The Snowfall in Antarctica is the primary way the continent gains mass. It sustains the massive Antarctic Ice Sheet, the largest freshwater reservoir on Earth. Antarctica is a polar desert with extremely low precipitation, but the cold temperatures mean almost all of it falls as snow and accumulates over time.

Snowfall is the only significant mass gain for Antarctica. Increased snowfall can temporarily slow sea-level rise by locking up more water on land.

Snowfall patterns are influenced by large-scale modes like the Southern Annular Mode (SAM), ENSO teleconnections, atmospheric blocking ridges, and remote ocean temperatures.

The Southern Annular Mode (SAM), also known as the Antarctic Oscillation, is the leading mode of atmospheric variability in the Southern Hemisphere extratropics. It describes the north-south shift and strength of the circumpolar westerly winds, quantified as the pressure difference between mid-latitudes (~40°S) and high latitudes (~65°S, around Antarctica).

Snowfall over the Antarctic continent—especially in remote interior areas—is more connected to global ocean temperature patterns than previously thought. Changes in distant sea surface temperatures can alter atmospheric circulation, moisture transport, and precipitation patterns that deliver snow to Antarctica.

Recent research showing that snowfall in the interior of Antarctica is linked to atmospheric patterns driven by sea surface temperatures in far-away ocean regions, not just local conditions.

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Interannual Variations of Precipitation Events at Dome Fuji Station, Antarctica

Title: Interannual Variations of Precipitation Events at Dome Fuji Station, Antarctica

Authors: Kyohei Yamada, Jun Inoue, Naohiko Hirasawa, Kazutoshi Sato

Journal: Journal of Geophysical Research: Atmospheres (2026)

DOI: DOI: 10.1029/2025jd045296

This open-access paper (Journal of Geophysical Research: Atmospheres, May 2026) provides a rigorous, high-resolution examination of precipitation dynamics at one of the most remote and driest sites on Earth. Here’s a deeper breakdown beyond the headline findings.

1. Validation of ERA5 vs. In-Situ Observations (2003–2004)

• Researchers used a full year of high-quality manned observations from the 44th Japanese Antarctic Research Expedition (JARE44) at Dome Fuji (DF: 77.32°S, 39.70°E, 3810 m elevation).
• ERA5 strengths: Excellent reproduction of surface temperature, downward radiation, wind, pressure, cloudiness, and the vertical structure of a major extreme event in early November 2003 (rapid ~10–40 K warming + heavy snowfall linked to a blocking ridge).
• Limitation: ~14% underestimation of precipitation amount (bias-corrected by a factor of ~1.16). This correction was applied for long-term analysis.
• ERA5 markedly outperformed the older ERA-Interim, especially for peak precipitation and cloud details during extreme events.

2. Long-Term Trends (1979–2024, 46 years)

• Mean annual precipitation (bias-corrected): 23.4 mm water equivalent (w.e.).
• Statistically significant increase (+0.11 mm w.e. per year, 99% confidence via Mann-Kendall test).
• Driver: Almost entirely from more frequent precipitation event days and Extreme Precipitation Events (EPEs).
  • EPE threshold: ~0.29 mm/day (mean annual + 2σ).
  • Average: 13.8 EPE days/year, contributing 7.1 mm (~29% of annual total).
  • Trend in EPE days: +0.20 days/year (99% confidence).
  • No significant trend in the intensity of individual EPEs — frequency is key. agupubs.onlinelibrary.wiley.com

Notable spikes occurred in years like 2009 and 2011 (linked to strong moisture intrusions across Dronning Maud Land).

3. Role of Atmospheric Blocking Ridges (K-means Clustering)

Atmospheric blocking patterns, specifically “blocking ridges” or “blocking highs,” are large-scale, quasi-stationary high-pressure systems that disrupt the typical west-to-east (zonal) flow of the mid-latitude jet stream. They force air to flow more meridionally (north south), often persisting for days to weeks.

