spatio-temporal exploration of paleo fire climate patterns using the superposed epoch analysis...

Spatio-temporal Exploration of

Paleo Fire Climate Patterns Using the

Superposed Epoch Analysis (S.E.A.)

Capstone Project Proposal, PSU MGIS

Author: Wendy Gross, Advisor: Dr. Alan Taylor

Proposal Outline

• Background

• Goals and Objectives

• Proposed Methodology

• Project Timeline

• Conclusions and Anticipated Results

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Background

Goals and Objectives ProposedMethodology

Project Timeline

Conclusionsand Anticipated Results

Wide ringindicating Wet Year

Narrow Ring indicating Dry Year

Paleoclimatology:

• the study of climate prior to the widespread availability of instrumental climate records

Paleoclimate Proxies:

• natural recorders of the environment

• used to yield quantitative reconstructions of past climate

• tree-rings are used as a proxy to study precipitation and temperature

Paleoclimatology and Paleoclimate Proxies

Increment Borer

Core Extracted from a tree via an Increment Borer

Fire Scar Pith(Seedling)

Dry Years

Bark

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Background


Project Timeline


Palmer Drought Severity Index Values for 1851

Extremely Dry PDSI Neutral PDSI Extremely Wet PDSI

Each 2.5x2.5 degree grid cellhas a time series of PDSI values

associated with it

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The Palmer Drought Severity Index (PDSI) Has Been Reconstructed from Tree-ring Data

(for 0 A.D. to 2000 A.D.)

Paleoenvironmental Proxies

• Fire Scars in the annual growth rings of trees are a paleoenvironmental proxy that allows us to determine when a fire event happened – called the fire event year

• Paleoclimate proxies can be linked to paleoenvironmental proxies to gain an understanding as to how climate effects ecosystem processes

• Linking PDSI drought data to fire event years to gain an understanding of how drought affects fire

,

Fire-scarred cross section from a ponderosa pine (photo © P.M.Brown)

Background


Project Timeline


4

Fire-scardata sites(NOAA/Paleo)

Superposed Epoch Analysis (S.E.A.) Basic Definition and Inputs

(2) A list of event dates that are within the start and end dates of the time series used as inputFor this project - Fire Event Years derived from fire scar sites

S.E.A. is a statistical technique that can be used to analyze the relationship between :

• proxy-base climatic phenomena (for example drought), and• environmental events such as Fire Event Years

Inputs to the S.E.A technique:

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(1) A time series, and the start and end dates over which the analysis is to take place For this project - a PDSI time series for one grid cell

Background


Conclusions

Anticipated Results

The Superposed Epoch Analysis “Window” (“Epoch”)

S.E.A. “Window”

Event Year(Year Zero)

Yr 2(lag 2)

Yr 1(lag 1)

( not to scale )

Yr -1(lag -1)

Yr- 2(lag -2)

Yr -3(lag -3)

Yr -4(lag -4)

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Computations (Averaging) Performed by the S.E.A.

AvgAvgAvg

Results

S.E.A.“Windows”

Avg AvgAvg Avg

Yr 2(lag 2)

Yr 1(lag 1)

Yr -1(lag -1)

Yr- 2(lag -2)

Yr -3(lag -3)

Yr -4(lag -4)


Legend: PDSI Values

Yr 2(lag 2)

Yr 1(lag 1)

Yr -1(lag -1)

Yr- 2(lag -2)

Yr -3(lag -3)

Yr -4(lag -4)


7Extremely Dry PDSI Neutral PDSI Extremely Wet PDSI

Goals - enhance the understanding of:

• spatio-temporal variability in fire and climate interaction

• the mechanisms that drive fire and climate interaction

Goals and Objectives

Objectives - develop a web-mapping tool that provides a spatially explicit representation of the S.E.A. technique results. This will:

• help researchers to spatially resolve the temporal patterns of fire and climate they are identifying in their analysis

• allow researchers to relate the spatial inference to the spatial footprint of different climatic mechanisms

Background


Project Timeline


8

Pilot Project Goal:

Verify that through a spatial representation of the S.E.A. technique results, I can reproduce published findings

Research questions had to do with the relationship of fire event years to drought and El Niño-Southern Oscillation

One of the primary questions addressed :

