NSF Org:	OPP Office of Polar Programs (OPP)
Recipient:	UNIVERSITY OF HAWAII
Initial Amendment Date:	March 9, 2022
Latest Amendment Date:	March 9, 2022
Award Number:	2141358
Award Instrument:	Standard Grant
Program Manager:	Penny Vlahos pvlahos@nsf.gov  (703)292-2671 OPP  Office of Polar Programs (OPP) GEO  Directorate for Geosciences
Start Date:	March 15, 2022
End Date:	February 28, 2026 (Estimated)
Total Intended Award Amount:	$321,184.00
Total Awarded Amount to Date:	$321,184.00
Funds Obligated to Date:	FY 2022 = $321,184.00
History of Investigator:	David Ho (Principal Investigator) ho@hawaii.edu
Recipient Sponsored Research Office:	University of Hawaii 2425 CAMPUS RD SINCLAIR RM 1 HONOLULU HI  US  96822-2247 (808)956-7800
Sponsor Congressional District:	01
Primary Place of Performance:	University of Hawaii at Manoa 1000 Pope Rd., Department of Oce Honolulu HI  US  96822-2336
Primary Place of Performance Congressional District:	01
Unique Entity Identifier (UEI):	NSCKLFSSABF2
Parent UEI:
NSF Program(s):	ANS-Arctic Natural Sciences
Primary Program Source:	0100CYXXDB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s):	1079, 5294, 9150
Program Element Code(s):	528000
Award Agency Code:	4900
Fund Agency Code:	4900
Assistance Listing Number(s):	47.078

ABSTRACT

Part 1:
The Arctic Ocean covers the North Pole and its surface is frozen each winter with a layer of sea ice that can be 1-3 meters thick. When seawater freezes, the ice expels the salt so that the layer of ice is composed mostly of freshwater. Therefore, when the sea ice melts in summer, it creates a thin layer of freshwater that floats on the saltier seawater beneath it. Traditional oceanographic measurements rarely measure this fresh layer because ships typically collect data from a depth of about 5 m. Yet, these freshwater lenses may play a key role influencing the atmosphere-ocean exchange of gases, including carbon dioxide, the principal gas responsible for global warming and the loss of nearly half of the summertime sea ice coverage of the Arctic Ocean. The Arctic Ocean is thought to absorb about 10% of the human emissions of carbon dioxide. Still, this number is highly uncertain, owing partly to the scarcity of observations at the very surface. This project aims to address that source of uncertainty by sampling the freshwater layer in the Beaufort Sea, both aboard a Research Vessel and on an autonomous surface platform called Wave Glider. We will compare the chemistry of the fresh layer to the saltier water just beneath it and use these data to correct estimates of carbon dioxide uptake for this previously-unmeasured impact across the entire portion of the Arctic that experiences seasonal sea ice melt, an area up to 2.5 times the size of Texas. Better estimates of ocean carbon uptake help us better understand the global carbon budget and monitor efforts to slow climate change. Project scientists will train a Ph.D. student and work with science communication experts at URI?s Metcalf Institute to engage journalists and public audiences in Arctic Ocean science through a webinar series.

Part 2:
The Arctic Ocean takes up about 10% of the carbon dioxide that humans emit, which helps diminish the effects of climate change. However, our knowledge about the Arctic Ocean carbon sink is uncertain due to the number of observations and how they are collected. The Arctic is warming faster than anywhere else on Earth, leading to dramatic changes in sea ice cover. The fresher meltwater layer left behind by the retreating sea ice typically lasts for 1 to 5 weeks. It has different carbon dioxide levels than the water just a few meters deeper, where ships generally have sampled due to the locations of their water intakes. Because the uptake of carbon by the ocean is determined by the carbon dioxide levels right at the surface, this difference between the meltwater and what is typically sampled by ships requires a correction to these ship-based measurements. This correction will affect the carbon sink over an area of the seasonally ice-free Arctic Ocean covering 0.35 to 1.75 million km2 (an area up to 2.5 times larger than Texas).

Carbon Levels at the Arctic Salinity?Stratified Sea Ice Edge (CLASSSIE) is a project to measure key carbon system parameters in the marginal ice zone of the Beaufort Sea. The project will collaborate with scientists funded by the NASA Physical Oceanography program in a project called Salinity and Stratification at the Sea Ice Edge (SASSIE). SASSIE will include measurements from a ship and autonomous surface vehicles called Wave Gliders. CLASSSIE will make carbon measurements in and under the meltwater layer from the ship and do the same from one of the Wave Gliders. From these measurements, CLASSSIE will determine a relationship between salinity and carbon dioxide levels for an ocean with meltwater input. Using that empirical relationship between salinity and carbon dioxide levels, a correction in the meltwater layer will be proposed and combined with meltwater layer statistics from a computer model to produce a modified map of Arctic Ocean carbon dioxide levels. Finally, a revised estimate of the Arctic Ocean carbon sink will be created with the modified map. Refining estimates of the Arctic Ocean carbon sink will help constrain the global carbon budget, which is crucial to monitoring climate change mitigation. The project will train a Ph.D. student. CLASSSIE will also work with the Metcalf Institute at URI to develop a four-part webinar series to engage journalists, public audiences, and interested researchers in Arctic Ocean science.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

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