Publication Date:
2023-10-24
Description:
The effect that sea ice topography has on the mo-
mentum transfer between ice and atmosphere is not fully
quantified due to the vast extent of the Arctic and limita-
tions of current measurement techniques. Here we present a
method to estimate pan-Arctic momentum transfer via a pa-
rameterization that links sea ice–atmosphere form drag coef-
ficients with surface feature height and spacing. We measure
these sea ice surface feature parameters using the Ice, Cloud
and land Elevation Satellite-2 (ICESat-2). Though ICESat-2
is unable to resolve as well as airborne surveys, it has a higher
along-track spatial resolution than other contemporary al-
timeter satellites. As some narrow obstacles are effectively
smoothed out by the ICESat-2 ATL07 spatial resolution, we
use near-coincident high-resolution Airborne Topographic
Mapper (ATM) elevation data from NASA’s Operation Ice-
Bridge (OIB) mission to scale up the regional ICESat-2 drag
estimates. By also incorporating drag due to open water, floe
edges and sea ice skin drag, we produced a time series of
average total pan-Arctic neutral atmospheric drag coefficient
estimates from November 2018 to May 2022. Here we have
observed its temporal evolution to be unique and not directly
tied to sea ice extent. By also mapping 3-month aggregates
for the years 2019, 2020 and 2021 for better regional anal-
ysis, we found the thick multiyear ice area directly north of
the Canadian Archipelago and Greenland to be consistently
above 2.0 × 10 −3 , while most of the multiyear ice portion of
the Arctic is typically around 1.5 × 10 −3 .
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
