Climate Reconstruction

This thesis investigates the interrelationships between settlement distributions, maize agricultural subsistence, and fluctuations in prehistoric climate in the Durango District of southwestern Colorado between A.D. 650-840, also known as the Basketmaker-III/Pueblo-I period. Previous research in the area indicates that large groups of people migrated into the Durango area around A.D. 760, altering age old settlement patterns and establishing some of the earliest villages in the northern Southwest. My focus is to further understandings of the complex interrelationships between settlement patterns and maize agricultural systems and to determine what role agriculture played in the development of these early villages.
Throughout this thesis, I investigate why Basketmaker-III/Pueblo-I peoples chose to live in dispersed or clustered settlement patterns from approximately A.D. 650-840 in the Durango area. This thesis integrates experimentation with dry land and ak’chin farming techniques, excavation and survey data, analysis of Basketmaker-III and Pueblo-I site distributions, modern and paleoclimatic reconstructions, prime agricultural soil and cold air drainage distributions, and aerial photography. I conducted fine-scale research of the agricultural potential around two prehistoric case study communities in the Durango District and then extrapolated my findings onto other communities in the larger area. Finally, I integrate these data into a conceptual model that can aid and direct future research into the prehistoric agroecological and anthropogenic landscapes of the Durango area.

In the present paper, an overview of studies and investigations, related to the field of historical climatology and impact of hydrometeorological extremes based on documentary evidence, is presented. In addition to this, earlier investigations as well as the present stage of historical climatology in Hungary are discussed, based on research studies of climatologists, meteorologists, historians, and geographers. Besides compilations and analyses on long-term climate change, case studies on weather-related extreme events and anomalies of the last thousand years (such as droughts and floods) are also included. As regards climate variability and change, an overview is provided on the research based on lake water-level changes.

The Eemian interglacial represents a natural experiment on how past vegetation with negligible human impact responded to amplified temperature changes compared to the Holocene. Here, we assemble 47 carefully selected Eemian pollen sequences from Europe to explore geographical patterns of (1) total compositional turnover and total variation for each sequence and (2) stratigraphical turnover between samples within each sequence using detrended canonical correspondence analysis, multivariate regression trees, and principal curves. Our synthesis shows that turnover and variation are highest in central Europe (47-55°N), low in southern Europe (south of 45°N), and lowest in the north (above 60°N). These results provide a basis for developing hypotheses about causes of vegetation change during the Eemian and their possible drivers.

Historical climatology is commonly defined as the study of past climates based on ‘documentary evidence’ before the establishment of modern networks of meteorological measurement, which excludes the last two centuries of recent global warming. This article reviews historical climatology with regard to the Anthropocene. In the Anthropocene the dynamics of climate change are essentially anthropogenic. The term ‘sociosphere’ will be advocated as a terminological improvement over existing attempts to define the place of human activities in Earth System Analysis. Theoretical and empirical advances in the study of social ecodynamics are called for. Historical climatology has a capacity to contribute making such advances, but a redefinition is inevitable for this potential to be realized: (1) historical climatology needs to expand temporally into the 19th and 20th centuries; and (2) it has yet to adjust to an important conceptual transition in climatology: from a descriptive (meteorological) concept of climate to climate dynamics.

