Sea Ice Observations: Where Would We Be Without the Arctic Observing Network? Jackie Richter-Menge ERDC-CRREL

Sea Ice Observations: Where Would We Be Without the Arctic Observing Network? Jackie Richter-Menge ERDC-CRREL Thanks to all who contributed!

Objectives Highlight scientific contributions of AON: Key outcome of the International Polar Year (2007-2008) Enabled significant advancement in coordinated use of instruments to observe arctic environmental change on decadal time scale Better understand processes governing change Improved ability to predict and respond to near and long term changes in condition of sea ice cover Overview of current observational capabilities Instruments deployed on satellite, airborne, submarine and in situ platforms Future challenges

Sea Ice Observations: Where Would We Be Without the Arctic Observing Network?

Satellites: Observing from afar Arctic Mosaic: 29 March Unparalleled spatial and temporal coverage

Satellite-derived products Immediately and widely available http://osisaf.met.no/p/ice/ http://arctic.atmos.uiuc.edu/cryosphere/ Basin scale properties: Ice extent and concentration Ice motion Ice thickness http://www.cpom.ucl.ac.uk/csopr/seaice.html

International Arctic Buoy Programme http://iabp.apl.washington.edu/index.html Maintain a network of drifting buoys to provide meteorological and oceanographic data for real-time operational requirements and research purposes Sea level pressure Surface air temperature Ice motion Since 1978: A sustained network of drifting buoys

2007 Ice Age Maps Tschudi et al., 2015 http://nsidc.org/data/docs/daac/nsidc0611-sea-ice-age/ Significant increase in amount of younger, seasonal ice: > 4 yrs old: 20% in 1985, 3 % in 2015 < 1 year old: 50% in 1985, 70% in 2015 State change in 2007, following record minimum Decreased overall thickness and volume Contemporary pack more vulnerable to summer melt Lower minimum extent

NSF AON: Sea Ice Deformation High resolution (~hourly) IABP position data Buoy Triads -> strain rate components -> average components, area weighting -> mean divergence (e I ) and max. shear (e II ) Mean Divergence Kim Martini & Jenny Hutchings, GRL paper submitted

NSF AON: Sea Ice Deformation K. Martini & J. Hutchings, GRL paper submitted Significant change in deformation patterns: Linked to change in composition in 2007?

Measures Position Barometric pressure Start of freezeup Start of melt Ice growth Surface melt Bottom melt Temperature profile Air, snow, ice, ocean For up to 3 years Ice mass balance buoys http://imb.erdc.dren.mil/index.htm Multi-year Ice Seasonal Ice Over 100 IMBs deployed since 2000 A way to attribute thermodynamically-driven change

Ocean heat flux (Wm -2 ) Barometric pressure (mb) Depth (cm) Water Temperature ( o C) Ice Mass Balance Buoys: Sea ice loss 1060 1040 1020 1000 980 10 0-10 -20-30 -40-50 50 Air Temperature ( o C) 960 0-50 -100-150 -200-250 -300-350 -0.5-1.0-1.5 Ice Snow IMB 2006C: Beaufort Sea Snow Ice 2006 2007 2008 Ocean -2.0 0 Sep Dec Mar Jun Sep Dec Mar Jun Sep Dec Mar Jun 100 50-20 -19-18 -17-16 -15-14 -13-12 -11-10 -9-8 -7-6 -5-4 -3-2 -1 0 Total summer melt (cm) 220 200 180 160 140 120 100 80 60 40 20 0 1959 1976 1993 1997 2005 2006 2007 2007 2013 2014 2014 Surface melt Bottom melt 1957 1958 2005 2006 2007 2008 2008 2008 2011 2013 Summer 2007: Ice concentration 41 sites 17 years 2000 2002 2004 2004 2004 2004 2005 2006 2006 2007 2008 2010 2013 Beaufort Intermediate North Pole Enhanced solar heating of upper ocean driving ice loss in Beaufort Sea 20-40 40-60 60-80 150 km 80-100

