Ingeborg Levin

Bio: Ingeborg Levin is an academic researcher from Heidelberg University. The author has contributed to research in topics: Greenhouse gas & Stratosphere. The author has an hindex of 55, co-authored 154 publications receiving 9906 citations.

The Tropospheric 14CO2 Level in Mid-Latitudes of the Northern Hemisphere (1959–2003)

Abstract: A comprehensive tropospheric (super 14) CO (sub 2) data set of quasi-continuous observations covering the time span from 1959 to 2003 is presented. Samples were collected at 3 European mountain sites at height levels of 1205 m (Schauinsland), 1800 m (Vermunt), and 3450 m asl (Jungfraujoch), and analyzed in the Heidelberg Radiocarbon Laboratory. The data set from Jungfraujoch (1986-2003) is considered to represent the free tropospheric background level at mid-latitudes of the Northern Hemisphere, as it compares well with recent (yet unpublished) measurements made at the marine baseline station Mace Head (west coast of Ireland). The Vermunt and Schauinsland records are significantly influenced by regional European fossil fuel CO (sub 2) emissions. The respective delta (super 14) CO (sub 2) depletions, on an annual mean basis, are, however, only 5 ppm less than at Jungfraujoch. Vermunt and Schauinsland both represent the mean continental European troposphere.

Inverse Modeling of Global and Regional CH4 Emissions Using SCIAMACHY Satellite Retrievals

Abstract: Methane retrievals from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument onboard ENVISAT provide important information on atmospheric CH_4 sources, particularly in tropical regions which are poorly monitored by in situ surface observations Recently, Frankenberg et al (2008a, 2008b) reported a major revision of SCIAMACHY retrievals due to an update of spectroscopic parameters of water vapor and CH_4 Here, we analyze the impact of this revision on global and regional CH_4 emissions estimates in 2004, using the TM5-4DVAR inverse modeling system Inversions based on the revised SCIAMACHY retrievals yield ∼20% lower tropical emissions compared to the previous retrievals The new retrievals improve significantly the consistency between observed and assimilated column average mixing ratios and the agreement with independent validation data Furthermore, the considerable latitudinal and seasonal bias correction of the previous SCIAMACHY retrievals, derived in the TM5-4DVAR system by simultaneously assimilating high-accuracy surface measurements, is reduced by a factor of ∼3 The inversions result in significant changes in the spatial patterns of emissions and their seasonality compared to the bottom-up inventories Sensitivity tests were done to analyze the robustness of retrieved emissions, revealing some dependence on the applied a priori emission inventories and OH fields Furthermore, we performed a detailed validation of simulated CH_4 mixing ratios using NOAA ship and aircraft profile samples, as well as stratospheric balloon samples, showing overall good agreement We use the new SCIAMACHY retrievals for a regional analysis of CH_4 emissions from South America, Africa, and Asia, exploiting the zooming capability of the TM5 model This allows a more detailed analysis of spatial emission patterns and better comparison with aircraft profiles and independent regional emission estimates available for South America Large CH_4 emissions are attributed to various wetland regions in tropical South America and Africa, seasonally varying and opposite in phase with CH_4 emissions from biomass burning India, China and South East Asia are characterized by pronounced emissions from rice paddies peaking in the third quarter of the year, in addition to further anthropogenic emissions throughout the year

Methane consumption in aerated soils of the temperate zone

Abstract: Quasi-continuous observations of the methane concentration in aerated soils of the temperate zone are presented. The flux of methane into the soil is calculated from the concentration gradient at the soil surface. Depending on the permeability of methane in soil air at an individual site, yearly mean uptake rates between 0.09 and 1.3 g CH 4 m -2 yr -1 have been observed in temperate forest soils. The methane flux from the atmosphere into the soil shows only a weak seasonality with an about 50% higher uptake rate in the summer than in the winter months. This indicates that the methane flux into the soil is mainly controlled by the transport resistance in the soil rather than by the potential microbial decomposition rate. DOI: 10.1034/j.1600-0889.1990.00002.x

