Eideard

Global differences between evaporation and precipitation

Salt is essential to human life. Most people don’t know, however, that salt — in a form nearly the same as the simple table variety — is just as essential to Earth’s ocean, serving as a critical driver of key ocean processes. While ancient Greek soothsayers believed they could foretell the future by reading the patterns in sprinkled salt, today’s scientists have learned that they can indeed harness this invaluable mineral to foresee the future — of Earth’s climate.

The oracles of modern climate science are the computer models used to forecast climate change. These models, which rely on a myriad of data from many sources, are effective in predicting many climate variables, such as global temperatures. Yet data for some pieces of the climate puzzle have been scarce, including the concentration of dissolved sea salt at the surface of the world’s ocean, commonly called ocean surface salinity, subjecting the models to varying margins of error. This salinity is a key indicator of how Earth’s freshwater moves between the ocean, land and atmosphere.

Enter Aquarius, a new NASA salinity-measurement instrument slated for launch in June 2011 aboard the SAC-D spacecraft built by Argentina’s CONAE. Aquarius’ high-tech, salt-seeking sensors will make comprehensive measurements of ocean surface salinity with the precision needed to help researchers better determine how Earth’s ocean interacts with the atmosphere to influence climate. It’s a mission that promises to be, to quote the old saying, “worth its salt…”

Density-driven ocean circulation, according to Gary Lagerloef, is controlled as much by salinity as by ocean temperature. Sea salt makes up only 3.5 percent of the world’s ocean, but its relatively small presence reaps huge consequences.

Salinity influences the very motion of the ocean and the temperature of seawater, because the concentration of sea salt in the ocean’s surface mixed layer — the portion of the ocean that is actively exchanging water and heat with Earth’s atmosphere — is a critical driver of these ocean processes. It’s the missing variable in understanding the link between the water cycle and ocean circulation. Specifically, it’s an essential metric to modeling precipitation and evaporation…

Until now, researchers had taken ocean salinity measurements from aboard ships, buoys and aircraft – but they’d done so using a wide range of methods across assorted sampling areas and over inconsistent times from one season to another. Because of the sparse and intermittent nature of these salinity observations, researchers have not been able to fine-tune models to obtain a true global picture of how ocean surface salinity is influencing the ocean. Aquarius promises to resolve these deficiencies, seeing changes in ocean surface salinity consistently across space and time and mapping the entire ice-free ocean every seven days for at least three years.

RTFA. The advance work has been accomplished, sensors and data collection have been tuned. Now the task of collecting data will begin with the launch of Aquarius, this month.

The world’s ocean surface temperature was the warmest on record for June, breaking the previous high mark set in 2005, according to a preliminary analysis by NOAA’s National Climatic Data Center in Asheville, N.C. Additionally, the combined average global land and ocean surface temperature for June was second-warmest on record.

* The combined global land and ocean surface temperature for June 2009 was the second warmest on record, behind 2005, 1.12 degrees F (0.62 degree C) above the 20th century average of 59.9 degrees F (15.5 degrees C).
* Separately, the global ocean surface temperature for June 2009 was the warmest on record, 1.06 degrees F (0.59 degree C) above the 20th century average of 61.5 degrees F (16.4 degrees C).
* Each hemisphere broke its June record for warmest ocean surface temperature. In the Northern Hemisphere, the warm anomaly of 1.17 degrees F (0.65 degree C) surpassed the previous record of 1.12 degrees F (0.62 degree C), set in 2005. The Southern Hemisphere’s increase of 0.99 degree F (0.55 degree C) exceeded the old record of 0.92 degree F (0.51 degree C), set in 1998.
* The global land surface temperature for June 2009 was 1.26 degrees F (0.70 degree C) above the 20th century average of 55.9 degrees F (13.3 degrees C), and ranked as the sixth-warmest June on record.

* El Niño is back after six straight months of increased sea-surface temperature anomalies. June sea surface temperatures in the region were more than 0.9 degree F (0.5 degree C) above average…
* Arctic sea ice covered an average of 4.4 million square miles (11.5 million square kilometers) during June, according to the National Snow and Ice Data Center. This is 5.6 percent below the 1979-2000 average extent. By contrast, the 2007 record for the least Arctic sea ice extent was 5.5 percent below average. Antarctic sea ice extent in June was 3.9 percent above the 1979-2000 average.

Just checking in on the weather – since the nutball skeptics tend to skip the bits which don’t fit their religion.

The pilots in the family are as bad as farmers when it comes to being weather freaks. We do a monthly discussion of El Niño/La Niña. Keep Skype in business between Asheville and Santa Fe.