The SUMup dataset
Surface mass balance, subsurface temperature and density measurements from the Greenland and Antarctic ice sheets

Quick links:

• The SUMup 2023 release
• The SUMup 2023 ReadMe file
• Example Python scripts / Jupyter notebooks to manipulate the 2023 files
• The new netcdf format
• The CSV files

The 2023 release

Reference:

Vandecrux, B., Amory, C., Ahlstrøm, A.P., Akers, P.D., Albert, M., Alley, R.B., Arnaud, L., Bales, R., Benson, C., Box, J.E., Buizert, C., Charalampidis, C., Clerx, N., Covi, F., Denis, G., Dibb, J.E., Ding, M., Eisen, O., Fausto, R., Fernandoy, F., Freitag, J., Gerland, S., Harper, J., Hawley, R.L., Hock, R., How, P., Hubbard, B., Humphrey, N., Iizuka, Y., Isaksson, E., Kameda, T., Karlsson, N.B., Kawakami, K., Kjær, H.A., Kuipers Munneke, P., Lewis, G., MacFerrin, M., Machguth, H., Mankoff, K.D., McConnell, J.R., Medley, B., Morris, E., Mosley-Thompson, E., Mulvaney, R., Niwano, M., Osterberg, E., Otosaka, I., Picard, G., Polashenski, C., Rennermalm, A., Rutishauser, A., Simonsen, S.B., Smith, A., Solgaard, A., Spencer, M., Steen-Larsen, H.C., Stevens, C.M., Sugiyama, S., Tedesco, M., Thompson-Munson, M., Tsutaki, S., van As, D., Van den Broeke, M.R., Wilhelms, F., Xiao, J., Xiao, C.: The SUMup collaborative database: Surface mass balance, subsurface temperature and density measurements from the Greenland and Antarctic ice sheets (1912 - 2023), Arctic Data Center, https://www.doi.org/10.18739/A2M61BR5M, 2023.

Important notes on the 2023 release:

• Snow depth on sea ice is dropped. This was discussed with Nathan Kurtz who initiated this part of SUMup. The sea ice community did not reuse or feeded into SUMup's snow depth on sea ice data. In absence of volunteer to mobilize that community, offshore data is being removed from the next release of the data.
• The next release will contain SMB data, instead of just snow accumulation.

In this working repository you will find:

• the scripts used to compile the SUMup dataset
• Q&A and suggestions for further additions in the issues section

Additional ressources

The original dataset was described in:

Montgomery, L., Koenig, L., and Alexander, P.: The SUMup dataset: compiled measurements of surface mass balance components over ice sheets and sea ice with analysis over Greenland, Earth Syst. Sci. Data, 10, 1959–1985, https://doi.org/10.5194/essd-10-1959-2018, 2018.

The 2022 release of the SUMup data is available at:

Megan Thompson-Munson, Lynn Montgomery, Jan Lenaerts, and Lora Koenig. 2022. Surface Mass Balance and Snow Depth on Sea Ice Working Group (SUMup) snow density, accumulation on land ice, and snow depth on sea ice datasets 1952-2019. Arctic Data Center. https://doi.org/10.18739/A24Q7QR58.

with some illustration available here: https://github.com/MeganTM/SUMMEDup2022/blob/main/SUMMEDup_2022.ipynb

Read about the genesis of SUMup as first supported by NASA:

Koenig, L., Box, J., and Kurtz, N. (2013), Improving Surface Mass Balance Over Ice Sheets and Snow Depth on Sea Ice, Eos Trans. AGU, 94( 10), 100. https://doi.org/10.1002/2013EO100006

The new netcdf structure:

The data files have two groups "DATA": values given for each measurements and "METDATA": that gives more information about a variable present in DATA.

density

	var	long_name	unit	description
0	# DATA	nan	nan	nan
1	measurement_id	measurement_index	-	index of density measurement (unique for each observation)
2	timestamp	timestamp	days since 1900-01-01	date at which measurement <measurement_id> was measured
3	start_depth	start_depth_of_measurement	m	Top depth of density measurement <measurement_id>
4	stop_depth	stop_depth_of_measurement	m	Bottom depth of density measurement <measurement_id>
5	midpoint	midpoint_depth_of_measurement	m	Midpoint depth of density measurement <measurement_id>
6	density	density	kg m^-3	Measured density for measurement <measurement_id>
7	error	error	kg m^-3	Error associated with the density measurement <measurement_id>
8	latitude	latitude	degree North	Latitude of measurement <measurement_id>
9	longitude	longitude	degree East	Longitude of measurement <measurement_id>
10	elevation	elevation	m	Elevation of measurement <measurement_id> (datum may vary)
11	profile_key	profile_key	-	Profile key associated with measurement <measurement_id>
12	method_key	method_key	-	Method key of measurement <measurement_id>
13	reference_key	reference_key	-	Reference key of measurement <measurement_id>
14	# METADATA	nan	nan	nan
15	profile	profile	-	name of the profile <profile_key>
16	reference	reference	-	full reference associated with <reference_key> (please cite)
17	reference_short	reference_short	-	short reference associated with <reference_key> (please cite)
18	method	method	-	method associated with <method_key>

