| NSF Org: |
OPP Office of Polar Programs (OPP) |
| Recipient: |
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| Initial Amendment Date: | August 8, 2011 |
| Latest Amendment Date: | August 8, 2011 |
| Award Number: | 1107651 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Neil R. Swanberg
OPP Office of Polar Programs (OPP) GEO Directorate for Geosciences |
| Start Date: | September 1, 2011 |
| End Date: | August 31, 2016 (Estimated) |
| Total Intended Award Amount: | $267,274.00 |
| Total Awarded Amount to Date: | $267,274.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
2601 WOLF VILLAGE WAY RALEIGH NC US 27695-0001 (919)515-2444 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
2601 WOLF VILLAGE WAY RALEIGH NC US 27695-0001 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | CDI TYPE II |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.078 |
ABSTRACT
In the Arctic, the arrival of spring is sudden. The abrupt onset of Arctic spring comes with the development of high pressure over Baffin Bay and the Labrador Sea and shifts in the jet stream and storm tracks. These changes are important for the Arctic climate and environment and have critical influences on Arctic peoples and ecosystems. This project will test the hypothesis that the spring Arctic transition is a dynamical phenomenon, driven by the downward influence of the springtime stratospheric final warming, abrupt changes in the flow over and around Greenland and in atmospheric waves over the North Atlantic, and shifts in the frequency and tracks of storms entering the Arctic. The spring transition effects the surface climate and is likely modified by feedbacks from surface processes. The implications of the dynamical onset of Arctic spring for future changes in the Arctic will be explored, through analyses of atmospheric and Arctic surface data, experiments with a global atmospheric model, and analyses of 20th Century and future climate simulations. This project will develop a dynamical understanding of the Arctic spring transition and its interactions with the Arctic environment. It will use this understanding to evaluate climate models based on their ability to simulate the spring transition, and it will examine model projections of future changes in the Arctic environment resulting from changes in the timing, strength, and structure of the spring transition.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The climate of the Arctic differs markedly from winter to spring. In the depths of winter, temperatures fluctuate strongly, but without any trend. Then, following the springtime transition, temperatures rise smoothly and rapidly. The timing of the transition varies from year to year, coming as early as the last week of February and as late as the first week of April. The springtime transition is a key feature of Arctic climate for anyone or anything that lives in or travels through this part of the globe.
In this project we performed a set of experiments using a global atmospheric model to try to answer three questions:
- Why does the springtime transistion happen? Why does its date vary?
- Why is Arctic wintertime climate so variable? Why does this variability drop off in spring?
- How will the springtime transition change as Earth's climate warms?
We found that the answers to these questions are all related, and they involve the warm ocean temperatures (compared to other places at the same latitude) in the North Atlantic Ocean east of Greenland. When winds blow from the south over this warm region, they bring heat into the Arctic. This transport of heat into the Arctic in winter is variable, because the southerly winds change from day to day and week to week. Thus, the far North Atlantic region, in wintertime, is a valve that opens and closes, alternately letting heat into the Arctic or not. In springtime, the opening and closing of the valve becomes weaker, and, at the same time, with the sun warming the continents, this region becomes less important for admitting heat to the Arctic.
In a future, warmer, climate, it is expected that the far North Atlantic will warm less than the rest of the globe (a consequence of expected changes in the ocean circulation). Therefore, we expect (and our future-climate simulations show) that this region will become less important for bringing heat to the Arctic, and that the present-day pronounced difference between wintertime and springtime climates will be diminished. In short, the Arctic springtime transistion is expected to be a less dramatic feature in the future.
Last Modified: 09/06/2016
Modified by: Walter A Robinson
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