Greenhouse gas emission rate estimates from airborne remote sensing in the short-wave infrared

The quantification of emissions of the greenhouse gases carbon dioxide (CO2) and methane (CH4) is essential for attributing the roles of anthropogenic activity and natural phenomena in global climate change. The current measurement systems and networks, whilst having improved during the last decades, are deficient in many respects. For example, the emissions from localised and point sources such as fossil fuel exploration sites are not readily assessed. A tool developed to better understand point sources of CO2 and CH4 is the optical remote sensing instrument MAMAP, operated from aircraft. With a ground scene size of the order of 50m and a relative accuracy of the column-averaged dry air mole fractions of about 0.3% for XCO2 and less than 0.4% for XCH4, MAMAP can make a significant contribution in this respect. Detailed sensitivity studies showed that the modified WFM-DOAS retrieval algorithm used for MAMAP has an approximate accuracy of about 0.24% for XCH4 and XCO2 in typical atmospheric conditions. At the example of CO2 plumes from two different power plants and CH4 plumes from coal mine ventilation shafts, two inversion approaches to obtain emission rates were developed and tested. One is based on an optimal estimation scheme to fit Gaussian plume models from multiple sources to the data and the other is based on a simple Gaussian integral method. Compared to CO2 emission estimates as reported by the power plants' operator within the framework of emission databases (24 and 13 MtCO2/yr), the results of the individual inversion techniques were within plus/minus 10% with uncertainties of plus/minus 20-30% mainly due to insufficient wind information and non-stationary atmospheric conditions. Measurements at the coal mine included on-site wind observations by an aircraft turbulence probe that could be utilised to calibrate the wind model. In this case, the inversion results have a bias of less than 1% compared to the reported CH4 emissions (50 ktCO2/yr) with an uncertainty of approximately plus/minus 13.5%. In cases where no elevated CO2 or CH4 is observed, MAMAP data are useful to provide upper limit constraints as was shown for a marine gas seep. The inversion techniques developed in this work have the potential to provide the basis for quantification and independent validation of anthropogenic and natural point source emission rates. These concepts are not restricted to airborne applications and are of particular value also for future satellite remote sensing missions

The Fossil Record of the Peronosporomycetes (Oomycota)

This is the publisher's version, which is being shared with permission. The original may be found at the following link: http://dx.doi.org/10.3852/10-278Evidence of fossil Peronosporomycetes has been slow to accumulate. In this review various fossils historically assigned to the Peronosporomycetes are discussed briefly and an explanation is provided as to why the fossil record of this group has remained inconsistent. In recent years there have been several new reports of fossil peronosporomycetes based on structurally preserved oogonium-antheridium complexes from Devonian and Carboniferous rocks that demonstrate the existence of these organisms as fossils and refute the long-standing assumption that they are too delicate to be preserved. Among these are several types characterized by oogonial surface ornamentation patterns not seen in any modern members of the group. To date at least three groups of fossil vascular plants (i.e. lycophytes, ferns and seed ferns) are known to host peronosporomycetes as endophytes; however only one form has been identified as a parasite

Fossil evidence of the zygomycetous fungi

Molecular clock data indicate that the first zygomycetous fungi occurred on Earth during the Precambrian, however, fossil evidence of these organisms has been slow to accumulate. In this paper, the fossil record of the zygomycetous fungi is compiled, with a focus on structurally preserved Carboniferous and Triassic fossils interpreted as zygosporangium-gametangia complexes and resembling those of modern Endogonales. Enigmatic microfossils from the Precambrian to Cenozoic that have variously been interpreted as, or compared to, zygomycetous fungi are also discussed. Among these, the spherical structures collectively termed 'sporocarps' are especially interesting because of their complex investments and abundance in certain Carboniferous and Triassic rocks. Circumstantial evidence suggests that at least some 'sporocarp' types represent mantled zygosporangia. Zygomycetous fungi probably were an important element in terrestrial paleoecosystems at least by the Carboniferous.Financial support for part of the research referred to here was provided by the National Science Foundation (EAR-0949947 to TNT and MK) and the Alexander von Humboldt-Foundation (V-3.FLFDEU/ 1064359 to MK)

Fossil evidence of the zygomycetous fungi

Molecular clock data indicate that the first zygomycetous fungi occurred on Earth during the Precambrian, however, fossil evidence of these organisms has been slow to accumulate. In this paper, the fossil record of the zygomycetous fungi is compiled, with a focus on structurally preserved Carboniferous and Triassic fossils interpreted as zygosporangium-gametangia complexes and resembling those of modern Endogonales. Enigmatic microfossils from the Precambrian to Cenozoic that have variously been interpreted as, or compared to, zygomycetous fungi are also discussed. Among these, the spherical structures collectively termed 'sporocarps' are especially interesting because of their complex investments and abundance in certain Carboniferous and Triassic rocks. Circumstantial evidence suggests that at least some 'sporocarp' types represent mantled zygosporangia. Zygomycetous fungi probably were an important element in terrestrial paleoecosystems at least by the Carboniferous.Financial support for part of the research referred to here was provided by the National Science Foundation (EAR-0949947 to TNT and MK) and the Alexander von Humboldt-Foundation (V-3.FLFDEU/ 1064359 to MK)