2.2. Биогеохимический круговорот элементов. Биогеохимический круговорот макроэлементов. Биомасса в степях на порядок меньше, чем в лесных ландшафтах: от 10 до 40 т/га, причем, в отличие от лесов, большая ее часть сосредоточена в корнях (70-90 %). Зоомасса в черноземных степях составляет n-10-1 т/гаоколо 6 % от биомассы (в тайге-0,01 %, тропических лесах-1 %). Ежегодная продукция прироста составляет 1,3-5,0 т/га, то есть 30-50 % от биомассы (в тайгеменее 10 %). Биологический круговорот в степных экосистемах более интенсивный, чем в лесных [58]. Во влажные годы в степях ярко выражены "волны жизни": биомасса и число видов возрастают, бурно развивается фауна. В целинных степях практически вся чистая продукция поступает в почву, поэтому они обладают наиболее замкнутым биогеохимического круговоротом среди всех типов наземных экосистем. В засушливые годы биомасса уменьшается, видовое разнообразие падает, ландшафт приобретает более пустынный облик. Надземная фитомасса во влажные годы может быть в 10 раз больше, чем в засушливые. Для степей характерны семейства злаков, сложноцветных, в меньшей степени рестоцветных, бобовых. По сравнению с тайгой здесь меньше мхов и лишайников, во многих ландшафтах они отсутствуют. В крупных флористических районах (Волжско-Донском, Причерноморском и др.) число видов высших растений в черноземных степях примерно такое же, как в широколиственных лесах, то есть близко к 2000. Химические черты степной флоры обусловлены геохимическими особенностями среды, так как отдельные виды и роды формировались в этих ландшафтах. По макроэлементному составу золы (общей биогенности) делят степные травы на три группы [77]. 1) злаки с высоким содержанием Si и невысоким N; 2) бобовые со значительным накоплением К, С и N; 3) разнотравье, занимающее промежуточное положение. Среди степного разнотравья сложноцветные имеют в основном кальциевый и кальциево-натриевый состав золы, а маревыекальциевонатриево-магниевый. Кальций, кремний, железо и алюминий преимущественно накапливаются в корнях, а натрий и калийв надземных органах. Содержание золы в степных растениях выше, чем в лесных, и нередко достигает 10 %. Характерной особенностью биогеохимического круговорота в степных экосистемах является скорость. Ежегодно в биогеохимические циклы вовлекаются сотни килограммов водных мигрантов (на га), то есть значительно больше, чем в тайге (луговые степи-700 кг/га, южная тайга-155). В экосистемах луговых степей с опадом ежегодно возвращается 700 кг/га водных мигрантов, в сухих-150 (в ельниках южной тайги-120) [58]. Биогеохимический круговорот микроэлементов. Микроэлементный состав флоры черноземных и сухих степей сходен и определяется в основном систематической, филогенетической, биогеохимической специализацией видов, родов и семейств. Выделяются гумидокатные виды, возникшие в гумидных ландшафтах и обогащенные в связи с этим катионогенными элементами, более подвижными в кислой среде и ариданитные виды, сформированные в аридных ландшафтах и активно поглощающие анионогенные элементы. Присутствует и переходная группа растений [2]. В большей степени такая группировка отражает биогеохимическую специализацию микроэлементов. Биогеохимическая структура экосистем в основном обусловлена ариданитными растениями (сложноцветные, маревые, частично злаки) с достаточно хорошо выраженной бормолибденовой (анионофильной) специализацией, к которой иногда добавляются и некоторые катионогенные элементы (серебро, медь), образующие в щелочной среде растворимые карбонатные комплексы, доступные растениям. На этом фоне локально встречаются гумидокатные (катионофильные) растения со стронциево-марганцево-цинковой биогеохимической специализацией, приуроченные преимущественно к переувлажненным лесоболотным незасоленным местообитаниям (береза, ива, степные кустарники) [58]. Биогеохимическая контрастность ландшафтов. В условиях фонового содержания химических элементов в питающей растения среде важную дифференцирующую роль приобретают ландшафтно-геохимические условия миграции элементов (окислительно-восстановительная и щелочно-кислотная обстановки, степень минерализации и состав вод и др.) и связанная с ними биогеохимическая специализация растений по видам, родам и семействам. Оба этих фактора в свою очередь, тесно связаны с геохимией элементов, их способностью мигрировать в определенных ландшафтно-геохимических условиях. В некоторых случаях существует зависимость химического состава растений от палеогеохимических особенностей ландшафтов, в которых происходило видообразование [1].

Earlywood ring-width chronologies derived primarily from Douglas-fir trees were used to reconstruct winter-spring (November-May) precipitation and fall-spring (September-June) streamflow volumes for the period 1765-1993 in the forested upper Nazas watershed in Durango, Mexico. The tree-ring data were obtained from mixed conifer stands within or adjacent to the upper Nazas watershed. Precipitation data were derived from one of the longest regional records. The streamflow data were obtained from a guage located in the upper Nazas watershed. The Principal Component 1 (PC1) of nine residual earlywood chronologies accounted for 73% of the variance in November-May precipitation 1967-1993, and 64% for the total period with available data 1941-1993. The mean of three residual earlywood chronologies from Douglas-fir explained 51% of the normalized streamflow at Sardinas from 1971-1992. The 20th century was characterized by severe droughts, especially between 1950 and 1963 that also affected other regions of Mexico and the southwestern United States. Additional droughts of similar or greater magnitude occurred in the 1790s, 1810s, 1860-1870s and 1890-1910s. Similar periods of low flow occur in the September-June streamflow reconstruction between 1765 and 1993. These results indicate that tree-ring chronologies from this region document a high percentage of the precipitation and streamflow variance. Spectral analysis detected significant high periodicities in both records at peaks of 4 and 7 years that could be related to the ENSO frequency bands (approximately 4.0 and 6.25 years). Analysis of the reconstructed records show strong influence of ENSO on precipitation and streamflow amounts on an interannual basis. These results can provide significant inputs to decisions regarding management of water resources that are used to irrigate land in the Comarca Lagunera: specifically they indicate that water budgeting should be managed over longer time periods to account for this ENSO-related variability rather than on the year-to-year basis that is presently used.