Temperature

	var	long_name	unit	description
0	# DATA VARIABLES	nan	nan	nan
1	measurement_id	measurement_index	-	index of temperature measurement (unique for each observation)
2	timestamp	timestamp_of_temperature_measurement	days since 1900-01-01	start date of measurement <measurement_id> (can be an estimation)
3	temperature	subsurface_temperature	deg C	Measured temperature for measurement <measurement_id>
4	depth	depth_of_subsurface_temperature	m	Depth of temperature measurement <measurement_id>
5	error	error	m w.e.	Error associated with the temperature measurement <measurement_id>
6	latitude	latitude	degree North	latitude of measurement <measurement_id>
7	longitude	longitude	degree East	longitude of measurement <measurement_id>
8	elevation	elevation	m	elevation of measurement <measurement_id>
9	name_key	name_key	-	Name key associated to measurement <measurement_id> (core name or location)
10	method_key	method_key	-	method key of measurement <measurement_id>
11	reference_key	reference_key	-	reference key of measurement <measurement_id>
12	# METADATA VARIABLES	nan	nan	nan
13	name	name	-	Name of the name key <name_key>
14	reference	reference	-	full reference corresponding to <reference_key> (please cite)
15	reference_short	reference_short	-	short reference corresponding to <reference_key> (please cite)
16	method	method	-	method corresponding to <method_key>

SMB

	var	long_name	unit	description
0	# DATA VARIABLES
1	measurement_id	measurement_index	-	index of smb measurement (unique for each observation)
2	start_date	start_date_of_smb_measurement	days since 1900-01-01	start date of measurement <measurement_id> (can be an estimation)
3	end_date	end_date_of_smb_measurement	days since 1900-01-01	end date of measurement <measurement_id> (can be an estimation)
4	smb	surface_mass_balance	m w.e.	Measured surface mass balance for measurement <measurement_id>
5	error	error	m w.e.	Error associated with the SMB measurement <measurement_id>
6	latitude	latitude	degree North	latitude of measurement <measurement_id>
7	longitude	longitude	degree East	longitude of measurement <measurement_id>
8	elevation	elevation	m	elevation of measurement <measurement_id>
9	name_key	name_key	-	Name key associated to measurement <measurement_id> (core name or location)
10	method_key	method_key	-	method key of measurement <measurement_id>
11	reference_key	reference_key	-	reference key of measurement <measurement_id>
12	# METADATA VARIABLES
13	name	name	-	Name of the name key <name_key>
14	reference	reference	-	full reference corresponding to <reference_key> (please cite)
15	reference_short	reference_short	-	short reference corresponding to <reference_key> (please cite)
16	method	method	-	method corresponding to <method_key>

The CSV files:

> SUMup 2023 beta/density/csv
    SUMup_2023_density_antarctica.csv
	  SUMup_2023_density_greenland.csv
	  SUMup_2023_density_methods.tsv
	  SUMup_2023_density_profile_names.tsv
	  SUMup_2023_density_references.tsv

import pandas as pd
df_density = pd.read_csv(path_to_SUMup_folder + 'density/csv/SUMup_2023_density_greenland.csv')
print(df_density.head(5).to_markdown())

	profile_key	reference_key	method_key	timestamp	latitude	longitude	elevation	start_depth	stop_depth	midpoint	density	error
0	57	4	4	2013-04-08	66.1812	-39.0435	1563	nan	nan	0.06	365.45	nan
1	57	4	4	2013-04-08	66.1812	-39.0435	1563	nan	nan	0.22	368.42	nan
2	57	4	4	2013-04-08	66.1812	-39.0435	1563	nan	nan	0.425	394.59	nan
3	57	4	4	2013-04-08	66.1812	-39.0435	1563	nan	nan	0.63	385	nan
4	57	4	4	2013-04-08	66.1812	-39.0435	1563	nan	nan	0.8025	378.05	nan

df_methods = pd.read_csv(path_to_SUMup_folder + 'density/csv/SUMup_2023_density_methods.tsv', 
                         sep='\t').set_index('key')
print(df_methods.head(5).to_markdown())

key	method
-9999	nan
1	1000 cc density cutter
2	250 cc density cutter
3	100 cc density cutter
4	ice or firn core section

df_names = pd.read_csv(path_to_SUMup_folder + 'density/csv/SUMup_2023_density_profile_names.tsv', 
                         sep='\t').set_index('key')
print(df_names.head(5).to_markdown())

key	profile
1	US_ITASE-02-6 (SPRESSO)
2	US_ITASE-07-4
3	US_ITASE-02-5
4	US_ITASE-03-1
5	US_ITASE-02-4

df_references = pd.read_csv(path_to_SUMup_folder + 'density/csv/SUMup_2023_density_references.tsv', 
                         sep='\t').set_index('key')
print(df_references.head(3).to_markdown())

key	reference	reference_short
1	US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data, Version 2- Mayewski, P. A. and D. A. Dixon. 2013. US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data. Version 2. [US_ITASE_Core Info-SWE-Density_2013.xlsx]. Boulder, Colorado USA: National Snow and Ice Data Center.	US ITASE: Mayewski and Dixon (2013)
2	SIMBA 2007 data - Lewis, M. J., Tison, J. L., Weissling, B., Delille, B., Ackley, S. F., Brabant, F., Xie, H., 2011. Sea ice and snow cover characteristics during the winter- spring transition in the Bellingshausen Sea: an overview of SIMBA 2007, Deep Sea Research II , doi:10.1016/j.dsr2.2010.10.027.	SIMBA: Lewis et al. (2007)
3	Satellite-Era Accumulation Traverse 2011 (SEAT11) snowpit density data – Brucker, L. and Koenig, L., SEAT11 Traverse snowpit density data.	SEAT11: Brucker and Koenig (2011)