Taxonomy term

Builders and masons take note: When it comes to the durability of limestone, grain size matters. New research combining field and lab data shows that fine-grained limestone is more susceptible than its coarser-grained cousins to a one-two punch of chemical and mechanical weathering. The findings, which arose in part from observations of Jerusalem’s historic Western Wall, could have implications for Earth’s carbon cycle and landscape — as well as for architectural preservation.

Saturn’s peculiar polar “hexagon” has proven perplexing for scientists studying the atmospheric phenomenon since Voyager 1 and 2 first observed it in the early 1980s. Now, an international team has completed the most thorough study of the six-sided jet stream yet, using images and data collected between 2008 and 2014 by the Cassini spacecraft.

Researchers have found that the number of foggy winter days in California’s agriculture-heavy Central Valley has dropped 46 percent on average over the past three decades. Fog shields the valley from sunlight and contributes to the amount of “winter chill” — the amount of time spent between zero and 7 degrees Celsius during winter dormancy — that fruit and nut trees there experience. Sufficient winter chill is necessary for buds, flowers and fruit to develop properly, and although winter chill has previously been observed to have decreased since the 1950s, no one had conducted a long-term analysis of fog occurrence trends in the area, according to Dennis Baldocchi and Eric Waller of the University of California at Berkeley.

Trading in “virtual water” — rainfall and irrigation water used in the production of food commodities or other goods and services, but that isn’t part of the final product — between water-rich and water-poor regions has been suggested as a means to allay water scarcity. And recently, the virtual water concept has gained a foothold among a number of governments and multinational businesses, potentially shaping approaches to water sustainability in the future.