Reanalyses find rising humidity in the Arctic

Jul 06, 2012

(Phys.org) -- Direct, reliable observations of atmospheric conditions stretch as far back as the mid seventeenth century, with otherwise consistent records being punctuated by periodic updates in methods, practitioners, and observational equipment. To bridge these shifts in technique and technology, scientists develop reanalysis models designed to tie together diverse observations into a coherent picture of the system's evolution. But, like all models or analytical techniques, reanalysis data sets can suffer from errors or biases. Identifying how the records produced by different reanalyses vary can be a difficult practice, but determining if a cluster of models consistently produces biased results can be even more difficult.

A number of reanalyses have recently been developed to track the rapidly changing Arctic atmosphere, and Serreze et al.compared them with one another and with the observational record. The authors focused on how the reanalyses represent the change in Arctic tropospheric water vapor from 1979 to 2010. They compared three of the most recent and complex reanalyses against meteorological measurements made using radiosondes at nine sites north of 70 degrees North. They find that the reanalyses consistently overestimate low-altitude temperatures and winter humidity. It is important to note that these positive biases caused the reanalyses to miss low-altitude wintertime temperature and humidity inversions identified by the radiosondes.

A finding shared by both reanalyses and radiosonde observations, however, is of an increasing availability of precipitable water in the low-altitude Arctic, which the authors suggest is associated with increasing air-, reduced , and other markers consistent with the polar amplification of global warming. Increasing Arctic humidity is a troubling result, as heightening could further drive up regional temperatures.

Explore further: Ice in Arctic seas shrinks to sixth-lowest recorded

More information: “Recent changes in tropospheric water vapor over the Arctic as assessed from radiosondes and atmospheric reanalyses” Journal of Geophysical Research-Atmospheres, doi:10.1029/2011JD017421 , 2012.

Related Stories

Water vapor confirmed as major player in climate change

Nov 17, 2008

(PhysOrg.com) -- Water vapor is known to be Earth's most abundant greenhouse gas, but the extent of its contribution to global warming has been debated. Using recent NASA satellite data, researchers have estimated ...

Value of drugs for pre-osteoporosis exaggerated

Jan 18, 2008

A series of recent scientific publications have exaggerated the benefits and underplayed the harms of drugs to treat pre-osteoporosis or “osteopenia” potentially encouraging treatment in millions of low risk women, warn ...

Central Europe getting warmer

Nov 11, 2005

Surface temperature analysis of Central Europe shows that temperatures there have risen three times faster than the Northern Hemisphere land average.

Recommended for you

Study links changing winds to warming in Pacific

10 hours ago

A new study released Monday found that warming temperatures in Pacific Ocean waters off the coast of North America over the past century closely followed natural changes in the wind, not increases in greenhouse ...

NASA image: Wildfires in Khabarovsk Krai, Russia

10 hours ago

Most of the fires captured in this image burn in Khabarovsk Krai, a territory occupying the coastline of the Sea of Okhotsk. Dozens of red hotspots, accompanied by plumes of smoke mark active fires. The smoke, ...

NASA sees Tropical Depression Polo winding down

13 hours ago

Infrared satellite imagery from NASA's Aqua satellite showed only a swirl of low-level clouds some deep clouds around Polo's weakening center on Sept. 22 as the storm weakened to a depression.

User comments : 0