A steady-state glacier equilibrium-line altitude (ELA) can be determined by the accumulation-area ratio (AAR) method. AAR varies with climate (balance ratio) and glacier type (glacier geometry). The method involves calculating steady-state accumulation area-ratios (AAR0) from mass balance characteristics of glaciers by statistical methods. In order to confirm the application of linear regression to calculate AAR0 in the case of outlet glaciers, a method to reveal the mathematical relationship between annual net balance (bn) and AAR was developed. Analyses carried out on (bn, AAR) data sets for 14 outlet glaciers showed that the best approximation for the (bn, AAR) relationship is linear, with an average squared correlation coefficient of 0.786, but relatively strong non-linearity was detected for several glaciers. A possible explanation lies in the hypsometry of the observed glaciers. Results confirm the application of linear regression to calculation of AAR0s for outlet glaciers. An average AAR0 of 0.58 was estimated as the type-specific AAR0 for outlet glaciers.

As a continuation of the first paper from the late medieval drought series related to medieval Hungary, we present, analyse and compare further late medieval drought data, based on contemporary direct and indirect written sources. The evidence, derived from documentary sources referring to the droughts and dry spells in 1361, 1439, 1473, 1480, 1482(?), 1502-3 and 1506, is further compared to the recent tree-ring based hydroclimate reconstruction of the OWDA (Old World Drought Atlas), and similarities, differences and complementary information are discussed in more detail. Additionally, documentary evidence related to Danube low water-levels of 1443, 1444, 1455 and 1502 are as well presented in a broader context: these cases provide evidence on the hydrological conditions of the Upper-Danube catchment, and not on the Carpathian Basin. The OWDA evidence in most cases shows good agreement with the discussed documentary-based drought reports; some differences in the spatial extension and intensity of the droughts were only exceptionally detected (e.g. 1455, 1482-3, 1507). Most of the written documentation refer to droughts that covered more than one calendar years.

In this paper, we present a 392-year-long preliminary temperature reconstruction for western Hungary. The reconstructed series is based on five vineand grain-related historical phenological series from the town of Kőszeg. We apply dendrochronological methods for both signal assessment of the phenological series and the resultant temperature reconstruction. As a proof of concept, the present reconstruction explains 57% of the temperature variance of May-July Budapest mean temperatures and is well verified with coefficient of efficiency values in excess of 0.45. The developed temperature reconstruction portrays warm conditions during the late seventeenth and early eighteenth centuries with a period of cooling until the coldest reconstructed period centred around 1815, which was followed by a period of warming until the 1860s. The phenological evidence analysed here represent an important data source from which non-biased estimates of past climate can be derived that may provide information at all possible time-scales.

Climate change during the last deglaciation was strongly influenced by the ‘bipolar seesaw’, producing antiphase climate responses between the North and South Atlantic. However, mounting evidence de- mands refinements of this model, with the occurrence of abrupt events in southern low to mid latitudes occurring in-phase with North Atlantic climate. Improved constraints on the northesouth phasing and spatial extent of these events are therefore critical to understanding the mechanisms that propagate abrupt events within the climate system. We present a 19,400 year multi-proxy record of climate change obtained from a rock hyrax midden in southernmost Africa. Arid anomalies in phase with the Younger Dryas and 8.2 ka events are apparent, indicating a clear shift in the influence of the bipolar seesaw, which diminished as the Earth warmed, and was succeeded after ~14.6 ka by the emergence of a dominant interhemispheric atmospheric teleconnection.

Wind data from ships' logbooks are used to reconstruct precipitation at three South African rainfall stations (Mthatha, Royal National Park and Cape Town) between 1796-1854. The reconstructions are based on relationships derived between NCEP-DOE 2 reanalysis u-wind data and station precipitation data over a calibration period of 1979-2008.

Although global warming is not overlooked as an anthropogenic climate change, this book is focused on natural climate changes and their environmental and societal implications in the last ten thousand years.
The motivation for this collective work originated in the impressive scientific progress in climate sciences, in the evaluation techniques of archaeological material, and in genetics and modelling in the last decade. It is astonishing that detailed past environmental information is recorded in natural archives, which can now be retrieved and analyzed and this necessitates the closer synergy, the consilience, of natural sciences and humanities.
The book, a collective work, is practically an application of the Unity of Knowledge, as highlighted by Wilson (Edward O. Wilson, 1998. Consilience: The Unity of Knowledge. New York: Vintage Books), and the current transition of the focus of the natural sciences from the search for new fundamental laws toward new kinds of synthesis in order to understand complex systems based on coherent cause-and-effect explanations. The system of our interest is the climate, in the frame of the Earth system, over the short— but critical for our civilization— period of the current interglacial.
CO-AUTHORS: Marie-Michele Ouellet-Bernier and Anne de Vernal, Michel Crucifix, Natalie Krivova, Sebastian Wagner and Eduardo Zorita, P. Nick Kardulias, Konstantinos Voskarides, Lisa J. Lucero and Jean T. Larmon, Savino di Lernia, Barbara E. Barich, Julien Charbonnier, Hans Georg K. Gebel and Kai Wellbrock, Guy D. Middleton, Cameron A. Petrie and Lloyd Weeks, Renato Sala, Mika G. Tosca, Nikolaos Koukouzas, Vasiliki Gemeni, and Nikolaos Tsoukalas, Timothy Karpouzoglou and Feng Mao.

