Subscribe free to our newsletters via your




CLIMATE SCIENCE
Volcanic eruptions slow down climate change - temporarily
by Staff Writers
Karlsruher, Germany (SPX) Jul 10, 2015


The IAGOS-CARIBIC air inlet system mounted at the IAGOS-CARIBIC Airbus. Image courtesy Deutsche Lufthansa AG. For a larger version of this image please go here.

Although global concentration of greenhouse gases in the atmosphere has continuously increased over the past decade, the mean global surface temperature has not followed the same path. A team of international reseachers, KIT scientists among them, have now found an explanation for this slowing down in global warming: the incoming solar radiation in the years 2008-2011 was twice as much reflected by volcanic aerosol particles in the lowest part of the stratosphere than previously thought. The team presents their study in Nature Communications (DOI: 10.1038/ncomms8692).

For the lowest part of the stratosphere - i. e. the layer between 10 and 16 kilometres - little information was available so far, but now the international IAGOS-CARIBIC climate project combined with satellite observations from the CALIPSO lidar provided new essential information. According to the study, the cooling effect due to volcanic eruptions was clearly underestimated by climate models used for the last Intergovernmental Panel on Climate Change (IPCC) report.

Led by the University of Lund, Sweden, and supported by the NASA Langley Research Center, USA, and the Royal Netherlands Meteorological Institute, three major German atmospheric research institutes were also involved: the Max Planck Institute for Chemistry in Mainz (MPI-C), the Leibniz Institute for Tropospheric Research in Leipzig (TROPOS) and the Karlsruhe Institute of Technology (KIT). Since more frequent volcanic eruptions and the subsequent cooling effect are only temporary the rise of Earths' temperature will speed up again. The reason is the still continuously increasing greenhouse gas concentration, the scientists say.

In the first decade of the 21st century the average surface temperature over the northern mid-latitude continents did increase only slightly. This effect can be now explained by the new study on volcanic aerosol particles in the atmosphere reported here. The study uses data from the tropopause region up to 35 km altitude, where the former is found between 8 km (poles) and 17 km (equator) altitude. The tropopause region is a transition layer between the underlying wet weather layer with its clouds (troposphere) and the dry and cloud-free layer above (stratosphere).

"Overall our results emphasize that even smaller volcanic eruptions are more important for the Earth's climate than expected", summarize CARIBIC coordinators Dr. Carl Brenninkmeijer, MPI-C, and Dr. Andreas Zahn, KIT. The IAGOS-CARIBIC observatory was coordinated and operated by the MPI-C until the end of 2014, since then by the KIT.

To collect their data the team combined two different experimental approaches: sampling and in situ measurements made by IAGOS-CARIBIC together with observations from the CALIPSO satellite. In the IAGOS-CARIBIC observatory trace gases and aerosol particles in the tropopause region are measured since 1997. A modified air-freight container is loaded once per month for four intercontinental flights into a modified Airbus A340-600 of Lufthansa.

Altogether about 100 trace gas and aerosol parameters are measured in situ at 9-12 km altitude as well as in dedicated European research laboratories after flight. TROPOS in Leipzig is responsible for the in situ aerosol particle measurements in this unique project. KIT runs 5 of the 15 installed instruments, also the one for ozone.

Collected particles are analyzed at the University of Lund, Sweden, using an ion beam accelerator for measuring the amount of particulate sulfur. When comparing this particulate sulfur concentration to the in situ measured ozone concentration this ratio is usually quite constant at cruise altitude.

However, volcanic eruptions increase the amount of particulate sulfur and thus the ratio becomes an indicator of volcanic eruption influencing the tropopause region. "The ratio of particulate sulfur to ozone from the CARIBIC measurements clearly demonstrates the strong influence from volcanism on the tropopause region", report Dr. Sandra M. Andersson and Professor Bengt G. Martinsson of the University of Lund, who are the lead authors.

The second method is based on satellite observations. The Cloud-Aerosol Lidar and Pathfinder Satellite Observation (CALIPSO) mission, a collaboration between the National Aeronautics and Space Administration (NASA) in the US and the Centre National d'Etude Spatiale (CNES) in France, has provided unprecedented view on aerosol and cloud layers in the atmosphere.

Until recently, the data had only been scrutinized above 15 km, namely where volcanic aerosol are known to affect our climate for a long time. Now also aeorosol particles of the lowermost stratosphere have been taken into account for calculating the radiative balance of the atmosphere, to evaluate the impact of smaller volcanic eruptions on the climate.

