Campus Map

Ignatius Rigor

Senior Principal Research Scientist

Affiliate Assistant Professor, Oceanography






Ignatius Rigor is the Coordinator of the International Arctic Buoy Program (IABP). His primary interests are in the use of data from the buoys to study air, sea, and ice interaction. His recent work has focused on analyzing surface air temperature observations in the Arctic, studying sea ice processes in the Russian marginal seas, and backtracking the source areas of pollutants found in sea ice. He joined the professional staff in 1987 after having worked in the APL-UW Student Assistant Program as an undergraduate.

Department Affiliation

Polar Science Center


B.S. Biology, University of Washington, 1986


International Arctic Buoy Programme

The participants of the IABP work together to maintain a network of drifting buoys in the Arctic Ocean to provide meteorological and oceanographic data for real-time operational requirements and research purposes including support to the World Climate Research Programme and the World Weather Watch Programme.


Sea Ice Thickness Estimates Obtained from Satellites Using Submarines and Other In Situ Observations

We compare the observations of arctic sea ice thickness estimates from satellites with in situ observations %u2013 collected by submarine cruises and moorings under the sea ice, by direct measurement during field camps, by electromagnetic instruments flown over the sea ice, and by buoys drifting with the sea ice %u2013 to provide a careful assessment of our capabilities to monitor the thickness of sea ice.


Arctic Surface Air Temperatures for the Past 100 Years

Accurate fields of Arctic surface air temperature (SAT) are needed for climate studies, but a robust gridded data set of SAT of sufficient length is not available over the entire Arctic. We plan to produce authoritative SAT data sets covering the Arctic Ocean from 1901 to present, which will be used to better understand Arctic climate change.


More Projects


International Cooperative Engagement Program for Polar Research

An international team dropped buoys by parachute from a C-130 operated by the Danish Royal Air Force. These buoys are floating weather stations that measure fundamental meteorological properties. Satellite-linked data are used to forecast weather, track sea ice movement, and study climate change in the Arctic. The September 2017 buoy drops enhanced the 100-buoy arctic network by targeting sparsely sampled regions near the North Pole and the Eurasian side of the Arctic Ocean.

30 Oct 2017

Polar Science Weekend @ Pacific Science Center

This annual event at the Pacific Science Center shares polar science with thousands of visitors. APL-UW researchers inspire appreciation and interest in polar science through dozens of live demonstrations and hands-on activities.

More Info

10 Mar 2017

Polar research and technology were presented to thousands of visitors by APL-UW staff during the Polar Science Weekend at Seattle's Pacific Science Center. The goal of is to inspire an appreciation and interest in science through one-on-one, face-to-face interactions between visitors and scientists. Guided by their 'polar passports', over 10,000 visitors learned about the Greenland ice sheet, the diving behavior of narwhals, the difference between sea ice and freshwater ice, how Seagliders work, and much more as they visited dozens of live demonstrations and activities.

The Polar Science Weekend has grown from an annual outreach event to an educational research project funded by NASA, and has become a model for similar activities hosted by the Pacific Science Center. A new program trains scientists and volunteers how to interact with the public and how to design engaging exhibits.

Snow Accumulations on Arctic Sea Ice

Snow plays a key role in the growth and decay of Arctic sea ice each year. APL-UW research assesses spring snow depth distribution on Arctic sea ice using airborne radar observations from Operation IceBridge compared with in situ measurements taken in spring 2012 and historical data from the Soviet drifting ice stations of the mid-20th century. Snow depths have declined in the western Arctic and Beaufort and Chukchi seas. Thinning is correlated with the delayed onset of sea ice freeze-up during autumn.

11 Sep 2014

More Videos


2000-present and while at APL-UW

Geophysical constraints on the Antarctic sea ice cover

Nghiem, S.V., I.G. Rigor, P. Clemente-Colón, G. Neumann, and P.P. Li, "Geophysical constraints on the Antarctic sea ice cover," Remote Sens. Environ., 181, 281-292, doi:10.1016/j.rse.2016.04.005, 2016.

More Info

1 Aug 2016


The stark contrast between Arctic and Antarctic sea ice change is explained.

Observations show a frontal ice zone protecting and enhancing Antarctic sea ice.

The frontal ice zone is strongly influenced by winds and ocean fronts.

