## 4 Discussion
### Paleoenvironmental Implication for Sediment Provenance Changes
The coarse grains characterizing the IRD content in Arctic sediments have been intensively affected by global warming and climate change, as demonstrated by many paleoceanographic studies [21; 23]. The IRD events may have occurred during weaker glacial periods when there was no permanent sea ice cover and icebergs could circulate freely in the Arctic Ocean [8]. Earlier studies have shown that IRD was transported and relayed in the Arctic Ocean during glacial periods, glacial terminations, or even interglacial periods [23; 32; 38]. The major IRD events in core ARA09C-St03 are mainly represented in Units 2, 4, and 7 (Figure 2). North America might be the sediment provenance of these units, characterized by abundant dolomite and K/C ratios. The dolomite-rich IRD events that occurred in the western Arctic Ocean reflect the initiation and disintegration of the Laurentic Ice Sheet [8; 39]. During deglacial and interglacial periods, rising sea levels led to ice shelf collapses, and the BG's circulation resumed close to modern patterns and transported icebergs across the open Arctic Ocean [23]. However, units 4 and 7 received sediment from the Canadian Archipelago, while the source area of Unit 2 sediment was determined as the Beaufort Sea. These differences in sediment provenance might be related to the scale of the Laurentic Ice Sheet. Our results suggest that the Laurentic Ice Sheet during the MIS 2 period (i.e., LGM) with the lowest sea level probably expanded significantly more than in other stadial periods since the late MIS 5 and thereby supplied sediments primarily from the Beaufort Sea. In the western Arctic Ocean, paleoenvironmental reconstruction has mainly been studied in the basin area with short or absent records for MIS 2. Because the study area or Chukchi Rise has high-resolution records of this period [17; 21], further studies in these areas are required to facilitate the reconstruction of the paleoenvironment during the LGM. Interglacial sediments likely correspond to Units 1, 4, and 6 in the core ARA09C-St03 (Figure 2). However, Unit 4's sediment exhibits both interglacial and deglacial characteristics, of which the latter are stronger. Interglacial sediments are of mixed origin from Eurasia and the Canadian Archipelago (Figures 4 and 5), which is consistent with previous results from the Chukchi Basin and Rise [21; 23]. The similar sediment provenances of two units during the interglacial period suggest similar sediment transport mechanisms, and we seek to understand the interglacial sediments through the records of Unit 1, probably corresponding to the Holocene. The Holocene Arctic Ocean is characterized by an increase in the surface water's primary productivity owing to reduced sea ice cover [21; 40]. In addition, the Laurentide Ice Sheet on the Canadian Arctic Archipelago was extinct completely at about 7-8 ka [41], and thus Unit 1 sediments can be transported by oceanic current and seasonal sea ice. Illite-rich sediment from the East Siberian Sea could be supplied to the study area through coastal current, and Canadian Archipelago-derived materials were likely transported via the BG. The Canadian Archipelago indicators characterized as abundant carbonate minerals are commonly found from the Chukchi Rise to the Chukchi Basin during the interglacial/interstadial period [21; 23]. The surface circulations are controlled by AO [12], and these periods were likely associated with the negative AO's intensification of the BG.