Ensemble-based estimation of sea-ice volume variations in the Baffin Bay

Abstract

Abstract. Sea ice in the Baffin Bay plays an important role in deep water formation in the Labrador Sea and contributes to the variation of the Atlantic meridional overturning circulation (AMOC) on larger scales. Sea-ice data from locally merged satellite observations (Sat-merged SIT) in the eastern Canadian Arctic and three state-of-the-art sea ice–ocean models are used to quantify sea-ice volume variations from 2011 to 2016. Ensemble-based sea-ice volume (SIV) fluxes and the related standard deviations in the Baffin Bay are generated from four different estimates of SIV fluxes that were derived from Sat-merged SIT, three modeled SITs and satellite-based ice-drift data. Results show that the net increase in the SIV in Baffin Bay occurs from October to early April with the largest SIV increase in December (113 ± 17 km3 month−1) followed by a reduction from May to September with the largest SIV decline in July (−160 ± 32 km3 month−1). The maximum SIV inflow occurs in winter with the amount of 236 (±38) km3 while ice outflow reaches the maximum in spring with a mean value of 168 (±46) km3. The ensemble mean SIV inflow reaches its maximum (294 ± 59 km3) in winter 2013 caused by high ice velocity along the north gate while the largest SIV outflow (229 ± 67 km3) occurs in spring of 2014 due to the high ice velocity and thick ice along the south gate. The long-term annual mean ice volume inflow and outflow are 411 (±74) km3 yr−1 and 312 (±80) km3 yr−1, respectively. Our analysis also reveals that, on average, sea ice in the Baffin Bay melts from May to September with a net reduction of 335 km3 in volume while it freezes from October to April with a net increase of 218 km3. In the melting season, there is about 268 km3 freshwater produced by local melting of sea ice in the Baffin Bay. In the annual mean, the mean freshwater converted from SIV outflow that enters the Labrador Sea is about 250 km3 yr−1 (i.e., 8 mSv), while it is only about 9 % of the net liquid freshwater flux through the Davis Strait. The maximum freshwater flux derived from SIV outflow peaks in March is 65 km3 (i.e., 25 mSv).

Impacts of snow data and processing methods on the interpretation of long-term changes in Baffin Bay early spring sea ice thickness

“…S5). The higher sea ice thickness in the northeast of Baffin Bay in the LARM CryoSat-2 sea ice thickness from this study is not present in the Min et al (2021) sea ice thickness ensemble product.…”

“…The spatial distribution of sea ice thickness is similar. Comparisons of CryoSat-2 mean sea ice thickness with a model-ensemble-based estimation in Baffin Bay (Min et al, 2021) show a similar spatial pattern and magnitude in sea ice thickness for most of Baffin Bay (Sect. S5).…”

Arctic Ocean Freshwater in CMIP6 Coupled Models

“…For models that do not provide the h i variable, we multiply sea ice concentration with sea ice thickness to calculate it. Taking all these values into the above equation, we can estimate the SFWC as $$$\mathrm{S}\mathrm{F}\mathrm{W}\mathrm{C}={\iint }_{A}\frac{{S}_{\mathrm{r}\mathrm{e}\mathrm{f}}-{S}_{i}}{{S}_{\mathrm{r}\mathrm{e}\mathrm{f}}}\frac{{\rho }_{i}}{{\rho }_{w}}{h}_{i}\mathrm{d}s\approx 0.79{\iint }_{A}{h}_{i}\mathrm{d}s$$$ which is consistent with other publications (e.g., C. Min et al., 2021; Spreen et al., 2020).…”

Revisiting Trans-Arctic Maritime Navigability in 2011–2016 from the Perspective of Sea Ice Thickness

“…As shown in Figure 5, there was a positive anomaly in most regions of the Baffin Bay (BB) for both OW and PC6 vessels in all years. The areas close to the Baffin Island were not perennially accessible because the thick ice (>1.2 m) was located east of Baffin Island in March [40]. The navigable days in the CAA were almost with negative anomaly for both vessels because thick ice obstructed the narrow strait, especially in the northwest of the CAA.…”