Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Model Helps Scientists Home In On Tropical Climate Controls


It has long been known that tropical climate - by redistributing vast amounts of solar energy through welling hot air and the formation of towering cumulous clouds - influences weather in other parts of the world.

It remains unclear, however, how much the tropics can be affected by higher latitudes.
Now, with the help of a sophisticated computer model, scientists at the University of Wisconsin-Madison have shown that vast atmospheric "bridges" and oceanic "tunnels," created by overturning air and water, link the high latitudes to the tropics and can warm ocean temperature near the equator.

The finding, reported in the May 13 issue of the journal Geophysical Research Letters, has implications for better understanding global and regional climate change, and is the first to identify high-latitude phenomena that significantly influence climate in the equatorial regions of the world.

The prevailing wisdom, according to Zhengyu Liu, lead author of the paper and director of UW-Madison’s Center for Climatic Research, was that climate and weather phenomena at higher latitudes tended to be static, with no far-reaching influence.

"That was the conventional thinking," he says. "But our model shows that these phenomena are equally weighted, that climate and weather at higher latitudes have as much of an influence on the tropics as tropical weather and climate influence the higher latitudes. Both are very important."

The discovery reveals a hidden climate mechanism that may be of critical importance to studies of past and future global and regional climate change, says Liu.

According to the scenario depicted by the modeling experiments conducted by Liu and colleague Haijun Yang, the heat carried via the atmospheric bridges from the tropics to higher latitudes is reduced as a result of warming climate in the higher latitudes. At the same time, warm extratropical water is funneled into the subsurface oceanic tunnels and is carried to the equator where it upwells and warms the tropical ocean.

The study suggests that even a 2-degree Celsius warming of the ocean in regions beyond the tropics can raise ocean surface and subsurface temperatures in the tropics by as much as 1 degree Celsius as less warm air flows out of the tropics and warm, extratropical water is channeled toward the equator by the oceanic tunnels depicted in the study.

"That is a significant change" in temperature, says Liu. "It is fundamentally important."

The new study, says Liu, provides a missing piece of the climate puzzle. It will enable scientists to gain more insight into climate and climate change as an unknown mechanism is revealed and added to the mix of variables that researchers must grasp as they wrestle with the hugely complex problem of understanding and forecasting climate change.

"The magnitude of this influence and the relative contributions of the atmospheric bridge and oceanic tunnel have remained uncertain," Liu says. "But we have found that the extratropics exert a strong control on tropical climate. This is our first estimate of the extratropical influence on the tropics."

The Center for Climatic Research at the University of Wisconsin-Madison is a leading center of research into world climate. It is a part of the UW-Madison Gaylord Nelson Institute for Environmental Studies.

Terry Devitt | University of Wisconsin
Further information:

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>