Trends in Rainfall and Temperature in the Peruvian Amazonandes

CP 7091 Lago Sul, 71635- Sul, CP 7091Lago 6 75252. ParisCedex05,France. 5 4 Belin,Edouard F 3 s/n LaManagement. Av. Lima Universidad Molina, 12. 2 * [email protected] Perú. 1 RONCHAIL CASIMIRO LAVADO SVEN WALDO over the 40years last (1965 Trends in rainfall andtemperature thePeruvian in Amazon Geosciences Environnement Toulouse (CNRS, IRD, Université de EnvironnementToulouse, Geosciences OMP),IRD (CNRS,IRD, Université Toulouse del Geofísico Instituto Badajoz, Ate (IGP). 169.Mayorazgo, Perú Calle Vitarte. SENAMHI, Nacionalde Hidrología, Servicio e 11Meteorología Casilla 1308,Lima 11, has notbeenhas through the copyediting, typesetting, pagination andproofreading process articleThis beenacceptedhas for publi this articlethis as an‘Accept maywhich todifferences between version lead andthe this of Version cite Record. Please UNALM; Lima Peru Lima UNALM; Université Paris 7et LOCE Accepted ArticleGeosciences Environnement (CNRS, Toulouse de IRD, Université Toulouse, OMP), 14Av

5 , JHAN CARLO ESPINOZA CARLO , JHAN - 31400 Toulouse, France. 31400 Toulouse, . PhD ProgrammeWater in Resources. Water resources engineering & ed Article’, doi:ed Article’, 10.1002/hyp.9418 971 Brasilia DF, Brasil.

AN (UP6

- 2007). - CNRS cation cation and scientific undergone full peer review but

4, 2 4, - IRD

- MNHN), Boite 100, Jussieu, Boite MNHN), 4 Place , DAVID LABAT , DAVID

- 3 Andes basin ,

Lima Peru. JOSYANE JOSYANE

change, Peru, SST.change, ENSO,Atlantic wordsKey events. events. On the contrary, the interannual temperature variability is mainly related to ENSO the tropical Atlantic Ocean while there are limited relationships between rainfall and ENSO important interannual variabili period occurred m the changes Finally, in over trendslocated the Andesregion. positive are data. Though,high a considering average decade meteorological time series. 1965 over the stations years. over twoseries PeruvianAmazon temperature (Tmean),maximum temperature (Tmax), andminimum temperature (Tmin) time and ofe originalextended analysis temporal the co Accepted Article rresponds to . However, annual, summer autumn and rainfall

I This analysis based is on a new The hydroclimatology ofPeruvianAmazon the

is n the PABn the

earlier inTmax

detected over there : Amazon basin, hydroclimatology, rainfall and temperature trend, climate trend, hydroclimatology, temperature basin, and climate Amazonrainfall : 7 % of% Amazon still poorlythe basin documented.is We propose here an , there - 2007 period and we focus our attention our we2007 and focus period (during 1980s). than Tminthe (during in 1970s) (during

is neither trend neither is A positive significant trendin of mean 0.09°C per temperature ty ty that associated is with the sea surface temperature (SST) in gion with similar values in the Andes and Rainforest when when the Rainforest in Andesand similar with values gion - Andes basins (Huallaga and Ucayali) over the last forty and morand Abstract nor mean

- change change volution rainfall,monthly ofmean - Andes basin (PAB) which surface in in southernthe Andes in rainfall, during the rainfall, 1965 in

on both annual and seasonal and annual on both

presents an ean ean values values - 2007 1974 and 19981974 and 0.10– AcceptedGlobal Historical Climatology Network in ofAndean regions PAB recently, respectively.1981 periods More water levelspositive trends in Iquitos Pucallpa and stations during the 1955 with deforestation. Their results were 1978 interval(compared the to 1961 identi shortperiodsobservations regarding ofinstance, time. and For Gentry Lopez dedicated to PAB. the 1998, al., 500mbelow a.s.l.). Articleorganisms (Pulgar naturalists and by topographically distinguished the not 500mbyPeruviangeographers only isohypse a.s.l geochemical and biologic parameters relatively flat lowland plains to the East being limited new ona extende Andes basin (PAB) based INTRODUCTION 0.11 °C per decade0.11 °C per between 1939 1998, and of and 0.32 fied significant rainfall decrease in 3 out of 8 PAB weather stations T The PAB is located in the western part of the andAmazon basin is This paper presents an analysis of recent climate changes over thePeruvian Amazon rends rends

Cost such as

by steep tall and (up 6000m to studies i

a anda Foley, 1999 that corresponds to a a to corresponds that UNESCO

- n Amazonthe mainly focus basin onthe Brazilian region et (Marengo Vidal, 1998 and Brac 1998and Vidal, The last ones are often based on a small number of stations and on

the mark of glacier mark Bradley Vuilleand the usingevolution. of the (2000) glacier

( 2006): the Andes (~ over 500 m a.s.l.) and the Rainforest (~ (~ Rainforest m the and 500 over a.s.l.) Andes(~ the 2006): , - Marengo, 2004Marengo, among others) 1969 reference period) and associated these differences may may tripling ofwarming the during rate the 25last years.

then discussed by et Nordin al. (1982) who found data show be progressive d climatological database. database. d climatological comprehensive studies have been realized in the

k and Mendiola, 2004) but also byinternational k andbut 2004) also Mendiola, (80 m a.s.l.)

a warming trend in the tropical Andes of Andes the in tropical of warmingtrend a ) mountain mountain the) ranges to west by and

in between, two regions tworegions between, in . Though changes in in Thoughphysical, changes – 0.34 °C per decade0.34 °C per between ;

while

during the 1970

- very contrasted, few studies are are studies few 1979 and 1957 - Parodi (1980) are usuallyare - - - 2000; IGP, 2005, Espinoza et al. 2009 et al. IGP, Espinoza2011). 2005,Espinoza and et 2000; specificallyPeru in 2011b al. Marengoet 2011a, al. et 2009,Yoon et Zeng,2010, Marengo and al Espinoza 1992 Marengo, and the SST in the Atlantic Ocean atmospheric indexes, such as the Southern Oscillation Index (SOI) al., 2011). et c.f. Espinoza last extreme documented the 2010drought the decades (e.g.2005and in to 1998; values low runoffand diminutionin westernAmazonas are related to high valuesduring 1970sthe and stationUcayalibasin meteorological a located the 2000 periodin in 1960 annual precipitation for in the also downward a trend (2006) et identify Haylock al. corroborated by a similar one in the discharge of theAmazonas Tamshiyacu at River . the in Peruvian period 8.3%decade al. a (2006) per et describe downward trend in 1970 over meanthe rainfall te decade1964 per the over basin basin), Mantaro Ucayali IGP (i.e. the (2005) outlines a trend decreasing rainfall of 3% PAB our In conditions. drier toward slightly tendency is there generala where Peru southern being PAB,exception only the the trendover rainfall 1950 the Vuille et al. (2003), Accepted Article the 1965 minimummperature during notrendforand temperature region: the region: contribution Also, Also, - 1994 temperature a interval

Uca , we focus ourwill attention on twolarge basins representative and of the ( based oni Tapley Waylen, and 1990; Rome yali and Huallaga basins (figure 1).Studying the high mountains of the mountains highof (figure 1).Studyingthe Huallagabasins yali and more recently , in put similarevidence in trends temperature and non a - Ecuadorian Amazon basin using 237 rainfall stations; t 237 using stations; rainfall AmazonEcuadorian basin - 2003 nd fluctuations rainfall n situ and Climate Research Unit (CRU) datacollected over in many in regions of (Aceituno, America tropical South 1988; interval Ronchail et al., 2002,and et al., Camargo,Ronchail Marengo 2008, , of positive fora trend decade 0.2°Cmaximum per

in in the Pacific Ocean and - . In fact, strong rainfall 2002 on large interval - scale his trend is - . signifi Espinoza

