Two solitudes - how seasonality biases drought from tree rings

•

1 gostou•661 visualizações

Scott St. George

Graphics prepared for an upcoming talk at the University of Arizona's Laboratory of Tree-Ring Research

Tecnologia Espiritual

TWO
SOLITUDES

how seasonality biases
drought records from tree rings

why are Canadian streamﬂow reconstructions so lousy?

100%

80%

60%
explained
variance
40%

20%

0%

Canada USA

100%

Woodhouse et al., 2006
Meko et al., 2001
80% Sacramento River
Upper Colorado River

Meko et al., 2007
Colorado River
Woodhouse, 2007
Middle Boulder Creek

60%
explained
variance
40%

20%

0%

Canada USA

why are Canadian tree rings not connected to climate modes?

Janice Lough and Hal Fritts
The Southern Oscillation and tree rings: 1600 - 1961
Journal of Applied Meteorology 24, 1985

Roseanne D’Arrigo and Gordon Jacoby
A thousand year record of northwestern New
Mexico winter precipitation reconstructed from tree
rings and its relation to El Niño and the Southern
Oscillation
The Holocene 1, 1991

David Stahle and collaborators
Experimental dendroclimatic reconstruction of the
Southern Oscillation Stahle et al., 1998

Bulletin of the American Meteorological Society 79, 1998

Prairie ringwidth records
138
Signiﬁcant correlation with ENSO
4
Expected from random chance
6.9

Trees, seasonality and climate forcings
The southwestern US

Trees, seasonality and climate forcings
The Canadian Prairies

DROUGHT AND SEASONALITY
How does the connection between reconstructed drought
1
and seasonal precipitation vary across North America?

DROUGHT AND SEASONALITY
How does the connection between reconstructed drought
1 and seasonal precipitation vary across North America?

CLIMATE MODES AND TREE RINGS
In which regions are drought reconstructions most strongly
2 connected to remote climate forcings (ENSO, PDO, AMO)?

The North American
Drought Atlas

Cook et al., 2007, Earth Science Reviews

Cook et al., 2007, Earth Science Reviews

PART ONE
tree rings, drought and seasonality

“
...the regional summer precipitation signal is strong in
Pseudotsuga menziesii latewood-width [in southeastern
Arizona].

David Meko and Chris Baisan
Pilot study of latewood-width of conifers as an indicator of variability of summer rainfall in
the North American monsoon region
International Journal of Climatology 21, 2001

Medicine Hat, Alberta

Source: Environment Canada, Adjusted Historical Canadian Climate Data, 1895 – 2006

Prairie ringwidth records
138
Signiﬁcant correlation with ENSO
4
Expected from random chance
6.9 45

PART TWO
drought records and climate modes

are these signals present in reconstructed drought?

Julia Cole and Ed Cook
The changing relationship between ENSO variability
and moisture balance in the continental United States
Geophysical Research Letters 25, 1998

COMPOSITES
where is it wet or dry when ENSO is strong?

LOW FREQUENCIES (>7yr)
TREE-RINGS and PDO

0.5

0.25

mean squared 61
0 coherence

3 Mexican PDSI 10

2
5
1

0 0

-1
-5
-2

-3 62
-10
1900 1920 1940 1960 1980 2000

3 PDO index Mexican PDSI 10

2
5
1

0 0

-1
-5
-2

-3 63
-10
1900 1920 1940 1960 1980 2000

IMPLICATIONS

what/where OK

what/where/why NOT OK

IMPLICATIONS

tree ring model output

Celine Herwiejer, Richard Seager and Ed Cook
North American droughts of the mid to late nineteenth century:
a history, simulation and implication for Mediaeval drought
The Holocene 16, 2006

M A N Y TH AN KS

Dave Meko
Ed Cook
Hal Fritts
Toby Ault

Mais conteúdo relacionado

Semelhante a Two solitudes - how seasonality biases drought from tree rings

Why the past matters - how tree rings and environmental history help us make ...

Scott St. George

Great Lakes Climate Global Warming Presentation

Healthy Lakes, Healthy Lives

Final presentation to Manitoba Hydro

Scott St. George

GEOG8260.8, The power of simplicity

Scott St. George

GEOG5839.21, The Colorado River

Scott St. George

Decadal Signals In Precipitation

Scott St. George

Faculty to Faculty

Jeff Dozier

Effect of Climate Change on South West WA Hydrology

Wayne Prangnell

Semelhante a Two solitudes - how seasonality biases drought from tree rings (8)

Why the past matters - how tree rings and environmental history help us make ...

