Zhou, Yingzhen (2024): Albedo Retrievals from MODIS Over the Sea of Okhotsk (Validation Data, 2002–2014) [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.972844 (DOI registration in progress)

This dataset contains satellite-based albedo retrievals and surface classifications from MODIS sensors over the Sea of Okhotsk, collected during multiple voyages of the Soya Icebreaker from 2002 to 2014. The dataset focuses on validating MODIS retrievals by comparing them to in-situ albedo measurements collected by the Soya Icebreaker. The retrieval data is standardized on a 1-km grid and includes albedo and surface classification values for each available time period. Only satellite retrievals were uploaded, without the in-situ measurements.

Key features of this dataset include:

- Albedo retrieval data using the retrieval algorithm is described in https://doi.org/10.5194/tc-17-1053-2023.

- Surface classification masks indicating different surface types (e.g., land, water, snow-covered ice).

The dataset was used to analyze and quantify the discrepancies between satellite-based retrievals and in-situ measurements under varying conditions of sea ice, snow, and meltwater, and to understand the impacts of time differences between satellite overpasses and ground-based measurements.

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Variables:

1. SW: Shortwave albedo values retrieved from the MODIS sensor using the SciML albedo retrieval algorithm. The retrievals were made over the Sea of Okhotsk region, focusing on the validation period (2002–2014).

2. mask: Surface classification mask for the MODIS sensor. This mask classifies each grid point based on surface type:

• 0: Invalid

• 1: Land

• 2: Water

• 3: Snow on land

• 4: Bare Sea-ice

• 5: Snow-covered Sea Ice

• 6: Cloud/Fog (nullified)

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Time Periods:

The dataset spans the following time periods, during which MODIS data was validated against in-situ measurements:

• 2002-02-14

• 2002-02-16

• 2003-02-06

• 2003-02-07

• 2003-02-11

• 2004-02-07

• 2004-02-08

• 2004-02-09

• 2004-02-10

• 2006-02-12

• 2007-02-10

• 2008-02-09

• 2008-02-10

• 2008-02-11

• 2009-02-10

• 2013-02-25

• 2013-02-26

• 2014-02-15

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Format: The data is provided in NetCDF format (.nc), with dimensions for date, latitude, and longitude. Each time step corresponds to a specific satellite overpass date, and the spatial data are aligned to a grid covering the Sea of Okhotsk.

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Usage: This dataset is intended for validating MODIS satellite retrievals against ground-based measurements, particularly for studying discrepancies in albedo measurements under different ice and snow conditions.