“Scientific research has found that in times prior to anthropogenic influence in the Southwestern United States,

there were wet years prior to Major Southwestern Fire Event Years,

and dry conditions during the actual Fire Event Years.” *

* Barton Et al, 2001; Grissino-Mayer, 2000; Swetnam and Betancourt, 1989

Work to Date – Pilot Project“Verification of Concept”

Background


Project Timeline


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Background


Project Timeline


Pilot Project – Southwest Study Area Depicting the PDSI Grid Cells and Fire Scar Sites

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Background



Pilot Project Southwest Fire Event Years Selected

Background


Project Timeline


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1700 1720 1740 1760 1780 1800 1820 18400

10

20

30

40

Years AD

Perc

ent

Scare

d

A total of 17 years were selected. Selected years are shown with yellow markers, and have at least 10% of trees scared.

Pilot Project - S.E.A. Results for Lags before/during/after Major Fire Events that Occurred in the Southwest

Grid Cell 104

Southwest Study Area

Year -2 Year -1 Year Zero Year 1 Year 2

PDSI SEA Results for Grid Cell 104 of Southwest Study Area

Extremely Dry PDSI | Extremely Wet PDSI Neutral PDSI from -0.5 to +0.5

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Background



Scientific discovery can be promoted by automation of computations, as well as interactive and dynamic visualization, and exploration of analysis results*

• software web-mapping software tool proposed will perform :

(1) automation of computations of the S.E.A. technique for every grid cell of the gridded dataset used as input

(2) creation of a full complement of interactive, and dynamic maps, in addition to graphs that depict the patterns realized for every lag

• significance of the results will be provided through graphical visualization of the certainty levels

Methodologies for Enhancing Scientific Discovery

Background


Project Timeline


13* Symanzik, 2007, Rubel, 2010

Background



Potential Geospatial Information Systems and Technologies (GIST)

Web-mapping:• ESRI’s ArcGIS geospatial web services (server-side) • ESRI’s ArcGIS Javascript Interface (client-side)

Automation of the S.E.A. computations and Geoprocessing:• PostreSQL/PostGIS RDBMS (server-side)• PHP programming language (server-side)

User Interface and Graphs:• ExtJS Javascript Library, Sencha.com (client-side)

Background


Project Timeline


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Project Timeline

Pilot Project/Verificaiton of Concept (Term Project, MGIS/GEOG 586, Geospatial Analysis, and beyond …)

Winter/Spring, 2010 and Winter, 2011

Project Proposal and Presentation Winter/Spring, 2011

Research and prototype of GIST tools for development of web-mapping tools

Spring/Summer, 2011

Define use cases for web-mapping tool, and research geo-visualization techniques

Spring/Summer, 2011

Develop Software tool, and finish MGIS coursework

Summer /Fall/Winter, 2011-2012

Create presentation for professional conference

Spring/Summer/Fall, 2012

Present software tool at professional conference

Possibilities: American Association of Geographers ConferenceNYC, Feb, 2012 Tree-Ring Society ConferenceUniversity of Arizona, Sep, 2011Association of Fire Ecologist Intl. ConferencePortland, Oregon, Dec, 2012

Publish report on software tool Winter/Spring, 2012

Background


Project Timeline


* Note: Dates will be adjusted, based on the conference that I present at, and the status of software development. 15

A spatial representation of Superposed Epoch Analysis results will help paleo fire researchers to spatially resolve the temporal patterns they are seeing. This will enhance researchers’ understanding of :

• spatial variability in fire climate interaction

• the climate mechanisms that drive fire climate interaction

The proposed web-mapping tool will facilitate this spatial representation of the S.E.A. results, as well as enhance visualization and exploration of the results through:

• the spatial representation of the S.E.A. results for all grid cells of gridded datasets via the automation of computations and creation

of interactive and dynamic maps and graphs for every lag

• interfacing with the FHEvent Software tool for assessment and visualization of confidence intervals

Summary, Conclusions and Anticipated Results

Background


Project Timeline


16

Acknowledgements

I am most grateful for the guidance and support of my Advisor:

Professor Alan Taylor, PSU

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Questions ?

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Spatio-temporal Exploration ofPaleo Fire Climate Patterns Using

the Superposed Epoch Analysis (S.E.A.)

spatio-temporal exploration of paleo fire climate patterns using the superposed epoch analysis...

Documents

pdsi values yr

wet pdsi slide

window event year year

dry pdsi neutral pdsi

windows avg yr

pdsi drought data

pdsi time series

time series of pdsi