The Western Arctic Ocean is a host to major ocean circulation systems, many of which generate eddies that can transport water masses and corresponding tracers over long distances from their formation sites. However, comprehensive observations of critical eddy characteristics are currently not available and are limited to spatially and temporally sparse in situ observations. Here we use high‐resolution spaceborne synthetic aperture radar measurements to detect eddies from their surface imprints in ice‐free sea surface roughness, and in sea ice patterns throughout marginal ice zones. We provide the first estimate of eddy characteristics extending over the seasonally ice‐free and marginal ice zone regions of the Western Arctic Ocean, including their locations, diameters, and monthly distribution. Using available synthetic aperture radar data, we identified over 4,000 open ocean eddies, as well as over 3,500 eddies in marginal ice zones from June to October in 2007, 2011, and 2016. Eddies range in size between 0.5 and 100 km and are frequently found over the shelf and near continental slopes but also present in the deep Canada Basin and over the Chukchi Plateau. We find that cyclonic eddies are twice more frequent compared to anticyclonic eddies at the surface, distinct from the dominating anticyclonic eddies observed at depth by in situ moorings and ice‐tethered profilers. Our study supports the notion that eddies are ubiquitous in the Western Arctic Ocean even in the presence of sea ice and emphasizes the need for improved ocean observations and modeling at eddy scales.

Eddies in the Western Arctic play an important role in transporting heat, salt, and biogeochemical tracers across the continental shelf and within the deep basins. However, comprehensive observations of the regional and temporal variability of the eddy field characteristics are difficult to obtain remotely due to the presence of sea ice, and the available in situ observations remain relatively sparse. Nonetheless, with continuing global warming, increasingly large areas of the Arctic Ocean become seasonally ice‐free and can be observed with remote sensing. Here, we use satellite altimetry data acquired between 1993 and 2018 over the seasonally ice‐free Western Arctic Ocean to detect the signatures and hot spots of large mesoscale eddies, validating their detection method using independent optical and infrared satellite observations. The altimetry measurements were most frequent from July to October, revealing signatures of over 2000 individual eddies that were roughly equally partitioned between cyclones and anticyclones, with radii between 20 and 60 km and characteristic orbital velocities of about 0.05–0.4 m/s. A maximum number of eddies were detected in October in the Beaufort Sea and in November in the Chukchi Sea. The interannual variability of eddies in the Beaufort Sea is correlated with variations of intensity and freshwater content in the Beaufort Gyre. Using the regional eddy statistics, we discuss the potential eddy formation mechanisms over the key regions of their observations in the Amundsen Gulf, the area adjacent to the Mackenzie River mouth, the western part of the Beaufort Sea, and the Chukchi Sea.