Mustan hiilen laskeumat Euroopan arktisella alueella esiteollisesta ajasta nykyaikaan asti

The Arctic has been warming twice as fast as the rest of the world during the last decades of global warming. Reasons for the amplified Arctic warming are thought to partly relate to positive feedbacks affecting the radiative budget of the area. Black carbon (BC) is a light-absorbing particulate produced by incomplete combustion of biomass and fossil fuels. BC strongly warms the atmosphere, and its climate effects are amplified in the Arctic where its deposition on light surfaces decreases their reflectivity, resulting in elevated heat absorption and further hastening melt of snow and ice. Globally, BC is estimated to be the second most important climate-warming agent after carbon dioxide. Historical information on BC deposition plays a significant role in the assessment of long-term climate effects of BC, but scarce data on this past variability has been available from the Arctic. Historical BC records can be attained from environmental archives, such as ice cores, peat deposits and marine and lake sediments, which store direct evidence of past BC deposition in chronological order. The objective of this thesis is to collect new spatial and temporal data on BC deposition in the European Arctic from the preindustrial to the present (i.e., the last ca. 300 years), and assess BC sources and climatic implications, by analysing five lake sediment cores from Arctic Finland and an ice core from Svalbard. No standard method exists to determine BC, and the precise definition of BC depends on the methodology used for its quantification. Here, three different analytical methods were used to quantify different components of BC. Spheroidal Carbonaceous Particles (SCP) and soot-BC (SBC) were analysed from the Arctic Finland lake sediments by SCP analysis and chemothermal oxidation at 375 °C, respectively, and elemental carbon (EC) from the Svalbard ice core with a thermal optical method. The results suggest temporal variation in past BC trends, both between study sites and between methods. While SCPs show a marked trend with fluxes peaking around 1980 and declining afterwards, they represent only a minor fraction of total BC. SBC and EC are better suited to indicate general historical BC trends. SBC fluxes vary between sites but some regional patterns are noticeable. The two northernmost lakes indicate generally decreasing SBC fluxes during the latter half of the 20th century which is in line with previous data from Greenland ice cores, modelling studies and atmospheric measurements. However, two other lake sites indicate increasing SBC fluxes from ca. 1970 to the end of the records, likely caused by local emissions from the Kola Peninsula, Russia. Moreover, an increasing EC deposition trend from ca. 1970 to 2004 is also recorded in the Svalbard ice core. This increasing trend is unexpected and unparalleled among available arctic records. The observed increase in the ice core is likely caused by flaring emissions from northern Russia. The fact that a similar trend in BC fluxes and deposition is recorded in two separate environmental archives analysed with different methods and receiving atmospheric transport from mostly different source areas, highlights the plausibility of such a trend, and implies that it may also be observable at other locations in the Arctic. In such a case, BC may have exerted a significant impact on the radiative forcing and thereby past climatic warming of the Arctic, in the most recent three or four decades. However, the present study indicates that local results cannot