Great Lakes Climate Global Warming Presentation

Final presentation to Manitoba Hydro

GEOG8260.8, The power of simplicity

GEOG5839.21, The Colorado River

Decadal Signals In Precipitation

Faculty to Faculty

Effect of Climate Change on South West WA Hydrology

Mais de Scott 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.

Boosting the Signal: Simple Strategies to Deliver Better Scientific Talks

Scott St. George

Ringing true: The scientific and societal relevance of dendrochronology at th...

Scott St. George

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.

How long do trees remember?

Scott 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.

Don’t call it a comeback: Studying ancient floods to prepare for future hazards

Scott St. George

Flood rings: Paleoflood evidence in tree-ring anatomy

Scott St. George

Historic accounts of extreme floods on the Red River of the North

Scott 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.

Disentangling the decadal ‘knot’ in high-resolution paleoclimatology

Scott 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.

A new framework to test the origins of western American megadrought

Scott 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 need for new theory in global dendroclimatology

Scott 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.

The societal value of historical and paleoflood research in Manitoba, Canada

Scott 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.

Solar ghosts: Weighing the evidence for sunspot cycles in fossil trees

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.

Long droughts: Using natural climate archives to gage the risks of future “me...

Scott 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.

Expecting the unexpected: The relevance of old floods to modern hydrology

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.

What to expect when you’re expecting decadal variability in hydroclimatic pro...

Scott St. George

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.

Decadal variability in tree rings

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.

Five Things You Can Do Right Now To Make Your Research Presentations Just A L...

Scott St. George

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.

Trees as flood sensors

Scott 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.

Expanding the window - the past, present, and future of Minnesota's water

Scott St. George

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.

Making Climate Data Sing

Scott 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.

Large-scale dendrochronology and low-frequency climate variability

Scott St. George

Mais de Scott St. George (20)

Boosting the Signal: Simple Strategies to Deliver Better Scientific Talks

Ringing true: The scientific and societal relevance of dendrochronology at th...

How long do trees remember?

Don’t call it a comeback: Studying ancient floods to prepare for future hazards

Flood rings: Paleoflood evidence in tree-ring anatomy

Historic accounts of extreme floods on the Red River of the North

Disentangling the decadal ‘knot’ in high-resolution paleoclimatology

A new framework to test the origins of western American megadrought

The need for new theory in global dendroclimatology

The societal value of historical and paleoflood research in Manitoba, Canada

Solar ghosts: Weighing the evidence for sunspot cycles in fossil trees

Long droughts: Using natural climate archives to gage the risks of future “me...

Expecting the unexpected: The relevance of old floods to modern hydrology

What to expect when you’re expecting decadal variability in hydroclimatic pro...

Decadal variability in tree rings

Five Things You Can Do Right Now To Make Your Research Presentations Just A L...

Trees as flood sensors

Expanding the window - the past, present, and future of Minnesota's water

Making Climate Data Sing

Large-scale dendrochronology and low-frequency climate variability

Último

Manulife - Insurer Innovation Award 2024

The Digital Insurer

Join our latest Connector Corner webinar to discover how UiPath Integration Service revolutionizes API-centric automation in a 'Quote to Cash' process—and how that automation empowers businesses to accelerate revenue generation. A comprehensive demo will explore connecting systems, GenAI, and people, through powerful pre-built connectors designed to speed process cycle times. Speakers: James Dickson, Senior Software Engineer Charlie Greenberg, Host, Product Marketing Manager

Connector Corner: Accelerate revenue generation using UiPath API-centric busi...

DianaGray10

Created by Mozilla Research in 2012 and now part of Linux Foundation Europe, the Servo project is an experimental rendering engine written in Rust. It combines memory safety and concurrency to create an independent, modular, and embeddable rendering engine that adheres to web standards. Stewardship of Servo moved from Mozilla Research to the Linux Foundation in 2020, where its mission remains unchanged. After some slow years, in 2023 there has been renewed activity on the project, with a roadmap now focused on improving the engine’s CSS 2 conformance, exploring Android support, and making Servo a practical embeddable rendering engine. In this presentation, Rakhi Sharma reviews the status of the project, our recent developments in 2023, our collaboration with Tauri to make Servo an easy-to-use embeddable rendering engine, and our plans for the future to make Servo an alternative web rendering engine for the embedded devices industry. (c) Embedded Open Source Summit 2024 April 16-18, 2024 Seattle, Washington (US) https://events.linuxfoundation.org/embedded-open-source-summit/ https://ossna2024.sched.com/event/1aBNF/a-year-of-servo-reboot-where-are-we-now-rakhi-sharma-igalia

A Year of the Servo Reboot: Where Are We Now?

