The annual growth rings from trees provide us with an incredibly powerful and adaptable tool to study Earth’s history. The rings tell us much more than just the age of tree. They also provide clues that help us understand how our environment has changed in the past, and provide insights into how key processes in atmosphere, biosphere and geological systems operate over long timescales.
This course will teach students the fundamental principles of dendrochronology through a combination of formal lectures, class discussion and laboratory exercises. Students will work in the University of Minnesota’s Center for Dendrochronology, where they will learn how to collect, prepare and date tree-ring specimens. By the end of the course, they will be able to explain both the key concepts underlying dendrochronology and discuss how evidence from tree rings is used to address contemporary issues in natural history, resource management and Earth Systems Science.
Tree rings tell us much more than just a tree’s age. They also provide clues that help us understand how our environment has changed in the past, and provide insights into how key processes in atmosphere, biosphere and geological systems operate over long timescales.
The annual growth rings from trees provide us with an incredibly powerful and adaptable tool to study Earth’s history. The rings tell us much more than just the age of tree. They also provide clues that help us understand how our environment has changed in the past, and provide insights into how key processes in atmosphere, biosphere and geological systems operate over long timescales.
This course will teach students the fundamental principles of dendrochronology through a combination of formal lectures, class discussion and laboratory exercises. Students will work in the University of Minnesota’s Center for Dendrochronology, where they will learn how to collect, prepare and date tree-ring specimens. By the end of the course, they will be able to explain both the key concepts underlying dendrochronology and discuss how evidence from tree rings is used to address contemporary issues in natural history, resource management and Earth Systems Science.
Tree rings tell us much more than just a tree’s age. They also provide clues that help us understand how our environment has changed in the past, and provide insights into how key processes in atmosphere, biosphere and geological systems operate over long timescales.
Bryophytes are a diverse group of land plants.
Have large ecological impact.
23,000 described species world wide.
Largest group of land plants except for the flowering plants.
Integral part of natural environment of forest ecosystems.
Bryophytes are of small size.
Some of them attain a height up to half meter or a little more.
Store large amount of water, nutrients and carbon in their biomass.
In peatlands, bryophytes function as carbon sinks, which is a matter of great concern when considered with the rise of global carbon dioxide level.
Ability to remain alive for a long period without water even
under high temperature, and then resume photosynthesis within seconds after being moistened by rain or dew.
Most bryophytes are ectohydric, i.e., ability to absorb water, inorganic nutrients and mineral elements directly from the atmosphere rather than the soil and substratum.
Bryophytes possess short-lived sporophytic and dominant gametophytic phase.
In this presentation you will get to know about aspects of paleobotany, about coal and petroleum exploration and its extraction and how paleobotany is related to coal and petroleum.
Plants have adaptations to help them survive (live and grow) in different areas. Adaptations are special features that allow a plant or animal to live in a particular place or habitat. These adaptations might make it very difficult for the plant to survive in a different place.
This explains why certain plants are found in one area, but not in another. For example, you wouldn't see a cactus living in the Arctic. Nor would you see lots of really tall trees living in grasslands.
This presentation focuses on anatomical adaptations of three major types of plants: Hydrophytes, mesophytes and xerophytes.
This is an excerpt of basic concepts and principles of palynology as it applies to systematics and taxonomy of plants. Credits are given to the authors and owners of photographs used in the entire presentation.
Every year, trees in temperate and boreal forests go through a cycle of dormancy and activity that produces a new layer of tracheids, fibers and other woody cells around their stem. The end result of this process - a tree ring - is one of the most obvious signs in nature documenting the passage of time and the character of that year’s weather. Measurements of tree-ring widths are the most widely-distributed and best replicated source of surrogate environmental information on the planet and are one of the main archives used to estimate changes in regional and global climate during the past several centuries or millennia.
In this lecture, I describe the structure and characteristics of the Northern Hemisphere tree-ring width network, and outline how these data are linked with key aspects of local climate and the global climate system. More generally, by describing the characteristics of the Northern Hemisphere tree-ring width network and the diversity of its relations with varying aspects of the global climate system, this presentation highlights the breadth and quality of environmental information that may be recovered from the width of annual growth layers in temperate and boreal trees.