necessarily be extrapolated over wider areas, and therefore further studies are required to establish regional BC deposition trends within the Arctic. In addition, the study highlights that BC results obtained using different analytical methods should be compared with caution.Musta hiili eli noki on ilmastoa voimakkaasti lämmittävä pienhiukkanen, jota syntyy biomassan ja fossiilisten polttoaineiden epätäydellisessä poltossa. Noki on maailmanlaajuisesti hiilidioksidin jälkeen toiseksi tärkein tekijä ilmaston lämpenemisessä, ja sen lämmittävät vaikutukset ovat voimakkaimpia arktisella alueella. Siellä noen laskeuma tummentaa vaaleita jää- ja lumipintoja minkä seurauksena lämmön sitoutuminen voimistuu ja jään ja lumen sulaminen kiihtyy. Historiallinen tieto noen laskeumista on tärkeää arvioitaessa noen pitkän aikavälin ilmastovaikutuksia, mutta sitä on olemassa vain harvakseltaan arktiselta alueelta. Historiallista noen laskeumatietoa voidaan kerätä niin sanotuista ympäristöarkistoista, kuten jääkairasarjoista tai suo-, järvi- ja merisedimenttikerrostumista. Tämän työn tarkoituksena on kerätä uutta tietoa noen laskeumasta viimeisen noin 300 vuoden aikana sekä arvioida sen lähteitä ja ilmastovaikutuksia Euroopan arktisella alueella. Lähdeaineistona käytetään pohjoissuomalaisia järvisedimenttisarjoja ja Huippuvuorilta kerättyä jääkairasarjaa, joista noen eri osatekijöitä määritetään kolmella menetelmällä. Tulokset osoittavat merkittävää ajallista vaihtelua nokilaskeumissa ja sekä tutkimuskohteiden että analyysimenetelmien välillä. Suurimpien nokihiukkasten, niin sanottujen nokipallojen, ajallinen vaihtelu on ollut Pohjois-Suomessa samanlaista kuin aiempien tutkimusten mukaan muualla Euroopassa: laskeumat kasvoivat 1950-luvusta lähtien toisen maailmansodan jälkeisessä voimakkaassa kivihiili- ja öljyvetoisessa teollistumisessa, olivat korkeimmillaan noin 1980 ja laskivat sen jälkeen polttomenetelmien tehostumisen ja kehittyneiden ilmansuojelutoimien myötä. Nokipallot edustavat kuitenkin vain pientä osaa kokonaisnoesta, ja ilmakehässä kauemmaksi kulkeutuva pienijakoinen noki on arktiselle alueelle sitä merkittävämpää. Pienijakoisen noen laskeuman vaihtelut ovat olleet tutkimusalueella moninaisempia kuin nokipallojen. Kahden pohjoisimman tutkimusjärven nokilaskeumat ovat vähentyneet noin 1960-luvulta lähtien, mikä vastaa aiempien ilmakehämittausten ja mallinnusten tuloksia. Toisaalta kahden itäisen järven nokilaskeumat ovat kasvaneet merkittävästi 1970-luvulta lähtien nykypäivään saakka, minkä oletetaan johtuvan Kuolan niemimaan teollisuustoiminnasta. Myös Huippuvuorilta kerätyssä jääkaira-aineistossa nokilaskeuma nousi selvästi noin 1970 ja 2004 välillä, mikä on luultavasti seurausta Pohjois-Venäjällä tapahtuvasta soihdutuksesta öljyn ja maakaasun porauksen yhteydessä. Tämä havaittu nouseva trendi on odottamaton ja ennennäkemätön arktisella alueella. Se, että nousevia nokilaskeumia on havaittu kahdesta eri alueilla sijaitsevasta erityyppisestä ympäristöarkistosta ja eri analyysimenetelmillä tutkittuina, korostaa kuvatun trendin luotettavuutta ja osoittaa, että kyseinen laskeumatrendi voisi olla havaittavissa arktisilla alueilla laajemminkin. Näin ollen noella on voinut olla merkittävä rooli ilmaston lämpenemisessä arktisella alueella viimeisten vuosikymmenten aikana. Samalla tutkimus osoittaa, ettei paikallisia tuloksia voi välttämättä yleistää laajemmalle alueelle ja että lisää tutkimuksia tarvitaan alueellisesti laajemman arktisen noen laskeumahistorian todentamiseksi. Lisäksi tutkimus korostaa varovaisuuden tarvetta vertailtaessa eri analyysimenetelmillä saatuja nokituloksia

