* denotes first author student  |  ** denotes first author postdoc/visiting professor

Journals

*Xia, W. and H. Xie, 2018. Assessing three waveform retrackers on sea ice freeboard retrieval from Cryosat-2 using Operation IceBridge Airborne altimetry datasets. Remote Sensing of Environment, 204: 456-471. doi:10.1016/j.rse.2017.10.010

Thomson, J., S. Ackley, H. H. Shen, and W. E. Rogers, 2017. The balance of ice, waves, and winds in the Arctic autumn, Eos, 98. doi:10.1029/2017EO066029

Zhao, J., D. Barber, S. Zhang, Q. Yang, X. Wang, and H. Xie, 2017. Record low sea ice concentration in the central Arctic during summer of 2010. Advances in Atmospheric Sciences. doi:10.1007/s00376-017-7066-6

Lee, C.M., J. Thomson, and the Marginal Ice Zone and Arctic Sea State (S.F. Ackley, et al) Teams, 2017. An autonomous approach to observing the seasonal ice zone in the western Arctic. Oceanography, 30(2):56–68. doi:10.5670/oceanog.2017.222

*Li, L., C. Ke, H. Xie, R. Lei, and A. Tao, 2017. Aerial observations of sea ice and melt ponds near the North Pole during CHINARE2010. Acta Oceanologica Sinica 36(1): 64-72. doi:10.1007/s13131-017-0994-2

Miao, X., H. Xie, S.F. Ackley, and S. Zheng, 2016. Object-based Arctic sea ice ridge detection from high spatial resolution imagery, IEEE Geoscience and Remote Sensing Letters. doi:10.1109/LGRS.2016.2544861

Huang, W., P. Lu, R. Lei, H. Xie, and Z. Li, 2016. Melt pond distribution and geometry in high Arctic sea ice derived from aerial investigations. Annals of Glaciology. 14 pp. doi:10.107/aog.2016.30

**Miao, X., H. Xie, S.F. Ackley, D.K. Perovich, and C. Ke, 2015. Object-based detection of Arctic sea ice and melt ponds using high resolution aerial photographs, Cold Regions Science and Technology, Vol 119: 211-222. doi:10.1016/j.coldregions.2015.06.014

Lei, R., H. Xie, J. Wang, M. Lepparanta, I. Jonsdottir, Z. Zhang, 2015. Changes in sea ice along the Arctic northeast passage since 1979: Results from remote sensing data, Cold Regions Science and Technology. Vol 119: 132-144. doi:10.1016/j.coldregions.2015.08.004

*Xia, W., H. Xie, C. Ke, J. Zhao, R. Lei, and S.F. Ackley, 2015. Summer surface albedo of sea ice in Pacific Arctic Sector as measured during the CHINARE 2010 cruise. Artic, Antarctic, and Alpine Research, Vol.47(4):645-656. doi:10.1657/AAAR0014-090

*Xia, W., H. Xie, and C. Ke, 2014. Assessing trend and variation of Arctic sea ice extent during 1979-2012 from a latitude perspective of ice edge. Polar Research. 33, 21249. doi:10.3402/polar.v33.21249

Xie, H., R. Lei, C. Ke, H. Wang, Z. Li, J. Zhao, and SF Ackley, 2013. Summer sea ice characteristics and morphology in the Pacific Arctic sector as observed during the CHINARE 2010 cruise. The Cryosphere, Vol.7: 1057-1072. doi:10.5194/tc-7-1057-2013

Xie, H., R. Lei, C. Ke, H. Wang, Z. Li, J. Zhao, and SF Ackley, 2012. Summer sea ice in the recent Arctic: morphological properties in the Pacific sector from the CHINARE 2010 cruise. The Cryosphere Discussion, Vol. 6: 1963-2004. doi:10.5194/tcd-6-1963-2012

Zhang, R., C. Ke, H. Xie, and B. Sun, 2012. Surface albedo measurements over sea ice in the Arctic ocean during summer 2010. Chinese Journal of Polar Research (in Chinese with English abstract). Vol. 24(3): 299-306. doi:10.3724/SP.J.1084.2012.00299

Tao, A., C. Ke, H. Xie, B. Sun, 2012. Variation of irradiance in the Arctic pole during the summer. Spectroscopy and Spectral Analysis (in Chinese with English abstract). Vol. 32 (8): 2037-2042. doi: 10.3964/j.issn.1000-0593(2012)08-2037-06

Ke, C., H. Xie, R. Lei, Q. Li, and B. Sun, 2012. Spectral features analysis of sea ice in the Arctic Ocean. Spectroscopy and Spectral Analysis (in Chinese with English abstract). Vol. 32(4): 1081-1084. pubmed:22715789