Bryophytes are a diverse group of land plants.
Have large ecological impact.
23,000 described species world wide.
Largest group of land plants except for the flowering plants.
Integral part of natural environment of forest ecosystems.
Bryophytes are of small size.
Some of them attain a height up to half meter or a little more.
Store large amount of water, nutrients and carbon in their biomass.
In peatlands, bryophytes function as carbon sinks, which is a matter of great concern when considered with the rise of global carbon dioxide level.
Ability to remain alive for a long period without water even
under high temperature, and then resume photosynthesis within seconds after being moistened by rain or dew.
Most bryophytes are ectohydric, i.e., ability to absorb water, inorganic nutrients and mineral elements directly from the atmosphere rather than the soil and substratum.
Bryophytes possess short-lived sporophytic and dominant gametophytic phase.
In this presentation you will get to know about aspects of paleobotany, about coal and petroleum exploration and its extraction and how paleobotany is related to coal and petroleum.
Plants have adaptations to help them survive (live and grow) in different areas. Adaptations are special features that allow a plant or animal to live in a particular place or habitat. These adaptations might make it very difficult for the plant to survive in a different place.
This explains why certain plants are found in one area, but not in another. For example, you wouldn't see a cactus living in the Arctic. Nor would you see lots of really tall trees living in grasslands.
This presentation focuses on anatomical adaptations of three major types of plants: Hydrophytes, mesophytes and xerophytes.
This is an excerpt of basic concepts and principles of palynology as it applies to systematics and taxonomy of plants. Credits are given to the authors and owners of photographs used in the entire presentation.
Every year, trees in temperate and boreal forests go through a cycle of dormancy and activity that produces a new layer of tracheids, fibers and other woody cells around their stem. The end result of this process - a tree ring - is one of the most obvious signs in nature documenting the passage of time and the character of that year’s weather. Measurements of tree-ring widths are the most widely-distributed and best replicated source of surrogate environmental information on the planet and are one of the main archives used to estimate changes in regional and global climate during the past several centuries or millennia.
In this lecture, I describe the structure and characteristics of the Northern Hemisphere tree-ring width network, and outline how these data are linked with key aspects of local climate and the global climate system. More generally, by describing the characteristics of the Northern Hemisphere tree-ring width network and the diversity of its relations with varying aspects of the global climate system, this presentation highlights the breadth and quality of environmental information that may be recovered from the width of annual growth layers in temperate and boreal trees.
The "Year Without A Summer" was not a year without a ringScott St. George
The Tambora eruption of 1815 cooled the planet and caused the "Year Without A Summer" in western Europe and eastern North America. But was it cold enough to cause trees across the Northern Hemisphere to skip a ring?
Guarding against false discovery in large-scale dendroclimatologyScott St. George
Measurements of tree-ring widths are the most widely-distributed and best replicated source of surrogate environmental information on the planet, and are one of the main archives used to estimate changes in regional and global climate during the past several centuries or millennia. Because the Northern Hemisphere ring-width network is now so large, it is more crucial than ever to ensure our understanding of tree-environment relations is not influenced by decisions to include or exclude certain records. It may be the case that a particular set of ring-width records are, for whatever reason, more tightly coupled to a particular climate factor than other records from the same region or species and, as a result, may be superior estimators of that factor’s past behavior. At the same time, it is known that selecting a small number of predictors from a large pool of potential candidates increases the likelihood of a Type I error. That effect may be particularly relevant to dendroclimatology because the total number of available ring-width records is often much larger than the number of records used to produce reconstructions of large-scale climate features. As an initial step, it would be helpful if paleoclimate reconstructions derived from tree rings described more explicitly the criteria used to select ring-width records as potential predictors and specified those records excluded by that screening. By comparing ring-width chronologies and their relations with climate against the standard set by thousands of records across the hemisphere, we should be better able to distinguish climate signals from proxy noise and produce more accurate reconstructions of climate during the late Holocene.
