the ‘detrended’ring-width

index

October 18

The linear aggregate model of tree growthOctober 30

Signal processing I

Cat Mesa (NM556)

Abouselman Spring (NM555)

Baca (NM558)

Fenton Lake (NM550)

Rito de los Frijoles (NM501)

Los Alamos New Mexico (NM046)

DOWNLOAD THESE DATA

h!p://www.ldeo.columbia.edu/tree-ring-laboratory/resources/so"ware

TREE-RING WIDTH DATApith

bark

Rt = At + Ct + δD1t + δD2t + Et

THE PRINCIPLE OF AGGREGATE TREE GROWTH

Rt = At + Ct + δD1t + δD2t + Et

size-related growth trendcaused by physiological aging

THE PRINCIPLE OF AGGREGATE TREE GROWTH

Atdoes not have a universal or predictable shape.

STANDARDIZATION

the ‘detrended’ring-width

index

ARSTANautoregressivestandardization

PROGRAM ARSTAN

PRODUCES CHRONOLOGIESFROM TREE-RING MEASUREMENT SERIES

BY DETRENDING AND INDEXING (STANDARDIZING) THE SERIES,

THEN APPLYING

A ROBUST ESTIMATION OF THE MEAN VALUE FUNCTION

TO REMOVE EFFECTS OFENDOGENOUS STAND DISTURBANCES.

DIVIDE(A) the raw ring-width databy (B) the ‘detrending’ curve

ARSTAN OUTPUT

CHRONOLOGY

Use several di#erent detrending methods to standardize our set of ring-width chronologies

EXERCISEand let’s see what happens!

Cat Mesa (NM556)

Abouselman Spring (NM555)

Baca (NM558)

Fenton Lake (NM550)

Rito de los Frijoles (NM501)

Los Alamos New Mexico (NM046)

STANDARDIZE THESE DATA

Horizontal line

Negative exponential curve

20-yr flexible spline

Flexible spline set to 67% of series length

USE FOUR DIFFERENT APPROACHES TO STANDARDIZATION

Source: Terry Bain

WHO WILL FIND THE FIRST

“DIRTY DOG”?

GEOG5839NEXT CLASS