Seasonal and Morphological Controls on Nitrate Retention in Arctic Deltas

Abstract Estimates of nitrate loading to the Arctic Ocean are limited by the lack of field observations within deltas partly due to logistical constraints. To overcome this limitation, we use a remote sensing framework to estimate retention of nitrate in Arctic deltas. We achieve this by coupling hy...

Full description

Saved in:
Bibliographic Details
Main Authors: Deon Knights, Anastasia Piliouras, Jon Schwenk, Jayaram Hariharan, Christopher Russoniello
Format: Article
Language:English
Published: Wiley 2023-04-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2022GL102201
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Estimates of nitrate loading to the Arctic Ocean are limited by the lack of field observations within deltas partly due to logistical constraints. To overcome this limitation, we use a remote sensing framework to estimate retention of nitrate in Arctic deltas. We achieve this by coupling hydrological and biogeochemical process models at the network scale for five major Arctic deltas. Binary masks of delta channels were used to simulate flow direction and magnitude through networks. Models were parameterized using historical and seasonal observations. Simulated nitrate retention ranged from 2.9% to 15% of the incoming load. Retention rates were largest during winter but smallest during spring conditions when increased discharges export large nitrate masses to the coast. Under future climate scenarios, retention rates fall by ∼1%–10%. Arctic deltas have an important effect on the magnitude of nitrate entering Arctic seas and the inclusion of processing in deltas can improve flux estimates.
ISSN:0094-8276
1944-8007