, ocean Kane, Kane, - ) 1997 1997

cant and and - - shows the spatial distribution shows the of77 in the stations Acceptedarestations located 77 Among the the in included et al. foundbe Farr (2007) in availabledata is 3 at arc second (~ 90m resolution). A detailed Topography the Radar Shuttle Mission through Administration (SRTM). (NASA) Elevation Digital Aeronautics (DEM)on the and providedbythe Model National Space basins area Basins areas respectively are 89 654 km the Rainforest region, and the Ucayali basin, with 50% of its total area located in each region. the Huallaga basin, with 75% of itsArticle total area located METHOD AND AVAILABILITY DATA temperature stations numberof rainfall higher Bradleyand ( variability. Ocean and the SST in theAtlantic and Pacific Ocean, in order to explain the climate atmospheric indexes temperature Amazonthe basin, This study study on This is from based data 77conventional meteorological stations on focuses Our study the twomainof Peru basins thatare partof the Amazon basin: Th is study study is In particular, we aimthe formerespecially complement works, study to corresponds to almost 7% of the entire Amazon basin. Amazon entire basin. the of to almost 7% corresponds . station This analysis is 2000), Vuille et al. (2003), or Espinoza et al. (2009), weather stat Peruvian Meteorology National and Hydrology Service SENAMHInetwork. present the data stations).(48 in in

in order fluctuations the Huallaga 53 and the Huallaga basin ions, 58 stations provide rainfall data and 48temperature and data providerainfall data 58stations ions, .

first detailed to to estimate rainfall trends andmeans change in rainfall and then then , such as the Southern Oscillation, such the as Index (SOI) relate than this last author d 2

regional regional ofclimate of poorly a documented region and 350 287km 350 and statisticallyand physically

(Fig. 1a), and(Fig. sum the of both

description of DEMcan this Basins subdivision isbased the basin.the Ucayali 1b Fig. but but to using a significantly ausing significantly large

- in in thePacific scale

(Table 1), (Table 1), including by Vuille by Vuille

SRTM SRTM ocean ed ed ;

24 in in - ,

climatic variables. described by 2000):al., mean and identify trends workto are used this in tests does not affect rainfall of forregion (14 rainfall and for 11 temperatures) thismayand produce over or underestimation 37for and temper for rainfall (44 Andesregion the over are of located that stations 2005).percentage note high Onea should (Vauchel, software based is method Hydraccess interpolation ofclimatic onKriging variables through the Method Brunet 1977and Vector (Hiez, Regional geographical stations database. both criteria. through mismatch detected is physiographicdiscardedif zone).a similar Thedataonly is out values are those that exceed the third quartile plus three times the interquartile range. Suspect months; temperature doubtful arefor computed suspect boxplot graphics plots, monthly methodology A procedure for quality analysis in temperature data is first applied temperature

Accepted Article values comparednearby valuesstationsliers in (over to are ofcorresponding period the - As rainfall series are not always normally distributed, two statistical distribution Rainfall and temperature

The Mann

Missing values or temperature )

data data developed Burn and Elnur (2002) as mostthe commonly for used detecting trends in Missing values including discarded data represent less than 5% the forthcomin

are available monthlyat from 1965resolution December January to 2007. - Kendall Kendall (MK) nonparametr

data by Vu when we focus onspecificgeographical zones,this but asymmetry . Rainfall over thedata 1965 were filled by a multiple correlation method g local g local ille et al.

(i.e. mean (Tmean), maximum (Tmax) and minimum (Tmin) scale analyses. (2000) . After a visual detection of suspect outliers in in outliers detection of suspect visual . Aftera ic trendic test (Mann, 1945and Kendall, 1975) Copyright ©Copyright Wiley 2012 John Sons, Ltd. & - Moret, 1979,Moret, atures) when compared to the Rainforest

- - changes in climate series (Robson et 2003 periodare validated using the Espi noza et al., 2009 al., et noza based onbased following the following the

of the total total the of ). ). nearby -

The The free free masl) and the Rainforest 500 Rainforest (under masl)masl) the and, and climatic evolution will be analyzed at a regional scale 300 hPa( derivedhumidityflux is from specific the and ground horizontal windbetween the the and These data NCEP 2.5using the x2.5 degree resolution horizontal vertical and winds and humidity data from significant correlations ofindex the the SOI, or SST (NATL difference Administration. fromClimatic the Prediction Centre of the US Nationa the in feature to computedSST SATLgradient and is tropicalAtlanticsouthern (SATL, 0 (1965 data (SOI) that is the standardized pressure difference between Tahiti and Darwin, monthly SST (June winter summer (December Temporal series are averaged over five periods: the year from January to December, austral statistical tests is rejected for mean T temporal series. he he

Accepted Article significancelevel ( - changes when none is present (Robson et al., 2000). In this study, study, this In 2000). (Robson al., et present is when none changes – Since both basins are characterized heterog are byhighly basins both Since Several regional climatic indexes were used: themonthly Southern Oscillation Index - NCAR reanalysis

the Pettitt (PT) non Peixoto and Oort, 1992) Peixoto Oort, and – were obtained fromNOAA the data server. The vertically integrated water vapor 2007) for the2007) northern tropicalAtlantic (NATL, 5 - July-

Then, t August - January α he ( ) is assumed is ) to be the probability that atest detects non α noted noted (

Kalnay et al., 1996 Kalnay al., et coefficients equal to 0.05) 0.05) to equal - February - parametric test (Pettitt, 1979) formean α JJA) and spring (September spring and JJA)

equal 0.05 equal (i.e. statistical significance the95 at – 20 °S, 30°W

noted DJF noted of correlation highlighted. we provide also amore scale local )

- ), autumn), (March to to describe theatmosphere characteristics. SATL) are SATL) are computed stations the and with Copyright ©Copyright Wiley 2012 John Sons, Ltd. & – 10 °E). The difference between the NATL the NATL between The difference 10 °E).

the Atlantic

but between Climate variability is also analyzed

distinguishing the Andes (over 500 thedistinguishing Andes (over - October eneous climatic conditions, conditions, eneous climatic l Oceanicl and Atmospheric –20°N climate

basin. All theseindexes are - April - Novem , 60 the -

- change detection inchange detection time series

May null hypothesis in hypothesis null – ber 30 °W) theand

noted noted noted noted - null trendor

analysis. level). % and and MAM), SON). the the the

(1990) and(1990) Espinoza (2009)et whoal. find peak a at around 1000m and (1976),Nobre Figueroa byJohnson whole a as Amazon describedthe basin been in the altitudeand betweenand linearity rainfall 500meters. above mm thanyear 1000 per often less eastern the vapourofof first over the water slope contrary, Andes. On annual the rainfall is linear (Figure 3c). apart. San f fromprotected moist airadvection. is This consistentwith et Espinoza (2009) whoal. data over arelief with northward exposure recordedin Aguaitiastation thein Pachiteavalleys on the h and therefore oriented towa veryannual rainfallrecordedthe high valleys particular, in directionof is in opened North duerainfall topographyto and theto exposition of the stations are noticeable on mountainous(about 1025m regions southern and regionslowland Annual Vizy 2003; Cook,and 2007). 1987;Rutllant, Vuilleet al., 1998; Chaffaut 1998; et al., Garreaud,1999; Garreaud et al., origin predominantly is moisture Ocean the Atlantic the and (FuenzalidaAmazon and basin Most rainfall is p CLIMATE REGIONAL ound

AcceptedGabá Article

high rainfall gradients over gradients over with this zone rainfall high

Rainfall tends to decrease when altitude increases but th cumulative cumulative n regions regions station station with roduced by convection in in roduced byconvection 2003)the PAB (Garreaud al., et the region and s Abundant rainfall at low altitude is related to the re uch and and 530 mm /year rainfall rainfall very highis in north and the the of centre PAB, about 2235mm/year

as theHuallaga high valley located

rd the humid trade winds ( winds therd humid trade ) . Th ese values recordedthe at

( table 2). Rainfall decreases toward the western presence of arainfall peak low at altitude have

