This is the first report of the Barents Sea Ice Edge (BIE) project. The BIE position has varied between latitude 76<span style="white-space:nowrap;">°</span>N and above 82<span style=&...This is the first report of the Barents Sea Ice Edge (BIE) project. The BIE position has varied between latitude 76<span style="white-space:nowrap;">°</span>N and above 82<span style="white-space:nowrap;">°</span>N during the last 440 years. During the period 10,000 to 6000 years ago, Arctic climate was significantly warmer than today. We review various oceanic and atmospheric factors that may have an effect on the BIE position. The Gulf Stream beat with respect to alternations in flow intensity and N-S distribution plays a central role for the changes in climate and BIE position during the last millennium. This occurred in combination with external forcing from total solar irradiation, Earth’s shielding strength, Earth’s geomagnetic field intensity, Earth’s rotation, jet stream changes;all factors of which are ultimately driven by the planetary beat on the Sun, the Earth and the Earth-Moon system. During the last 20 years, we see signs of changes and shifts that may signal the end of the late 20<sup>th</sup> century warm period. The BIE position is likely to start advancing southward in next decade.展开更多
This is the second paper in a series of two, which analyze the position of the Barents Sea ice-edge (BIE) based on a 442-year long dataset to understand its time variations. The data have been collected from ship-logs...This is the second paper in a series of two, which analyze the position of the Barents Sea ice-edge (BIE) based on a 442-year long dataset to understand its time variations. The data have been collected from ship-logs, polar expeditions, and hunters in addition to airplanes and satellites in recent times. Our main result is that the BIE position alternates between a southern and a northern position followed by Gulf Stream Beats (GSBs) at the occurrence of deep solar minima. We decompose the low frequency BIE position variations in cycles composed of dominant periods which are related to the Jose period of 179 years, indicating planetary forcings. We propose that the mechanism transferring planetary signals into changes in BIE position is the solar wind (SW), which provides magnetic shielding of the Earth in addition to geomagnetic disturbances. Increase in the solar wind produces pressure which decelerates the Earth’s rotation. It also transfers electrical energy to the ring current in the earth’s magnetosphere. This current magnetizes the earth’s solid core and makes it rotate faster. To conserve angular momentum the earth’s outer fluid mantle rotates slower with a delay of about 100 years. In addition will geomagnetic storms, initiated by solar coronal mass ejections (CMEs) penetrate deep in the Earth’s atmosphere and change pressure pattern in the Arctic. This effect is larger during solar minima since the magnetic shielding then is reduced. The Arctic may then experience local warming. The transition of solar activities to a possibly deep and long minimum in the present century may indicate Arctic cooling and the BIE moving south this century. For the North Atlantic region, effects of the BIE expanding southward will have noticeable consequences for the ocean bio-production from about 2040.展开更多
文摘This is the first report of the Barents Sea Ice Edge (BIE) project. The BIE position has varied between latitude 76<span style="white-space:nowrap;">°</span>N and above 82<span style="white-space:nowrap;">°</span>N during the last 440 years. During the period 10,000 to 6000 years ago, Arctic climate was significantly warmer than today. We review various oceanic and atmospheric factors that may have an effect on the BIE position. The Gulf Stream beat with respect to alternations in flow intensity and N-S distribution plays a central role for the changes in climate and BIE position during the last millennium. This occurred in combination with external forcing from total solar irradiation, Earth’s shielding strength, Earth’s geomagnetic field intensity, Earth’s rotation, jet stream changes;all factors of which are ultimately driven by the planetary beat on the Sun, the Earth and the Earth-Moon system. During the last 20 years, we see signs of changes and shifts that may signal the end of the late 20<sup>th</sup> century warm period. The BIE position is likely to start advancing southward in next decade.
文摘This is the second paper in a series of two, which analyze the position of the Barents Sea ice-edge (BIE) based on a 442-year long dataset to understand its time variations. The data have been collected from ship-logs, polar expeditions, and hunters in addition to airplanes and satellites in recent times. Our main result is that the BIE position alternates between a southern and a northern position followed by Gulf Stream Beats (GSBs) at the occurrence of deep solar minima. We decompose the low frequency BIE position variations in cycles composed of dominant periods which are related to the Jose period of 179 years, indicating planetary forcings. We propose that the mechanism transferring planetary signals into changes in BIE position is the solar wind (SW), which provides magnetic shielding of the Earth in addition to geomagnetic disturbances. Increase in the solar wind produces pressure which decelerates the Earth’s rotation. It also transfers electrical energy to the ring current in the earth’s magnetosphere. This current magnetizes the earth’s solid core and makes it rotate faster. To conserve angular momentum the earth’s outer fluid mantle rotates slower with a delay of about 100 years. In addition will geomagnetic storms, initiated by solar coronal mass ejections (CMEs) penetrate deep in the Earth’s atmosphere and change pressure pattern in the Arctic. This effect is larger during solar minima since the magnetic shielding then is reduced. The Arctic may then experience local warming. The transition of solar activities to a possibly deep and long minimum in the present century may indicate Arctic cooling and the BIE moving south this century. For the North Atlantic region, effects of the BIE expanding southward will have noticeable consequences for the ocean bio-production from about 2040.