Igalia

Bajaj Allianz Life Insurance Company - Insurer Innovation Award 2024

The Digital Insurer

Scaling API-first – The story of a global engineering organization

Radu Cotescu

MINDCTI Revenue Release Quarter One 2024

MIND CTI

Polkadot JAM Slides - Token2049 - By Dr. Gavin Wood

Juan lago vázquez

The value of a flexible API Management solution for Open Banking Steve Melan, Manager for IT Innovation and Architecture - State's and Saving's Bank of Luxembourg Apidays New York 2024: The API Economy in the AI Era (April 30 & May 1, 2024) ------ Check out our conferences at https://www.apidays.global/ Do you want to sponsor or talk at one of our conferences? https://apidays.typeform.com/to/ILJeAaV8 Learn more on APIscene, the global media made by the community for the community: https://www.apiscene.io Explore the API ecosystem with the API Landscape: https://apilandscape.apiscene.io/

Apidays New York 2024 - The value of a flexible API Management solution for O...

apidays

GenAI Risks & Security Meetup 01052024.pdf

lior mazor

How to Troubleshoot Apps for the Modern Connected Worker

ThousandEyes

2024: Domino Containers - The Next Step. News from the Domino Container commu...

Martijn de Jong

Real Time Object Detection Using Open CV

Khem

🐬 The future of MySQL is Postgres 🐘

RTylerCroy

Axa Assurance Maroc - Insurer Innovation Award 2024

The Digital Insurer

Partners Life - Insurer Innovation Award 2024

The Digital Insurer

ProductAnonymous-April2024-WinProductDiscovery-MelissaKlemke

Product Anonymous

With more memory available, system performance of three Dell devices increased, which can translate to a better user experience Conclusion When your system has plenty of RAM to meet your needs, you can efficiently access the applications and data you need to finish projects and to-do lists without sacrificing time and focus. Our test results show that with more memory available, three Dell PCs delivered better performance and took less time to complete the Procyon Office Productivity benchmark. These advantages translate to users being able to complete workflows more quickly and multitask more easily. Whether you need the mobility of the Latitude 5440, the creative capabilities of the Precision 3470, or the high performance of the OptiPlex Tower Plus 7010, configuring your system with more RAM can help keep processes running smoothly, enabling you to do more without compromising performance.

Boost PC performance: How more available memory can improve productivity

Principled Technologies

Abhishek Deb(1), Mr Abdul Kalam(2) M. Des (UX) , School of Design, DIT University , Dehradun. This paper explores the future potential of AI-enabled smartphone processors, aiming to investigate the advancements, capabilities, and implications of integrating artificial intelligence (AI) into smartphone technology. The research study goals consist of evaluating the development of AI in mobile phone processors, analyzing the existing state as well as abilities of AI-enabled cpus determining future patterns as well as chances together with reviewing obstacles as well as factors to consider for more growth.

Exploring the Future Potential of AI-Enabled Smartphone Processors

debabhi2

Bajaj Allianz Life Insurance Company - Insurer Innovation Award 2024

The Digital Insurer

This presentations targets students or working professionals. You may know Google for search, YouTube, Android, Chrome, and Gmail, but did you know Google has many developer tools, platforms & APIs? This comprehensive yet still high-level overview outlines the most impactful tools for where to run your code, store & analyze your data. It will also inspire you as to what's possible. This talk is 50 minutes in length.

Powerful Google developer tools for immediate impact! (2023-24 C)

wesley chun

Two solitudes - how seasonality biases drought from tree rings

1. TWO SOLITUDES how seasonality biases drought records from tree rings

10.

11.

12. TWO SOLITUDES how seasonality biases drought records from tree rings

13.

14. why are Canadian streamﬂow reconstructions so lousy?

15. 100% 80% 60% explained variance 40% 20% 0% Canada USA

16. 100% Woodhouse et al., 2006 Meko et al., 2001 80% Sacramento River Upper Colorado River Meko et al., 2007 Colorado River Woodhouse, 2007 Middle Boulder Creek 60% explained variance 40% 20% 0% Canada USA

17. 100% Woodhouse et al., 2006 Meko et al., 2001 80% Sacramento River Upper Colorado River Meko et al., 2007 Colorado River Woodhouse, 2007 Middle Boulder Creek 60% Case and MacDonald, 2003 explained Saskatchewan River Beriault and Sauchyn, 2006 Churchill River variance Bonin and Burn, 2005 Athabasca River 40% Watson and Luckman, 2005 Gedalof et al., 2007 Bow River Columbia River 20% 0% Canada USA

18. why are Canadian tree rings not connected to climate modes?