Copyright ©Copyright Wiley 2012 John Sons, Ltd. & m/year), but local maximumminimum local but and m/year), contrastwith rainyless for instance 6000 mm/year 6000 instance for Similar results showing the absence of Paucartambo

for example 4160 mm/year are mm/year are for example 4160 on lee a side isand consequently igh Ucayali, or along massive massive along or Ucayali, igh is

asl station ,almoststation relation appears asnon lease of high quantity quantity oflease high . In Equator. In annual cumulative cumulative annual especially recorded at at recorded f igure 2. In ,

the peak 110 km in also

the th e

temperature is much lower in the Andes during the night than during the day (Figure 2c and and the2c (Figure than day Andes the during the night in during muchtemperature is lower highsouthern Andes.The eastern boundaries with Brazil while the lowest measured are in the south temperature values (more than 25°C for themean annual temperature) are an highlight April from to one rainyfrom drier a very and Octobera January (Figureperiod to June 4e). a Equator (Garr winds that alloweasterly upliftmoisture ofupper the fromthe Amazon the Andes towards coupled austral summer drivesvapour in Amazon toward water the basin that System Monsoon American (SAMS) is marked related to seasonality the warming continent to and ofthe the oftheonset South season from May to S tropicaland The one south 2009). a mountainous et dry regimea al., first is with Espinoza respectively 2). (table Two regimes coexist over theHuallaga and Ucayali basins (see values ofannual 24% and the 11%, 1 by i.e. usingproposed StreckerTRMM Bookhagenand data, (2008) on depend Zongo the Bolivia in valley ( 1990, al. et Bolivia(Roche or 1992) locatedis at 700 around Acceptedquasi Article eaud 1999)eaud - The The ofaround28%, 38%, region represent whole rainfallstudy the valuesin Seasonal permanent moisture and heating availability It . in the Andes thein

corresponds to a a tocorresponds th

temperature east east e location of location e and to its demise in winter (Zhou Lau demiseand winter in its to and . – The second The second west and north and west eptember and a wet season from December to March (Figure 4c). The together together - spatial spatial 800 m most severe the the lower impact regime a Ronchail Gallaire and 2006). These altitudes rain gauge gauge rain fluctuations with the sl -

south gradients not by Laraque et al. (2007), inas Venezuela Pulwarty et( al.

is observed in low and northern regions close regions the to northern lowand observedin is Guyot spatial

considering considering presence of the upper level BolivianHigh of and of onset and the demise ofSAMS the and

stations appear in direct relationship with elevation

that are generally lower than that the but a little higher,around little a 1200m but directl summer, autumn, winter andsummer, spring autumn,winter correspond to explain explain y , 1998). features These also are related to latitude. The latitude. highest to related less rainfall se 300 masl Tmin recorded

fluctuations and fluctuations .

asonality with - that strongly that strongly western and western and along the along the asl value value , in , in and and to to

plotted in the in f plotted level significant ofstatistical 0.05. 1965 the over TEMPERATURE AND PRECIPITATION IN TRENDS TEMPORAL during than within Andes density inlowlands lesscloudthe consistent cover than the different radiative characteristics that have been commented before. All, these results are Andes the pronounced in (about4°C) inlowlands 1. than the (about cloudy and rainy season. Theannu the before winter Tmaxhighest of the nebulosity lack season, radiation and temperature elevation australrainy summer,thean in the nebulosity season, avoids intense Andes.Indeed, the observed in usually tropical regions This(Table 2). is also observedfor Tmax 4f) and (Figure lo alsothat explain nebulosity in differences These lowlands. differences nebulosityin may thatTmax explain whereas drop in temperature in the Andes, especially in winter, where thesky remains often clear 3c).figure The stronger Tmin This 2). table and 4c 2d, figure Accepted Article in wer (about10°C the lowlands

(about The existence ofmean trendsand donot Tmin variables The Tmax and it is always somewhat cloudy in the lowlands (figure 4d). On the contrary, the contrary, On 4d). the lowlands (figure the in it somewhatcloudy is always summer, and finally during night during night time time.summer, day finally and during than - - 0.54°C per 1 igure 5. igure 2007 interval, is examined using Mann Kendall and Pettitt respectively with a Pettittrespectivelya and with Kendall Mann using examined is 2007 interval, values the the annual amplitude (about 1°C) is much 1°C) than annual lower amplitude(about is

are observed October in November, and after sunnythe but “cold”

Tmin 00 m, figure 3d) than Tmax than 3d) figure m,00

temperature gradient may be related to the important radiative

leads to allows a good solar irradiation and heating. However,the irradiationheating. and allowssolar good a )

than in in than the Andes (about15°C)(f Results are reported in t ,

while a more more - change change significantly , on contrary, the pronounced pronounced Copyright ©Copyright Wiley 2012 John Sons, Ltd. & in in temperature recordsat regional scale, data variations ( variations vary during the year inlowland the year during the vary

differ between less Andes and temperature gradient

al amplitude of Tmin more is temperature able 3and able the i n winter n about igures 4d and 4dand igures 4f). the the 5°C), becauseof the -

daily amplidaily

0.48°C per 100m, daily amplitude is and duringand

which iswhich dry the timeseries are

flucutations considering considering tude, as as tude, winter

in in with significantwith positive negative or trends in mean summer, annual, autumn,and winter Accepted or in stations mid- who findchangethe a (2000) in 1 Cthe in 0.2º the mid systematically not occur and during Andes,changes are synchronized the over Tmax), while eighties beginningof the and end the ofseventies at the characterizedbychanges systematically more much pronounced trend is significant positive trends over the Rainforest region during all the seasons, but fluctuations Article and (0.15°C/decade) °C per(+0.1 decade). in trend upward an (2009) who al. find Bradley et with accordance theto value found byVuille et al. (2003) region.The+0. whole precipitation inthe Andes of Per 1994 interval,5stations ofout 42(2) highlight significant increase (decrease) in the annual (2003) Based on the Mann After this regional analysis, we propose asystematic analysis of the data from the77 the Moreover, Andes, the In Tmax strongsignificant timeexhibit trends series Annual Tmean time series exhibit in large majority positive significant trends over the rainfall seriesThisRegional is notrend. exhibit results that indicates that annual precipitation thein Andes of during the Peru 1950 -

seventies as well as latter on (+0.04 ºC anomaly on 1981- ºC during the welllatter (+0.04 as seventies (+0.15 of ºC anom . In the Rainforest, Tmax . Rainforest, the In der tohighlight localized effects over this region. 965- 1980 for Tmax). This is partly in accordance with Vuille and with Bradley accordance Vuille in partly is This 1980 for Tmax).

in spring (0.13°C/decade) while they are much they (0.13°C/decade) while lower spring in

9°C per decade trend value obtained for Tmean time series is similar temperature - Kendall test, figure 6 highlights the spatial distribution of stations aly in 1981 in aly in summer (0. u during the 1950-u during seventies formean temperature in the Andes.

variability in the Rainforest increases only during winter. Tmin time series exhibit exhibit Tmin time during winter. series increases only - 1995 comparing for the eastern slopes of the Andes and it is in 15°C/decade). Copyright ©Copyright Wiley 2012 John Sons, Ltd. & 1994 interval

in accordanceetin with al. Vuille to to

- 0.2º C in1965 0.2º the .

the (table 3) 3) (table

1995 comparing to to 1995 comparing freezing lineheight freezing considering this posit in summer summer in

- 1980 for is quasiis Tmin ive ive - -

Tmax and Tmin may be related to the diminution in humidity observed by Vuille et al. (2003) al. (2003) et byVuille observed thehumidity to diminutionin mayrelated Tmax be Tmin and for timings different These eighties. during and the ofstations) 30% the seventies (in the AcceptedTmin. On the otherhand, mean 1990 interval(in aboutof 30% theand latter stations) also on, during p last the 1991- stations 2007.Mean- 1991to 1990 and on 1965temperature 1980,1981to timeclassified 1970,1971to four series, timeto intervals: out winter(11 7k,region in (Figures m,of l, o). 48stations) nand the percentagein whole oftrends tosmallest a positive Tminwith but applied be remarks can region, Rainforest out(Figures tablethe and (9 In of7f,j in and 4). 37stations) g,h,i frequent winter Articlefreque Rainforest). of the 5out Andes and 11in spread sea or as when considering similar annual distribution appears mainly 4). positive overare theirtrends and theSignificant spatial twobasins(Table all corresponds 40trends ofstations to distributed 50% the to of 22stations (~ out 48stations), significant exhibit that of stations Thenumber e. dand b,c, 7a, Figures in depicted table 4). spring rainfall. 2007 interval for annual series 2007 intervalforregions. annual series both in nt innt ofsummer out 48 (19 especially stations), in Andes, theythe while are less

Tmean and Tmin time series exhibit significant mean Table 5 reports the percentage of stations with significant mean The spatial distribution in in summer asthey are

a few cases of negative trends are observed, especially in summe Positive trends also are observed in Tmax (about 10%), mainly during the 1981