Radiocarbon - a unique tracer of global carbon cycle dynamics

Abstract: Climate on earth strongly depends on the radiative balance of its atmosphere, and, thus, on the abundance of the radiatively active greenhouse gases. Largely due to human activities since the Industrial Revolution, the atmospheric burden of many greenhouse gases has increased dramatically. Direct measurements during the last decades and analysis of ancient air trapped in ice from polar regions allow to quantify the change of these trace gas concentrations in the atmosphere. From a presumably "undisturbed" pre-industrial situation several hundred years ago until today, the CO2 mixing ratio increased by almost 30%. In the last decades this increase was nearly exponential, leading to a global mean CO2 mixing ratio of almost 370 ppm by the turn of the millenium. The atmospheric abundance of CO2 the main greenhouse gas containing carbon, is strongly controlled by exchange with the organic and inorganic carbon reservoirs. The world oceans are definitely the most important carbon reservoir, with a buffering capacity for atmospheric CO2 largest on time scales of centuries and longer. In contrast, the buffering capacity of the terrestrial biosphere is largest on shorter time scales from decades to centuries. Although today equally important, the role of the terrestrial biosphere as a sink of anthropogenic CO2 emissions is still poorly understood. Any prediction of future climate strongly relies on an accurate knowledge of the greenhouse gas concentrations in the present day atmosphere, and of their development in the future. This implies the need to quantitatively understand their natural geophysical and biochemical cycles including the important perturbations by man's impact. In attempting to disentangle the complexity of these cycles, Radiocarbon observations have played a crucial role as an experimental tool enlightening the spatial and temporal variability of carbon sources and sinks. Studies of the “undisturbed” natural carbon cycle profit from the radioactive decay of 14C in using it as a dating tracer, e.g. to determine the turnover time of soil organic matter or to study internal mixing rates of the global oceans. Moreover, the anthropogenic disturbance of 14C through atmospheric bomb tests has served as an invaluable tracer to get insight into the global carbon cycle on the decadal time scale.

Very Strong Atmospheric Methane Growth in the 4 Years 2014–2017:Implications for the Paris Agreement

Abstract: Atmospheric methane grew very rapidly in 2014 (12.7±0.5 ppb/yr), 2015 (10.1±0.7 ppb/yr), 2016 (7.0± 0.7 ppb/yr) and 2017 (7.7±0.7 ppb/yr), at rates not observed since the 1980s. The increase in the methane burden began in 2007, with the mean global mole fraction in remote surface background air rising from about 1775 ppb in 2006 to 1850 ppb in 2017. Simultaneously the 13C/12C isotopic ratio (expressed as δ13CCH4) has shifted, in a new trend to more negative values that have been observed worldwide for over a decade. The causes of methane's recent mole fraction increase are therefore either a change in the relative proportions (and totals) of emissions from biogenic and thermogenic and pyrogenic sources, especially in the tropics and sub-tropics, or a decline in the atmospheric sink of methane, or both. Unfortunately, with limited measurement data sets, it is not currently possible to be more definitive. The climate warming impact of the observed methane increase over the past decade, if continued at >5 ppb/yr in the coming decades, is sufficient to challenge the Paris Agreement, which requires sharp cuts in the atmospheric methane burden. However, anthropogenic methane emissions are relatively very large and thus offer attractive targets for rapid reduction, which are essential if the Paris Agreement aims are to be attained.

IntCal13 and Marine13 radiocarbon age calibration curves 0-50,000 years cal BP

Abstract: Additional co-authors: TJ Heaton, AG Hogg, KA Hughen, KF Kaiser, B Kromer, SW Manning, RW Reimer, DA Richards, JR Southon, S Talamo, CSM Turney, J van der Plicht, CE Weyhenmeyer

A Large and Persistent Carbon Sink in the World’s Forests

Abstract: The terrestrial carbon sink has been large in recent decades, but its size and location remain uncertain. Using forest inventory data and long-term ecosystem carbon studies, we estimate a total forest sink of 2.4 ± 0.4 petagrams of carbon per year (Pg C year–1) globally for 1990 to 2007. We also estimate a source of 1.3 ± 0.7 Pg C year–1 from tropical land-use change, consisting of a gross tropical deforestation emission of 2.9 ± 0.5 Pg C year–1 partially compensated by a carbon sink in tropical forest regrowth of 1.6 ± 0.5 Pg C year–1. Together, the fluxes comprise a net global forest sink of 1.1 ± 0.8 Pg C year–1, with tropical estimates having the largest uncertainties. Our total forest sink estimate is equivalent in magnitude to the terrestrial sink deduced from fossil fuel emissions and land-use change sources minus ocean and atmospheric sinks.

Climate Change 2007: The Physical Science Basis.

Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.