Antarctic winds are controlled by topography and ocean fronts by bathymetry.

Topography/bathymetry are stable geological factors constraining Antarctic sea ice.

Interannual variations of light-absorbing particles in snow on Arctic sea ice

Doherty, S.J., M. Steele, I. Rigor, and S.G. Warren, "Interannual variations of light-absorbing particles in snow on Arctic sea ice," J. Geophys. Res., 120, 11,391-11,400, doi:10.1002/2015JD024018, 2015.

More Info

16 Nov 2015

Samples of snow on sea ice were collected in springtime of the 6 years 2008–2013 in the region between Greenland, Ellesmere Island, and the North Pole (82°N – 89°N, 0°W – 100°W). The meltwater was passed through filters, whose spectral absorption was then measured to determine the separate contributions by black carbon (BC) and other light-absorbing impurities. The median mixing ratio of BC across all years' samples was 4 ± 3 ng g-1, and the median fraction of absorption due to non-BC absorbers was 36 ± 11%. Variances represent both spatial and interannual variability; there was no interannual trend in either variable. The absorption Angstrom exponent, however, decreased with latitude, suggesting a transition from dominance by biomass-burning sources in the south to an increased influence by fossil-fuel-burning sources in the north, consistent with earlier measurements of snow in Svalbard and at the North Pole.

Seasonal evolution of melt ponds on Arctic sea ice

Webster, M.A., I.G. Rigor, D.K. Perovich, J.A. Richter-Menge, C.M. Polashenski, and B. Light, "Seasonal evolution of melt ponds on Arctic sea ice," J. Geophys. Res., 120, 5968-5982, doi:10.1002/2015JC011030, 2015.

More Info

4 Sep 2015

The seasonal evolution of melt ponds has been well documented on multiyear and landfast first-year sea ice, but is critically lacking on drifting, first-year sea ice, which is becoming increasingly prevalent in the Arctic. Using 1 m resolution panchromatic satellite imagery paired with airborne and in situ data, we evaluated melt pond evolution for an entire melt season on drifting first-year and multiyear sea ice near the 2011 Applied Physics Laboratory Ice Station (APLIS) site in the Beaufort and Chukchi seas. A new algorithm was developed to classify the imagery into sea ice, thin ice, melt pond, and open water classes on two contrasting ice types: first-year and multiyear sea ice. Surprisingly, melt ponds formed ~3 weeks earlier on multiyear ice. Both ice types had comparable mean snow depths, but multiyear ice had 0–5 cm deep snow covering ~37% of its surveyed area, which may have facilitated earlier melt due to its low surface albedo compared to thicker snow. Maximum pond fractions were 53 ± 3% and 38 ± 3% on first-year and multiyear ice, respectively. APLIS pond fractions were compared with those from the Surface Heat Budget of the Arctic Ocean (SHEBA) field campaign. APLIS exhibited earlier melt and double the maximum pond fraction, which was in part due to the greater presence of thin snow and first-year ice at APLIS. These results reveal considerable differences in pond formation between ice types, and underscore the importance of snow depth distributions in the timing and progression of melt pond formation.

More Publications

In The News

Evidence mounts against so-called climate change hiatus

Live Science, Laura Geggel

Evidence is mounting against the so-called climate change hiatus — a period lasting from 1998 to 2012 — when global temperatures allegedly stopped rising as sharply as they had before. Data collected by scientists from the APL-UW Polar Science Center were used in the recent study.

22 Nov 2017

Fra Aalborg til Nordpolen: Paa mission for NASA (with video)

TV2 Nord (Denmark), Lasse Dieckmann

Ice-hardened buoys, known as Air Expendable Ice Beacons (AXIB), were deployed in the Arctic Ocean near the North Pole from a Royal Danish Airforce C-130 aircraft flying out of Thule Air Base in Greenland.

13 Sep 2017

U.S. Navy leads international effort to deploy buoys into the Arctic Ocean

U.S. Navy News Service

Air-Deployable Expendable Ice Buoys are deployed in the high Arctic near the North Pole from a Royal Danish Air Force C-130 aircraft operating out of Thule Air Force Base in Greenland, as part of the International Arctic Buoy Program (IABP).

12 Sep 2017

More News Items

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center