NASA's Aqua satellite captured strong thunderstorms with colder cloud tops that have grown within Tropical Storm Rachel in the Eastern Pacific Ocean.

Aqua passed over the large Tropical Storm Rachel on Sept. 25 at 4:41 p.m. EDT and the Atmospheric Infrared Sounder or AIRS instrument, saw that the extent of colder cloud tops had increased, indicating thunderstorm heights were increasing and it was strengthening. The expansion of those stronger thunderstorms also suggests that the northeasterly wind shear may be relaxing a little. The strongest thunderstorms remain limited to the southwest of the low-level center, 

Earth's atmosphere is a complicated dance of molecules involving the output of plants, animals and human industry in sequences of chemical reactions.

Such processes help maintain the atmosphere's chemical balance; most topically during protest week in New York City, they break down pollutants emitted from the burning of fossil fuels.

Understanding exactly how these reactions proceed is critical for predicting how the atmosphere will respond to environmental changes, but some of the steps of this dance are so quick that all of the molecules involved haven't been measured in the wild.

Periodontitis, gum infection that damages the soft tissue and destroys the bone that supports teeth, is the sixth most prevalent condition in the world affecting 743 million people worldwide, according to research from 2010.

Between 1990 and 2010, the global age-standardized prevalence of severe periodontitis was static at 11.2%. The age-standardized incidence of severe periodontitis in 2010 was 701 cases per 100,000 person-years, a non-significant increase from the 1990 incidence of severe periodontitis.

Ryan Rykaczewski, an oceanographer and assistant professor at the University of South Carolina, is part of a team that are looking deep into the ocean's past, and they have shown that natural processes can cause dramatic year-to-year drops in fish populations and growth rates.

They also raise questions about whether human activities might be making those declines more frequent.

Upwelling means phytoplankton, the perfect 'sea food'

The focus of the research is the California current, which stretches from Washington state to the Baja peninsula and is one of a handful of coastal waters on Earth from which an inordinately large portion of the world's fish harvest originates.

Ice ebbs and flows, that is no secret - but lost in claims that ice is as widespread as ever is the reality that it is now thinner, and the difference is so noticeable the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite can detect it.

The strength of gravity at Earth’s surface varies subtly from place to place owing to factors such as the planet’s rotation and the position of mountains and ocean trenches. Changes in the mass of large ice sheets can also cause small local variations in gravity.

Outside the developed world, global population continues to rise but all of the best agricultural locations are in use. If we want people to be self-sufficient (and we do) science is going to need to be able to help the developing world with innovative and sustainable solutions.

Modern agriculture has not reached any kind of limit, we can easily boost food production by as much as 70-100% in the next few decades. To grow in more difficult areas, and to be resistant to swings in weather, more drought-tolerant food crops are essential.