Late Pleistocene Tephrostratigraphy of the Eastern Bay of Plenty Region, New Zealand

<p>This thesis has produced the compilation of a complete tephrostratigraphic record of the eastern Bay of Plenty, New Zealand. About fifty Late Pleistocene tephras (i.e. those older than the Rotoiti eruption), ranging in age from c. 600 to 50 ka, are recorded in a terrestrial sequence of loess and paleosols in the eastern Bay of Plenty. Tephra correlations are based on the distinctive physical characteristics of the airfall beds and confirmed by microprobe analysis of glass shards ("fingerprinting"). Chemical analysis of hornblendes and titanomagnetites is used as a supplementary correlation tool where the tephras are too weathered to retain glass. The eastern bay of Plenty deposits are divided into seven subgroups with their boundaries marked either by major tephras or by significant changes in the paleo-climate indicator deposits such as loess and paleosols. These subgroups, and their estimated age ranges, are: Age control on the eastern Bay of Plenty tephras has been obtained by fitting the paleoclimatic information inferred from field observations to the Low Latitude Stack (LLS) and SPECMAP oxygen isotope curves, with correlations to a few well dated eruptives providing key time planes within this record; in particular, the Mamaku Ignimbrite (correlates to the Kutarere Tephra), and the Kaingaroa (Kaingaroa), Matahina (Matahina) and Rangitaiki (Kohioawa) Ignimbrites. Tentative correlations of several eastern Bay of Plenty tephras to the western, coastal central, and Southeast-central Bay of Plenty areas (Tauranga Matata cliffs and Reporoa, respectively) have been achieved. Three additional subgroups are proposed: the Welcome Bay (with at least 6 tephras) in the west, the Ohinekoao (14 tephras) in the coastal central, and the Reihana (13 tephras) in the southeast-central Bay of Plenty; all of which overlap in time with the eastern Bay of Plenty stratigraphy. The tephras recorded in the Bay of plenty have been used to estimate the ages of formation and uplift rates for many of the landforms that are observed throughout the region. A tectonic regime of subsidence in the west towards Tauranga, block faulting on either side of the subsiding Whakatane Graben in the central Bay of Plenty, and further large scale block faulting towards the far eastern margin of the Bay of Plenty has been proposed. Activity at the Okataina Volcanic Centre is now thought to have initiated at or before c. 370 ka, with the eruption of the Paerata Tephra. This tephra has a distribution pattern consistent with an Okataina source, and contains abundant cummingtonite, which is a signature mineral within tephras from the Okataina Volcanic Centre during the late Quaternary time period. However, the much older, but less well understood, Reeves-A and Wilson Tephras - both with estimated ages of c. 0.5 Ma - also contain cummingtonite, which indicates that activity may have been initiation at a much earlier time, or that a volcanic centre other than Okataina has produced cummingtonite. Activity in the Rotorua Volcanic Centre prior to the eruption of the Mamaku Ignimbrite is also indicated, as is activity at the Reporoa Volcanic Centre prior to the Kaingaroa Ignimbrite eruption.</p>

Late Pleistocene Tephrostratigraphy of the Eastern Bay of Plenty Region, New Zealand

<p>This thesis has produced the compilation of a complete tephrostratigraphic record of the eastern Bay of Plenty, New Zealand. About fifty Late Pleistocene tephras (i.e. those older than the Rotoiti eruption), ranging in age from c. 600 to 50 ka, are recorded in a terrestrial sequence of loess and paleosols in the eastern Bay of Plenty. Tephra correlations are based on the distinctive physical characteristics of the airfall beds and confirmed by microprobe analysis of glass shards ("fingerprinting"). Chemical analysis of hornblendes and titanomagnetites is used as a supplementary correlation tool where the tephras are too weathered to retain glass. The eastern bay of Plenty deposits are divided into seven subgroups with their boundaries marked either by major tephras or by significant changes in the paleo-climate indicator deposits such as loess and paleosols. These subgroups, and their estimated age ranges, are: Age control on the eastern Bay of Plenty tephras has been obtained by fitting the paleoclimatic information inferred from field observations to the Low Latitude Stack (LLS) and SPECMAP oxygen isotope curves, with correlations to a few well dated eruptives providing key time planes within this record; in particular, the Mamaku Ignimbrite (correlates to the Kutarere Tephra), and the Kaingaroa (Kaingaroa), Matahina (Matahina) and Rangitaiki (Kohioawa) Ignimbrites. Tentative correlations of several eastern Bay of Plenty tephras to the western, coastal central, and Southeast-central Bay of Plenty areas (Tauranga Matata cliffs and Reporoa, respectively) have been achieved. Three additional subgroups are proposed: the Welcome Bay (with at least 6 tephras) in the west, the Ohinekoao (14 tephras) in the coastal central, and the Reihana (13 tephras) in the southeast-central Bay of Plenty; all of which overlap in time with the eastern Bay of Plenty stratigraphy. The tephras recorded in the Bay of plenty have been used to estimate the ages of formation and uplift rates for many of the landforms that are observed throughout the region. A tectonic regime of subsidence in the west towards Tauranga, block faulting on either side of the subsiding Whakatane Graben in the central Bay of Plenty, and further large scale block faulting towards the far eastern margin of the Bay of Plenty has been proposed. Activity at the Okataina Volcanic Centre is now thought to have initiated at or before c. 370 ka, with the eruption of the Paerata Tephra. This tephra has a distribution pattern consistent with an Okataina source, and contains abundant cummingtonite, which is a signature mineral within tephras from the Okataina Volcanic Centre during the late Quaternary time period. However, the much older, but less well understood, Reeves-A and Wilson Tephras - both with estimated ages of c. 0.5 Ma - also contain cummingtonite, which indicates that activity may have been initiation at a much earlier time, or that a volcanic centre other than Okataina has produced cummingtonite. Activity in the Rotorua Volcanic Centre prior to the eruption of the Mamaku Ignimbrite is also indicated, as is activity at the Reporoa Volcanic Centre prior to the Kaingaroa Ignimbrite eruption.</p>