The influence from volcanic eruptions on the stratosphere was small in the northern hemisphere between 1999 and 2002. However, strong signals of volcanic aerosol particles were observed between 2005 and 2012. In particular three eruptions stand out: the Kasatochi in August 2008 (USA), the Sarychev in June 2009 (Russia), and the Nabro in June 2011 (Eritrea).

Each of the three eruptions injected more than one megaton sulfur dioxide (SO2) into the atmosphere. "Virtually all volcanic eruptions reaching the stratosphere lead to more particles there, as they bring in sulfur dioxide, which is converted to sulfate particles", explains Dr. Markus Hermann of TROPOS, who conducts the in situ particle measurements in CARIBIC.

Whether a volcanic eruption has a global climate impact or not depends on several factors. There is the amount of volcanic sulfur dioxide as well as the injection height. But also the latitude of the eruption is important: As the air flow in northern hemispheric stratosphere is largely disconnected from the southern hemisphere, only volcanic eruptions near the equator can effectively distribute the emitted material over both hemispheres. As in the Tambora eruption on the Indonesian Island Sumbawa 200 years ago. This eruption led to such a strong global cooling that the year 1816 was called "year without summer", including worldwide crop failures and famines.

Also the Krakatau eruption 1883 on Indonesia or the Pinatubo 1991 on the Philippines led to noticeable cooling. The present study now indicates that "the cooling effect of volcanic eruptions was underestimated in the past, because the lowest part of the stratosphere was mostly not considered. Interestingly our results show that the effect also depends on the season. The eruptions investigated by us had their strongest impact in late summer when the incoming solar radiation is still strong", explains Dr. Sandra M. Andersson.

Publication: Sandra M. Andersson, Bengt G. Martinsson, Jean-Paul Vernier, Johan Friberg, Carl A. M. Brenninkmeijer, Markus Hermann, Peter F. J. van Velthoven and Andreas Zahn (2015): Significant radiative impact of volcanic aerosol in the lowermost stratosphere. Nature Communications, doi: 10.1038/ncomms8692.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Karlsruher Institut fur Technologie
Climate Science News - Modeling, Mitigation Adaptation






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








CLIMATE SCIENCE
Timeline links volcanic eruptions to centuries of cold temp extremes
New Haven CT (SPX) Jul 09, 2015
A new study reorders the timing and reveals the climate impact of nearly 300 major volcanic eruptions worldwide, dating back to the early Roman period. The analysis, published in the journal Nature, resolves longstanding inconsistencies between historic atmospheric sulfate data taken from ice cores and corresponding temperature data derived from tree rings and other sources. The new chrono ... read more


CLIMATE SCIENCE
Nepal quake: Flat owners baulk at return to high-life

We're headed for Titanic-like crash, climate talks hear

Pope takes message to defend poor, environment to Bolivia

Amnesty urges EU to focus on rescuing migrants

CLIMATE SCIENCE
Russian, Chinese Navigation Systems to Accommodate BRICS Members

Russia, India Cooperate on Space Exploration, Glonass Satellite System

Global Positioning System: A Generation of Service to the World

Blind French hikers cross mountains with special GPS

CLIMATE SCIENCE
Neuroscientists establish brain-to-brain networks in primates, rodents

Researchers find the organization of the brain is perfect

World's oldest man dies at 112 in Japan

Revised view of brain circuit reveals how we avoid powerful odors

CLIMATE SCIENCE
The bizarre mating habits of flatworms

Plant's sonar-bouncing leaves attract bats -- and their poo

Unraveling iridescence

Bats do it, dolphins do it - now humans can do it, too

CLIMATE SCIENCE
Study explains how dengue virus adapts as it travels

As blacklegged ticks migrate, Lyme disease follows

Scientists, feds aim to curb spread of brucellosis in Yellowstone

Five-year window for preventing AIDS rebound: experts

CLIMATE SCIENCE
China firm to punish 'unscheduled' pregnancies: report

Dalai Lama birthday celebrations draw support, protests in US

Millions of silver pieces for China's official Christians

Chinese tourists boost Thai economy but stir outrage

CLIMATE SCIENCE
Piracy, other maritime crimes rise in Southeast Asia

Mexico army ordered soldiers to kill criminals: NGO

Malaysian navy shadows tanker, urges hijackers to give up

Polish bootcamp trains security contractors for mission impossible

CLIMATE SCIENCE
China consumer inflation rate rises to 1.4% in June: govt

World Bank removes critical section from China report

China brokers to invest $19 mn to curb market plunge

China manufacturing sees slight pick-up in June




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.