Large-scale dendrochronology and low-frequency climate variabilityScott St. George
Large-scale low-frequency variability has emerged as a priority for climate research, but instrumental observations are not long enough to characterize this behavior or gage its impacts on dependent geophysical or ecological systems. As the leading source of high-resolution paleoclimate information in the middle- and high-latitudes, tree rings are essential to understand low-frequency variability prior to the instrumental period. But even though tree rings possess several advantages as climate proxies, like other natural archives they also have their own particular impediments. In this lecture, Dr. St. George will describe the structure and characteristics of the Northern Hemisphere tree-ring width network, and outline how the fingerprint of decadal and multidecadal climate variability encoded within ancient trees varies across the hemisphere.
Disentangling the decadal ‘knot’ in high-resolution paleoclimatologyScott St. George
Even after more than a century of coordinated monitoring, instrumental weather observations are still too short to adequately constrain decadal or multidecadal behavior in the Earth’s climate system. Leading climatologists and climate modelers have called for the wider application of high-resolution proxy records to decadal variability and prediction studies, and our community has responded by producing new paleoclimate products that specifically target this type of ‘intermediate-term’ behavior. But we now also know our medium changes that message: the biological and geological systems that encode climate information into natural archives often also alter the original ‘input’, usually due to either seasonal filtering or non-climatic persistence. In this talk, we’ll discuss some of the challenges inherent to the use of high-resolution proxies to study decadal or multi-decadal climate variability, and suggest strategies that might clarify how climate acts on those timescales. And we’ll also present a new theoretical framework that could help paleo-scientists evaluate competing ideas about the causes of decadal- or multi-decadal events known to have occurred during the past one or two millennia.
How we know what we know about climate changeLisa Gardiner
Presentation for science educators at the National Science Teachers Association conference in Denver, CO 2013 about how climate scientists use data from paleoclimate proxies, current observations of the Earth system, and models of future climates to gain an understanding of Earth's climate.
How has our climate changed in the past? What caused those changes, and can understanding the Earth’s climate history help us better predict the future? Does the past really matter?
In this seminar course, we will examine these questions through the lens of paleoclimatology, which uses physical and cultural evidence to make inferences about climates of the past. We will review the processes that govern our modern climate and explore what paleoclimate records tell us about how these systems respond to (and express) climate change.
Boosting the Signal: Simple Strategies to Deliver Better Scientific TalksScott St. George
A good talk can open the doors to new collaborations, increase your chances of funding success, and make it more likely other people will respond to your ideas. But scientific presentations are too often confusing, boring, and overstuffed. Here are some suggestions, based on our experience as speakers, audience members, and presentation trainers, that we hope will make your next conference talk or seminar more enjoyable, engaging and effective.
Ringing true: The scientific and societal relevance of dendrochronology at th...Scott St. George
Tree rings and other natural archives empower us to extend our perspective on environmental change, resources, and hazards. But many contemporary applications of paleoclimatology and paleohydrology are useful because of the lasting disruption to our collective environmental memory caused by colonization.
Much of what we know regarding variations in Earth's climate during the past millennium comes from tree rings. But tree rings, like other proxies, attenuate some climate signals but amplify others, and their fidelity at longer timescales is difficult to gage. Even though dendroclimatology is well-established, questions remain about the climate clues encoded in tree rings — particularly at decadal-to-centennial timescales.
Don’t call it a comeback: Studying ancient floods to prepare for future hazardsScott St. George
How long do we need to watch a river before its behavior holds no more surprises? In this country, instrumental measurements of river stage and discharge stretch back a century or more, but this observed history still provides only a rough guide to the risks of future extreme floods. In this lecture, I’ll outline how paleoflood hydrology expands our perspective on river history by combining historical, botanical, and geological evidence of earlier (and ofttimes unknown) floods. And I’ll explain how we can interpret those physical clues left behind by ancient floods to improve hazard assessments for at-risk communities, support decisions about flood infrastructure, and investigate the long-term effects of climate or land-use changes on flooding. Because what has happened before can happen again, most everyone near a river would profit by keeping a longer memory of old floods.
Flood rings: Paleoflood evidence in tree-ring anatomyScott St. George
In low-gradient, low energy rivers, forms of tree-ring evidence such as impact scars or stem deformation do not provide useful evidence of past floods. In this talk, I explain the strengths and limitations of wood anatomy as tools in in paleoflood hydrology.
