A Revised Scheme to Compute Horizontal Covariances in an Oceanographic 3D-VAR Assimilation System.

We propose an improvement of an oceanographic three dimensional variational assimilation scheme (3D-VAR), named OceanVar, by introducing a recursive filter (RF) with the third order of accuracy (3rd-RF), instead of an RFwith first order of accuracy (1st-RF), to approximate horizontal Gaussian covariances. An advantage of the proposed scheme is that the CPU's time can be substantially reduced with benefits on the large scale applications. Experiments estimating the impact of 3rd-RF are performed by assimilating oceanographic data in two realistic oceanographic applications. The results evince benefits in terms of assimilation process computational time, accuracy of the Gaussian correlation modeling, and show that the 3rd-RF is a suitable tool for operational data assimilation

Combining Aerosol Aging and Data Assimilation for Improving Volcanic Aerosol Forecast

Der Ausbruch des Eyjafjallajökull in Island 2010 zeigte eindrucksvoll, welche Folgen ein Vulkanausbruch für den internationalen Luftverkehr haben kann. Mehr als 100.000 Flüge wurden gestrichen, da vulkanisches Aerosol eine Gefahr für Flugzeuge darstellt. Aus diesem Grund sind die Flugsicherung sowie Fluggesellschaften sehr an zuverlässigen Vorhersagen der Ausbreitung dieses Aerosols nach Vulkanausbrüchen interessiert. Die numerische Aerosolausbreitungsvorhersage ist ein klassisches Anfangswertproblem. Das bedeutet erstens, dass die Vorhersage mit einem möglichst genauen atmosphärischen Zustand sowie deren Zusammensetzung initialisiert werden muss. Zweitens muss das numerische Modell alle Prozesse und Rückkopplungsmechanismen berücksichtigen, welche für den Transport vulkanischer Aerosole relevant sind. Im Rahmen dieser Arbeit möchte ich die Ausbreitungsvorhersage vulkanischer Aerosole mit Hilfe einer En-Var Datenassimilation sowie durch die Berücksichtigung der Aerosol-Strahlung-Wechselwirkung von intern gemischtem Aerosol verbessern. Hierfür werden in das ICON-ART (ICOsahedral Nonhydrostatic - Aerosols and Reactive Trace gases) Modell aerosol-dynamische Prozesse wie die Koagulation, die Nukleation von Sulfatpartikeln und der Kondensation von gasförmigen Komponenten auf Aerosolpartikel implementiert. Diese mikrophysikalischen Prozesse bilden intern gemischte Partikel. Für diese intern gemischten Partikel bestimme ich optische Eigenschaften, welche eine Interaktion mit kurz- und langwelliger Strahlung ermöglichen. Darüber hinaus wird eine En-Var-Datenassimilationsmethode für vulkanisches Aerosol innerhalb der Datenassimilationsumgebung des DWD (Deutscher Wetterdienst) entwickelt. Die Datenassimilation liefert eine Schätzung des anfänglichen Zustands sowie der Zusammensetzung der Atmosphäre. Diese Neuentwicklungen werden für die ersten vier Tage nach dem Raikoke-Ausbruch 2019, einem der größten Vulkanausbrüche der vergangenen 30 Jahre, ausgewertet. Die Berücksichtigung aerosol-dynamischer Prozesse führt zu einer Zunahme der Partikelgröße, was deren Sedimentationsgeschwindigkeit erhöht. Meine Ergebnisse zeigen, dass die Sedimentation großer Partikel für die Beseitigung von etwa $50$% der Vulkanasche während der ersten $12$ h nach dem Ausbruch des Raikoke verantwortlich ist. In meinen Simulationen ist die Koagulation von grobkörnigen (coarse mode) Aschepartikeln mit sekundärem vulkanischem Aerosol, d.h. Sulfatpartikeln, eine der Hauptursachen für diese hohe Abnahme. Die Wechselwirkung von kurz- und langwelliger Strahlung mit intern gemischtem vulkanischem Aerosol führt zu einem Anheben von Teilen der Wolke aus vulkanischen Aerosolen. Meine Ergebnisse deuten darauf hin, dass die Wolkenoberseite des vulkanischen Aerosols nach dem Ausbruch des Raikoke während der ersten $12$ h etwa $3$ km angehoben wird und nach vier Tagen eine Höhe von etwa $20$ km erreicht. Die Assimilation von Beobachtungsdaten mit der ART En-Var-Methode kann Rauschen in den Beobachtungsdaten herausfiltern. Die Ergebnisse dieser Arbeit verdeutlichen die Bedeutung der aerosol-dynamischen Prozesse sowie der Wechselwirkung von Aerosolen mit kurz- und langwelliger Strahlung für die operationelle Ausbreitungsvorhersage vulkanischer Aerosole. Darüber hinaus kann die Verwendung einer ensemblebasierten Assimilationsmethode für zukünftige Ausbreitungsvorhersagen vulkanischer Aerosole empfohlen werden

The Impact of Background Error on Incomplete Observations for 4D-Var Data Assimilation with the FSU GSM

Abstract. To assess the impact of incomplete observations on the 4D-Var data assimilation, twin experiments were carried out with the dynamical core of the new FSU GSM consisting of a T126L14 global spectral model in a MPI parallel environment. Results and qualitative aspects are presented for incomplete data in the spatial dimension and for incomplete data in time, with and without inclusion of the background term into the cost functional. The importance of the background estimate on the 4D-Var analysis in the presence of small Gaussian errors in incomplete data is also investigated

