Nivl Melt Watch
Where the 43D–Maitri route leaves the shelf. Updated 28 Oct 2026 08:16 UTC.
Satellite and station data, not a forecast. The decision stays with the field team.
Newest data: Passive microwave: 17 Oct (11 days ago) · Sentinel-1: 23 Oct (5 days ago) · Optical: 21 Oct (7 days ago) · NISAR: 22 Oct (6 days ago) · Stations: 28 Oct (today)
Temperature
MaitriNovolazarevskayaforecast Maitri (AMPS)forecast C13, grounding zone (AMPS)
Daily maximum at the two stations (both on rock, warmer than the ice), with the AMPS forecast dashed. ❄ snowfall, ≈ drifting or blowing snow reported.
Days above 0 °C since 1 Nov
0 / 0
Maitri / Novolazarevskaya
Current warm run
0 / 0 days
consecutive days above 0 °C
Degree days since 1 Nov
0 median 0
Novolazarevskaya (daily mean above 0)
Since snow or blowing snow
3 days
last: 25 Oct
this seasonlast summer, 2025/261990-2025 median1990-2025, 10-90 %
Degree days follow melt more closely than counts of warm days.
Route crossing
| Wet snow microwave | Radar Sentinel-1 | Open water optical | Radar NISAR | |
|---|---|---|---|---|
| A Grounding-line crossing (km 24-60) | 0 / 5 cells wet 17 Oct | +0.1 dB hotspots +0.0 dB 23 Oct | 0.0 km² water hotspots 0 % wet 21 Oct | -0.1 dB hotspots -0.0 dB 20 Oct |
| B Blue-ice ponds before Maitri (km 60-100) | 0 / 6 cells wet 17 Oct | +0.1 dB hotspots +0.1 dB 23 Oct | 0.0 km² water hotspots 0 % wet 21 Oct | -0.1 dB hotspots -0.1 dB 19 Oct |
| C Grounding zone near the crossing | 0 / 3 cells wet 17 Oct | +0.1 dB hotspots +0.1 dB 23 Oct | 0.0 km² water hotspots 0 % wet 21 Oct | -0.1 dB hotspots -0.0 dB 20 Oct |
Each cell is the latest measurement for the whole zone, and below it for the zone's recurrent-melt hotspots (where Landsat saw water in at least 2 of 16 seasons, Tuckett et al.). Deeper blue means more of the signal (wetter); grey means no data yet.
First wet day: this season against 2002–25
2002-25 seasons (one dot each)medianlast summer, 2025/26 (ring)this season
Share of each zone wet (passive microwave)
Zone A
Zone B
Zone C
this seasonlast summer, 2025/262002-25 median2002-25, 10-90 %
Radar change from October: Sentinel-1 and NISAR
Zone A
Zone B
Zone C
Sentinel-1, C-band (surface; every few days)Sentinel-1 over the recurrent-melt hotspotsNISAR, L-band (deeper; every 12 days, provisional)
Wet snow darkens both. A wet surface shows first in Sentinel-1; water below a refrozen crust can stay dark in NISAR after Sentinel-1 has recovered.
Zones A (red), B (orange), C (yellow) on the route (white, km from Depot 43D); cyan dashes: grounding line (Rignot et al. 2023); magenta: recurrent-melt hotspots; blue fill = latest wet share. Background: NISAR radar, winter 2026.
All numbers per zone
A Grounding-line crossing route km 24-60
- Passive microwave (wet snow, 10 km)
- 17 Oct: 0 of 5 cells wet; no wet day yet this season
2002-25: first wet day median 11 Dec (earliest 08 Nov, latest 22 Dec); by 17 Oct, 0 of 23 seasons had had a wet day - Sentinel-1 radar (change from October)
- 23 Oct (orbit 118): +0.1 dB, 0 % of the zone 3 dB or more darker
- Sentinel-2 / Landsat (clear days only)
- 21 Oct (Landsat): 0.0 km² open water (0.0 % of the clear part, 100 % clear)
- NISAR L-band (provisional)
- 20 Oct (track 122): -0.1 dB, 0 % 3 dB or more darker
B Blue-ice ponds before Maitri route km 60-100
- Passive microwave (wet snow, 10 km)
- 17 Oct: 0 of 6 cells wet; no wet day yet this season
2002-25: first wet day median 14 Dec (earliest 08 Nov, latest 26 Jan); by 17 Oct, 0 of 23 seasons had had a wet day - Sentinel-1 radar (change from October)
- 23 Oct (orbit 118): +0.1 dB, 0 % of the zone 3 dB or more darker
- Sentinel-2 / Landsat (clear days only)
- 21 Oct (Landsat): 0.0 km² open water (0.0 % of the clear part, 100 % clear)
- NISAR L-band (provisional)
- 19 Oct (track 101): -0.1 dB, 0 % 3 dB or more darker
C Grounding zone near the crossing early-warning area
- Passive microwave (wet snow, 10 km)
- 17 Oct: 0 of 3 cells wet; no wet day yet this season
2002-25: first wet day median 12 Dec (earliest 08 Nov, latest 24 Dec); by 17 Oct, 0 of 23 seasons had had a wet day - Sentinel-1 radar (change from October)
- 23 Oct (orbit 118): +0.1 dB, 0 % of the zone 3 dB or more darker
- Sentinel-2 / Landsat (clear days only)
- 21 Oct (Landsat): 0.0 km² open water (0.0 % of the clear part, 100 % clear)
- NISAR L-band (provisional)
- 20 Oct (track 122): -0.1 dB, 0 % 3 dB or more darker
Latest images of the route area
Elsewhere
- Terminal lake: first wet day this season none yet (2002-25 median 14 Dec)
- Rest of the shelf: first wet day this season none yet (2002-25 median 03 Dec)
- Sea ice in front of the shelf (27 Oct): concentration west 88.4 %, central 92.3 %, east 89.0 %
What past seasons show
- Melt starts at the grounding zone and in the blue-ice belt, then spreads along the channels to the terminal lake; the ice front comes last (Dell et al. 2024; project analysis).
- Zone A, 2002–25: first wet day median 11 Dec, earliest 8 Nov (2007), latest 22 Dec. Recent: 21 Nov 2017, 5 Dec 2019, 10 Dec 2024, 27 Nov 2025.
- Channel water builds from about 12–20 Dec; in lake years water reaches the terminal lake 27 Dec–11 Jan.
- Snowfall delays ponding; the five warmest seasons by degree days were the five biggest melt seasons.
How this page works
- Wet snow: AMSR2 microwave product (Picard & Fily, Grenoble), 10 km, daily, about 10 days behind.
- Sentinel-1 radar: every few days through cloud; change from the October median of the same orbit. Wet snow is darker; 3 dB is the usual mark.
- Optical (Sentinel-2, Landsat): clear days only; open water must also be at least twice as dark as in October, which keeps blue ice out. Below about 2 km² in zone A, low sun can give false water.
- NISAR: L-band radar every 12 days, also senses water below the surface; provisional data.
- Stations: Ogimet reports every 6 h and NOAA daily values. Forecast: AMPS, from the MINIS weather site.
- Checked daily, station reports every 6 h, until the end of February 2027. Code and rules: github.com/vikramonice/nivl-melt-watch.