Geoscience Reference
In-Depth Information
SOI.in.both.analyses..Examination.of.the.location.of.these.sites.(Figure 9.3).shows.
that.each.of.these.sites.is.located.well.within.a.region.dominated.by.correlation.with.
the.SOI..That.is,.they.do.not.lie.near.a.regional.boundary..None.of.the.other.catego-
ries.exactly.match.for.both.classiications..At.the.AND.site,.the.station.data.fell.into.
a.class.dominated.by.the.PNA.and.SOI.patterns,.whereas.the.region.includes.both.
of.those.modes,.plus.the.PDO..This.precipitation.grid,.in.which.the.AND.station.is.
adjacent.to.a.small.region,.is.dominated.exclusively.by.the.PDO..The.disagreement.
between.the.two.classiications.may.be.an.artifact.of.comparing.a.gridded.data.set.to.
a.point.observation..The.AND.station.may.therefore.be.representative.of.a.somewhat.
larger.region.that.receives.some.inluence.of.all.three.circulation.modes..Although.
located.in.a.different.climatic.setting.(midlatitude.mesic.versus.coastal),.the.KNZ.
and.KBS.sites.show.a.similar.pattern.of.association.to.AND..Again,.both.sites.are.
located.in.the.boundaries.between.classiied.regions,.and.thus.may.be.responding.to.
ine-scale.variations.in.climate.inluences.that.are.lost.when.the.precipitation.values.
within.a.0.5°.×.0.5°.region.are.gridded.
Among.the.four.circulation.patterns,.the.PDO.occurred.much.more.commonly.as.
a.signiicant.correlate.in.the.gridded.data,.compared.to.the.station.data..For.a.number.
of. sites,. including. BNZ,. KNZ,. KBS,. and. VCR,. the. PDO. was. the. most. signiicant.
classiication. variable. in. the. gridded. data. set,. but. did. not. contribute. to. classifying.
the.actual.station.data..Again,.examination.of.the.location.of.these.sites.shows.that.
each.lies.nearby.a.different.class,.suggesting.that.scale.effects.might.be.affecting.the.
classiication..In.particular,.the.BNZ.site.lies.within.a.small.region.of.dominance.by.
PDO/SOI,. which. is. embedded. in. a. larger. homogeneous. region. dominated. by. SOI..
Only.SOI.emerged.as.a.determinant.of.class.membership.in.the.station.classiication..
Only.one.site.(HFR).had.no.common.signiicant.classiiers.between.the.two.analyses..
SUMMARY
The.major.goal.of.this.chapter.was.to.determine.how.geographically.representative.
the.precipitation.climatology.of.each.LTER.site.is,.using.four.well-known.circula-
tion.indices.as.the.basis.for.regionalizing.climate..The.results.of.the.analysis.are.not.
simple,.but.in.general.suggest.that.while.the.precipitation.regime.for.the.grid.cell.in.
which.most.LTER.sites.are.located.responds.to.climate.circulation.modes.in.a.way.
that.is.consistent.with.the.region.in.which.they.are.located,.the.values.for.the.station.
data.associated.with.each.site.present.a.much.murkier.picture..Of.the.four.indices.
used,.the.SOI.has.the.largest.overall.inluence..This.relects.the.fact.that,.with.the.
exception. of. the. NAO,. the. other. circulation. modes. are. thermodynamically. linked.
to.it.
In. evaluating. these. results,. it. is. important. to. keep. in. mind. that,. as. in. any. cor-
relative.study,.it.cannot.be.said.whether.a.particular.circulation.pattern.determines.
the.response.at.a.place,.or.whether.both.the.pattern.and.the.response.are.related.to.
some.other.process..In.climate.research,.teleconnections.between.circulation.modes.
and. climatic. responses. are. widely. studied,. and. modeling. has. provided. theoretical.
grounding.for.the.empirical.relationships.between.circulation.modes.and.some.cli-
matic.state.variables.(Lau.1985)..It.is.also.important.to.consider.the.nature.of.the.
comparison. being. made.. Recall.that. the. cells. for. the. gridded. data. are. 0.5°. ×. 0.5°,.
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