Historic accounts of extreme floods on the Red River of the NorthScott St. George
Here I explain how Canadian and American communities along the Red River of the North have developed fundamentally different responses to the threat of flooding, and argue that these differences in flood mitigation reflect disparate experiences with particular floods during the past two hundred years.
A new framework to test the origins of western American megadroughtScott St. George
We know from tree rings and other natural drought records that the western United States has been affected by several 'megadroughts' during the past millennium. But are these exceptionally long-lasting droughts due to unusual external forcings, or are they inevitable given a sufficiently long period of time? Here we present a statistical model that combines sea surface temperature records and drought severity statistics from the western USA, and use that tool to set out an expectation for megadrought, given no other changes in the climate system. Even though this model was trained using only modern climate data (and incorporates no information from tree rings or other proxies), it still produced megadroughts. Moreover, those simulated megadroughts were just as long-lasting, covered as large an area, and were just as severe as real megadroughts estimated from tree rings. That result means that megadroughts can occur in the western United States even if nothing else changes in the climate -- they really are just a matter of time. On the other hand, the only aspect of real-world megadroughts that the model cannot duplicate was the high number of these events during the so-called Medieval Climate Anomaly (800 to 1300 CE). So that cluster of megadroughts may have been caused by some sort of unusual climate circumstances that have not been observed by us during the past few decades. The proxy record tells us that many different kinds of exceptional or unusual climate events happened in the past. But it is often difficult to determine what caused those exceptional events because even, within a period of a thousand years, we still have very few cases. So besides being an aid to understand the causes of past megadroughts, we hope this approach can be applied to other paleoclimate records to distinguish between real interrelations between separate components of the climate system and simple coincidences.
The need for new theory in global dendroclimatologyScott St. George
So much of what we know about the Earth’s climate during the past two millennia comes from tree rings. Information gleaned from the physical or chemical properties of growth rings in trees have allowed us to extend hemispheric-scale temperature records back by several centuries, construct annual maps of drought severity that span several continents, and generate proxy estimates for many of the leading modes within the climate system. The theoretical foundation that underpins these products — and most others in dendroclimatology — was fully mature by the early 1990s and set out in detail by Cook and Kairiukstis in their seminal book, ‘Methods in Dendrochronology’. Most of the core analytical methods used to infer past climate from tree rings that appear in this reference (as well as prior works) depend on two concepts in particular: first, the idea that patterns common to many trees at many sites are more likely to be related to synoptic-scale climate variability (the principle of replication), and second, the notion that the most useful tree-ring records are found in forests where growth is particularly sensitive to a specific aspect of local climate (the principle of site selection). But because of (i) the gradual expansion, extension, and in-filling of the global tree-ring network and (ii) the emphasis given to atypical or even unique site-specific signals by some novel reconstruction methods, it is a point of debate within our community, at least implicitly, whether these principles remain valid. This presentation will review several recent studies that illustrate the possible advantages offered by a disregard for the usual ‘rules’ of dendroclimatology but will also discuss the potential pitfalls of placing too much emphasis on apparently optimal records. We hope this talk will encourage the sharing of ideas on how best to extract climate information from the ever-expanding network of tree-ring records across our planet and help open a discussion on the relevance of our standard theoretical framework to contemporary global dendroclimatology.
The societal value of historical and paleoflood research in Manitoba, CanadaScott St. George
Southern Manitoba is one of the most flood-prone regions in Canada, with the Red River of the North being the cause of most significant floods. The realization that the then-recent 1950 flood disaster was dwarfed by the historical 1826 flood led Canadian government officials to set an unusually high design standard for the Red River floodway, a 48-km long diversion built in the 1960s to protect the provincial capital of Winnipeg. And after paleoflood research confirmed new evidence of the 1826 flood, that event was cited as the main justification for expanding the Red River floodway, a $668 billion CAN infrastructure project that began in 2010. Without these insights from historical and paleoflood research, it’s almost certain flood risk estimates would have been unrealistically low and Winnipeg would have adopted a lesser level of flood protection. Because widespread Euro-American settlement in the Pembina Territory (the present-day Red River basin within the United States) did not occur until the 1870s, there are no historical accounts that indicate whether the 1826 flood was also so severe in North Dakota or Minnesota. As a result, the 1997 flood, which was nearly 1.5 times larger than any other previous flood in the US gage record, overwhelmed the dikes protecting Grand Forks and East Grand Forks. By having a deeper understanding of the history of flooding, communities are better able to anticipate future floods, make sound decisions about flood protection and migration, and protect people and their property more effectively.