African Handbook of Climate Change Adaptation

This open access book discusses current thinking and presents the main issues and challenges associated with climate change in Africa. It introduces evidences from studies and projects which show how climate change adaptation is being - and may continue to be successfully implemented in African countries. Thanks to its scope and wide range of themes surrounding climate change, the ambition is that this book will be a lead publication on the topic, which may be regularly updated and hence capture further works. Climate change is a major global challenge. However, some geographical regions are more severly affected than others. One of these regions is the African continent. Due to a combination of unfavourable socio-economic and meteorological conditions, African countries are particularly vulnerable to climate change and its impacts. The recently released IPCC special report "Global Warming of 1.5º C" outlines the fact that keeping global warming by the level of 1.5º C is possible, but also suggested that an increase by 2º C could lead to crises with crops (agriculture fed by rain could drop by 50% in some African countries by 2020) and livestock production, could damage water supplies and pose an additonal threat to coastal areas. The 5th Assessment Report produced by IPCC predicts that wheat may disappear from Africa by 2080, and that maize— a staple—will fall significantly in southern Africa. Also, arid and semi-arid lands are likely to increase by up to 8%, with severe ramifications for livelihoods, poverty eradication and meeting the SDGs. Pursuing appropriate adaptation strategies is thus vital, in order to address the current and future challenges posed by a changing climate. It is against this background that the "African Handbook of Climate Change Adaptation" is being published. It contains papers prepared by scholars, representatives from social movements, practitioners and members of governmental agencies, undertaking research and/or executing climate change projects in Africa, and working with communities across the African continent. Encompassing over 100 contribtions from across Africa, it is the most comprehensive publication on climate change adaptation in Africa ever produced

Nostratic Dictionary

A revised edition can be found at http://www.dspace.cam.ac.uk/handle/1810/244080.Aharon Dolgopolsky is the leading authority on the Nostratic macrofamily. His 'Nostratic Dictionary' presented here is, of course, something very much more than a dictionary. It is the most thorough and extensive demonstration and documentation so far of what may be termed the Nostratic hypothesis: that several of the world's best- known language families are related in their origin, their grammar and their lexicon, and that they belong together in a larger unit, of earlier origin, the Nostratic macrofamily. It should at once be noted that several elements of this enterprise are controversial. For while the Nostratic hypothesis has many supporters, it has been criticized on rather fundamental grounds by a number of distinguished linguists. The matter was reviewed some years ago in a symposium held at the McDonald Institute, and positions remain very much polarized. It was a result of that meeting that the decision was taken to invite Aharon Dolgopolsky to publish his Dictionary - a much more substantial treatise than any work hitherto undertaken on the subject - at the McDonald Institute. For it became clear that the diversities of view expressed at that symposium were not likely to be resolved by further polemical exchanges. Instead, a substantial body of data was required, whose examination and evaluation could subsequently lead to more mature judgments. Those data are presented here, and that more mature evaluation can now proceed.McDonald Institute for Archaeological Research Alfred P. Sloan Foundatio

Triple Helix as a Strategic Tool to Fast-Track Climate Change Adaptation in Rural Kenya: Case Study of Marsabit County

AbstractThe lack of affordable, clean, and reliable energy in Africa's rural areas forces people to resort to poor quality energy source, which is detrimental to the people's health and prevents the economic development of communities. Moreover, access to safe water and food security are concerns closely linked to health issues and children malnourishment. Recent climate change due to global warming has worsened the already critical situation.Electricity is well known to be an enabler of development as it allows the use of modern devices thus enabling the development of not only income-generating activities but also water pumping and food processing and conservation that can promote socioeconomic growth. However, all of this is difficult to achieve due to the lack of investors, local skills, awareness by the community, and often also government regulations.All the above mentioned barriers to the uptake of electricity in rural Kenya could be solved by the coordinated effort of government, private sector, and academia, also referred to as Triple Helix, in which each entity may partially take the other's role. This chapter discretizes the above and shows how a specific county (Marsabit) has benefited from this triple intervention. Existing government policies and actions and programs led by nongovernmental organizations (NGOs) and international agencies are reviewed, highlighting the current interconnection and gaps in promoting integrated actions toward climate change adaptation and energy access

Plants and Plant Products in Local Markets Within Benin City and Environs

AbstractThe vulnerability of agriculture systems in Africa to climate change is directly and indirectly affecting the availability and diversity of plants and plant products available in local markets. In this chapter, markets in Benin City and environs were assessed to document the availability of plants and plant products. Markets were grouped into urban, suburban, and rural with each group having four markets. Majority of the plant and plant product vendors were women and 88 plant species belonging to 42 families were found. Their scientific and common names were documented as well as the parts of the plant and associated products available in the markets. Most of the plant and plant products found in local markets belong to major plant families. Urban markets had the highest diversity of plants and plant products. Three categories of plants and plant products were documented. Around 67% of the plants and plant products were categorized as whole plant/plant parts, 28% as processed plant parts, while 5% as reprocessed plant/plant parts. It was revealed that 86% of these plants are used as foods, 11% are for medicinal purposes, while 3% is used for other purposes. About 35% of plants and plant products across the markets were fruits, which is an indication that city and environs are a rich source of fruits. The local knowledge and practices associated with the plants and plant products can contribute towards formulating a strategic response for climate change impacts on agriculture, gender, poverty, food security, and plant diversity