Former Lake Komořany, located in Northwest Bohemia in Central Europe, provides multiple proxies (pollen, plant macrofossils, diatoms, chironomids and sediment chemistry) that allowed reconstruction of the development of its aquatic environment and catchment, throughout the Holocene. In order to reconstruct the climatic forcing of this development, we performed a pollen-based reconstruction of climate changes using the best modern analogue method. The climate reconstruction was successful for the interval of 10.0–3.2 ka BP. We demonstrate that shifts in climate were coupled with biotic changes within the lacustrine environment. Both processes were interconnected mainly through changes in the water level status of the lake. The most
significant climatic and environmental changes were recorded at 9.1, 6.3, 4.8/4.7, 3.8 and 3.5 ka BP.

Monthly temperature series for Central Europe back to AD 1500 are developed from documentary index series from Germany, Switzerland and the Czech Republic (1500-1854) and 11 instrumental temperature records . Documentary evidence from the Low Countries, the Carpathian Basin and Poland are used for cross-checking for earlier centuries. The instrumental station records are corrected for inhomogeneities, including insufficient radiation protection of early thermometers and the urban heat island effect. For overlapping period (1760-1854), the documentary data series correlate with instrumental temperatures, most strongly in winter (86% explained variance in January) and least in autumn (56% in September). For annual average temperatures, 81% of the variance is explained. Verification statistics indicate high reconstruction skill for most months and seasons. The last 20 years (since 1988) stand out as very likely the warmest 20-year period, accounting for the calibration uncertainty and decreases in proxy data quality before the calibration period. The new reconstruction displays a previously unobserved P. Dobrovolný (B) · R. Brázdil · M. Halíčková · J. Macková Climatic Change long-term decrease in DJF, MAM and JJA temperature variability over last five centuries. Compiled monthly, seasonal and annual series can be used to improve the robustness of gridded large-scale European temperature reconstructions and possible impact studies. Further improvement of the reconstruction would be achieved if documentary data from other European countries are further developed.

Climate change during the last deglaciation was strongly influenced by the ‘bipolar seesaw’, producing antiphase climate responses between the North and South Atlantic. However, mounting evidence demands refinements of this model, with the occurrence of abrupt events in southern low to mid latitudes occurring in-phase with North Atlantic climate. Improved constraints on the north–south phasing and spatial extent of these events are therefore critical to understanding the mechanisms that propagate abrupt events within the climate system. We present a 19,400 year multi-proxy record of climate change obtained from a rock hyrax midden in southernmost Africa. Arid anomalies in phase with the Younger Dryas and 8.2 ka events are apparent, indicating a clear shift in the influence of the bipolar seesaw, which diminished as the Earth warmed, and was succeeded after ∼14.6 ka by the emergence of a dominant interhemispheric atmospheric teleconnection.

The late Miocene is marked by pronounced environmental changes and the appearance of strong temperature and precipitation seasonality. Although environmental heterogeneity is to be expected during this time, it is challenging to reconstruct palaeoenvironments using plant fossils. We investigated leaves and dispersed spores/pollen from 6.4–6 Ma strata in the intermontane Florina-Ptolemais-Servia Basin (FPS) of northwestern Greece. To assess how well plant fossils reflect the actual vegetation of the FPS, we assigned fossil-taxa to biomes providing a measure for environmental heterogeneity. Additionally, the palynological assemblage was compared to pollen spectra from modern lake sediments to assess biases in spore/pollen representation in the pollen record. We found a close match of the Vegora assemblage with modern Fagus–Abies forests of Turkey. Using taxonomic affinities of leaf fossils, we further established close similarities of the Vegora assemblage with modern laurophyllous oa...

Earlywood ring-width chronologies derived primarily from Douglas-fir trees were used to reconstruct winter-spring (November-May) precipitation and fall-spring (September-June) streamflow volumes for the period 1765-1993 in the forested upper Nazas watershed in Durango, Mexico. The tree-ring data were obtained from mixed conifer stands within or adjacent to the upper Nazas watershed. Precipitation data were derived from one of the longest regional records. The streamflow data were obtained from a guage located in the upper Nazas watershed. The Principal Component 1 (PC1) of nine residual earlywood chronologies accounted for 73% of the variance in November-May precipitation 1967-1993, and 64% for the total period with available data 1941-1993. The mean of three residual earlywood chronologies from Douglas-fir explained 51% of the normalized streamflow at Sardinas from 1971-1992. The 20th century was characterized by severe droughts, especially between 1950 and 1963 that also affected other regions of Mexico and the southwestern United States. Additional droughts of similar or greater magnitude occurred in the 1790s, 1810s, 1860-1870s and 1890-1910s. Similar periods of low flow occur in the September-June streamflow reconstruction between 1765 and 1993. These results indicate that tree-ring chronologies from this region document a high percentage of the precipitation and streamflow variance. Spectral analysis detected significant high periodicities in both records at peaks of 4 and 7 years that could be related to the ENSO frequency bands (approximately 4.0 and 6.25 years). Analysis of the reconstructed records show strong influence of ENSO on precipitation and streamflow amounts on an interannual basis. These results can provide significant inputs to decisions regarding management of water resources that are used to irrigate land in the Comarca Lagunera: specifically they indicate that water budgeting should be managed over longer time periods to account for this ENSO-related variability rather than on the year-to-year basis that is presently used.