Analysis of climate indicator association with hotspots in Indonesia using heterogeneous correlation map

In several regions, land and forest fires of Indonesia occurred almost annually during the drought season. The severity of Indonesia's drought season is mainly influenced by the Australian Monsoon, local cloud formation controlled by Sea Surface Temperature (SST) around Indonesia. Moreover, it affects the severity of land and forest fires itself indirectly. This research aims to examine the association of the Australian Monsoon and local SST with land and forest fires in Indonesia. This research uses the Australian Monsoon Index (AUSMI) as an indicator for the Australian Monsoon and SST in the Karimata Strait and the Java Sea as indicators of local SST. An indicator of land and forest fires that will be used is the number of hotspots. A heterogeneous Correlation Map (HCM) is used to describe hotspots associated with AUSMI and local SST. The analysis shows that the east wind pattern of AUSMI associated with hotspots in Indonesia, especially in years when zonal winds enter an upward phase more slowly. Karimata Strait’s SST is associate with hotspots in the coastal part of Riau. Meanwhile, Java Sea’s SST is associate with hotspots in Lampung, South Sumatra, Jambi, and Kalimantan.

Improving the usability of climate indicator visualizations through diagnostic design principles

Visual climate indicators have become a popular way to communicate trends in important climate phenomena. Producing accessible visualizations for a general audience is challenging, especially when many are based on graphics designed for scientists, present complex and abstract concepts, and utilize suboptimal design choices. This study tests whether diagnostic visualization guidelines can be used to identify communication shortcomings for climate indicators and to specify effective design modifications. Design guidelines were used to diagnose problems in three hard-to-understand indicators, and to create three improved modifications per indicator. Using online surveys, the efficacy of the modifications was tested in a control versus treatment setup that measured the degree to which respondents understood, found accessible, liked, and trusted the graphics. Furthermore, we assessed whether respondents’ numeracy, climate attitudes, and political party affiliation affected the impact of design improvements. Results showed that simplifying modifications had a large positive effect on understanding, ease of understanding, and liking, but not trust. Better designs improved understanding similarly for people with different degrees of numerical capacity. Moreover, while climate skepticism was associated with less positive subjective responses and greater mistrust toward climate communication, design modification improved understanding equally for people across the climate attitude and ideological spectrum. These findings point to diagnostic design guidelines as a useful tool for creating more accessible, engaging climate graphics for the public.

Climate Change and Its Impact on Agriculture

We live in the times of climate change when global temperatures are constantly rising. The impacts of climate change will also be felt in agriculture in Slovakia: increased productivity and yields in colder areas, reduced production in warmer areas due to temperature stress, risk of erosion as a result of more extreme weather conditions (stronger winds, more intense precipitation), the occurrence of new pests etc. Hence, we should be prepared for adaptation measures that would help mitigate it. The aim of this paper is to present the impacts of climate change on agriculture and land, and to offer adaptation measures, and show the prognosis of the climate indicator Ts >10 °C from now until 2100.

