UNIVERSITY OF HAWAII SYSTEMS
The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate system. Paleo-evidence suggests that this circulation has experienced rapid reorganizations, particularly during the last glacial period. Understanding the driving mechanisms of this climate engine and its sensitivity to past and future perturbations requires an in-depth understanding of the dynamical processes that maintain the AMOC. Here, we focus on the processes that establish its sinking branch. This project will conduct a comprehensive study of the dynamics of thermally-driven circulation in the subpolar North Atlantic. The overall goal is to understand the fundamental, 3-dimensional dynamics of the AMOCs large-scale descending branch, including its dependence on horizontal and vertical mixing, buoyancy fluxes, winds, bottom topography and basin geometry, and southern-hemisphere forcing. To address this goal, we will develop a hierarchy of solutions to an ocean general circulation model (OGCM) and, when useful, obtain corresponding solutions to layer models. At the base of our hierarchy is a thermally forced, inviscid, OGCM solution that develops no diapycnal overturning. A first task in our study, then, is to understand in detail the processes (horizontal vs. vertical mixing, diffusion vs. viscosity, strength of surface heating) that breakdown this null state. Further tasks will sequentially consider the impacts of the other processes listed in our goal.The expected outcome is an improved understanding of the processes that determine the strength and location of deep subpolar downwelling and its relationship to the large-scale AMOC. Through our focus on the physics of the AMOC sinking branch, this research will provide important dynamical insights that will help to assess the stability of the AMOC with respect to density perturbations. It will also help in the interpretation of paleo-proxy data that show evidence of rapid AMOC transitions in the North Atlantic region and in the evaluation of non-eddy resolving future climate change model simulations.
Choose a quarter and click "Go."
| AWARD OVERVIEW |
| Award Number |
0849747 |
Funding Agency |
National Science Foundation |
| Total Award Amount |
$443,595 |
Project Location - City |
HONOLULU |
| Award Date |
06/01/2009 |
Project Location - State |
HI |
| Project Status |
More than 50% Completed |
Project Location - Zip |
96822-2303
|
| Jobs Reported |
0.55 |
Congressional District |
01 |
| Project Location - Country |
US |
|
|
Recipient Information
(Grants)
| Recipient Information (Grants) |
|
Recipient Name
|
UNIVERSITY OF HAWAII SYSTEMS |
| Recipient DUNS Number |
965088057
|
| Recipient Address |
2425 CAMPUS RD SINCLAIR LIBRARY RM 1 |
| Recipient City |
HONOLULU |
| Recipient State |
Hawaii |
| Recipient Zip |
96822-2247 |
| Recipient Congressional District |
01 |
| Recipient Country |
USA |
Required to Report Top 5
Highly Compensated Officials |
No |
Projects and Jobs Information
| Projects and Jobs Information |
| Project Title |
Dynamics of the Descending Branch of the Atlantic Meridional Overturning Circulation |
| Project Status |
More than 50% Completed |
| Final Project Report Submitted |
No |
| Project Activities Description |
Science & Technology, General/Other |
| Quarterly Activities/Project Description |
The overall goal of the project is to understand the basic processes that cause the Atlantic meridional circulation (AMOC) and determine its strength. Last year, we published our first paper from the project, which considers in detail how surface heating impacts AMOC strength and structure (Task 1). During the last quarter, Fabian Schloesser (now a postdoctoral fellow at the University of Rhode Island) submitted a second paper that discusses how wind forcing alters the heat-driven solutions reported in our first paper (Task 2). Research is continuing on exploring the impact of heat forcing confined to the interior of the ocean, and initial results show that such forcing drives a much weaker AMOC (Task 1A). We have begun to study the impact of continental shelves on AMOC circulations (Task 3): We submitted a paper on the dynamics of the Leeuwin Current, which is closely related to the AMOC dynamics; it suggests that the presence of a continental shelf along the eastern and northern ocean boundaries can modify AMOC pathways |
| Jobs Created |
0.55 |
| Description of Jobs Created |
PI/Assistant Researcher |
Purchaser Information
(Grants)
| Purchaser Information |
| Contracting Office ID |
Not Reported |
| Contracting Office Name |
Not Available |
| Contracting Office Region |
Not Available |
| TAS Major Program |
49-0101 |
| Award Information |
| Award Date |
06/01/2009 |
| Award Number |
0849747 |
| Order Number |
|
| Award Type |
Grants |
| Funding Agency ID |
49 |
| Funding Agency Name |
National Science Foundation |
| Funding Office Name |
Not Available |
| Awarding Agency ID |
49 |
| Awarding Agency Name |
National Science Foundation |
| Amount of Award |
$443,595 |
| Funds Invoiced/Received |
$403,889 |
| Expenditure Amount |
$403,889 |
| Infrastructure Expenditure Amount |
$0 |
| Infrastructure Purpose and Rationale |
Not Reported |
| Infrastructure Point of Contact Name |
Not Reported |
| Infrastructure Point of Contact Email |
Not Reported |
| Infrastructure Point of Contact Phone |
Not Reported |
| Infrastructure Point of Contact Address |
Not Reported |
| Infrastructure Point of Contact City |
Not Reported |
| Infrastructure Point of Contact State |
Not Reported |
| Infrastructure Point of Contact Zip |
Not Reported |
Product or Service Information
(Grants)
| Product or Service Information |
| Primary Activity Code |
U01 |
| Activity Description |
Science & Technology, General/Other |
| Sub-Awards Information |
| Sub-awards to Organizations |
0 |
| Sub-award Amounts to Organizations |
$0 |
| Sub-Awards to Individuals |
0 |
| Sub-Award Amounts to Individuals |
$0 |
| Number of Sub-awards less than $25,000/award |
0 |
| Amount of Sub-awards less than $25,000/award |
$0 |
| Number of payments to vendors greater than $25,000 |
0 |
| Total Amount of payments to vendors greater than $25,000/award |
$0 |
| Number of payments to vendors less than $25,000/award |
17 |
| Total Amount of payments to vendors less than $25,000/award |
$5,382 |
| Location Information |
| Latitude, Longitude |
21º 19' 10",
-157º 48' 35" |
| Congressional District |
01 |
| Address 1 |
UH MANOA |
| Address 2 |
POST 4TH FLOOR |
| City |
HONOLULU |
| County |
Honolulu |
| State |
HI |
| Zip |
96822-2303 |
|
 |