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Dinitrogen (N2) fixation is widely recognized as an important process in controlling ecosystem responses to global environmental change, both today and in the past; however, significant discrepancies exist between theory and observations of patterns of N2 fixation across major sectors of the land biosphere.

Anantapur, July 6: The agriculture minister, Mr N. Raghuveera Reddy, said that cloud seeding would be taken up in another 10 days due to lack of rains in Anantapur district. Speaking to newsmen here on Sunday, he said tenders were called to conduct cloud seeding for the next five years. He said that a government committee would examine the tenders and finalise them within two days. The minister said that steps would be taken to conduct cloud seeding on a war-footing.

The Montreal Protocol with its subsequent amendments and adjustments has been providing a global regulatory framework for the phase out of ozone depleting substances. Till date, CFCs, CTC, HBFCs, methyl chloroform and halons have been already phased out completely by the developed countries and a number of other ODSs are scheduled to follow.

Increasing tropospheric ozone levels over the past 150 years have led to a significant climate perturbation; the prediction of future trends in tropospheric ozone will require a full understanding of both its precursor emissions and its destruction processes. A large proportion of tropospheric ozone loss occurs in the tropical marine boundary layer and is thought to be driven primarily by high ozone photolysis rates in the presence of high concentrations of water vapour.

Halogens are known to decrease the levels of stratospheric ozone. The latest measurements show that something similar occurs in the lower atmosphere over tropical oceans

The state government on Wednesday decided to continue the controversial cloud seeding operations for another five years. Tenders have been called to select the company which will conduct the operations. A top official said that there was actually no scientific reason for continuing the programme but added that there was

Reactive nitrogen (Nr) includes the inorganic (NH3, NH4, NOx, HNO3, N2O, NO3) and organic forms (urea, amines, proteins, nucleic acids) that readily participate in various reactions of the global N cycle. Over the last half a century, anthropogenic perturbations of the natural N cycle have led to the increasing accumulation of inorganic Nr in the soil, water and air, intentionally through agriculture and unintentionally through fosill-fuel consumption and other activities, adversely affecting human health, biodiversity, environment and climate change.

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Clouds contribute significantly to the formation of many of the natural hazards. Hence cloud mapping and its classification becomes a major component of the various physical models which are used for forecasting natural hazards.

Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to ~3% of the annual new marine biological production, ~0.3 petagram of carbon per year. This input could account for the production of up to ~1.6 teragrams of nitrous oxide (N2O) per year.

Dust aerosols can suppress rainfall by increasing the number of cloud condensation nuclei in warm clouds and affecting the surface radiation budget and boundary layer instability. The extent to which atmospheric dust may affect precipitation yields and the hydrologic cycle in semiarid regions remains poorly understood. We investigate the relationship between dust aerosols and rainfall in the West African Sahel where the dust-rainfall feedback has been speculated to contribute to sustained droughts.