For all seasons, there are very few stations with a significant trend also(see changes consisting indecreasing rainfall, are observed ina few put in evidence in 27 out of 48 stations (22 out of 37 in the the in (22 of out stations 37 in of in27out 48 put evidence

- of of change inchange Tmax time series sooner, mostlyoccurred during stations with

- 1990 s Copyright ©Copyright Wiley 2012 John Sons, Ltd. & ignificant trends in Tmean time series is ( 17 out of 48 stations) and and also more ofare 17 out 48stations) interval - change mostlythe 1981 change over in in Andesthe and during the sonal series. - chan r and winter. Similar ge in and rainfall They are widely eriod, for for eriod, Tmean -

2 LaNiñaduring eventsas authors previously (Aceituno shown byvarious 1988,V Andes northern and central during and scale observed in the La Plata basin (see Aceituno lowlands the in duringrainfall LaNiña spring 8a events (see Fig. rainfall). of extreme with the studied the region of during El more rainfall south less Niño eventsand al., 2012 et 2009, al., et al 2008; 2008,Espinoza et al. Lagos Silva et 2003; Waylen, Rome 1990; and thereducing uplift of moisturefrom Amazon the basin to the A disturbing reinforced, and is upper circulation level western Nino,the El during that who find Elduring Niño eventsand more during abundant La Niña, in accordance with Nino events Fig.(see 8a, summer rainfall). These results suggest that rainfall is less a Ucayali basinsouthern (Andes especially region) during the rainyseason,peak at the of El figure 8and figure 9. in depicted NATL INDEXES OCEANIC L AND TEMPERATURE AND RAINFALL BETWEEN RELATION time day and it temperatureactsnight. elevation waywhile opposite during an the in the secondduring half ofXX the 003, among others 003, among Accepted Article - Tmean timeseries appear asnegatively correlated with SOI, especially at annual time Rainfall appe The coefficient SATL are computed and the stations with significant correlations ). However, in spring,this rela

of Bolivian Amazon basin (Ronchail and typically and 2006) is and Gallaire (Ronchail Amazonof basin Bolivian summer and autumn seasons, in a large number of stations .). Therefore, as the impact of ENSO on temperature is particularly strong is Therefore, particularlystrong .). as impact temperature ofthe ENSO on ars as positively correlated with SOI in a small number of stations of the s

of correlation between rainfall or

Gaspaldy and Ronchail, 1998; Vuille et al., 2000; Vuille et al. et 1998; al.,Vuille 2000; Vuille Ronchail, and Gaspaldy region

. Tmean valuesare higher during El Niño events lowerand century. Indeed,century. diminution a in humidity favors insolation tionship is reversed some in intra , 1988since many and then). others Copyright ©Copyright Wiley 2012 John Sons, Ltd. & Tmean time Tmean This signal has also been

Lavado et al., 2012, Espinoza 2012,Espinoza al., et Lavado ndes ndes (Aceituno, 1988; Tapley (Aceituno,

series series ( α

equal to 0.05) to equal - ARGE Andean stations and the and

located many authors

uille et al., -

reported reported SCALE SCALE

bundant SOI, or in the the in are are Peruvian Amazonas River accordance rainfall fluctuation In alrecent Espinoza(2011)and et about hydrological 10b (Figure This 10d). and has beenby also commented Marengo et al receives a of center meaning towardthe and the AmazonAtlantic, oriented basin vapor 10aflux is is southernanomaly water warmer 10c),Atlantic the and (figures the than tropical northern when the show that MAM. Theyclearly 10dfor and 10c figures and for DJF SATL and negative anomalies NATL autumn in and 8b). (Figure s basin number second change in the the century. ENSO halfof20th the during Vuille alapproach, et greenhouse gas concentration increase in the terrestrial at et(Mantua 1997) 9a).al. (seeFig. It seventies ( may be associated with the stronger frequency of Elevents Niño since the in the Andes, the observed Tmean significant positive increase ignificant

Acceptedconsequence, NATL Article . R Rainfall time series appear The SST and the water vapor flux differences between seasons with positive NATL of stations ainfall is more abundant when NATL SST is low compared to SATL SST to compared more when NATL is SSTlow abundant is ainfall Trenberth 1994) and Hurell, lower

correlation between these variables is with Espinoza et al. (2011) who explain the th the extreme in recent (2011) who al. explain droughts Espinoza et with

quantity of water vapor than usually and and a in than explaining reduction rainfall usually vapor ofquantity water located than SOI in Andeanthe upper basinsof the Amazon Peru. in This is in . (2003) shows that a great part of the temperature elevation is due to of great a is theto due part temperature(2003) elevation showsthat - SATLfluctuations SSTappearto more a be

(1995, (1995, in the southern south and

as 1998,

negatively correlated wi - may SATL anomalies are reported in figures 10a and 10b 10b 10a and figures in are reported SATLanomalies together witha 2005 and 2010) and with Silva et al. (2008) for the (2008) for the al. Silva et with and 2010) 2005 and

also also relatedbe toglobal the warming to due the

Copyright ©Copyright Wiley 2012 John Sons, Ltd. & observe extreme events thein Amazon basin. - western Andeanregions of the Ucayali change in Pacific Decadal Oscillation mosphere. Thought, mosphere. using modela d annualat time scale, in summer th NATL th

( figure( over 7) the region - SATL SST in a large large a SSTin SATL . decisive

(2011a and(2011a 2011b)

that

end of the forcing

the PAB

and and for for e -

mid elevation of temperature coincides with a change in the Pacific Decadal Oscillation in the Tmax the in Andesand Tminin the in Rainforest (1.5°/decadeboth in cases). Moreover, 2007 al., et Christensen 100years, last over the decade per 0.07 °C warmingestimations of global (~ the 1939 the estimation is close to the 0.10 +0.09°C is about decade rainforest, per clear trend workalso documents43(1965 This last changes climate during the years rainfall and tem CONCLUSIONS NATL seems themo to have Atlantic in favor daytime.the temperatureevent duringnorthern that high the (s usual than colder Atlantic Ocean SST NATL with etduring the 1960- (2000) by Vuille al. 1970- -

seventies and a change in the frequency of El NiEl of frequency the in change a and seventies Accepted Article 2004 - A clear positive temperature trend is put in evidence over the last 40 years whereas no spatial variabilitysome the provides contribution about The present of information The annual, summe SATL SST, in the Andes region, over Andesregion,over SST, the in SATL However, considering the percentage of stations with significant correlation, SOI correlation, SOI thesignificant percentagewith ofHowever, considering stations - 1998

interval in rainfall is globalin is the rainfall highlighted. Themeanregion,Andesandwarming over ) - . SATL SST in the Andes. Temperatures are higher when the northern tropical northern are higherwhen the Andes.Temperatures the in SATL SST

The strongest increases occurred in summer perature perature interval

ee Fig.ee This 9b). mayof result droughtclear and during the sky be warm in theMantaro Valley is is st important influence on mean temperature fluctuations compared fluctuations tomean on temperature influence important st

warmer than usual and thesouthern tropical Atlantic Ocean SST in the different regions of the Peruvian Amazon ofPeruvian regions different the the in on the eastern slopes of the tropical Andes. It is higher Andes. the is eastern than slopesoftropical It on the the r and autumn Tmean and positivelyr appearas fluctuations correlated - 0.11°C increase per decade reported by Vuille et al. (2003 perbyVuilleet decade reported 0.11°C increase 1990 interval . Though, is in to it opposition

and Ucayali basins. about half of the stations. This about halfofstations. This the . T hey ar hey e more pronounced in e in more pronounced -

- what was Andes basin (PAB). Andes basin (PAB). 2007). 2007).

