Is there any explanation for the large amount of sea ice around Antarctica in 2014?
Antarctic sea ice extent for April 2014 reached 9.00 million square kilometers (3.47 million square miles), the largest ice extent on record by a significant margin.
  
  Is there any explanation for such an extreme excess of sea ice around Antarctica recently?  


I'll give four separate answers:


It's not as significant an increase as you think.
The Interdecadal Pacific Oscillation is strongly in its negative phase.
The Southern Annular Mode is at a 1000 year high.
Natural and man-made variations have collectively caused increased melting of the Antarctica ice sheet.


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.


References

Abram, N. et al., "Evolution of the Southern Annular Mode during the past millennium," Nature Clim. Change, (2014)

Meehl, G. et al., "Externally forced and internally generated decadal climate variability associated with the interdecadal pacific oscillation,"J. Climate 26 (2013), 7298–7310.

Shepherd, A. et al., "A Reconciled Estimate of Ice-Sheet Mass Balance," Science 338.6111 (2012): 1183-1189.

Rignot, E. et al., "Ice-Shelf Melting Around Antarctica," Science 341.6143 (2013): 266-270.

William, K. "Abrupt mid-twentieth-century decline in Antarctic sea-ice extent from whaling records," Nature 389.6646 (1997): 57-60.

Zhang, J., "Increasing Antarctic sea ice under warming atmospheric and oceanic conditions," J. Climate, 20 (2007), 2515-2529.

Zhang, J., "Modeling the Impact of Wind Intensification on Antarctic Sea Ice Volume," J. Climate, 27 (2014), 202–214.