Solar ghosts: Weighing the evidence for sunspot cycles in fossil treesScott St. George
In their study of tree rings from the Chemnitz Fossil Forest (Germany), Luthardt and Rößler (2017) claim to identify a regular near-11-yr cyclicity in growth, and present that pattern as evidence of the influence of the Schwabe solar cycle (Usokin and Mursula, 2003) on climate and forest productivity during the early Permian. If correctly interpreted, these fossil tree rings would indicate the sunspot cycle was the dominant influence on interannual variability in Earth’s climate during this period and that it has been a consistent aspect of our Sun’s behavior for at least the past 300 m.y. We argue the fossil tree-ring record from Chemnitz does not constitute reliable evidence of solar activity during the Permian because the individual tree-ring sequences are not correctly aligned (dendrochronologically dated) and, as a result, the mean ring-width composite is not a meaningful estimate of year-to-year variations in tree growth in this ancient forest.
Long droughts: Using natural climate archives to gage the risks of future “me...Scott St. George
In the Biblical story of Joseph, following seven years of abundance, the Kingdom of Egypt was confronted by seven years of drought and famine. In the parlance of modern climate science, intervals with several consecutive extremely dry years are described as ‘“megadroughts”. In this short talk, I’ll describe how climate scientists combine clues from natural weather archives (including corals, tree rings, lake sediments, and many other sources) to reveal the history of ancient megadroughts across our planet. And I’ll highlight new research that combines these surrogate drought records with simulations from state-of-the-art climate models to help us better anticipate the risks of unusually persistent droughts during the coming century.
Expecting the unexpected: The relevance of old floods to modern hydrologyScott St. George
As one of the most destructive hazards on our planet, floods kill thousands of people and cause billions of dollars in property damage every year. We usually try to gage the risk of future floods by fitting mathematic functions to hydrological data and then extrapolating the upper tail of those distributions. But because large floods are rare and river gage records are short, the conventional approach can sometimes drastically underestimate the threat posed to communities and infrastructure by extreme floods. In this lecture, I’ll argue that paleoflood hydrology — the study of ancient floods as recorded by river and lake sediments, trees, caves, and historical documents — is absolutely essential to judge the real risk of large, rare floods. And I’ll use examples from North America to illustrate how a ‘deeper river memory’ can help people evaluate their own vulnerability to floods, weigh the potential benefits of proposed infrastructure projects, and become more aware of what nature is truly capable of producing.
What to expect when you’re expecting decadal variability in hydroclimatic pro...Scott St. George
Prolonged episodes of persistently dry or wet conditions are common features of most proxy-based reconstructions of past hydroclimatic variability. These so-called “Joseph” events might be due to external forcings that push sea-surface temperatures into warm or cold states, and thereby increase the likelihood of widespread megadroughts or megapluvials. Alternatively, internal ocean-atmosphere variability alone might be able to produce long-lasting and spatially extensive wet or dry intervals, even in the absence of any exotic external influences. In this study, we use a simple statistical emulator to establish benchmarks for decadal or multidecadal patterns in the western United States. We constructed a linear inverse model that included three key aspects of the El Niño-Southern Oscillation (monthly sea-surface temperatures, zonal surface wind stress, and sea-surface height), and restricted the spatial domain of each field to include only the tropical Pacific. By also including western United States hydroclimate information in the LIM, we are able to test whether ENSO variability and stochastic weather ‘noise’ could be sufficient to create low-frequency coherence within proxy networks. More broadly, if simulated drought patterns generated by the LIM are able to match the frequency, intensity, or spatial extent of droughts reconstructed by proxies, that implies that neither exotic forcings nor climate variability outside the tropical Pacific are required to produce widespread megadroughts in this region. If prolonged departures from the mean are indeed emergent but unremarkable features of western North America’s hydroclimate, we might be able to estimate their future occurrence as a linear combination of changes in the mean state and the linear dynamics that have governed their behavior in the past.