concludes concludes ) for t h is is is

the Climatic Prediction Centre of the National Oceanic and Atmospheric Administration Mission Topography (SRTMRadar Accepted by Nationalprovided the Aeronautics Space and Administration (NASA) through the Shuttle ( SENAMHI Service, MeteorologyHydrology National and Peruvian and University La Molina the Institute of Research for the Development (IRD, www.ird.fr) fromFrance and the Agraria ofHYBAM( isprogram result the a study This Acknowledgements climate features in the PAB. time. through noticed be can that Atlantic summer and theend at of therainy season part ofUcayalibasin,southern the is poor ArticleHowever, rainfall such the downstream Amazon (2006) in rainfall Only 10 of% thestations regional at exhibit scale amean neither trendin is nor rainfall, There mean 2006). al., et communities located in altitudeshigh th in temperature willhave important consequences for Andes eastern glaciers and for which influence thetemperature, especially in the Andes regions. In any case, these changes as the northern Marañó northern the as and recently Lavado et al. (2012) find a strong decrease in rainfall and discharge in in discharge and rainfall in decrease (2012) findstrong Lavadoa al. recently et and . As Vuille et al. (2000) did not find the same results for the 1960 for the same et did findal. the not As (2000) results Vuille , since

www.senamhi.gob.pe This workdevelopments This to opens forpromising the future comprehensionof

the eighties Andesthe in the al. thein and the nineties et rainforest. As Espinoza also also fluctuates

the relationships between rainfall and oceanic indicators may vary as River

n basin, mayn basin,

at interannual time scale and this variability, at least in the

basin Tamshiyacu,at seemsit tha ) -

from Peru www2.jpl.nasa.gov/srtm). at rely on glacier al - s change in the PAB the the 1965 in during change ly ly related to ENSO but essentially associated o with the SST gradient variability in the tropical reflect . Thed www.ore Copyright ©Copyright Wiley 2012 John Sons, Ltd. &

the signal of rainfall diminution. igital Elevation Model (DEM) is - - - change characterized by a decrease fed water (IGP, 2005and Bradley hybam.org All climate indexes fromare t other Peruvian basins, Peruvianbasins, other t ) , supported in in by Peru , supported - 1990 - 2007 interval interval

, it it , in in .

Espinoza, J.C., P.,Espinoza, J.J., Fraizy, Guyot, J.L.,Ordoñez, Pombosa, R. Ronchail,(2006). and J. AcceptedChristensen, J.H., Hewitson, B.,A., Busuioc, Chen, A., Gao, X., I Held, A.D.,B.E. Genio, B and Carlson, Chen, Del J., Chaffaut, Coudrian I., M.H.Foley, and Costa, in J.A. (1999). Trends hydrologicthe cycleof Amazon the basin. va and trends Detection of M.A.H.hydrologic Elnur, (2002). and Burn, D.H. Brunet freezing changes in Recent H.D. level Hardy , Diaz and (2009). R., Keimig Bradley F. R.S.,Bradley, Vuille, D M., Article E. andEcología2daBrack, V.Perú. Mendiola, (2004). Ed.del Bruño.Lima Perú. W.,Buytaert, Cuesta Bookhagen B. Strecker and M of geographicalboundaries Amazonia. the for defining AACTO proposal (2005). P. OnAceituno, (1988). functionning of Oscillationthe the Southern in the American South References comment useful their (CPC - NOAA: NOAA: - Workshop organized by Workshop organized European Commissioncollaborationthe in withAmazon the of Synthesis from the Expert O.results an Consultation Eva and (Editors), Huber Partsector. 1 :surface climate. Mon variabilité des débitsdu Rio Amazonas au Pérou. ClimateVariability and Change KingdomUnited N and M. and Averyt, Tignor UniversityH.L. Cambridge Press, Miller (eds.)]. Cambridge, Z. [Solomon, Manning, K.B. Climate Qin,M. Chen,Marquis, Change S., M. D. Wor of Science .Contribution Basis. ClimateThe Physical Change2007: Projections. In: J., Räisänen, Rinke, P.Whetton, A., Regional Climate Sarr, A. (2007). and W. R.K., Kwon, Long- I: structure of twentieth l’ de dud'altitude Nord Journal of Geophysical Research of Hydrology 3- Hydrologie., 16: regions. in heights the Tropics for withimplications the deglacier Andes.tropical 9972- Biogeography regions. of environmentalGlobaland humid alpine Ecology the services tropical 35 rainfall, and relief variations along the eastern Andes. Geophysical Research Letters, Organization - Treaty Cooperation Moret, Y. (1979). Homogénéisation des précipitations Cahiers ORSTOM, Série CahiersORSTOM, Série desMoret, précipitations Homogénéisation Y. (1979). ( L06403)

king Groupking I to Assessmentthe Fourth of Report the Intergovernmental Panel on Inst 1- http://www.cdc.noaa.gov/ 0327- term trend. J term trend. itute Geophysical Research Letters .

Français des Etudes Andines - doi:10.1029/2007GL032011 s. 7. 495pp. Camacho, C., (2010). F., Tobon, 255 20

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JRC 7 Ispra, thly

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: 505- : 14198. - resolution TRMM ., R., Jones, Kolli, 524. riability. Journal imate change on imate change

Précipitations In: H.D. In: H.D. ISBN: ISBN: etin etin La La - Kal Cambio de yMedidas el ante Climático Actual yFutura Vulnerabilidad IGP (2005). AM. (1976). Johnson The climate and Climates ofEcuador. and Bolivia Peru, of Central L'homogénéité G.Hiez, (1977). M Haylock, fleuves bolivienne. Hydrogéochimie des l'Amazonie ORSTOM,de Paris Guyot J.L.(1993). A.H.Gentry, Lopez and R.D.Garreaud, of (1999). Multiscale Analysis Summertimethe over the Precipitation Central R., Garreaud, Vuille, M. A.C.Theclimate Clement, and (2003). ofAl the el sobre precipita que (1987).vapor J. Origenagua de del H. Rutllant, Fuenzalida, and T.G., Farr, Rosen, P.A., E., Caro, R., R., Duren, Crippen, H Espinoza JC., Ronchail GuyotJ.L.,J., Junquas C., Drapeau G., MartinezJM., Santini W., JC., P., C.,L Espinoza Vauchel Ronchail GuyotJ.L.,Junquas J., J.C., J.L.Guyot,Filizola, J., Espinoza, Ronchail, N., Noriega, L.,W., Lavado, R. Pombosa,

Accepted E.,nay, Article Geophys River Pombosa R. (2011). Climate variability and extremes in the drought upper Solimões Climatology countries (Brazil, Peru, Bolivia, Romero,and R. (2009). flooding: understandingflooding: the abrupt 2010 W.S., Espinoza and J. P.,Ordoñez Lavado Vauchel 2006. Cuba,Habana, September Impacts, 424 Hydrological American Meteorological Society, 437 Meteorological 77(3), American Joseph. Ebisuzaki, Saha, la 9972 Cuenca RíoMantaro, Climático para del Adaptación en la Cuenca del Río Mantaro. Evaluación local Integrada de Cambio Company; Ne 12. of World Climatology, Vol. Survey America, South Hydrologie, Links with Sea Surface Temperature. (2006). J. Quintana, Grimm, Karoly, A.M., D., Marengo,J.A., Marino, M.B., Moncunill, D.F., Nechet, D., V.J., V., Garcia, G., Corradi, Coronel, V.R.,M., M.A.,Barros, Berlato, Bidegain, 261(France), p. Amazon. Weather Review Andes. Monthly P Palaeogeography, changes. mechanisms and past conditions of current Am. de paperAltiplano Chile, presented II Congresoat InterAmericanoMeteorología, de mission. Rev. Geophys., Radar Topography TheShuttle D. (2007). Alsdorf, D. Burbank, M., and Oskin, M., Werner, Umland, J., J., D.,S., E.,Shimada, Roth,L.,Shaffer, Seal, Rodriguez, M., Amazonas River and tributaries. Environmental Research Letters accepted alaeoclimatology, Palaeoecologyalaeoclimatology,

.R., Peterson, T.C., Alves, L.M., Ambrizzi, T., Anuncia, o, Y.M.T., Baez, J., T.,J., Baez, L.M.,Ambrizzi, o,Y.M.T.,.R., Anuncia, T.C., Peterson, Alves, Meteorol. Soc.,BuenosAires. Meteorol. M. Kanamitsu, M.

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Applied Applied 107 ). - scale scale

The The (1 as as ): ): -

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261 -

Atmospheres 27 - 445. –264 112 (23): 3885- (23): (D

59 07107 (1 Documentos -

2): 75-

3888. eophysical eophysical 103 ). .