Homogenisation of monthly temperatures of the Swedish observational network 1850-2020

&lt;p&gt;Monthly averages of statistical temperature variables (i.e. monthly averages of daily maximum, minimum, and mean temperatures) are homogenised for a large part of the Swedish observational network dataset from 1850 to 2020. Data from 573&amp;#8211;587 weather stations (depending on variable) are coupled into 299&amp;#8211;303 time series. The coupling of time series is partly performed automatically following a set of criteria of geographical proximity, altitude, proximity to coast line, time series overlap, and correlation of the data series.&lt;/p&gt;&lt;p&gt;The homogenisation of the data set is performed with the recently developed homogenisation tool Bart. Bart is a fully automatic modification of the homogenisation tool HOMER. Bart uses a set of input parameters to accept or reject potential homogeneity break points suggested by the different functions of HOMER. Bart performs correction and gap filling of the data series according to the accepted homogeneity break points. A rudimentary sensitivity test is performed to examine how sensitive the homogenisation is to the selection of the input parameters assumed most important and to find a optimal set up of these parameters. Other features in Bart include a novel procedure for the selection of reference time series to account for uneven data coverage, and parallel computing to reduce the computational time.&lt;/p&gt;&lt;p&gt;An important application of the homogenised data set is the calculation of the climate indicator of temperature. The climate indicator of temperature is the average annual mean temperatures of thirty-nine weather stations, carefully selected to represent the climate in Sweden over the last 170 years. The use of homogenised data gives a 1.8 &amp;#176;C (10 a)-1&amp;#160;greater warming than if raw data is used from 1860 to present, the period for which data coverage is sufficient.&lt;/p&gt;&lt;p&gt;&lt;img src=&quot;https://contentmanager.copernicus.org/fileStorageProxy.php?f=gnp.18ad2b13c10069128270161/sdaolpUECMynit/12UGE&amp;app=m&amp;a=0&amp;c=73e0a62bb7be6a58ba81126e3ce2b48e&amp;ct=x&amp;pn=gnp.elif&amp;d=1&quot; alt=&quot;&quot;&gt;&lt;/p&gt;

Improving the usability of climate indicator visualizations through diagnostic design principles

Visual climate indicators have become a popular way to communicate trends in important climate phenomena. Producing accessible visualizations for a general audience is challenging, especially when many are based on graphics designed for scientists, present complex and abstract concepts, and utilize suboptimal design choices. This study tests whether diagnostic visualization guidelines can be used to identify communication shortcomings for climate indicators and to specify effective design modifications. Design guidelines were used to diagnose problems in three hard-to-understand indicators, and to create three improved modifications per indicator. Using online surveys, the efficacy of the modifications was tested in a control versus treatment setup that measured the degree to which respondents understood, found accessible, liked, and trusted the graphics. Furthermore, we assessed whether respondents' numeracy, climate attitudes, and political party affiliation affected the impact of design improvements. Results showed that simplifying modifications had a large positive effect on understanding, ease of understanding, and liking, but not trust. Better designs improved understanding similarly for people with different degrees of numerical capacity. Moreover, while climate skepticism and affiliation with the Republican party were associated with less positive subjective responses and greater mistrust toward climate communication, design modification improved understanding equally for people across the climate attitude and ideological spectrum. These findings point to diagnostic design guidelines as a useful tool for creating more accessible, engaging climate graphics for the public.

Aridity in the Central and Southern Pannonian Basin

For the investigation of geographical, monthly, seasonal, and annual distributions of aridity and its annual trend in the region of the Central and Southern Pannonian Basin (CSPB), which includes the territories of Hungary and Vojvodina (Northern Serbia), the De Martonne Aridity Index (DMAI) was used. The DMAI was originally calculated from a total of 78 meteorological stations with the maximum available time series of climatological data in three cases: 1931–2017 for Hungary; 1949–2017 for Vojvodina; and 1949–2017 for Hungary and Vojvodina jointly. The Palmer Drought Severity Index (PDSI) was used to control the DMAI results. Temperature and precipitation trends were also investigated to understand their effects on the aridity trend. Three aridity types are distinguished on the annual level, five on the seasonal level, and four on the monthly level. The annual aridity had no trends in all three periods. It seems that aridity can be considered a more stable climate indicator of climate change than the temperature, at least in the CSPB.

Deep drilling reveals massive shifts in evolutionary dynamics after formation of ancient ecosystem

The scarcity of high-resolution empirical data directly tracking diversity over time limits our understanding of speciation and extinction dynamics and the drivers of rate changes. Here, we analyze a continuous species-level fossil record of endemic diatoms from ancient Lake Ohrid, along with environmental and climate indicator time series since lake formation 1.36 million years (Ma) ago. We show that speciation and extinction rates nearly simultaneously decreased in the environmentally dynamic phase after ecosystem formation and stabilized after deep-water conditions established in Lake Ohrid. As the lake deepens, we also see a switch in the macroevolutionary trade-off, resulting in a transition from a volatile assemblage of short-lived endemic species to a stable community of long-lived species. Our results emphasize the importance of the interplay between environmental/climate change, ecosystem stability, and environmental limits to diversity for diversification processes. The study also provides a new understanding of evolutionary dynamics in long-lived ecosystems.