Corporate Banner
Satellite Banner
Scientific Communities
Become a Member | Sign in
Home>News>This Article

Seasonal CO2 Amplitude is Growing as More is Added to the Atmosphere

Published: Friday, August 09, 2013
Last Updated: Friday, August 09, 2013
Bookmark and Share
Northern Hemisphere terrestrial ecosystems are taking “deeper breaths,” according to a multi-agency study.

Levels of carbon dioxide in the atmosphere rise and fall annually as plants take up the gas in spring and summer and release it in fall and winter through photosynthesis and respiration. Now the range of that cycle is growing as more CO2 is emitted from the burning of fossil fuels and other human activities, according to a study led by Scripps Institution of Oceanography, UC San Diego.

The findings are the result of a multi-year airborne survey of atmospheric chemistry called HIAPER Pole-to-Pole Observations (HIPPO). Steven C. Wofsy, Abbott Lawrence Rotch Professor of Atmospheric and Environmental Science at the Harvard School of Engineering and Applied Sciences (SEAS), is lead principle investigator of the HIPPO project. HIPPO research flights from the Arctic to the Antarctic produced an unprecedented portrait of greenhouse gases and particles in the atmosphere, the first detailed three-dimensional mapping of the global distribution of gases and particles that affect Earth’s climate.

Observations of atmospheric CO2 made at altitudes between 3 and 6 kilometers (10,000-20,000 feet) show that seasonal CO2 variations have substantially increased in amplitude over the last 50 years. The amplitude increased by roughly 50 percent across high latitude regions north of 45° N, in comparison to previous aircraft observations from the late 1950s and early 1960s.

This means that more carbon is accumulating in forests and other vegetation and soils in the Northern Hemisphere during the summer, and more carbon is being released in the fall and winter, said study lead author Heather Graven, a postdoctoral researcher in the Scripps CO2 Program led by geochemist Ralph Keeling.

It is not yet understood why the increase in seasonal amplitude of CO2 concentration is so large, but it is a clear signal of widespread changes in northern ecosystems.

“The atmospheric CO2 observations are important because they show the combined effect of ecological changes over large regions,” said Graven. “This reinforces ground-based studies that show substantial changes are occurring as a result of rising CO2 concentrations, warming temperatures, and changing land management, including the expansion of forests in some regions and the poleward migration of ecosystems.”

The study, “Enhanced seasonal exchange of CO2 by northern ecosystems since 1960,” appears in print editions of the journal Science on Aug. 30 and in Science Express Aug. 8. The National Science Foundation, the federal Department of Energy, the National Center for Atmospheric Research (NCAR), NOAA, and the Office of Naval Research funded the study.

The researchers compared recent aircraft data with older aircraft data gathered from 1958 to 1961 using U.S. Air Force weather reconnaissance flights and analyzed by Scripps geochemist Charles David Keeling, the father of Ralph Keeling.  These aircraft measurements were done at the same time C.D. Keeling was beginning continuous CO2 measurements at Mauna Loa, Hawaii.  While the Mauna Loa measurements are now recognized as the famous “Keeling Curve,” the early aircraft data were all but forgotten.

Carbon dioxide concentrations in the atmosphere varied between 170 and 280 parts per million over the past 800,000 years. By the time C.D. Keeling began collecting data at Mauna Loa in 1958, the concentration had risen to about 315 parts per million. In May 2013, daily CO2 measurements at Mauna Loa exceeded 400 parts per million for the first time in human history.

Recent observations aboard a modified Gulfstream V jet known as HIAPER were made during research flights conducted by NCAR with scientists from Harvard, Scripps, NOAA, NCAR, Princeton University, and the University of Miami in the HIPPO campaign between 2009 and 2011. The aircraft repeatedly ascended and descended from a few hundred meters to roughly 12 kilometers (40,000 feet) between the North Pole and the coast of Antarctica to construct a unique snapshot of the chemical composition of the atmosphere. Additional recent data comes from regular flights conducted at a network of locations by NOAA. Increasing CO2 amplitude since 1960 had already been observed at two ground-based stations: Mauna Loa and Barrow, Alaska. Other stations operated by Scripps and NOAA only began measuring CO2 in the 1970s to 1990s. The aircraft-based observations uniquely show the large area in the northern high latitudes where CO2 amplitude increased strongly since 1960.

The reasons for the wider seasonal swings in CO2 concentration remain to be determined, said researchers. Even though plant activity can increase with warmer temperatures and higher CO2 concentrations, the change in CO2 amplitude over the last 50 years is larger than expected from these effects, the researchers said. CO2 concentration has increased by 23 percent and average temperature north of 30°N has increased by 1° C (1.8° F) since 1960. Additional factors may involve changes in the amount of carbon allocated to leaves, wood, or roots, changes in the extent or species composition of the ecosystems, or changes in the timing of photosynthesis and respiration.