J (D10): ournal 99. doi: doi: ate

Accepted Article location, basin and measured variables at the weather stations. 1 Table Sihuas Aucayacu Maria Tingo Chavin Huanuco Cayhuayna San Rafael Yanahuanca Cerro De Pasc Weather Station Tunel Cero Tunel Urubamba San Rafael Paucartambo Cusco Curahuasi Granja Kcayra Ccatcca Vilcashuaman Andahuaylas Paruro Acomayo Paucaray Combapata Sicuani Chalhuanca TomasSanto Pampahuasi Yauri La Angostura Caylloma Yurimaguas Jamalca San Ramon Moyobamba Rioja Chachapoyas Navar Lamas Tarapoto PorvenirEl Sauce Bellavista WeberbauerAugusto Juanjui San Marcos Tocache

Characteristics of the

45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Code

stations: Name, Code reported in figure in 1b, Name, Code reported stations:

Latitud ------(°S) 13.254 13.311 13.321 13.324 13.537 13.553 13.557 13.610 13.644 13.657 13.768 13.917 14.051 14.100 14.254 14.393 14.399 14.484 14.817 15.180 15.184 5.894 5.898 5.949 6.000 6.034 6.203 6.356 6.424 6.513 6.593 6.694 7.051 7.152 7.175 7.322 8.184 8.567 8.600 9.288 9.586 9.966 10.322 10.491 10.694

------(°W) Longitud ------76.525 76.372 76.322 76.203 76.559 78.491 76.734 78.169 76.500 77.650 75.934 76.000 77.176 76.237 76.169 76.508 76.254 75.085 72.124 74.169 71.591 71.944 72.735 71.875 71.560 73.949 73.371 71.845 71.684 73.644 71.433 71.237 73.179 72. 74.250 71.417 71.649 71.767 76.118 78.237 76.085 76.967 77.169 77.881 75.779 089 Copyright ©Copyright Wiley 2012 John Sons, Ltd. &

920 282 230 620 247 2536 280 3200 508 2716 600 6 3160 1947 2600 3170 4260 (m a.s.l.) Altitud 4700 2863 2600 3042 3399 2763 2360 3729 3590 2866 3084 3160 3250 3464 3574 3358 3253 3650 3927 4150 4420 187 1200 184 860 880 2490 190 86

(

R: Rainfall; T: Temperature.) e

Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Basin Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga Huallaga

R,T T R,T R R,T R R,T R R,T R R R,T R R,T R,T R R Variable R R,T R R,T T R,T R,T T R R,T T R,T R T R,T R R R R R,T T R,T R R R,T T T R

Geographical Geographical

Accepted Article Comas Jauja San Lorenzo Huayao Laive Pilchaca Paucarbamba Huancavelica Quillabamba Lircay La Quinua Wayllapampa Machu Picchu Tamshiyacu Genaro Herrera Requena Juancito Contamana Pucallpa Tournavista Aguaytia Pozuzo Oxapampa Sepa Pichanaky San Ramon OcopaPuerto Satipo Huasahuasi Tarma Marcapomacocha Ricran

77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46

------12.856 12.983 13.034 13.068 13.167 4.003 4.900 5.043 6.034 7.353 8.384 8.932 9.034 10.051 10.593 10.817 10.966 11.117 11.136 11.220 11.254 11.389 11.405 11.542 11.745 11.779 11.850 12.034 12.252 12.406 12.467 12.779

------73.284 74.830 75.334 74.254 74.627 75.627 75.695 76.325 75.525 75.118 7 75.384 75.339 75.355 75.085 74.567 75.034 72.692 74.729 74.135 74.220 72.546 73.161 73.650 73.836 74.867 75.006 74.576 74.711 75.508 75.559 75.390 5.474 Copyright ©Copyright Wiley 2012 John Sons, Ltd. &

307 547 904 788 607 2737 3000 4479 3500 3300 3322 300 3308 3990 3570 3000 367 990 3150 3232 2500 2563 141 132 128 150 185 160 185 338 798 1814 6

Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali Ucayali

R R T T R R T R,T R R R,T T R,T R,T T R T R,T R,T R,T T R,T R R R,T R,T R,T R,T R,T R T T

Accepted Article Temperature; 500(under m 2 Table Mean (1965 Mean

Tmin

Rainforest Andes Total .s .l .: Minimum Temperature; . Spring Winter Autumn Summer Anual Spring Winter Autumn Summer Anual Spring Winter Autumn Summer Anual ) and Rainforest) the region (above 500 m

- 2007) seasonal climate values for the entire zone, the Andes region

Rainfall 2235.3 1024.9 1296.2 568.3 317.4 640.0 709.7 235.0 275.6 427.4 309.7 138.5 357.3 490.7 (mm) 86.9

.: MeanTemperature Tmax 32.0 31.1 31.0 31.4 31.4 22.7 21.8 21.7 21.6 22.0 24.8 23.9 23.9 23.9 24.1 (°C)

a .s .l Tmin . 20.2 19.1 20.4 20.6 20.1 10.1 11.4 11.5 12.5 11.1 (°C) ). 8.8 6.0 8.8 8.4 9.0

Tmax

.: Maximum Maximum .: Accepted Article Tmax brackets are years of mean trends 3 Table .: Maximum Temperature;

values

Rainforest Andes Total Rainfall Spring Winter Autumn S Annual Spring Winter Autumn Summer Annual Spring Winter Autumn Summer Annual

ummer

using Mannusing

and and

temperature mm/decade Rainfall - - 14.74 10.25 Kendall test change usingchange - - - - - 19.4 3.76 6.06 4.64 8.01 - 10.2 2.16 2.96 2.34 4.58 7.7 7.6 2.3

Tmin

linear 0.09**(1981) 0.09**(1981) 0.08**(1979) 0.08**(1976) 0.09**(1978) 0.07**(1993) 0.06 0.10** 0.11**(1986) 0 0.08**(1993) 0.07** 0.09** 0.10**(1976) 0.09**(1986) .: Minimum Temperature; .09**(1986)

°C/decade ( Pettitt test α

Tmean

trends (over thetrends (over 1965 at 0.05) are with asterisks (**). Values between

( α at 0.05). at 0.08 0.02 0.07(1978) 0.13**(1993) 0.09 0.11 0.15**(1976) 0.12**(1976) 0.12**(1993) 0.09 0.1 0.12**(1976) 0.11**(1976) 0.08(1978) 0.11**(1981) °C/decade

Tmax

Tmean .

- 2007 period). Significa 2007 period).

.: MeanTemperature 0.09**(1982) 0.15**(1986) 0.11**(1981) 0.02 0.04 0.09 0.08**(1996) 0.06** 0.04 0.05 0.09** 0.09**(1996) 0.07** 0.11**(1981) 0.08**(1981) °C/decade

Tmin

nt nt .

Accepted Article discernible percentage 10%). (0 to of stations zones.analyzed *Number of each stations in of one the zones. temperatures and considering(1965 rainfall series negative), Neg.: and 4 Table

Temperature Temperature Temperature Number Rainfall Minimum Maximum Mean Rainforest *37 Andes Regional Rainforest Andes Regional Rainforest Andes Regional Rainforest *44 Andes Regional Zones *11 *4 *11 *37 *48 *11 *37 *48 *13 *58 8

of stations with significant trends Mann significant using with of stations

Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Trend

Annual 12 18 13 17 18 23 0 5 1 1 2 0 2 3 4 3 1 4 3 3 2 4 2 4

Autumn 16 15 20 12 17 12 0 5 1 1 0 0 1 3 1 3 1 4 2 2 1 4 2 3

- Kendall test (Pos.: positive

Gray indicate no boxes Winter 15 14 19 11 0 5 3 4 1 0 2 2 3 2 1 2 4 8 5 2 6 1 9 3 -

2007) in the in three2007)

Spring 19 13 19 15 15 0 6 2 2 2 0 1 0 4 0 1 2 3 8 3 1 3 2 3

Accepted Article percentage indicate nodiscernible boxes of10%). to stations (0 Mean Temperature Winter;Sp: Spring usingPettit test 5 Table . Percentage ofstations with significant year ofmean

Tmin. Tmax. Tmean. Rainfall Variable

over the three analyzed

. Tmax . . 1981 1991 1965 1991 1981 1971 1965 1991 1971 1965 1991 1981 1971 1981 1971 1965 Period

For number the of each stations in one ofzones the see ------1990 2007 1990 1980 1970 1970 2007 1990 1980 1980 1970 1970 2007 2007 1980 1990