This paper discusses the research carried out to check the climatic characteristics of the late Maunder Minimum (LMM) (ad 1675-1715) in the southwestern part of the Iberian Peninsula and as an aid towards pressure patterns reconstruction in the NE Atlantic and Europe. Documentary evidence reveals that interannual precipitation variability was similar to the present one, although some very severe dry periods occurred (particularly one in 1694). On the other hand, during the LMM there was a higher percentage of cold winter months, some of them with snowfall. A brief comparison is made with other areas from the Mediterranean. The relationships between weather similarities and differences for particular months is analysed in the light of the reconstructed synoptical patterns, and further research into historical climatic change of southern Europe is suggested.

Following floods experienced in southwestern Alberta in June 2013, 36 palaeoenvironmental sediment samples were collected from the banks of four affected streams: the Kananaskis River, Highwood River, Tongue Creek and Jumpingpound Creek. The sampled layers were deposited during the Holocene, and provide evidence of riparian ecology in the region since the end of the last glacial interval. The samples were processed to extract sub-fossil macroremains (including seeds, fruits, and aquatic and terrestrial mollusc shells). Macrofossils are particularly useful for creating fine-resolution (site-specific) reconstructions. An innovative aspect of this study was the derivation of regional bioclimatic trends through time. This was achieved by applying a dual-layered weighted calibration function which incorporated the relative productivity of indicator taxa, their modelled climatic optima, and the influence of climate (temperature and precipitation) on their ecological niche. Optima and climatic influence values were calculated using the machine-learning maximum entropy environmental niche modelling tool, MAXENT, trained on global occurrence records for the taxa. This study aimed to address gaps in prior palaeoenvironmental research, allowing for a spatially explicit quantitative reconstruction of climate in the transitional foothill region near Calgary. Results indicated warm conditions immediately following glacial retreat, followed by an early to mid-Holocene cooling which coincided with the driest interval. Temperature and moisture regimes oscillated in the mid-Holocene, exhibiting the highest values for both parameters. Increased moisture was at least in part prompted by increased input from summer glacial meltwater (the result of higher summer temperatures) which added to the riparian water budget. The mid- to late Holocene, and up to modern times, showed a gradual decrease in both moisture and temperature, until stabilizing near the Holocene average.

The Neogene sediments of Southeast Bulgaria are poorly studied in terms of palaeobotany. This paper provides new data about the macro- and microflora from the upper undivided part of the Elhovo Formation (Toundzha Basin). Data from current palaeobotanical study contribute to the elucidation of evolution of the local and regional Late Miocene flora, vegetation patterns, palaeoecological peculiarities, and palaeogeography of the Balkan Peninsula. The taxonomic composition of the fossil flora includes 33 species identified as leaf imprints/carpo remains, and 47 palynomorph taxa. On the basis of palaeoecological analysis we suggest the development of riparian forests, mesophytic and xeromesophytic forests, herbaceous and hydrophyllous communities. Calculations of the quantitative climate data indicate a warm temperate climate, with mean annual temperature of 14.4-15.8 °C and annual precipitation over 800 mm.

Mountains are most sensitive to climate change and the impacts are already evident in different sphere and sector of mountain regions, especially in the vulnerable countries like Nepal. This research was designed to integrate hydro-climatic data analysis and climate sensitivity through dendrochronology to generate an understanding on how Larix griffithii, one of the least studied conifers in Nepal, is responding to climate variability and change. A significant warming trend of 0.021°C year-1 was observed in the region. Precipitation was more erratic without any significant increasing, decreasing or cyclic trend. Between 1962 and 2012, the warmest year on record was 2010 while 1997 was the coolest year on record. After 1997 a clear shift in temperature regime was observed with the recent decade experiencing a sharp increase in temperature. A site chronology extending 1745- 2015 AD was prepared. Very strong significant correlation was observed between the standard chronology and monthly temperature especially in summer months indicating a potential for summer months’ temperature reconstruction. The reconstructed summer month’s temperature data for the period 1770-2015 captured 34% variability. The short cold episodes were observed around the 1810s, 1910s, and 1970s while warm periods were observed around 1890s, 1920s and 2000s. Radial growth of Larix griffithii in the site shows a highly significant negative relationship with the monthly temperature of the previous year and current year summer months especially for June, July, August, September of previous year and July, August and September of the current year. Significant positive correlation was observed for both previous year and current year July precipitation. The summer temperature coupled with precipitation is seen to limit the tree growth through moisture limitations. With the temperature in increasing trend, it is likely that the growth of Larix will face more heat stress in future, making them more dynamic to the changing climate.