S. St. George, T. Ault, C. Carrillo, S. Coats, J. Mankin, J. Smerdon, What to expect when you’re expecting decadal variability in hydroclimatic proxies, PAGES 5th Open Science Meeting, Zaragoza, Spain, May 9-13, 2017.
Strong variance at decadal and multidecadal timescales is a common feature of most tree-ring width records. But does this aspect of tree growth exhibit such long-memory behavior due to biology, climate, or some combination of the two factors? Understanding the origins of this behavior is crucial for efforts to evaluate the causes of decadal variability in the climate system.
Presentation at Johann Gutenburg University (Mainz) on February 16, 2017.
Five Things You Can Do Right Now To Make Your Research Presentations Just A L...Scott St. George
The ability to deliver effective and engaging oral presentations is a critical skill for all researchers. Unfortunately, despite the importance of clear communication, too many scientific presentations at conferences and workshops are confusing, abstract, and boring. In this short workshop, participants learn several key strategies and tips that will make their professional presentations just a little bit better than the rest. We discuss strategies for presentation planning, show how basic design principles can create more memorable slides, and point towards an outstanding set online tools and resources. Become a presentation superstar!
Scott St. George is Associate Professor in the Department of Geography, Environment and Society at the University of Minnesota and a Resident Fellow at UMN's Institute on the Environment. Prior to joining the faculty at Minnesota, he was a research scientist with the Geological Survey of Canada. Scott shares some of his experiences ‘doing presentations differently’ at conferences, outreach opportunities, and the classroom.
In many settings, trees growing on floodplains provide an important source of indirect evidence that may be used to infer the occurrence, extent, and magnitude of floods prior to direct observations. That evidence may take several forms, including external scars caused by abrasion or impact from floating debris, anatomical changes within the annual growth increment following prolonged stem or root inundation, or tilting or uprooting due to the hydraulic pressure of floodwaters. Likely the most useful characteristic of paleoflood studies based on floodplain trees is their relatively high temporal resolution and dating accuracy compared to most other methods. Dendrochronological methods can routinely date past floods to the year of their occurrence and, in rare cases, can estimate the timing of floods that occur during the growing season to within two weeks. This high degree of chronological control, which is surpassed only by that provided by direct observation or instrumentation, can be used to determine whether floods in separate watersheds were synchronous or offset by several years and test hypotheses that suppose linkages between extreme floods and specific forcing mechanisms. Furthermore, the wide geographic distribution of tree species with dateable rings combined with the broad suite of methods available to examine interconnections between floods and tree growth allow this style of paleoflood hydrology to be applied to many settings that are not suitable for techniques that depend on geological evidence. Future paleoflood research involving tree rings will need to strike a balance between improving our understanding of the biological and fluvial processes that link tree growth to past events, and providing answers to questions about flood dynamics and hazards that are needed to safeguard people and property from future floods.
Expanding the window - the past, present, and future of Minnesota's waterScott St. George
Nearly all decisions about water in Minnesota relate either directly or indirectly to data collected by the state’s hydrological observing network. Because most gauges were installed in early 20th century, as a whole the network provides us with roughly a 100-year ‘window’ to estimate flood risks, develop worst-case scenarios for drought, and set maximum allowable withdrawals for aquifers. But when we rely exclusively on observations made during this relatively brief interval, we may inadvertently increase our exposure to hydrological ‘surprises’. In order to make sound decisions about water in Minnesota, we need to expand this window: into the past, drawing upon historical accounts and natural archives; and into the future, via projections from climate and hydrological models. By cultivating a broader perspective on hydrological variability and extremes across the state, we will be better prepared to ensure adequate water supplies and mitigate the impacts of future floods and droughts.
These visuals were prepared to support a string quartet performance and panel on climate change at Northwestern University in February 2106.
A well-designed graphic can help audiences to quickly understand the main message embedded within a complex set of climate data and to retain those ideas longer than they would have if they were conveyed by words alone. But the visual aids used regularly by climate scientists also have their limitations: they are most easily understood by people who are already fluent in technical illustrations; they're usually static and sometimes do not tell an obvious story; and for many, they don't elicit a strong emotional response.
Music, by contrast, is inherently narrative and is known to exert a powerful influence on human emotions. Because of this, sonification — the transformation of data into acoustic signals — may have considerable promise as a tool to enhance the communication of climate science.