.: Maximum Temperature;

17 33 4 0 10 27 0 13 29 17 0 9 0 0 An Regional 17 14

23 15 27 35 2 0 0 10 23 21 0 7 9 2 0 Su 15

25 8 27 2 0 4 10 0 6 31 6 0 2 9 0 0 Au

17 13 10 8 29 4 0 10 0 13 21 13 0 3 0 0 Wi

zones

10 33 15 21 6 0 10 0 21 13 19 0 5 3 0 0 Sp

. An: Annual; Summer; Su: Au: Autumn; Wi:

30 5 0 8 0 14 30 14 0 0 0 An 19 16 22 13 11 Andes

11 30 14 30 11 30 3 0 0 11 24 19 0 7 2 0 Su

Tmin

22 3 0 0 0 8 30 3 0 2 9 0 0 Au 11 11 19

.: MinimumTemperature; 11 14 8 32 3 0 8 5 0 11 19 11 0 4 0 0 Wi

3 11 41 16 8 0 5 0 22 11 19 0 7 4 0 0 Sp -

change for periods ( for periods change

9 45 0 0 0 9 27 27 0 0 0 0 An 18 18 45 15 Rainforest

27 18 18 0 55 0 0 0 9 18 27 0 8 0 0 0 Su

0 45 0 0 9 0 0 36 18 0 0 8 0 0 Au 18 45

36 18 27 9 18 9 0 0 18 27 18 0 8 0 0 0 Wi

Table 4.

27 36 36 0 0 9 0 18 18 18 0 0 0 0 0 Sp 27

α Tmean

= 0.05) 0.05) = Gray Gray .: .: arebydashed regions limited black Rainforest a The Andesand line codes given in theTable 1. The Ucayali East 1 Figure

Accepted : Ucayali basin. b). Localization of the weather stations with number corresponding to Article . a). Localization and elevation of the region under study,. a).elevation and ofregionunder Localization the

and Huallaga basins separated are by a plain line.

(500 masl)(500 : Huallaga basin and Huallaga : .

in theinterpolation. Huallaga and the Ucayali basins are separated by a basins.Ucayali TheAndes Rainforest and regionare limited by (°C), c)maximum temperature 2 Figure \ -16 -16 -12 -10 -14 -12 -10 -14 -8 -6 -4 Accepted -8 -6 Article -4 -78 -78 ° ° ° ° ° ° ° ° ° ° ° ° ° ° Maximum Temperature(°C) Maximum

. ° °

Mean (1965 Mean -76 -76 Rainfall(mm/year) ° °

-74 -74

° °

- 2007) 2007) -72 -72 c) a) ° °

-70 -70 annual

(°C) and b)minimum temperature (°C) ° °

values values -5 0 1000 0 2000 5 3000 4000 10 15 20 25 30 35 for a) rainfall (mm/year), b)mean temperature

Mean Temperature(°C) Mean ° °

plain plain -76 -76 ° °

line. Kriging method wasused -74 -74 ° °

-72 -72 blue b) d) ° °

dashed line. The The line. dashed -70 -70 in Huallagain and

° °

-5 -5 0 5 10 0 5 10 15 20 15 25 20 25 30 35

Accepted Articlewhole station data in the temperature (°C), c) maximum temperature (°C) and d) minimum temperature (°C) using the 3 Figure . Mean (1965- . Mean mm/year °C 1000 2000 3000 4000 5000 10 15 20 25 30 35 -5 0 0 5 0 0 c) Maximumc) Temperature vs Elevation 1000 1000 a) Rainfalla) vs Elevation 2007) annual 2007) annual Elevation (m a.s.l.) (m Elevation a.s.l.) (m Elevation 2000 2000

Huallaga and Ucayali basins. 3000 3000 4000 4000 values 5000 5000

versus elevation

d) Minimum Temperature vs Elevation b) Mean Temperature vs Elevation 1000 1000

for a) rainfall (mm/day),b) mean Elevation (m a.s.l.) (m Elevation a.s.l.) (m Elevation 2000 2000 3000 3000 4000 4000 5000 5000 . Accepted Article are (1 4f).the and Xmonth axis ofyear the minimum Regionalat temperatures and(4a 4b), Andes(4c and 4d) and Rainforest region (4e 4 Figure .

Month mm °C 200 400 25 30 15 20 10 0 5 0

b) a) b) 1 1 2 2 3 3 ly ly Regional Rainfall (mm) Rainfall Regional 4 Temperature(°C) 4 5 5 regimes of rainfall mean temperatures, maximum temperatures and month 6 6 7 7 8 8 9 9 10 10 11 Rainfall 11 12 12

mm 400 °C 200 30 20 25 10 15 5 0 0 c) d) 1 1 2 2 3 3 : January, 2 : February,…). February,…). January,2: : Andes Rainfall(mm) Andes 4 Temperature(°C) 4 5 5

mm °C 200 400 30 25 15 20 10 5 0 0

f) e) 1 1 2 2 3 3 Rainforest Rainfall(mm) Rainforest 4 Temperature(°C) 4 5

5 Mean Temperature Mean Minimum Temperature Minimum Temperature Maximum month 6 6 7 7 8 8 9 9 10 10 11 11 12 12

Accepted Article the in region 5 Figure . Plot of annual values means over the Regional region, Andes regionyRainforest 1000 1200 1400 1600 10.5 11.5 16.5 17.5 18.5 11 12 23 24 25 1960 1960 1960 1960 1965- d) c) b) a) Maximum Temperature(°C) Minimum Temperature(°C) 1970 1970 1970 1970 Mean Temperature(°C) Mean 2007 period. Black 2007 period. the line represents trend linear regression. using Rainfall(mm) 1980 1980 1980 1980 Regional 1990 1990 1990 1990 2000 2000 2000 2000 2010 2010 2010 2010 1000 1200 1400 14.5 15.5 800 9.5 7.5 8.5 22 23 21 16 15 1960 1960 1960 1960 8 9 h) g) f) e) Maximum Temperature(°C) Minimum Temperature(°C) 1970 1970 1970 1970 Mean Temperature(°C) Mean Andesregion Rainfall(mm) 1980 1980 1980 1980

1990 1990 1990 1990 Copyright ©Copyright Wiley 2012 John Sons, Ltd. & 2000 2000 2000 2000 2010 2010 2010 2010 1500 2000 2500 3000 19.5 20.5 25.5 26.5 20 21 31 32 33 30 25 26 1960 1960 1960 1960 l) k) j) i) Maximum Temperature(°C) Minimum Temperature(°C) 1970 1970 1970 1970 Mean Temperature(°C) Mean Rainforest region Rainfall(mm) 1980 1980 1980 1980 1990 1990 1990 1990 2000 2000 2000 2000 2010 2010 2010 2010

are limited bl are bya Ucayalibasins separated the Theand are dark bya plain line. Andesandregion Rainforest with negative significant trend ( with positive significant trend ( analyze 6 Figure -14 -12 -10

-16 -8 -6 -4 Accepted Article -78

° ° ° ° ° ° °

° d summer, (annual, autum

-76

Annual Rainfall Annual . °

Presence of alocal trend (M -74

-72

a) °

-70 ue °

dashed line. dashed line.

-14 -12 -10 -16

-8 -6 -4 -78

° ° ° ° ° ° °

-76

Summer Rainfall Summer °

-74

-72 b) α α °

n, winter n, winter and over spring) the 1965

-70 equal 0.05) with a downward downward a with 0.05) equal equal 0.05) are with an an areequal with 0.05) upward °

-14 -12 -10

-16 -8

-6 -4 -78

° ° ° ° ° ° °

ann- -76

Autumn Rainfall Autumn °

-74

endall

-70 °

test) in Rainfall for the five period

-14 -12 -10 -16

-8 -6 -4

-78 ° ° ° ° ° ° °

-76 Winter Rainfall Winter °

-74

blue blue

-72 d) °

red red

-70 ° triangle

- 2007 period.Stations triangle and stations

-14 -12 -10 -16

-8 -6 -4

-78 ° ° ° ° ° ° °

-76 Spring Rainfall Spring . °

The The

-74

-72 e) Huallaga °

-70 °

AcceptedTemperature. M forin trends but 7 Figure Article . Top: As in Figure 3 Figure AsTop: in

-10 -14 -12 -14 -12 -10 -14 -12 -10 -16 -16 -16

-8 -6 -4 -8 -6 -8 -6 -4 -4 Annual Maximum Temperature Maximum Annual

-78

-78 -78 Annual Minimum Temperature Minimum Annual ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

Annual Mean Temperature Mean Annual ° ° °

-76 -76 -76

° ° °

-74 -74 -74 axim ° ° °

-72 -72 -72 a) k) f) ° ° °

-70 -70 -70 um ° ° °

-14 -12 -14 -12 -10 -14 -12 -10 -10

-16 -16 -16

-8 -6 -4 -8 -6 -8 -6 -4 -4

Summer Maximum Temperature Maximum Summer

Summer Minimum Temperature Minimum Summer

-78 -78 -78 Temperature. Temperature. Summer Mean Temperature Mean Summer ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

° ° °

-76 -76 -76

, but for trends in Mean Temperature.