To better understand long-term drought variations in the central Himalaya, we developed new tree-ring width
chronologies of Himalayan spruce (Picea smithiana (Wall.) Boiss.) from three sites in the north-western Nepal. The
local site chronologies showed high cross correlations and similar growth-climate responses to regional spring
drought variability. We thus combined all site chronologies into a regional composite (RC) standard chronology
that spans 516 years (1498–2013 CE). The RC chronology showed significant positive (negative) correlations
with spring (March–May) precipitation (temperature) variability. Meanwhile, RC chronology showed the highest
correlation with spring self-calibrating Palmer drought severity index (scPDSI, r = 0.652, p < 0.001), indicating
that radial growth of P. smithiana is strongly limited by spring moisture availability. Using RC chronology, we reconstructed
the spring drought variability for the period 1725–2013, which explained 42.5% variance of the actual
scPDSI during the calibration period 1957–2012. Our reconstructed spring drought variability in the central
Himalaya showed consistent wet-dry episodes with other regional drought and precipitation reconstructions from
the Himalaya and nearby regions. Spectral peaks and spatial correlation analysis indicate that spring drought
variability in the central Himalaya may be linked to large scale climatic drivers, mainly Atlantic Multidecadal
Oscillation activities due to sea surface temperatures variation in the Atlantic Ocean. Our reconstruction revealed
a continuous shift toward drier conditions in the central Himalaya since early 1980s that coincide with continental-
scale warming and reduced spring precipitation in the central Himalaya.

We present the first summer sunshine reconstruction from tree-ring data for the western part of the Balkan Peninsula. Summer sunshine is tightly connected with moisture stress in trees, because the moisture stress and therefore the width of annual tree-rings is under the influence of the direct and interactive effects of sunshine duration (temperature , precipitation, cloud cover and evapotranspiration). The reconstruction is based on a calibrated z-scored mean chronology, calculated from tree-ring width measurements from 7 representative black pine (Pinus nigra Arnold) sites in Bosnia and Herzegovina (BiH). A combined regression and scaling approach was used for the reconstruction of the summer sunshine. We found a significant negative correlation (r = −0.54, p < 0.0001) with mean June–July sunshine hours from Osijek meteorological station (Croatia). The developed model was used for reconstruction of summer sunshine for the time period 1660–2010. We identified extreme summer events and compared them to available documentary historical sources of drought, volcanic eruptions and other reconstructions from the broader region. All extreme summers with low sunshine hours (1712, 1810, 1815, 1843, 1899 and 1966) are connected with volcanic eruptions.

Our study examines the climatic aspects of the first city plan of Tel-Aviv (1925). This paper examines how the 1925 plan effected outdoor human thermal comfort in two periods: at the time of its implementation (1920-30s) and in the present (2010s). Additionally, the paper asks which of the two - shade or wind velocity – has greater influence on outdoor thermal comfort in the urban areas along the Israeli Mediterranean seashore.

The city of Tel-Aviv provides an ideal case study to examine these issues. Tel-Aviv was established in 1909 and grew rapidly. In 1925, the city had 34,000 inhabitants and there was a demand for a city plan. The task was given to Professor Patrick Geddes, who planned a city for 100,000 inhabitants that would spread along the Mediterranean seashore and would be suited to local environmental conditions. Geddes planned a grid of main streets, where the wide commercial streets stretched from north to south parallel to the sea. As a result, the main streets of Tel-Aviv were shaded most of the summer days but blocked from the sea wind. The plan was implemented during the late 1920s and 1930s.

To examine the thermal comfort at street level during the 1920's and 30's, a series of summer and winter climatological measurements were taken in the years 2010-13 and compared to historical climatic data from the 1920-30s. The historical city structure was then reconstructed virtually and the climatological measurements for 2010-13 were fed into the RayMan model to produce thermal comfort data (PET). The results show that in both summer and winter, solar radiation has a greater effect on thermal comfort than wind velocity. Consequently, the 1925 urban plan created improved thermal sensation in the main streets of Tel Aviv, mainly by the reduction of solar radiation.

