Standardized_Manual_Visual_Ship-Based_SeaIceObservations_Arctic

hdl:21.14106/ba180d73e2a79220ec1058896db1453204d068ac

Kern, Stefan

Dataset
Summary
This data set contains standardized, manual, visual ship-based sea-ice observations for the Arctic Ocean. These are observations mainly from research ships navigating in sea-ice covered waters. These observations are carried out according to the ASSISt/IceWatch protocol (http://icewatch.gina.alaska.edu/) which is based on the ASPeCt protocol (http://www.aspect.aq) modified for the Arctic.
The data set includes:
- date and time
- latitude, longitude
- a ship-cruise identifyer
- total sea-ice concentration
- concentration, ice type, ice thickness, floe size, surface type, snow depth, ridged ice fraction, ridge height, stage of melt, melt pond concentration for ice thickness category I (the thickest sea ice)
- concentration, ice type, ice thickness, floe size, surface type, snow depth, ridged ice fraction, ridge height, stage of melt, melt pond concentration for ice thickness category II (the 2nd thickest sea ice)
- concentration, ice type, ice thickness, floe size, surface type, snow depth, ridged ice fraction, ridge height, stage of melt, melt pond concentration for ice thickness category III (the 3rd thickest sea ice)
- other ice type thinner than category III
- other ice type thicker than category III
- observer and comments
- significant weather, visibility, total cloud cover, wind speed, wind direction, air temperature,sea water temperature,relative humidity, air pressure (hPa)
- ship speed, ship heading
- other comments
Data are given for each ship cruise in chronological order. For temporally overlapping ship cruises data of the cruise starting first come first.
For times or geographic locations without observations and/or for cases where not all parameters listed above were observed, missing values are included.
Project
ESA-SICCI_SHIPBASED_SEAICEOBS (ESA-CCI sea-ice-ecv project phase 2 bi-polar standardized manual visual ship-based sea-ice observations)
Additional Information
citations_northern_hemisphere.txt
Spatial Coverage
Longitude 0 to 360 Latitude 55 to 90 Altitude: 0 m
Temporal Coverage
2002-05-08 to 2015-11-04 (calendrical)
Use constraints
Creative Commons Attribution 4.0 International (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/)
Data Catalog
World Data Center for Climate
Access constraints
registered users
Size
271.93 KiB (278459 Byte)
Format
GZ
Status
completely archived
Creation Date
Future Review Date
2029-10-02
Download Permission
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Cite as
[ Derived from parent entry - See data hierarchy tab ]
Kern, Stefan (2019). ESA-CCI_Phase2_Standardized_Manual_Visual_Ship-Based_SeaIceObservations_v01. World Data Center for Climate (WDCC) at DKRZ. https://doi.org/10.26050/WDCC/ESACCIPSMVSBSIO

BibTeX RIS
Description
This compilation of observational data has
Level 2b - Geophysical Variable - Basic Quality Control

The data set has been standardized in the sense that for all cruises the same number of columns exist and that for all parameters without a valid observation a missing value is included.

The data set has been successfully employed in the evaluation of sea-ice products (sea-ice concentration, sea-ice thickness) based on satellite observations.

Users of the data set should note the following:
1) Observations are carried out (usually) by a group of voluntary observers of varying experience and skills. It should be taken into account, therefore, that the same ice conditions might be observed differently by different observers. It is therefore recommended to NOT use this data on a point-by-point basis but, for instance, as an along-track daily average.
2) The accuracy of all parameters describing the sea-ice conditions is 5-10% for fractions, (2-)5-10 cm for snow depth, and (0.05-)0.1-0.3 m for sea-ice thickness and ridge height; the values in parenthesis denoting values for thin snow and thin sea ice.
3) Ships tend to follow easy-to-navigate sea-ice conditions. Therefore, basically all parameters can be expected to be biased towards conditions encountered in a lead and/or within level sea ice of the thinnest category encountered. Particularly, it can be expected that the snow depth and the sea-ice thickness is biased low year-round. Sea-ice concentrations are likely biased low during summer.

Approved by author, August 28 2019
Description
The data set comprises observations along ship-trajectories at irregular time intervals and at irregular distances between successive ship-based observations. As such this is an irregularly distributed data set in space and time. Typically, time differences between successive observations should be around one hour.

For the same date, observations from several cruises can exist.

Each single ship-based observation comprises the parameters listed in the summary. Parameters not observed, i.e. missing, are assigned a missing value. These missing values are constant for one parameter, e.g. the sea-ice thickness of ice of thickness category I, for the entire data set but they may vary between different parameters, e.g. between sea-ice thickness: -9.9 and sea-ice concentration: -9 or a missing comment: noval.

Each single ship-based observation of the sea-ice conditions likely represent different areas around the ship. The goal is to observe within a radius of one kilometer around the ship. However, ships' speed, visibility, sea-ice conditions, and experience of the observer result in an elliptically shaped observation area with a semi-minor axis close to one kilometer and a semi-major axis between an estimated 1 and 2.5 kilometers.
Variable
air_pressure
CF
air_temperature
CF
area_type-where_lake_ice_or_sea_ice
CF
area_type_at_top_of_sea_ice
area_type_due_to_melting-where_lake_ice_or_sea_ice
cloud_area_fraction
CF
melt_pond_area_fraction_at_top_of_sea_ice
relative_humidity
CF
sea_ice_area_fraction
CF
sea_ice_ridges_area_fraction
sea_ice_ridges_thickness_at_top_of_sea_ice
sea_ice_thickness
CF
sea_water_temperature
CF
surface_snow_thickness
CF
wind_from_direction
CF
wind_speed
CF
Contact typePersonORCIDOrganization
Investigator
Dr. Stefan Kern
-
Center for Earth System Research and Sustainability, University of Hamburg
Metadata
Dr. Stefan Kern
-
Center for Earth System Research and Sustainability, University of Hamburg

Parent

ESA-CCI_Phase2_Standardized_Manual_Visual_Ship-Based_SeaIceObservations_v01
Details

Additional Info

Details for selected entry

Parent project(s)

ESA-CCI sea-ice-ecv project phase 2 bi-polar standardized manual visual ship-based sea-ice observations

[Entry acronym: SMVSBSIOA_3875805] [Entry id: 3875805]