23 Sep 2026
| 23 Sep 2026
Status: this preprint is open for discussion and under review for The Cryosphere (TC).
Brief communication: First NISAR Interferometric snow water equivalent change retrieval evaluated against airborne lidar
Abstract. NISAR's global L-band repeat-pass interferometry should be sensitive to snow water equivalent change (ΔSWE). We compare ΔSWE from an operational NISAR interferogram to near-coincident airborne lidar snow-depth change over a February 2026 pair in southwest Idaho. Across the scene, ΔSWE correlates well with the lidar depth change (r = 0.82, rising to r = 0.93 above a coherence of 0.2). The agreement is dominated by variability at scales above ~1 km (r ≈ 0.94), while the correlation at sub-kilometer scales is weaker (r ≈ 0.42), improving over open terrain and at incidence angles below 50°. These results provide the first direct evidence that NISAR phase can measure dry-snow accumulation.
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