Quantifying Watershed Export in the Arctic:Quantifying Watershed Export in the Arctic:Challenges and Rewards of Capturing Highly Variable River Challenges and Rewards of Capturing Highly Variable River

Water Chemistry over Time and SpaceWater Chemistry over Time and Space

James W. McClelland, University of Texas, Port Aransas, USAR. Max Holmes, Woods Hole Research Center, Woods Hole, USA

PARTNERS Project PARTNERS Project (2002(2002--2007): Six 2007): Six largest rivers in the largest rivers in the panpan--arctic watershedarctic watershed

ArcticArctic--GRO (2009GRO (2009--2012): Six largest 2012): Six largest rivers in the panrivers in the pan--arctic watershedarctic watershed

SNACS Project SNACS Project (2005(2005--2007): Three 2007): Three largest river draining largest river draining the North Slope of the North Slope of Alaska Alaska

Annual water Annual water dischargedischargeRiver km3/yYenisey 620Lena 525Ob’ 404Mackenzie 308Yukon 200Kolyma 132Colville 11Sag. 1Kuparuk 1

Mississippi 530Hudson 17

OutlineOutline

• Seasonality of water discharge

• Seasonality of water chemistry

• Sample collection and processing

• Sample preservation and transport

• Analyses

• Working across national borders

• Novel approaches

River runoff River runoff ClimatologyClimatologyin the Arcticin the Arctic

Average mm/moAverage mm/mofor 1990for 1990--19991999

Barents Sea

0

20

40

60

80

100

120

East Siberian Sea

0

20

40

60

80

100

120

Kara Sea

0

20

40

60

80

100

120

Laptev Sea

0

20

40

60

80

100

120

Beaufort Sea

Mon

thly

Run

off (

mm

)

0

20

40

60

80

100

120

Hudson Bay

0

20

40

60

80

100

120

J F M A M J J S OA N D J F M A M J J S OA N D

J F M A M J J S OA N D J F M A M J J S OA N D

J F M A M J J S OA N D J F M A M J J S OA N D

Variability within and among individual riversVariability within and among individual riversBeaufort Sea

0

20

40

60

80

KuparukMackenzieAnderson

J F M A M J J S OA N DJ F M A M J J S OA N D

Laptev SeaM

onth

ly R

unof

f (m

m)

020406080

100120140160

AnabarLenaOlenekYana

Lena River

Dai

ly R

unof

f (m

m)

0.00.51.01.52.02.53.03.54.04.5

200420052006

J F M A M J J S OA N D

Mackenzie River

0.0

0.5

1.0

1.5

2.0 200420052006

J F M A M J J S OA N D

SummerSummer

Seasonality of water chemistrySeasonality of water chemistrySpringSpring

Seasonality of water chemistrySeasonality of water chemistry(changes between winter low flow and the spring freshet)(changes between winter low flow and the spring freshet)

Increase at all rivers

Total suspended solidsParticulate organic N (PON)Particulate organic C (POC)

POC-δ13CDissolved organic N (DON)Dissolved organic C (DOC)

DOC-Δ14CLignin Phenol

Specific UV abs. (SUVA)pH

CeriumLanthanumNeodymium

PraseodymiumThalliumVanadium

Total = 16

Decrease at all rivers

H2O-δ18OH2O-δ2HAlkalinityChlorideSulfateSodium

PotassiumMagnesium

CalciumNitrateSilicateBariumLithium

MolybdenumRheniumStrontiumUranium

Total = 17

Variable among rivers

PON-δ15NDOC-δ13C

Total dissolved phosphorusAmmonium

ArsenicCadmium

CobaltChromium

CesiumCopper

IronManganese

NickelLead

RubidiumZinc

Total = 16

Dissolved Organic CarbonDissolved Organic Carbon

Dis

char

ge (1

03 m3 /s

)

0

20

40

60

80

100

120

Bul

k di

ssol

ved

orga

nic

carb

on (μ

M)

400

600

800

1000

1200

Spe

cific

UV

abs

orba

nce

(L/m

gC/m

)

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

Lign

in p

heno

l rel

ativ

e to

Bul

k D

OC

(%)

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

DischargeBulk DOCSUVA% Lignin Phenol

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percentage variation among seasons

DOC: Yukon > Yenisey > Kolyma > Lena > Ob’ > Mackenzie SUVA: Yenisey > Yukon > Ob’ > Mackenzie > Lena > KolymaLP: Yukon = Kolyma > Yenisey = Ob’ > Lena > Mackenzie

Lena River

Comparison of Comparison of water discharge water discharge and DOC conc.and DOC conc.in the Lena andin the Lena andMississippi riversMississippi rivers

DO

C μ

M

2004 2005 2006 0

2

4

6

8

10

12

14

0

200

400

600

800

1000

1200

1400

1600

Wat

er d

isch

arge

(km

3 /d)

1996 1997 1998 0

2

4

6

8

10

12

14

0

200

400

600

800

1000

1200

1400

1600

20 m

Depth and cross section integrated samplingDepth and cross section integrated sampling

D-96 Depth Integrating Sampler 14 L Teflon Churn

Greatest challenges associated with samplingGreatest challenges associated with sampling

• Mobilization of personnel for freshet

• Water collection during ice break-up

• Getting representative samples for particulate analyses

• Standardization versus flexibility

• Idealism versus practicality

But sample collection is just the beginning!But sample collection is just the beginning!

• Preservation and transport of samples

• Central versus distributed analyses

• Added challenges when working internationally– Communication– Visas and other paperwork for travel– Customs– Unpredictable costs

Novel approachesNovel approaches

• Establishment/use of regional analytical capabilities

• Greater involvement of local personnel

• Moorings and/or shore-based flow through systems– Standard measurements (temp., cond., DO, pH, chl.)– Optical properties– Water isotopes– DIC conc. and isotopes

RewardsRewards

• Better constrained flux and tracer estimates that support ocean work

• Improved understanding of watershed processes within pan-arctic domain

• Baseline for assessing future changes

• PARTNERS and Arctic-GRO personnel

• NSF Office of Polar Programs (ARCSS, AON)

AcknowledgementsAcknowledgements