Phenology of sea ice and ocean algal blooms in the Arctic

Rubao Ji1, Meibing Jin2, Øystein Varpe3

1. Woods Hole Oceanographic Institution2. University of Alaska – Fairbanks3. Norwegian Polar Institute

OS 072

Phenology of ice algae and phytoplankton blooms in the Arctic

Rubao Ji1, Meibing Jin2, Øystein Varpe3

1. Woods Hole Oceanographic Institution2. University of Alaska – Fairbanks3. Norwegian Polar Institute

OS 072

Background

Minimum Sea Ice Extent

1978 2011

Ext

ent

(Mill

ion

km2)

NS

IDC

Conceptual model

Derived from: Wassman 2011 Søreide et al. 2010 Leu et al., 2011

Implications for zooplankton

Calanus hyperboreusClimatology Start 2-weeks earlier

Ji et al., PiO 2011Individuals can reach overwinter stage within growth season

Methods

Modeling analysis

Satellite data analysis:•Ocean color (SeaWiFS)

•Ice (SMMR& SSM/I)

•Snow (SMMR& SSM/I) Melt onset: Drobot & Anderson. 2001

Western transect

Eastern transect

POPPOP CICECICE

Pelagic food web Pelagic

food web Ice-algae module

Ice-algae module

LANL/NCAR

Model run: 1992-2007(Jin et al., 2011)

Observation: W. transect

Snow-melt

Ice-melt

SeaWiFSChl-a

Observation: E. transect

Snow-melt Ice-melt

SeaWiFSChl-a

Observation vs modelIce-melt (obs.) Ice-melt (model)

Phyto peak (obs.) Phyto peak (model)

Taylor diagram

- Model capture basic timing pattern

- Model skill similar among years

- Model phyto peak earlier than obs.

Phyto peak

Ice melt

Modeled timing

BTphyto-peak

Lag: B-A

ATice-algae-peak

Timing correlation

corr(Tice-melt, Tphyto-peak) (model)

r (all) r (p<0.05)

0-1.0 1.0

Timing correlation

corr(Tice-melt, Tice-algae-peak) (model)

r (all) r (p<0.05)

0-1.0 1.0

Timing correlation

corr(Tice-melt, Lag) (model)

r (all)

0-1.0 1.0

r (p<0.05)

Model results: W. transect

Summary

Earlier ice-meltEarlier ice-melt

Earlier phytoplankton bloomEarlier phytoplankton bloom

Earlier ice-algae bloomEarlier ice-algae bloom

Shrinking lag between phyto. & ice-algae blooms

Shrinking lag between phyto. & ice-algae blooms

only in E. Arctic

Potential henological match/mismatch between algae blooms and zooplankton

Need for further study (model development and validation; more phenology analysis).

Acknowledgement

NSF Shelf-Basin Interaction (SBI) project

WHOI Arctic Research Initiative

IARC, University of Alaska

DOE EPSCoR Program

Centre for Ice, Climate and Ecosystems (ICE), Norwegian Polar Institute