the Agulhas ocean current system transports warm, salty water from the Indian Ocean to the Atlantic Ocean. This study shows that the mesoscale variability of the Agulhas system has intensified over recent decades, apparently owing to enhanced trade winds over the tropical Indian Ocean.

The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia.