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<br />FIGURE 1. la} T;m~ scneJ 01 daily maximum fcmpuat"rtl at all fou, Moun/ai" RC$('(Jrch Sltuio" .llef
<br />for /951-1997, lap 11ft (Id), 'op right (8/). bollam I~ft (C/). and bollam righl (DI). Tht! s,ri"s art!
<br />eOnlltICltJ wilh IQWUS smoothing (roblUllocally "',ighlt!d rtgrt!ssion: CI,vdond. J979). Anomolous Jlue.
<br />rua,,'ons at "aeh ,nd "f,h.. uri..s tuist! JJI.. ro IuuuJling of,nd poinu. Gaps ",;rhin rlt, unu aU con"'er"d
<br />wilh straighr li""s, RtUstioruhips disclUUQ i" rht ,,,n ar~ bastd on /in"ar ugrts,ion of 0/1 ser'M"d daily
<br />val...., ogD.nsr riiJU. Missing data or" not included in rh..u rtgr..ssians. (/1) Similar tim.. stn..s of daily
<br />mll1imu", temptralJlns at allfo..rMOlUlrai,. RtStarch Slar"'n siltls (/952-J997).
<br />
<br />1381 ARCTIC, ANTARCTIC, A.ND ALPINE REsEARCH
<br />
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<br />
<br />TABLE 4
<br />ACSO/1l1t Itmp"ratllr" and IDpst ralt ehongts (J9J2-/997) eOr-
<br />u~tion c~ffiei"nlS and slopt
<br />
<br /> P', !'lith'
<br /> S,,..onh) ,. Slope SiB ,. 51_ SiB
<br /> I.onKm'''.. 0,016 0.0134 ." -0.002 -0,0012 "
<br />" AI -O.OlO -0.0256 " -QOll -0000l5 "
<br /> " oms 0,0250 00 O,Oll 0.0110 ,,'
<br /> " 0,0)8 O.026S '0 -0.048 -0.0278 00
<br /> p, -O,Oll -00223 0,0 -O,ij.l~ -0,0329 0,'
<br /> L-ooB"",,,lIAI 0.1179 IH).l\l1 0,0 0021 0.0106 "
<br /> L..mg""""'81 -11,016 -0,1~166 '" -O.OH -0.11117 "0
<br /> L""KmonllCl -O.OSO -O.OIS~ "0 ll.Ol6 0.00\17 00
<br /> L..,.,1l""",lI01 0.056 0,0112 '" OOW 0.0088 "
<br /> UI'P"ICIIDI) 0,2)7 0.0700 '" 0.017 0,0013 ,,'
<br /> Lo.....1AlfBll -0.2M -0.1211 00 -0156 -0.0611 00
<br /> 'SIope&I..-e K'~.n in'C km" ~.-'. ".nllk."". 10..1. in or.
<br />
<br />eninl in the lower !i1ope lapse rale (AI vs BI) is masl marl<ed
<br />in summer. especially from June lhrough AugusI. when a cor-
<br />rclalionofO.452 is oblaincd belweendaily lapserale and lime
<br />(n" 1062). Significanl wcakemng is also experienced during
<br />mosloth<:rlllOnths,boihdayandrught.
<br />
<br />SYNOPTIC CUM/l.TOLOGY
<br />
<br />Asynoplic approach 10 lapse ralechangc can separalelbe
<br />influences of changes in ~lIno~pheric cin:ulation ~uems (be-
<br />Iween-Jype climate change) from changes occurring within alr-
<br />flow Jypes (wilhin-type climale change). The laner are likely 10
<br />have causes m1ginalingoutside the i/nIlltJdialelocale and as
<br />such,arelllO~likelylabeindicativeofglobalclimaticchanges_
<br />
<br />Melhod
<br />
<br />Mast synoptic classificalion methods require spatial pres-
<br />~ure dala, usually on a relular grid. In this study sea-level p~s-
<br />sure values (1013 mb) and geopalential height dala al 850. 100,
<br />and500mbwereoblltincdfora5deglatilUdeby5deglonguude
<br />grid for lhe Northern Hemisphere from \he National Cellle. for
<br />Allnospbcric Research (NCAR) in Boulder. Colora4o. The 25
<br />grid values used in \he synoptic classification method streich
<br />from 50 10 JO"N, and from 115 10 95~. The research siles lie
<br />in th<: cenle. of this arca (-4O"N, 105"W). I experimenled with
<br />extending lhe grid farther weSI. bUI\h.is resulled in domil1\U\Ce
<br />ofth<: Pacific high on lhe synoptic classification wlueh I fell 10
<br />beun<.ksinlble.
<br />Pressure d,"a for each day from 1952 10 1991 were clas-
<br />sified using an objecl1ve melhod hased on lhat of Jenkinson and
<br />Collison (1911) and used by aliler aulhor~ sinee (Jones el aI.,
<br />1993; Goodeu el al" 1998; Pepin el ill.. 1999). The procedure
<br />prudllCessimil;arclasseSIOlhesubjecliveclassllicali"nofLamb
<br />(1912), origilially developed for the Etrilish 1s1e~. combining a
<br />measurc of Isobaric cur va lure WIth one of lIow direclion 10 an"ive
<br />al a synopli<: class.1l1e now direclion (one of eighlpoinls of
<br />the compas~) is combined with isobaric curvalure Which can be
<br />anlicyclonic. cyclonic or slraighl. e.g., anticyclonic north-easl-
<br />e.ly (referred 10 as ANE). An unclassified class means confused
<br />isobaric~nems.
<br />Fourcin::ulalion indices were cal<:ulaled for ea<:h daily grid
<br />(12 Z or 5 am MST) al sea level (l013 mb), 850 mb (roughly
<br />equivalent 10 Denver). 100 mb (at approximately CI), and 500
<br />
<br />'t'\
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<br />c,
<br />Cookng l~ Daytime
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<br />Warm"'9 bll~
<br />WarmLng at
<br />concenualed 1~
<br />alClallabl 1~
<br />
<br />LONGMONT
<br />
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<br />Willm~ :';~
<br />Warrroll9 ~-
<br />eoro:enlraled Allal
<br />Slbl ~
<br />LONGMONT
<br />FIGURE J. Carletp/lUIl summary of slgnifieam absol,,/t and
<br />rela/iv, /empera/"re c/u;;,ngtS 01011 si/tsfrom 1)152-/997. nlt
<br />twO diasrams relau la doy/lmt (m=imwn Itmptraturu) and
<br />nigh/lime (minimum /emperal"us). Venical arrows are /WI 10
<br />KQ/~.
<br />
<br />mb (well above \he highe$t Front Range peaks). Conslants in
<br />\he index algorithms lake accounl of lhe huilude (Goodes$, pefS
<br />comm., 1998). The S index measW"es southerly now ~treng1h.
<br />being slrongly posilive forslrongsou\herlyairilowandnegalive
<br />for northerly airflow. The W index measures westerly !low
<br />slrength. The F index measures 10lal flow streng\h. calculaltd
<br />wough resolulion of Sand W. a,,;d ~s high if \h~ cir<:ulali"n IS
<br />
<br />on.,,,.. . '0" ~".
<br />
<br />N'O"'''~' "0" 0".
<br />
<br /> 0
<br />0 .,
<br />0
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<br />j '"
<br /> "
<br />
<br />~{)\ TT-
<br />., , I" I j.
<br />VIII V I \jY 'f \r"
<br />~t-c\- -i-
<br />V< I I VI'^ \vk\
<br />
<br />1~" l~O l<'''' '01" ;~~ '980 '9~' ..00 100.
<br />
<br />FIGURE 4. Mtan onnllal "pper slape ICI VtrSllS DJJ lapu
<br />role (J952-/997). Bo/h da)l/ime laps, raft (crrelts) and "rghl'
<br />lime lapse raU (/rianglu) art sho",,,. Ulpse ralU ar" ntga/ive
<br />os u",ptral..rud<ler"ase with ~leVGlian.
<br />
<br />N. PEPIN I 139
<br />
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