Simulating complex processes in terrestrial ecosystems with models is recognized to be a challenge, and the observed change in CO2 amplitude is larger than simulated by models used by the Intergovernmental Panel on Climate Change (IPCC). While this underestimate does not call into question the response of climate to CO2 concentration in the IPCC models, it does suggest that a better understanding of what happened over the last 50 years could improve projections of future ecosystem changes. The bottom line is that northern ecosystems appear to be behaving differently than they did 50 years ago, said study authors.

Besides Heather Graven, Ralph Keeling, and Steven Wofsy, study co-authors include Stephen Piper, Lisa Welp, and Jonathan Bent of Scripps Oceanography; Prabir Patra of the Research Institute for Global Change in Yokohama, Japan; Britton Stephens of NCAR; Bruce Daube, and Gregory Santoni of Harvard; Colm Sweeney of NOAA and the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder, and Pieter Tans of NOAA; John Kelley of the University of Alaska Fairbanks; and Eric Kort of the Jet Propulsion Laboratory.

Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More Than 5,200+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

3D-Printed Heart-On-A-Chip with Integrated Sensors
Researchers have created the first 3D-printed organ-on-a-chip with integrated sensors, paving the way for more complex, customizable devices.
Tuesday, October 25, 2016
Less Frequent Cervical Cancer Screening
HPV-vaccinated women may only need one screening every 5 to 10 years with screening starting later in life.
Wednesday, October 19, 2016
A Diversity of Genomes
New DNA from understudied groups reveals modern genetic variation, ancient population shifts.
Friday, September 23, 2016
Diverse Fungi Secrete Similar Suite of Decomposition Enzymes
A recent study reveals different fungal species secrete a rich set of enzymes that share similar functions, despite species-specific differences in the amino acid sequences of these enzymes.
Tuesday, August 30, 2016
Biological Barcodes Using CRISPR
Using genome editing tools, researchers are getting closer to understand differentiation of various cell types during development.
Thursday, August 25, 2016
Toxic Chemicals Found in Drinking Water of 33 States
High levels of fluorinated compounds have been linked to cancer, hormone disruption.
Thursday, August 11, 2016
New Approach To Severe Bacterial Infections And Sepsis
Protein fragment could provide a defense when antibiotics fail.
Friday, July 08, 2016
Harvard Licenses Genotyping Platform
Novel approach aids development of drug resistance testing products for HIV.
Tuesday, May 24, 2016
A New Platform for Discovering Antibiotics
Harvard chemists hope to shorten time, difficulty in measuring their effectiveness, potential.
Monday, May 23, 2016
New Weapon Against Breast Cancer
Molecular marker in healthy tissue can predict a woman’s risk of getting the disease, research says.
Thursday, April 07, 2016
Collaboration to Develop Cancer Therapeutics
Major license agreement with Merck, enabled by Blavatnik Biomedical Accelerator, aims to develop therapy for most common form of acute leukemia.
Tuesday, March 22, 2016
Scaling Up Tissue Engineering
Wyss Institute has invented Bioprinting technique that creates thick 3D tissues composed of human stem cells and embedded vasculature, with potential applications in drug testing and regenerative medicine.
Tuesday, March 15, 2016
Into Thin Air
Lower oxygen intake could be used to prevent mitochondrial diseases from forming.
Tuesday, March 01, 2016
High Poverty’s Effect on Childhood Leukemia
Patients more likely to suffer early relapses, which can be harder to treat.
Thursday, February 25, 2016
A Cancer’s Surprise Origins, Caught in Action
First demonstration of a melanoma arising from a single cell.
Monday, February 01, 2016
Scientific News
How it Works: Advanced Data Analysis Using Visualization
Visualisation of data can be used to help molecular biologists tackle the vast datasets their experiments create.
Unravelling the Role of Key Genes and DNA Methylation in Blood Cell Malignancies
Researchers from the University of Nebraska Medical Center have demonstrated the role of Dnmt3a in safeguarding normal haematopoiesis.
Salford Lung Study - The First Real World Clinical Trial
In this podcast, we learn about the Salford Lung Study and its potential to revolutionize the way we assess new drugs and treatments around the world.
Point of Care Diagnostics - A Cautious Revolution
Advances in molecular biology, coupled with the miniaturization and improved sensitivity of assays and devices in general, have enabled a new wave of point-of-care (POC) or “bedside” diagnostics.
Robotic Cleaning Technique Could Automate Neuroscience Research
New robotic cleaning technique allows pipettes used in patch-clamping to be re-used up to 11 or more times.
Influential Cancer Researcher Receives Agilent Thought Leader Award
Biologist Scott Lowe receives award in recognition for his contributions to cancer biology.
Ebola-Affected Countries Receive NIH Support
The National Institutes of Health has established a new program to further research capacity to study Ebola and other epidemics.
Skin Patch to Treat Peanut Allergy
NIH-funded study suggests peanut protein patch is a safe and convenient method of treatment.
Startup Seeks More Precise Prostate Cancer Screening
Gregor Diagnostics aims to bring a non-invasive prostate cancer screening test to the market.
Scientists Uncover Why Hepatitis C Vaccine is Difficult to Make
Scientists have uncovered one reason why a successful hepatitis C vaccine continues to be elusive.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,200+ scientific videos