Seasonal Ice Zone Observing Network Airborne ice surveys: 2007-2015 Ice mass balance site: 2000-2015 Subsistence trail mapping: 2007-2015 Under-ice moorings: 2009-2015 Local ice observations: 2007-2015 SIZONet.org Provided by A. Mahoney

SIZONet: key findings First-year sea ice at Barrow is thinning Interannual thickness changes representative of regional ice pack Coastal ice heavily influenced by ocean Mid-winter bottom ablation linked to upwelling North Atlantic water Local ice motion opposes wind ~25% of the time Hanna Shoal is source of some of the thickest ice in Chukchi Sea Significant as both habitat and hazard Provided by A. Mahoney 2011 AEM survey

NASA IceBridge Mission: 2009-2018 http://nsidc.org/data/icebridge/index.html 2015 Quick Look Products Snow depth Objectives Document spatial and interannual changes in sea ice thickness distribution between ICESat and ICESat-2 Improve sea ice thickness retrieval algorithms by advancing technologies for measuring sea ice surface elevation, freeboard, and snow depth Ice thickness

Sea Ice Thickness: Interannual Variability March/April 2009-2015 Beaufort/Chukchi Central Arctic: Predominantly multi-year Stable mean and modal ice thickness Mean: 3.2 m, mode: 2.5 m Beaufort/Chukchi seas: More seasonal in nature Mix of multiyear (~25 %) and first-year ice (~75 %) Ice thickness distribution more variable Mean: 2.1 m, mode 1.8 m Inter-annual variability primarily related to presence and location of a band of multi-year sea ice in the southern Beaufort Sea Central Arctic Richter-Menge and Farrell (2013) GRL, updated

NASA IceBridge: Snow depth on sea ice Surprise! OIB snow depth (2009-2013) compared to Warren et al. (1999) Change in Snow Depth (cm) Evolution of surface conditions Pond Pond formation formation function function of of ice ice types types Ponds Ponds formed formed on on MYI MYI before before FYI FYI Snow Snow depth depth distributions distributions drive drive timing timing and and progression progression of of melt melt Webster et al., 2014 Snow climatology Snow depth decline in western Arctic Most pronounce in Beaufort and Chukchi seas region Thinning negatively correlated with the delayed onset of fall freezeup Webster et al., 2015

Sea ice thickness: Crosscheck NASA IceBridge and ESA CryoSat-2 Strong gradient to thinner, seasonal ice in the Canada Basin and the eastern Arctic Ocean, where ice is between 1-2 m thick Oldest ice north of Greenland and the Canadian Arctic Archipelago remains > 3 m Provided by Sinead L. Farrell Good consistency between independent estimates of sea ice thickness

Sea ice thickness: Inter-comparison CroySat-2: Ice draft Kwok and Cunningham, 2015 Beaufort Gyre EO: Moored upward looking sonar SCICEX: Ice draft Airborne EM: Snow + ice thickness OIB: Ice thickness Multiple Platforms: Establishes confidence in results

Sea ice thickness Basin scale trend: 1978-2015 Kwok and Cunningham, 2015 Significant contrast between the 1980s and 2000, decreasing by ~ 1.5 m

Summary AON key to significant scientific advancements in observing and understanding Arctic sea ice environment Corroborating evidence shows significant shift in the state of the sea ice cover in western Arctic Ocean Largely a result of compositional changes in the Beaufort and Chukchi seas Influencing both thermodynamic and dynamic processes Affecting both sea ice and snow properties

Summary Long term observations required to document and understand changes occurring on decadal time scales Complementary platforms key to robust results Guide development of comprehensive process studies (e.g. ONR MIZ and Sea State DRIs) Data accessibility facilitates novel usage Ultimately lead to improved predictability

Future Challenges Sustainability: The art of leveraging Interagency Arctic Research Program Committee (IARPC) Private interests International collaboration Communication of results Single portal with links to data Broad interpretation of AON components Highlight outcomes Get a logo!