Three New Species of Typhlocybine Leafhoppers from Mexico (Homoptera: Cicadellidae)

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus 1

Novel structural features of the ripple phase of phospholipids

We have calculated the electron density maps of the ripple phase of dimyristoylphosphatidylcholine (DMPC) and palmitoyl-oleoyl phosphatidylcholine (POPC) multibilayers at different temperatures and fixed relative humidity. Our analysis establishes, for the first time, the existence of an average tilt of the hydrocarbon chains of the lipid molecules along the direction of the ripple wave vector, which we believe is responsible for the occurrence of asymmetric ripples in these systems

Studies of the Genus Kunzeana : III. New Species of Mexican Kunzeana

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus 1

Four New Species of Joruma from Mexico (Homoptera: Cicadellidae)

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus 1

Two New Unique Species of Alconeura from Mexico (Homoptera: Cicadellidae)

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus 1

Deep Basin Coal (Lignite) in WilcoxGroup, Sabine Uplift, East Texas: Potential for Unconventional Coal Gas Resource Development

The Wilcox Group in the Sabine Uplift, East Texas, contains relatively large amounts of deep-basin (220- to 2,000-ft depth) coal that may in turn contain large coalbed methane resources. The objective of the proposed study is to assemble and prepare data on coal resources in the Sabine Uplift area of East Texas for inclusion in the U.S. Geological Survey National Coal Resources Data System (NCRDS). Coal occurrence and lithofacies maps created in "The Wilcox Group (Paleocene-Eocene) in the Sabine Uplift Area, Texas: Depositional Systems and Deep-Basin Lignite" (Kaiser, 1990) were digitized and converted into a Geographic Information System (GIS) format. Associated data that were derived from geophysical logs to create these maps were then compiled into a digital spreadsheet. These digital maps and data enable prediction of coal seam thickness, geometry, and continuity and, therefore, areas of potential coalbed methane resources. The distribution of the Wilcox coals is depositionally controlled, and the stratigraphic framework of the targeted horizons defines coalbed methane exploration fairways. According to available data, the highest potential for coal bed methane production and development in the Sabine Uplift, East Texas, exists in the lower Wilcox Group coal seams in Panola and Shelby Counties.Bureau of Economic Geolog

Scientific results from Gulf of Mexico Gas Hydrates Joint Industry Project Leg 1 drilling : introduction and overview

This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 25 (2008): 819-829, doi:10.1016/j.marpetgeo.2008.02.007.The Gulf of Mexico Gas Hydrates Joint Industry Project (JIP) is a consortium of production and service companies and some government agencies formed to address the challenges that gas hydrates pose for deepwater exploration and production. In partnership with the U.S. Department of Energy and with scientific assistance from the U.S. Geological Survey and academic partners, the JIP has focused on studies to assess hazards associated with drilling the fine-grained, hydrate-bearing sediments that dominate much of the shallow subseafloor in the deepwater (>500 m) Gulf of Mexico. In preparation for an initial drilling, logging, and coring program, the JIP sponsored a multi-year research effort that included: (a) the development of borehole stability models for hydrate-bearing sediments; (b) exhaustive laboratory measurements of the physical properties of hydrate-bearing sediments; (c) refinement of new techniques for processing industry-standard 3-D seismic data to constrain gas hydrate saturations; and (d) construction of instrumentation to measure the physical properties of sediment cores that had never been removed from in situ hydrostatic pressure conditions. Following review of potential drilling sites, the JIP launched a 35-day expedition in Spring 2005 to acquire well logs and sediment cores at sites in Atwater Valley lease blocks 13/14 and Keathley Canyon lease block 151 in the northern Gulf of Mexico minibasin province. The Keathley Canyon site has a bottom simulating reflection at not, vert, ~ 392 m below the seafloor, while the Atwater Valley location is characterized by seafloor mounds with an underlying upwarped seismic reflection consistent with upward fluid migration and possible shoaling of the base of the gas hydrate stability (BGHS). No gas hydrate was recovered at the drill sites, but logging data, and to some extent cores, suggest the occurrence of gas hydrate in inferred coarser-grained beds and fractures, particularly between 220 and 330 m below the seafloor at the Keathley Canyon site. This paper provides an overview of the results of the initial phases of the JIP work and introduces the 15 papers that make up this special volume on the scientific results related to the 2005 logging and drilling expedition.Supported by the U.S. Department of Energy, under award DE-FC26-01NT4133