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有大量的解释2014年南极海冰的?

从以下数据可以看出,在过去一年左右的时间(2014年),南极洲周围的海冰已远高于正常。当前,南极海冰空前纪录高位,每年的这个时候,1344000平方公里高于正常(或大小的西班牙、法国和德国的总和)。

有什么解释这样一个极端的过度最近南极海冰的吗?

南极海冰

南极冰看到异常

数据的来源美国国家冰雪数据中心对2014年4月海冰消息(上面的图)和伊利诺伊大学的“今天的冰冻圈”(下面的图)。

在上面的链接中,美国国家冰雪数据中心“南极海冰范围为2014年4月达到900万平方公里(347万平方英里),最大的冰程度显著高于历史上。”

更新6/30/2014:

现在海冰异常高的南部为一年的任何时候达到创纪录的水平,超过200万平方公里的速度高于正常。

在这里输入图像描述

回答

南极海冰范围> 2014年4月达到900万平方公里(347万平方英里),最大的冰程度上记录以明显的优势。>有什么解释这样一个极端过剩最近南极海冰的吗?我给四个不同的答案:1。它不是像你想的那么显著增加。2。太平洋年代际振荡强烈的负相。3所示。南环模式是在1000年高。4所示。自然和人为的变化有集体增加南极冰盖的融化造成的。 **It's not as significant an increase as you think.** It's important to remember what that "largest ice extent on record" means. That "on record" means *in the satellite era*. Data from before the satellite era (pre-1981) are rather spotty. Except they aren't. There's a nice proxy for sea ice extent, at least during Antarctic summer, in the locations at which whalers made their catches and established their factory ships (Williams 1997). In the first half of the 20th century, whalers sought species that concentrated near the edge of the Antarctic sea ice. By the early 1930s whalers had developed a practice of anchoring factory ships within 20 km of the ice edge and followed the ice southward as summer progressed. This practice continued throughout the 1930s and resumed after WWII through to the mid 1950s. The practice was later restarted in the mid to late 1970s. Every whale caught by Norwegian whalers was tagged with date, latitude, and longitude. The practice of setting up shop near the ice edge gave Williams a nice way of estimating the pre-satellite era ice extent. What Williams found was that summer Antarctic sea ice suffered a massive decline that continued throughout the 1950s and 1960s. The ice levels we are seeing now, at least during Antarctic summer, are on par with the levels seen eighty years ago. **The Interdecadal Pacific Oscillation is strongly in its negative phase.** The Interdecadal Pacific Oscillation (IPO) is highly correlated with a hiatus in perceived global warming and also with increased precipitation in the Antarctic (Meehl 2013). An increase in precipitation means that surface waters are less salty (increasing the freezing point) and cooler. The combination of reduced sea surface temperatures and reduced salinity makes for increased ice formation during the Antarctic winter during periods when the IPO is in its negative phase. **The Southern Annular Mode is at a 1000 year high.** It has long been suspect that stronger winds are one of the causes of the increase in the Antarctic sea ice levels (Zhang 2007, Zhang 2014). Winds help create polynyas, open areas of water surrounded by ice. That open water is subject to freezing during the Antarctic winter. Not only are the winds strong now, they are stronger than they have been for at least 1000 years (Abram 2014). **Natural and man-made variations have collectively caused increased melting of the Antarctica ice sheet.** Just as increased precipitation leads to increased ice formation, so does increased melting of the continental Antarctic ice sheet. And the ice sheet is melting (Shepherd 2012, Rignot 2013). Gravity measurements from the GRACE satellites, combined with ice height measurements from ICESat collectively show that Western Antarctica and the Antarctica Peninsula are decreasing in mass, and at a significantly greater rate than the slight increase in the mass of the Eastern Antarctica ice sheet. This influx of cold, fresh water during the Antarctic summer makes for increased sea ice production during the Antarctic winter. <br> **References** [Abram, N. et al., "Evolution of the Southern Annular Mode during the past millennium," *Nature Clim. Change*, (2014)](http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2235.html) [Meehl, G. et al., "Externally forced and internally generated decadal climate variability associated with the interdecadal pacific oscillation,"*J. Climate* 26 (2013), 7298–7310.](http://www.cawcr.gov.au/staff/jma/Decadal.trends.Meehl.JClim.2013.pdf) [Shepherd, A. et al., "A Reconciled Estimate of Ice-Sheet Mass Balance," *Science* 338.6111 (2012): 1183-1189.](http://www.sciencemag.org/content/338/6111/1183) [Rignot, E. et al., "Ice-Shelf Melting Around Antarctica," *Science* 341.6143 (2013): 266-270.](http://www.sciencemag.org/content/341/6143/266.abstract) [William, K. "Abrupt mid-twentieth-century decline in Antarctic sea-ice extent from whaling records," *Nature* 389.6646 (1997): 57-60.](https://data.aad.gov.au/analysis/crc/eceawiki/files/delamare1997.pdf) [Zhang, J., "Increasing Antarctic sea ice under warming atmospheric and oceanic conditions," J. Climate, 20 (2007), 2515-2529.](http://journals.ametsoc.org/doi/abs/10.1175/JCLI4136.1) [Zhang, J., "Modeling the Impact of Wind Intensification on Antarctic Sea Ice Volume," J. Climate, 27 (2014), 202–214.](http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00139.1)

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\ begingroup美元谢谢你的回答,我真的很感激捕鲸的参考数据从1931年至87年,值得一个upvote独自一人。然而,你的语句“冰水平我们看到现在,至少在南极的夏天,是大大降低(25%或以上)八十年前水平”是不正确的。威廉的数据显示了一个夏天冰下降25%,至1987。在这个数据可以看出:arctic.atmos.uiuc.edu/cryosphere/…所有1979年- 87年度最小值< 200万平方。公里,但2013年和2014年最小值~ 250万平方的地方。公里。 \ endgroup美元
- - - - - -DavePhD
2014年5月14日在破发吗
\ begingroup美元伟大的回答(比我)。通过认为全球变暖的中断,我想你是只谈论意味着大气温度(不考虑海洋热含量)?可能是良好的显式地指出这一点(我让这个评论无论…)提到的“中断”。 \ endgroup美元
- - - - - -gerrit ♦
2014年5月14日在十五11吗

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