Daniel Crawford and Scott St. George report on a collaboration between scientists and artists that uses music to transmit the evidence of climate change in an engaging and visceral way.
Noah, Joseph, And High-Resolution PaleoclimatologyScott St. George
In 1968, Benoit Mandelbrot and James Wallis published an article titled ‘Noah, Joseph, and operational Hydrology’ in the journal Water Resources Research. In it, they argued that hydrological models of the day were not able to estimate the true risk of extreme floods or prolonged drought, and that rare hydrological events were much more common than usually assumed.
In this lecture, I’ll review how high-resolution paleoenvironmental archives can help us judge more accurately the risks posed by the ‘Noah’- and ‘Joseph’-style events described by Mandelbrot and Wallis. I’ll give particular emphasis to the environmental information recovered from the rings of ancient trees, and explain how dendrochronology (tree-ring research) has been used to redefine the ‘flood of record’, test potential avenues for long-lead climate predictions, and gage the performance of state-of-the-art climate models.
A Song of Our Warming Planet: Using Music to Communicate Critical Concepts in...Scott St. George
When climate science is communicated to the broader public, many of its key findings are shared in the form of conceptual diagrams or information-dense data graphics. In this collaboration, we applied a data sonification approach to express NASA’s global temperature record as a musical composition for the cello. The resulting piece, which we titled ‘A Song of Our Warming Planet’, transformed 133 years of annual global temperature anomalies into a haunting, atonal melody that stretched across almost all of the instrument’s range. Since its release in June 2013, the song has been featured by several national and international media outlets, including the New York Times, the Weather Channel, and National Public Radio, and its accompanying video has received more than 140,000 views from nearly every corner of the world. We are currently preparing a new composition for string quartet that will add a geographic dimension to describe both the pace and place of global warming. We believe the success of our initial sonification project is testament to the power of music to reach audiences who respond less enthusiastically to traditional methods used to communicate climate science. We also imagine this approach could be applied more broadly to allow students to create novel, visceral, and memorable encounters with other aspects of the geophysical sciences.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
3. “ Tree-ring-derived records have played a
prominent role in a empts to establish how
climate has varied in the recent past.
”
Jones et al.
The Holocene, 2009
4. What characteristics of tree-ring records
make them useful tools
to understand ancient climates?
10. THE PRINCIPLE OF AGGREGATE TREE GROWTH
Ct = Rt - At - δD1t - δD2t - Et
11. THE PRINCIPLE OF
CROSS-DATING
THE PRINCIPLE OF
AGGREGATE TREE GROWTH
THE PRINCIPLE OF
REPLICATION
STANDARDIZATION
THE PRINCIPLE OF
ECOLOGICAL AMPLITUDE
THE PRINCIPLE OF
SITE SELECTION
12. How do we KNOW that tree rings are
tracking a SPECIFIC climate?
16. rain gauges
tree rings
Source: Hughes and Funkhouser, 1998
17. correlation The Pearson product-moment
correlation coefficient is probably the single
most widely used statistic for summarizing
the relationship between two variables.
35. Long, temperature-sensitive tree-ring records have been used to estimate
average temperatures across the entire hemisphere or globe.
Source: Esper et al., Science, 2002
42. “ Tree-rings also allow the reconstruction of
large-scale regional or global temperature pa erns
defined by large networks of chronologies.
”
Brian Luckman
Geoscience Canada, 2010
58. “ Tree rings are not thermometers or rain gages.
Keith Briffa and colleagues
Climate Variations and Forcing Mechanisms of the Last 2000 Years, 1996
”
61. the ‘divergence problem’ is defined as the tendency
for tree growth at some previously temperature-
limited northern sites to demonstrate a weakening in
mean temperature response in recent decades.
Source: D’Arrigo et al., 2008
63. “ It is important to stress that not all high-latitude
regions display this apparent decoupling
between observed and dendroclimatically
”
estimated temperatures.
Phil Jones and colleagues
The Holocene, 2009
68. “ Tree-ring-derived records have played a
prominent role in a empts to establish how
climate has varied in the recent past.
”
Jones et al.
The Holocene, 2009