Atmospheric circulation in the oceans surrounding southern Africa plays an important role in determining its precipitation. This study uses wind information recorded in ships’ logbooks in order to statistically reconstruct summer and winter season precipitation at four southern African weather stations from 1796-1854. The reconstruction was obtained by first relating gridded 8° x 8° NCEP-DOE reanalysis seasonal mean wind vectors in the adjacent oceans to station precipitation. Over a 30-year calibration period (1979-2008), significant correlations between wind and precipitation at Cape Town, Mthatha and Royal National Park showed particular correspondence with those areas with the greatest concentration of logbook observations. Principal Component Regression was used to assess the potential of the dominant patterns of variability in the wind vectors as predictors to reconstruct precipitation. Cross-validation in the calibration period gave confidence that precipitation could be reconstructed at several stations across South Africa, meaning the regression relationships derived in the calibration period could be applied to the gridded seasonal mean logbook data to produce reconstructions of precipitation from 1796-1854. The reconstructions show a degree of correspondence with other regional datasets. For instance, the decade beginning in 1810 was the wettest of the period at Mthatha and Royal National Park, while the 1820s were the driest. At Cape Town, the 1820s were the wettest decade, with drier conditions observed in the 1830s. An index of west-east circulation in the summer season revealed correspondence with two documentary reconstructions of El Niño events and increased westerliness, though this did not always result in drier conditions. Attention is also drawn to the remaining 3000 yet to be digitised English East India Company logbooks which would provide a high-resolution picture of atmospheric circulation back to 1700 in the region under consideration.

Understanding present-day global sea level rise requires a correct evaluation of
past sea level field variability. We use sea level height fields obtained by satellite
altimeters between 1992 and 2006, sea level height fields from recent reanalyses
of oceanic circulation (SODA) and worldwide tide gauges series for the time
interval 1958–2006, to investigate the limitations inherent in reconstructing the
past ~50 years of sea level variation using empirical orthogonal function (EOF)
decomposition. To understand some of the weaknesses we found, we tested the
influence of the spatial distribution of tide gauges as well as the ability to properly
reconstruct sea level in certain frequencies bands. The presence of the particularly
strong 1997–1998 El Nin˜o event, and the short time span of the base period
(1992–2006), limits the determination of other spatial teleconnections and then
the reconstruction over preceding epochs. More particularly, during the pre-
satellite era and outside the tropics, the non-stationary characteristics of heat
transport at interannual time scales and other low frequencies oscillations
associated with sea level height fields undermine the methodology.

The late Miocene is marked by pronounced environmental changes and the appearance of strong temperature and precipitation seasonality. Although environmental heterogeneity is to be expected during this time, it is challenging to reconstruct palaeoenvironments using plant fossils. We investigated leaves and dispersed spores/pollen from 6.4–6 Ma strata in the intermontane Florina-Ptolemais-Servia Basin (FPS) of northwestern Greece. To assess how well plant fossils reflect the actual vegetation of the FPS, we assigned fossil-taxa to biomes providing a measure for environmental heterogeneity. Additionally, the palynological assemblage was compared to pollen spectra from modern lake sediments to assess biases in spore/pollen representation in the pollen record. We found a close match of the Vegora assemblage with modern Fagus–Abies forests of Turkey. Using taxonomic affinities of leaf fossils, we further established close similarities of the Vegora assemblage with modern laurophyllous oa...

Mammalian body, blood and hard tissue oxygen isotope compositions (δ 18 O values) reflect environmental water and food sources, climate, and physiological processes. For this reason, fossil and archaeological hard tissues, which originally formed in equilibrium with body chemistry, are a valuable record of past climate, landscape paleoecology, and animal physiology and behavior. However, the environmental and physiological determinants of blood oxygen isotope composition have not been determined experimentally from large herbivores. This class of fauna is abundant in Cenozoic terrestrial fossil assemblages, and the isotopic composition of large herbivore teeth has been central to a number of climate and ecological reconstructions. Furthermore, existing models predict blood water, or nearly equivalently body water, δ 18 O values based on environmental water sources. These have been evaluated on gross timescales, but have not been employed to track seasonal variation. Here we report how water, food, and physiology determine blood water δ 18 O values in experimental sheep (Ovis aries) subjected to controlled water switches. We find that blood water δ 18 O values rapidly reach steady state with environmental drinking water and reflect transient events including weaning, seasons, and snowstorms. Behavioral and physiological variation within a single genetically homogenous population of herbivores results in significant inter-animal variation in blood water δ 18 O values at single collection times (1 s.d. = 0.1–1.4‰, range = 3.5‰) and reveals a range of water flux rates (t 1/2 = 2.2–2.9 days) within the population. We find that extant models can predict average observed sheep blood δ 18 O values with striking fidelity, but predict a pattern of seasonal variation exactly opposite of that observed in our population for which water input variation was controlled and the effect of physiology was more directly observed. We introduce to these models an evaporative loss term that is a function of environmental temperatures. The inclusion of this function produces model predictions that mimic the observed seasonal fluctuations and match observations to within 1.0‰. These results increase the applicability of available physiological models for paleoseasonality reconstructions from stable isotope measurements in fossil or archaeological enamel, the composition of which is determined in equilibrium with blood values. However, significant blood δ 18 O variation in this experimentally controlled population should promote caution when interpreting isotopic variation in the archaeological and paleontological record.