° ° °

-74 -74 -74

° ° °

-72 -72 -72

b) l) g) ° ° °

-70 -70 -70 ° ° °

-14 -14 -12 -14 -12 -10 -12 -10 -10 -16 -16 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4 Bottom: As in Figure 3 Autumn Maximum Temperature Maximum Autumn Autumn Minimum Temperature Minimum Autumn

-78 -78 -78 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Autumn Mean Temperature Mean Autumn

° ° °

-76 -76 -76

° ° °

-74 -74 -74 ° ° °

-70 -70 -70 ° ° °

-14 -12 -10 -14 -12 -10 -14 -12 -10 -16 -16 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4 -78

-78 Temperature Maximum Winter -78

Winter Minimum Temperature Minimum Winter ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

Winter Mean Temperature Mean Winter ° ° °

-76 -76 -76

° ° °

-74 -74 -74 ° ° °

-72 -72 -72 n) i) d) , but for trends in M in for trends , but ° ° °

-70 -70 -70 ° ° °

Center: As in Figure 3

-14 -12 -14 -12 -10 -10 -14 -12 -10 -16 -16 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4 -78 -78

-78

Spring Maximum Temperature Maximum Spring Spring Minimum Temperature Minimum Spring ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

Spring Mean Temperature Mean Spring ° ° °

-76 -76 -76

° ° °

-74 -74 -74 ° ° °

-72 -72 -72 o) j) e) ° ° °

-70 -70 -70 ° ° °

inimum

Accepted Article TheAndes Rainforestline. and region limited bl are bya downwa andby ones negative triangles red byupward represented are correlations Positives Stations with positive and negative significant correlation (p > 95%) are represented. basins 8 Figure A) the Southern Oscillation Index (SOI), B) SST difference between NATL rd blue triangles. blue TheHuallagard and basinsthe Ucayali are separated by dark a plain B) A) . Correlation annualbetweenand seasonal rainfalltheHuallagaand in -14 -12 -10 -16

-14 -12 -10 -14 -12 -10 -14 -12 -10 -16 -16 -16

-8 -6 -4

-8 -6 -4 -8 -6 -4 -8 -6 -4

-78

-78 -78 -78

° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

Anual Mean Temperature Mean Anual ° ° ° °

-76

-76 -76 -76

Anual Rainfall Anual Anual Rainfall Anual Anual Rainfall Anual ° ° ° °

-74

-74 -74 -74

° ° ° °

-72

-72 -72 -72

° ° ° °

-70

-70 -70 -70

° ° ° °

-10 -14 -12 -10 -14 -12 -16 -14 -16 -12 -10 -16

-14 -12 -10 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4

-8 -6 -4

-78 -78 -78

-78

Summer Mean Temperature Mean Summer ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

° ° ° °

Summer Rainfall Summer Summer Rainfall Summer Summer Rainfall Summer -76 -76

-76

° °

-74 -74 -74

-74

° ° ° °

-72 -72 -72

-72

° ° ° °

-70 -70 -70

-70

° ° ° °

-14 -12 -10 -14 -12 -10 -14 -16 -12 -16 -10 -16

-14 -12 -10 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4

-8 -6 -4

-78 -78 -78 -78

° ° ° ° ° ° ° Temperature Mean Autumn ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

° ° ° °

-76 -76

-76 Autumn Rainfall Autumn Autumn Rainfall Autumn

-76

Autumn Rainfall Autumn

° ° ° °

-74 -74 -74

-74

° ° ° °

-72

° ° ° °

-70 -70 -70

-70

° ° ° °

-14 -12 -10 -14 -12 -10 -16 -16 -14 -12 -10 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4

-14 -12 -10 -16

ue -8 -6 -4

-78 -78 -78 -78

° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

° ° ° ° ° ° ° Winter Mean Temperature Mean Winter

° ° °

dashed line. -76 -76

-76

Winter Rainfall Winter Winter Rainfall Winter Winter Rainfall Winter

° ° °

-74 -74 -74

-74

° ° °

-72 -72 -72

-72

° ° °

-70 -70 -70

-70

° ° °

-14 -12 -10 -14 -12 -10 -16 -16 -14 -12 -10 -16

-8 -6 -4 -8 -6 -4 -8 -6 -4

-14 -12 -10 -16

-8 -6 -4

-78 -78 -78

-78

° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °

Spring Mean Temperature ° ° ° ° ° ° °

° ° °

-76 -76 -76

-76

Spring Rainfall Spring Spring Rainfall Spring

Spring Rainfall Spring

° ° °

-74 -74 -74

-74

° ° °

-72 -72 -72

-72

° ° °

-70 -70 -70

-70

° ° °

Ucayali - SATL. SATL.

line. TheAndes Rainforestline. and region limited bl are bya triangles.downward blue TheHuallaga and basinsthe Ucayali are separated by dark a plain and ones negative triangles red byupward represented are correlations Positives SATL. Stations with positive and negative significant correlation (p > 95%) represented. are Ucaya 9 Figure Accepted Article li basins . Correlation between annual and seasonal mean temperature B) A) -14 -12 -10 -16

-14 -12 -10 -16 -8 -6 -4

-8 -6 -4

-78

-78 ° ° ° ° ° ° ° A) the Southern Oscillation Index (SOI), B) SST difference between NATL ° ° ° ° ° ° °

Anual Mean Temperature Mean Anual Anual Mean Temperature Mean Anual ° °

-76

-76 ° °

-74

° °

-72

-72 ° °

-70

-70 ° °

-14 -12 -10 -16

-14 -12 -16 -10

-8 -6 -4

-78 -78 Summer Mean Temperature Mean Summer Summer Mean Temperature Mean Summer ° ° ° ° ° ° ° ° ° ° ° ° ° °

° °

-76 -76 ° °

-74

° °

-72

° °

-70

-14 -12 -10 -16

-8 -6 -4

-14 -12 -10 -16

-8 -6 -4

-78

Autumn Mean Temperature Mean Autumn ° ° ° ° ° ° °

-76 -76

-74

-72

ue -70

-70

° dashed line.

-14 -12 -10 -16

-8 -6 -4

-14 -16 -12 -10

-8 -6 -4

-78 -78 ° ° ° ° ° ° °

Winter Mean Temperature Mean Winter ° ° ° ° ° ° °

Winter Mean Temperature Mean Winter °

-76

-76 °

-74

-72

in in the Huallaga and -70

-70

-14 -12 -10 -16

-8 -6 -4

-14 -16 -12 -10

-8 -6 -4

-78

° ° ° ° ° ° °

-78

Spring Mean Temperature ° ° ° ° ° ° °

Spring Mean Temperature °

-76

-76 °

-74

-72

-70

- higher than standardare2 × plotted. deviation (from 300 until ground water vapor hPa) the flux differencesm (kg 2009 day (fromintegrated 300Vertically flux groundwater vapor hPa) the until differences m (kg 1997, 2001 10 Figure −

Accepted Article1 ). ). minus 1970, 1978, 1983, 1997, 2005, 2010 for c) SST ( SST for c) 2005, 2010 1983, 1997, minus1970, 1978, c ) and) differences d) between MAMseasonsfor 1974, 1981,1984, 1989,1994, 2008, . - 2002 minus 1972 a) and a) b) Differences between DJF seasons for 1969 - 1973, 1984 - 1985, 1988

day − 1 ). Only values Only values ). - 1996, 199 ˚C) and b) b) and ˚C) 6- − 1