19. Janice Lough and Hal Fritts The Southern Oscillation and tree rings: 1600 - 1961 Journal of Applied Meteorology 24, 1985 Roseanne D’Arrigo and Gordon Jacoby A thousand year record of northwestern New Mexico winter precipitation reconstructed from tree rings and its relation to El Niño and the Southern Oscillation The Holocene 1, 1991 David Stahle and collaborators Experimental dendroclimatic reconstruction of the Southern Oscillation Stahle et al., 1998 Bulletin of the American Meteorological Society 79, 1998

20. Prairie ringwidth records 138 Signiﬁcant correlation with ENSO 4 Expected from random chance 6.9

21.

22.

23.

24. seasonality

25. Trees, seasonality and climate forcings The southwestern US

26. Trees, seasonality and climate forcings The Canadian Prairies

27.

28. DROUGHT AND SEASONALITY How does the connection between reconstructed drought 1 and seasonal precipitation vary across North America?

29. DROUGHT AND SEASONALITY How does the connection between reconstructed drought 1 and seasonal precipitation vary across North America? CLIMATE MODES AND TREE RINGS In which regions are drought reconstructions most strongly 2 connected to remote climate forcings (ENSO, PDO, AMO)?

30. The North American Drought Atlas Cook et al., 2007, Earth Science Reviews

31. Cook et al., 2007, Earth Science Reviews

32. CORRELATION COMPOSITES COHERENCE

33. PART ONE tree rings, drought and seasonality

34.

35. signiﬁcant (α=0.05)

36. instrumental tree rings

37. SUMM ER PRECIP ITAT ION

38.

39. WINTER PRECIPITAT ION

40.

41. do tree rings replicate these patterns?

42.

43.

44. +

45. summer mixed winter

46. DOMINANT not exclusive

47. “ ...the regional summer precipitation signal is strong in Pseudotsuga menziesii latewood-width [in southeastern Arizona]. David Meko and Chris Baisan Pilot study of latewood-width of conifers as an indicator of variability of summer rainfall in the North American monsoon region International Journal of Climatology 21, 2001

48. Medicine Hat, Alberta Source: Environment Canada, Adjusted Historical Canadian Climate Data, 1895 – 2006

49. Prairie ringwidth records 138 Signiﬁcant correlation with ENSO 4 Expected from random chance 6.9 45

50. ENSO and winter precipitation

51. PART TWO drought records and climate modes

52. ENSO PDSI from tree rings PDO AMO

53. are these signals present in reconstructed drought?

54. Julia Cole and Ed Cook The changing relationship between ENSO variability and moisture balance in the continental United States Geophysical Research Letters 25, 1998

55. ENSO PDSI from tree rings PDO AMO

56.

57.

58. COMPOSITES where is it wet or dry when ENSO is strong?

59.

60.

61. ENSO PDSI from tree rings PDO AMO

62.

63.

64. LOW frequency

65. LOW FREQUENCIES (>7yr) TREE-RINGS and PDO 0.5 0.25 mean squared 61 0 coherence

66. LOW FREQUENCIES (>7yr) TREE-RINGS and PDO 0.5 0.25 mean squared 61 0 coherence

67. 3 Mexican PDSI 10 2 5 1 0 0 -1 -5 -2 -3 62 -10 1900 1920 1940 1960 1980 2000

68. 3 PDO index Mexican PDSI 10 2 5 1 0 0 -1 -5 -2 -3 63 -10 1900 1920 1940 1960 1980 2000

69.

70. ENSO PDSI from tree rings PDO AMO

71.

72. SEAS ONALITY AND D ROUGHT

73. summer mixed winter

74. IMPLICATIONS 1590s

75. IMPLICATIONS what/where OK

76. IMPLICATIONS what/where OK what/where/why NOT OK

77. IMPLICATIONS tree ring model output Celine Herwiejer, Richard Seager and Ed Cook North American droughts of the mid to late nineteenth century: a history, simulation and implication for Mediaeval drought The Holocene 16, 2006

78. summer mixed winter

79. M A N Y TH AN KS Dave Meko Ed Cook Hal Fritts Toby Ault

Two solitudes - how seasonality biases drought from tree rings

Recomendados

Recomendados

Mais conteúdo relacionado

Semelhante a Two solitudes - how seasonality biases drought from tree rings

Semelhante a Two solitudes - how seasonality biases drought from tree rings (8)

Mais de Scott St. George

Mais de Scott St. George (20)

Último

Último (20)

Two solitudes - how seasonality biases drought from tree rings