In the Southern Hemisphere, these often appear as ridges of high geopotential height (e.g., at 500 hPa) that extend poleward, sometimes forming omega-shaped or dipole (Rex) block configurations.

K-means clustering on 500 hPa geopotential height (GPH500) and precipitation patterns identified four main regimes:

• C45E (blocking ridge near 45°E): Only 7.1% of days, but drives ~50% of EPE days (up to 100% of the most extreme percentiles). This pattern features a high-pressure ridge that channels moist air from lower latitudes toward DF.
• Frequency and southward deepening of this ridge increased over 46 years (statistically significant).
• Changes are periodic/not purely linear, suggesting oscillatory behavior rather than a steady climate-driven shift.

This mechanism explains rapid warming, cloud formation, and deposition/snowfall during events, sometimes with atmospheric river-like moisture transport.

4. Teleconnection to Distant Ocean Temperatures

• Strongest interannual correlation: Precipitation at DF with subtropical South Atlantic SSTs (roughly 40–50°S).
• Warmer SSTs in this remote region favor stronger/more frequent C45E blocking patterns, enhancing moisture transport to interior East Antarctica.
• This highlights ocean-atmosphere teleconnections bridging thousands of kilometers, potentially via Rossby wave trains or modulation of subtropical highs.

5. Broader Implications

• Ice Sheet Mass Balance: Increased interior snowfall provides a modest positive contribution to surface mass balance, partially offsetting dynamic ice losses elsewhere (especially West Antarctica). However, it is regionally limited and does not reverse overall Antarctic mass loss.
• Ice Core Records: EPEs with associated warming significantly affect stable isotopes (δ¹⁸O, etc.), snow chemistry, and layer interpretation — critical for paleoclimate reconstructions.
• Climate Change Context: While the trend aligns with expectations of increased moisture capacity in a warming atmosphere and more frequent blocking/AR intrusions, the periodic nature and Atlantic SST link suggest natural variability plays a strong role alongside anthropogenic forcing.
• Consistency with other work: Atmospheric rivers (ARs) and blocking events are increasingly recognized as dominant drivers of extreme snowfall across broader East Antarctica.

Limitations noted:

Pre-1979 ERA5 has fewer observations (lower reliability); single-station focus (though representative of high interior Dronning Maud Land); challenges distinguishing precipitation from blowing snow.

This study elegantly bridges local observations, reanalysis validation, synoptic pattern analysis, and large-scale teleconnections. It underscores that even in the “stable” East Antarctic interior, precipitation is highly episodic and sensitive to remote influences.

Abstract

Precipitation is key to the water budget of inland Antarctica, with extreme precipitation events strongly influencing snowfall and surface climatology.

To investigate the contribution and trends of such events at Dome Fuji station (DF) in inland Antarctica, this study analyzed precipitation variability using the ERA5 product validated against observational data from February 2003 to January 2004.

ERA5 more accurately reproduces surface temperature, downward radiation, wind speed, surface pressure, and cloudiness throughout the year compared with the previous reanalysis, ERA-Interim. Although precipitation in ERA5 is slightly underestimated (by approximately 14%), the peak precipitation amount and rapid temperature increase observed during an extreme precipitation event in early November 2003, caused by high-pressure blocking with a strong ridge near 45°E, is greatly improved compared with the previous reanalysis.

Over a 46-year period (1979–2024), bias-corrected ERA5 data show a statistically significant increase in the annual precipitation amount at DF at the 99% confidence level, primarily because of an increase in the number of precipitation event days.

Application of k-means clustering analysis to the 46-year precipitation distribution revealed that the frequency of occurrence of a blocking ridge near 45°E, which favors precipitation over Dronning Maud Land, increased and deepened southward.

The change in blocking was not uniform but exhibited periodic variability. Interannual variability of precipitation at DF shows a strong correlation with that of sea surface temperature in the subtropical South Atlantic Ocean.

Therefore, it is suggested that periodic changes in sea surface temperature might affect the synchronized blocking high that brings precipitation to the DF.