Contributions of advection and melting processes to the decline in sea ice in the Pacific sector of the Arctic Ocean
<p>The Pacific sector of the Arctic Ocean (PA, hereafter) is a region sensitive to climate change. Given the alarming changes in sea ice cover during recent years, knowledge of sea ice loss with respect to ice advection and melting processes has become critical. With satellite-derived products...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-05-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/13/1423/2019/tc-13-1423-2019.pdf |
| Summary: | <p>The Pacific sector of the Arctic Ocean (PA, hereafter) is a region sensitive
to climate change. Given the alarming changes in sea ice cover during recent
years, knowledge of sea ice loss with respect to ice advection and melting
processes has become critical. With satellite-derived products from the
National Snow and Ice Center (NSIDC), a 38-year record (1979–2016) of the
loss in sea ice area in summer within the Pacific-Arctic (PA) sector due to
the two processes is obtained. The average sea ice outflow from the PA to the
Atlantic-Arctic (AA) Ocean during the summer season (June–September) reaches
<span class="inline-formula">0.173×10<sup>6</sup></span> km<span class="inline-formula"><sup>2</sup></span>, which corresponds to approximately 34 %
of the mean annual export (October to September). Over the investigated
period, a positive trend of <span class="inline-formula">0.004×10<sup>6</sup></span> km<span class="inline-formula"><sup>2</sup></span> yr<span class="inline-formula"><sup>−1</sup></span> is also
observed for the outflow field in summer. The mean estimate of sea ice
retreat within the PA associated with summer melting is <span class="inline-formula">1.66×10<sup>6</sup></span> km<span class="inline-formula"><sup>2</sup></span>, with a positive trend of <span class="inline-formula">0.053×10<sup>6</sup></span> km<span class="inline-formula"><sup>2</sup></span> yr<span class="inline-formula"><sup>−1</sup></span>. As a result, the increasing trends of ice
retreat caused by outflow and melting together contribute to a stronger
decrease in sea ice coverage within the PA (<span class="inline-formula">0.057×10<sup>6</sup></span> km<span class="inline-formula"><sup>2</sup></span> yr<span class="inline-formula"><sup>−1</sup></span>) in summer. In percentage terms, the melting
process accounts for 90.4 % of the sea ice retreat in the PA in summer,
whereas the remaining 9.6 % is explained by the outflow process, on
average. Moreover, our analysis suggests that the connections are relatively
strong (<span class="inline-formula"><i>R</i>=0.63</span>), moderate (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>R</mi><mo>=</mo><mo>-</mo><mn mathvariant="normal">0.46</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="4f9f533dc4b1268318e991872a7b2e14"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-1423-2019-ie00001.svg" width="52pt" height="10pt" src="tc-13-1423-2019-ie00001.png"/></svg:svg></span></span>), and weak (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>R</mi><mo>=</mo><mo>-</mo><mn mathvariant="normal">0.24</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="eaa0dff95117737796b4c60d4a76287d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-1423-2019-ie00002.svg" width="52pt" height="10pt" src="tc-13-1423-2019-ie00002.png"/></svg:svg></span></span>) between
retreat of sea ice and the winds associated with the dipole anomaly (DA),
North Atlantic Oscillation (NAO), and Arctic Oscillation (AO), respectively.
The DA participates by impacting both the advection (<span class="inline-formula"><i>R</i>=0.74</span>) and melting
(<span class="inline-formula"><i>R</i>=0.55</span>) processes, whereas the NAO affects the melting process (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M19" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>R</mi><mo>=</mo><mo>-</mo><mn mathvariant="normal">0.46</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="55f9c6455fa1e60f5f64769b5b88a549"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-1423-2019-ie00003.svg" width="52pt" height="10pt" src="tc-13-1423-2019-ie00003.png"/></svg:svg></span></span>).</p> |
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| ISSN: | 1994-0416 1994-0424 |