Seasonal variation in rainfall and temperature are major determinants of ecosystem structure and productivity and influence physical processes such as erosion rates and glaciation. By extension, seasonality can drive evolutionary change, and is hypothesized to have influenced early human subsistence and technological development. Rainfall patterns are reflected by oxygen isotope ratios (d 18 O values) in mammalian tooth enamel, which records environmental chemistry as reflected by blood chemistry during mineralization. Fossilized herbivore molars are commonly used to study paleoseasonality, since temporal variation in precipitation d 18 O results in spatial variation in tooth mineral d 18 O. However, this approach has been hampered by incomplete knowledge of isotope incorporation during tooth mineralization. Here we test a new synchrotron-based min-eralization model and demonstrate its potential to quantitatively reconstruct original seasonal input histories under a Baye-sian computational framework. To accomplish this, we first integrate the mineralization model with blood water oxygen isotope turnover to produce high-resolution spatial d 18 O predictions. We test these predictions using fine-scaled tooth enamel phosphate d 18 O measurements (n = 109 locations sampled in a 2D grid format) in a sheep (Ovis aries) subjected to a controlled water switch (switch d 18 O magnitude of 12‰). Tooth mineralization, blood oxygen turnover and isotopic measurements demonstrate that enamel secretion and maturation waves advance at nonlinear rates with distinct geometries. Final enamel isotopic composition may be influenced by isotopic shifts during enamel maturation from amorphous precursors. We combine these observations to produce a Bayesian inverse model for reconstructing water d 18 O inputs from tooth isotopic measurements. The system accurately reproduces the controlled switch of the experimental animal and reveals transient documented meteorological events that were unplanned during the experiment. A simulation approach shows that given appropriate priors and search methodologies, this system also reconstructs precipitation histories at different latitudes with striking fidelity. We show that in some contexts even simple sampling approaches (i.e. 1D transects) can yield accurate reconstructions of seasonality. Finally, we refine our mineralization model further by exploring the possible extent of isotopic resetting during mineral phase transitions. This work demonstrates that tooth isotopic measurements can be employed to reconstruct past

Following floods experienced in southwestern Alberta in June 2013, 36 palaeoenvironmental sediment samples were collected from the banks of four affected streams: the Kananaskis River, Highwood River, Tongue Creek and Jumpingpound Creek. The sampled layers were deposited during the Holocene, and provide evidence of riparian ecology in the region since the end of the last glacial interval. The samples were processed to extract sub-fossil macroremains (including seeds, fruits, and aquatic and terrestrial mollusc shells). Macrofossils are particularly useful for creating fine-resolution (site-specific) reconstructions. An innovative aspect of this study was the derivation of regional bioclimatic trends through time. This was achieved by applying a dual-layered weighted calibration function which incorporated the relative productivity of indicator taxa, their modelled climatic optima, and the influence of climate (temperature and precipitation) on their ecological niche. Optima and climatic influence values were calculated using the machine-learning maximum entropy environmental niche modelling tool, MAXENT, trained on global occurrence records for the taxa. This study aimed to address gaps in prior palaeoenvironmental research, allowing for a spatially explicit quantitative reconstruction of climate in the transitional foothill region near Calgary. Results indicated warm conditions immediately following glacial retreat, followed by an early to mid-Holocene cooling which coincided with the driest interval. Temperature and moisture regimes oscillated in the mid-Holocene, exhibiting the highest values for both parameters. Increased moisture was at least in part prompted by increased input from summer glacial meltwater (the result of higher summer temperatures) which added to the riparian water budget. The mid- to late Holocene, and up to modern times, showed a gradual decrease in both moisture and temperature, until stabilizing near the Holocene average.

The chemical composition of palaeosols of archeological monuments was studied. The possibility of the using different geochemical ratios was considered for reconstruction of the natural environment and ancient conditions of soil formation. The researches different ages palaeosols with use geochemical ratios was revealed cyclic changes of soils are connected with ancient dynamics of the climate.

"The analog method (AM) has found application to reconstruct gridded climate fields from the information provided by proxy data and climate model simulations. Here, we test the skill of different setups of the AM, in a controlled but realistic situation, by analysing several statistical properties of reconstructed daily high-resolution atmospheric fields for Northern Europe for a 50-yr period. In this application, station observations of sea-level pressure and air temperature are combined with atmospheric fields from a 50-yr high-resolution regional climate simulation. This reconstruction aims at providing homogeneous and physically consistent atmospheric fields with daily resolution suitable to drive high resolution ocean and ecosystem models.

Different settings of the AM are evaluated in this study for the period 1958–2007 to estimate the robustness of the reconstruction and its ability to replicate high and low-frequency variability, realistic probability distributions and extremes of different meteorological variables. It is shown that the AM can realistically reconstruct variables with a strong physical link to daily sea-level pressure on both a daily and monthly scale. However, to reconstruct low-frequency decadal and longer temperature variations, additional monthly mean station temperature as predictor is required. Our results suggest that the AM is a suitable upscaling tool to predict daily fields taken from regional climate simulations based on sparse historical station data."