DOI: 10.5281/zenodo.18328597
title: Western disturbance tracks and impact diagnostics from ERA5 (1950–2025)

description: This dataset contains objectively detected and tracked Western Disturbance (WD) trajectories and associated impact/diagnostic metrics derived from ERA5 reanalysis for 1950–2025. Tracks are produced using feature detection on upper-tropospheric relative vorticity, followed by predictive linking, and are filtered to retain systems that affect the western/central Himalaya and northern India region.

𝗧𝗲𝗺𝗽𝗼𝗿𝗮𝗹 𝗿𝗲𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻: 3-hourly track points𝗣𝗲𝗿𝗶𝗼𝗱: 1950–2025𝗙𝗼𝗿𝗺𝗮𝘁: CSV (one row per track point)

𝗧𝗿𝗮𝗰𝗸 𝗴𝗲𝗻𝗲𝗿𝗮𝘁𝗶𝗼𝗻 (𝘀𝘂𝗺𝗺𝗮𝗿𝘆)



Candidate detection: vortex-like features are identified in upper-tropospheric relative vorticity fields using a trackpy-style local-maxima feature detector.

Linking into tracks: candidate points are linked across time using a nearest-velocity predictor, with search_range = 3.0 degrees, memory = 0, and minimum duration MIN_DURATION = 12 frames (≥36 hours at 3-hourly resolution).

Regional filter: tracks are retained only if they touch [60–80°E, 20–50°N] at any time.


𝗗𝗮𝘁𝗮 𝘀𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗲Each row represents a single 3-hourly track point, keyed by track_id.

𝗖𝗼𝗿𝗲 𝗶𝗱𝗲𝗻𝘁𝗶𝗳𝗶𝗲𝗿𝘀• track_id: unique track identifier• frame: integer time index used for linking• year, month, day, hour: timestamp components (UTC)• lon, lat: feature centroid position (degrees east / degrees north)• circulation: feature intensity proxy from the detection step (arbitrary units; useful for relative ranking within this dataset)

𝗗𝗶𝗮𝗴𝗻𝗼𝘀𝘁𝗶𝗰𝘀 𝗶𝗻𝗰𝗹𝘂𝗱𝗲𝗱 (𝗳𝘂𝗹𝗹 𝗹𝗶𝘀𝘁)All diagnostics below are attached to every track point (where the required ERA5 fields are available).

𝗨𝗽𝗽𝗲𝗿-𝘁𝗿𝗼𝗽𝗼𝘀𝗽𝗵𝗲𝗿𝗶𝗰 𝘃𝗼𝗿𝘁𝗶𝗰𝗶𝘁𝘆 (𝗹𝗼𝗰𝗮𝗹 𝘀𝘁𝗮𝘁𝗶𝘀𝘁𝗶𝗰𝘀; ×1e5 s^-1)• ut_vo_max_200km: maximum UT relative vorticity within 200 km• ut_vo_mean_400km: mean UT relative vorticity within 400 km

𝗣𝗿𝗲𝗰𝗶𝗽𝗶𝘁𝗮𝘁𝗶𝗼𝗻 (𝗮𝗿𝗲𝗮-𝗺𝗲𝗮𝗻 𝘄𝗶𝘁𝗵𝗶𝗻 𝗿𝗮𝗱𝗶𝘂𝘀)• precip_1hr_400km: mean precip rate within 400 km (mm hr^-1)• precip_1hr_800km: mean precip rate within 800 km (mm hr^-1)• precip_24hr_400km: 24 h accumulation within 400 km (mm)• precip_24hr_800km: 24 h accumulation within 800 km (mm)

𝗦𝘂𝗿𝗳𝗮𝗰𝗲 𝗱𝗶𝗮𝗴𝗻𝗼𝘀𝘁𝗶𝗰𝘀 (𝘄𝗶𝘁𝗵𝗶𝗻 400 km)• mslp_min_400km: minimum mean sea-level pressure (hPa)• ws10_max_400km: maximum 10 m wind speed (m s^-1)• ws10_mean_400km: mean 10 m wind speed (m s^-1)

𝗠𝘂𝗹𝘁𝗶-𝗹𝗲𝘃𝗲𝗹 𝘃𝗼𝗿𝘁𝗶𝗰𝗶𝘁𝘆 (𝗺𝗲𝗮𝗻 𝘄𝗶𝘁𝗵𝗶𝗻 400 km; ×1e5 s^-1)• vo_mean_925_400km• vo_mean_850_400km• vo_mean_700_400km• vo_mean_600_400km• vo_mean_500_400km• vo_mean_400_400km• vo_mean_300_400km

𝗥𝗲𝗴𝗶𝗼𝗻𝗮𝗹 𝗽𝗿𝗲𝗰𝗶𝗽𝗶𝘁𝗮𝘁𝗶𝗼𝗻 𝗯𝗼𝘅𝗲𝘀 (𝗯𝗼𝘅 𝗺𝗲𝗮𝗻, 1 h and 24 h)For each named box below, the dataset includes:• precip_box_1hr_<name>: mean precip rate in box (mm hr^-1)• precip_box_24hr_<name>: 24 h accumulation in box (mm)

Boxes: karakoram, hindu_kush, western_himalaya, central_himalaya, north_india

𝗡𝗼𝘁𝗲𝘀• Vorticity diagnostics are stored as ×1e5 s^-1 (i.e. relative vorticity multiplied by 1e5).• Precipitation rates are mm hr^-1 and 24 h values are mm (time-window integrated accumulation).• circulation is an intensity proxy from the detection step and should be treated as relative/unitless, not a directly physical circulation integral.

𝗗𝗲𝗿𝗶𝘃𝗲𝗱 𝗳𝗿𝗼𝗺: ERA5 reanalysis (Copernicus Climate Change Service / ECMWF).