About one-fifth of organic carbon in sediments is bound to reactive iron phases, which are metastable over geological timescales and may therefore serve as a sink for the long-term storage of organic carbon.

India has the second largest population, one of fastest growing economies and is ranked third in greenhouse gas emissions by fossil-fuel burning in the world. However, there has been little monitoring of atmospheric CO2 concentration over India to date. Here we reanalyse pioneering atmospheric CO2 observations at Cape Rama, India (CRI) during the period from February 1993 to October 2002, using three forward transport models to simulate atmospheric CO2 and separate tracers of terrestrial and oceanic fluxes, and fossil-fuel emissions.

Throughout the year, average sea surface temperatures in the Arabian Sea are warm enough to support the development of tropical cyclones1, but the atmospheric monsoon circulation and associated strong vertical wind shear limits cyclone development and intensification, only permitting a pre-monsoon and post-monsoon period for cyclogenesis. Thus a recent increase in the intensity of tropical cyclones over the northern Indian Ocean5 is thought to be related to the weakening of the climatological vertical wind shear.

A recent surge in the intensity of tropical cyclones in the Arabian Sea has brought unprecedented damage and loss of life. Anthropogenic air pollution might be increasing the destructiveness of these storms.

The Indian subcontinent witnessed a severe monsoon drought in the year 2009. India as a whole received 77% of its long period average during summer monsoon season (1 June to 30 September) of 2009, which is the third highest deficient all India monsoon season rainfall year during the period 1901–2009. Therefore, an attempt is made in this paper to study the characteristic features of summer monsoon rainfall of 2009 over the country and to investigate some of the possible causes behind the anomalous behaviour of the monsoon.