2010 Fall AGU abstract

The Fourth Chinese National Arctic Research Expedition (CHINARE) from July 1 to Sep. 20, 2010, the last Chinese campaign in Arctic Ocean contributing to the fourth International Polar Year (IPY), conducted comprehensive scientific studies on ocean-ice-atmosphere interaction and the marine ecosystem's response to climatic change in Arctic. This paper presents an overview on sea ice (ice concentration, floe size, melt pond coverage, sea ice and snow thickness) of the Pacific Arctic sector, in particular between 150°W to 180°W to 88.5°N, based on (1) underway visual observations of sea ice at half-hourly and automatic camera recording (side looking in both starboard sides of the R.V. Xuelong) every 10 to 15 seconds; (2) a downward-looking video mounted on the left port side of the Xuelong at a height of 7 m above waterline recording overturning of ice floes; (3) on-site measurements of snow and ice thickness using drilling and electromagnetic instrument EM31 (9.8 kHz) at eight short-term (~3 hours each) and one 12-day ice stations; (4) six flights of aerial photogrammetry from helicopter, and (5) Satellite data (AMSE-E ice concentration, ENVISAT ASAR, and NIC ice charts) that extended the observations/measurements along the ship track and airborne flights. In the northward leg, the largest ice concentration zone was in the area starting from ~75°N (July 29), with ice concentration of 60-90% (mean ~80%), ice thickness of 1.5-2m, melt ponds of 10-50% of ice, ridged ice of 10-30% of ice, and floe size of 100's m to kms. The 12-day ice station (from Aug 7-19), started at 86.92°N/178.88°W and drifted a total of 175.7km, was on an ice floe over 100 km2 in size and ~2 m in mean thickness. There were two heavy and several slight snowfall events in the period (July 29 to Aug 19). Snow thickness varies from 5cm to 15 cm, and melted about 5cm during the 12-day ice camp. In the southward leg, the largest sea ice concentration zone was in the area between 87°N to 80°N (from August 21 to August 24). In this area, the ice concentration varied from 70-100%, melt pond varied from 20-50% of ice, ridged ice varied from 10-30% of ice, and floe size was dominated by 10's km to several km's in one or two dimensions. The overall ice thickness decrease southwards from 1.8-2m to 0.6-1m. The ice type of the area was multiyear ice dominated, with small portion of first year ice. In the area from ~85°N to 83.5°N, we saw dirty ice (brownish, rich hills and valleys, mostly multiyear ice), varying from 10-20% of ice. Similar dirty ice was only seen 72°N-75°N in the northward leg (July 24-29). The ice situation in this cruise will be compared with that from the CHINARE-2008 cruise, in the similar area and season, so change of the two years for this sector of Arctic Ocean during the middle-later summer can be deduced.

(Acknowledgements: The study was partially supported by the NASA grant (#NNX08AQ87G), the Chinese NSF grant (#40930848), and the Norwegian grant (#193592/S30). Travel expenses for H. Xie were covered by the NOAA's Climate Research/Sea Ice Outlook Program. We sincerely acknowledge the supports from the Chinese Arctic and Antarctic Administration and the The fourth Chinese Arctic Expedition Team)

2011 CryoSat Validation Workshop (February 1-3, Frascati/Rome, Italy)

The Fourth Chinese National Arctic Research Expedition (CHINARE) from July 1 to Sep. 20, 2010, conducted ocean-ice-ecosystem-atmosphere study in the Pacific Arctic sector, in particular between 150°W to 180°W to 88.5°N. Sea ice thickness measurements were performed at 8 short-term ice stations and one long-term ice station using electromagnetic induction sounding (EM31). The EM-estimated thicknesses were compared with borehole-drilling thicknesses. The error found is between 3-7%. In each short-term ice station, one or more profiles covering the work zone were surveyed with a fixed sampling interval of approximately one meter (two steps). In the long-term ice station (~86°50'N-87°20'N), a grid of 8 profiles of 100 meters in work zone 2 and two other profiles (200m and 125m) in work zone 3 were surveyed with repeat intervals of 3 to 4 days. A mean of 1.8cm per day in ice melting (primarily bottom melting) was obtained at the long-term station from Aug 10-19. The mean sea ice thickness at the long-term ice station was ~1.8m, while it was from 1.2-2.1m for the 8 short-term ice stations. Those thicknesses data are valuable in calibrating/validating Cryosat sea ice thickness, if available for the time and for the region.

(Acknowledgements: The study was partially supported by the NASA grant (#NNX08AQ87G) and the Chinese NSF grant (#40930848). Travel expenses for H. Xie were covered by the NOAA's Climate Research/Sea Ice Outlook Program. We sincerely acknowledge the supports from the Chinese Arctic and Antarctic Administration and the The fourth Chinese Arctic Expedition Team)