Sea ice activities and cooperation on ice camps

Sea ice activities and co-operation on ice camps H. Skourup, R. Forsberg, S. M. Hvidegaard hsk@space. dtu. dk DTU Space Division of geodynamics

Sea ice thickness mapped from space NASA ICESat: 2002 – Feb 2010 2 Danmarks Tekniske Universitet ESA Cryo. Sat: April 2010

Cryo. Sat error sources Radar penetration (e. g. snow temperature, snow structure) Identify the sea surface height • Directly by identification of leads • Models Conversion of freeboard into thicknesses (snow depth, density of snow, water and ice) 3 Danmarks Tekniske Universitet 08 September

Cryo. Sat validation campaigns Cryo. Sat Validation Experiment (Cryo. VEx) initiated by ESA to estimate and quantify the error sources over land sea ice pre-launch campaigns since 2002 Post-launch campaigns 2011, 2012, 2014 Collaboration with NASA Operation Ice Bridge 4 Danmarks Tekniske Universitet 08 September

Validation Ku-band radar laser 5 Danmarks Tekniske Universitet 08 September

ASIRAS radar and laser scanner Laser scanner (Riegl LMS Q 240 i/Q 140 i): Near-infrared, 40 Hz At 300 m flight altitude Resolution: 1 m x 1 m Swathwidth: 300 m ASIRAS Radar: Credits: Hendricks et al, IGARSS 2010 ku-band (13. 5 GHz) At 300 m flight altitude Resolution: 10 m x 3 m GPS kinematic positioning INS movements of the aircraft Danmarks Tekniske Universitet

Havis, iskapper og gletsjere Geikie ice cap Danmarks Tekniske Universitet

Installation Norlandair Twin Otter TF-POF Danmarks Tekniske Universitet

Instruments ALS INS Honeywell INS Ox. TS HEATERS 30 cm Camera RIEGL ALS 9 Danmarks Tekniske Universitet 25 cm 08 september

Calibration of systematic misalignment angles (pitch, roll and heading) is performed by overflights from different directions of buildings with known positions of the corners Danmarks Tekniske Universitet

Calibration flights Station Nord CFS Alert Akureyri Kangerlussuaq 11 Danmarks Tekniske Universitet 08 september

Example ALS cross-over statistics Devon Sea ice 03 -05 -2012 29 -04 -2012 Mean: 0. 0 m Mean: -0. 03 m Std: 0. 04 m Std: 0. 14 m Errors are typically less than 10 cm in good conditions, and primarily due to errors in GPS solutions due to long baselines 12 Danmarks Tekniske Universitet 08 September

Cryo. VEx 2014 Flight hours 123 16 Cryo. Sat underflights Danmarks Tekniske Universitet

Coordinated airborne measurements AWI: EM induction sounder to measure draft of sea ice NASA: multiple-instrument mission, e. g. snow radar and ATM Freeboard to thickness conversion under assumption of isostacy: tice = k * hf 14 Danmarks Tekniske Universitet 08 september

Collaboration ice camps Sea ice camps 2014 US Office Naval Research (ONR) 2009 Green. Arc ice camp north of Greenland 2007 APLIS/SEDNA APLIS 07 ONR 14 Green. Arc 09 15 Danmarks Tekniske Universitet 08 September

Cryo. VEx 2014 US Office of Naval Research (ONR) ICECAMP 2014 flights out of Inuvik ASIRAS/ALS, AEM: March 21 -23, 2014 16 Danmarks Tekniske Universitet 08 September

Green. Arc 09 Drifted 190 km between 11 -27/4 (16 days), normal conditions is 40 km 1979 -2006 with extremes 2002 (60 km) and 1997 (147 km) 17 Danmarks Tekniske Universitet 08 September

Green. Arc 09 Organized by DMI, DTU Space in collaboration with CRREL and NASA OIB Overflight of in situ validation line with NASA OIB P-3 to validate snow radar Along the validation line the snow depth was measured with ground penetrating radar Paper by Farrell et al 18 Danmarks Tekniske Universitet 08 September

APLIS 07 The Applied Physics Laboratory Ice Station (APLIS) has occurred every 2 to 4 years since 1978. In 2007, APLIS was one of the first events of the International Polar Year (March 2007 -March 2009). In the first week of March, 2007, the Applied Physics Laboratory built an ice station approximately 190 miles north of Prudhoe Bay. This station was built for a Navy operation, headed by the Arctic Submarine Laboratory. On April 2 nd, the camp was handed over to the National Science Foundation, who are supporting fundamental Arctic sea ice and snow research. The ice station hosted a group of international scientists who study pack ice dynamics, sea ice thickness and mercury deposition chemistry in the Arctic (it also hosted a Danmarks Tekniske Universitet few 19 actors). 08 September

APLIS 07/SEDNA sea ice Experiment 20 Danmarks Tekniske Universitet 08 September

APLIS 07: flight tracks Improving understanding of the dynamic of sea ice mass balance • GPS buoy array • Stress buoy array • Ice Mass Balance buoy • Meteorological Observations • Surface ocean current observations • In-situ survey of ice thickness, calibration transe • In-situ snow survey • EM-bird ice thickness survey • AUV multi-beam sonar ice survey • Ridge study 21 Danmarks Tekniske Universitet 08 September

Overflight of ice camp Runway Danmarks Tekniske Universitet

APLIS 07 science results Journal of Geophysical Research, Vol. 116, C 00 E 03, doi: 10. 1029/2011 JC 007076, 2011 The relationship between Arctic sea ice surface elevation and draft: A case study using coincident AUV sonar and airborne scanning laser M. J. Doble, H. Skourup, P. Wadhams, and C. A. Geiger 23 Danmarks Tekniske Universitet 08 September

Future activities … Cryo. Sat validation, ESA Cryo. Val project Sentinel-3, mid-2015 ICESat-2, 2017 UAV from newly established science platform at Station Nord 24 Danmarks Tekniske Universitet 08 September