Ocean Weather Station M - from weather forecast Ocean Weather Station M - from weather forecast to climate monitoringto climate monitoring

Ingunn SkjelvanIngunn SkjelvanBjerknes Centre for Climate Research and Bjerknes Centre for Climate Research and Geophysical Institute, University of BergenGeophysical Institute, University of Bergen

M/S PolarfrontM/S Polarfront

Start in 1948Start in 1948

6161 yrs with temperature and salinity, yrs with temperature and salinity, GFIGFI, , 5 t/w5 t/w

5656 yrs with oxygen, yrs with oxygen, GFIGFI, , weeklyweekly2828 yrs with atmospheric greenhouse gasses, yrs with atmospheric greenhouse gasses, NOAANOAA, , 2 t/w2 t/w

1818 yrs with biological parameters, yrs with biological parameters, IMRIMR, , weeklyweekly

88 yrs with carbonate system, yrs with carbonate system, BCCRBCCR, , monthlymonthly

44 yrs with sea and air pCO yrs with sea and air pCO22, , BCCRBCCR, , continuouslycontinuously

33 yrs with carbon isotopes,yrs with carbon isotopes, BCCRBCCR, , monthlymonthly

33 yrs with direct flux/eddy correlation studies, yrs with direct flux/eddy correlation studies, NOCNOC, , continuouslycontinuously

+ moorings/sensors+ moorings/sensors

Non-meteorological time seriesNon-meteorological time series

WARMER deep water during the last 25 yrsWARMER deep water during the last 25 yrs

Annual mean temperature at 2000 m depth

Øst

erh

us

20

09

Geophysical Institute, University Geophysical Institute, University of Bergen (GFI)of Bergen (GFI)

1950 1960 1970 1980 1990 2000

Year

6.9

7

7.1

Dis

olv

ed O

xyg

en (

ml/l

)

1500

1200

2000

1950 1960 1970 1980 1990 2000

Year

-0 .9

-0 .8

-0 .7

Te

mp

era

ture

°C

1500

1200

2000

The recent warming is due to different processesThe recent warming is due to different processes

Østerhus (2009), BCCR/GFI

TEMPERATURE OXYGEN

INCREASING INCREASING atmospheric COatmospheric CO22 content content

INCREASING INCREASING annual mean wave heightannual mean wave height

Norwegian Meteorological Norwegian Meteorological InstituteInstitute

NOAANOAA

INCREASING oceanic pCOINCREASING oceanic pCO22

timepC

O2

ocean surfaceatmosphere

2020

2060

2100

2140

2180

2001 2002 2003 2004 2005 2006 2007 2008

CT

[mm

ol k

g-1]

10 m

50 m

2000 m2120

2130

2140

2150

2160

2170

2180

20

01

20

02

20

03

20

04

20

05

20

06

20

07

20

08

salt

no

rma

lize

d C

t [u

mo

l/kg

]

2000 m

10 m (winter values)

CT = +1.3 mmol kg-1 yr-1 (~2.6 uatm yr-1)

CT = +0.6 mmol kg-1 yr-1

Bjerknes Centre for Climate Bjerknes Centre for Climate Research (BCCR)Research (BCCR)

DECREASING sink DECREASING sink for atm COfor atm CO22

0

1000

2000

0 10 20 30 40

CTant [mmol kg-1]

Dep

th [

m]

~25 μmol kg-1

(~1.1 μmol kg-1 yr-1)

~9 μmol kg-1 (~0.4 μmol kg-1 yr-1)

- changing deepchanging deep circulation circulation- anthropogenic origin- anthropogenic origin

INCREASING ocean acidificationINCREASING ocean acidification

0

1000

2000

8.000 8.050 8.100 8.150 8.200 8.250

pH

Dep

th [

m]

pH 1981

pH 2005

8.010

8.020

8.030

8.040

8.050

2001 2002 2003 2004 2005 2006 2007 2008

year

pH

-0.03 pH units over 6 years -0.03 pH units over 6 years (-0.005 pH units/yr)(-0.005 pH units/yr)

Findlay et al., 2008Findlay et al., 2008

OWSM carbon OWSM carbon data used to verify data used to verify modelsmodels

Coupled carbon-Coupled carbon-ecosystem model used to ecosystem model used to examine carbon and examine carbon and nutrient mixed layer nutrient mixed layer dynamicsdynamics

Aim: continuation of the long time seriesAim: continuation of the long time series Moorings / buoys / sea glidersMoorings / buoys / sea gliders Ship time for water sampling and deployment / recoveryShip time for water sampling and deployment / recovery

Future monitoring at OWSMFuture monitoring at OWSM

pH pCO2

1st application partly financed1st application partly financed2nd application pending2nd application pending

Major challengesMajor challenges

Not enough time for overlapping Not enough time for overlapping measurements/calibrationsmeasurements/calibrations

AppendiksAppendiks

Decrease in surface-ocean pH is already measurable

Anthropogenic decline in surface pH:

• 0.1 since 1750 (indirect method)

• 0.02 pH units per decade since 1980 (direct method)

based on Bates, Dore, Gonzàles-Dàvila et al. in Willebrand, Bindoff et al. (IPCC AR4, 2007)

Spreading of Intermediate from the Greenland Sea

Greenland Sea Norwegian SeaMM

Recent warming

Ice cover

Arctic Ocean Greenland Sea Norwegian SeaAtlantic Ocean

Cooling

Heating

Intermediate depth:Warming due to warmer water convected in Greenland Sea convection

~2000 M: Warming due to lack of GSDW (replaced by AODW)

Below 2500 m:Warming due to geothermal driven convection and heating