Iken et al. 1993 Jakobshavn isbræ

[BaptisteVandecrux]

Hey Ken, I just found this: Iken A, Echelmeyer Κ, Harrison W and Funk M (1993) Mechanisms of fast flow in Jakobshavns Isbræ, West Greenland: Part I. Measurements of temperature and water level in deep boreholes. Journal of Glaciology 39(131), 15–25 (doi:10.3189/S0022143000015689)

https://www.cambridge.org/core/journals/journal-of-glaciology/article/mechanisms-of-fast-flow-in-jakobshavns-isbrae-west-greenland-part-i-measurements-of-temperature-and-water-level-in-deep-boreholes/88D663D991221318E513075E1BF6C5A1

Is it already in?

[mankoff]

Yes it's in under jakobshavn_{left,center,sheet}. See for example https://github.com/GEUS-Glaciology-and-Climate/greenland_ice_borehole_temperature_profiles/tree/main/jakobshavn_center . Could rename, perhaps to iken_1993_{a,b,c} ?

For some reason one of the profiles is digitized from Lüthi (2002) rather than Iken (1993). I think the logic was that using more recent papers might be better re higher fidelity graphics? Or the hope that more recent papers would eventually provide digital data.

[mankoff]

@MartinLuethi do you have digital data for any of the profiles in Iken (1993) or Lüthi (2002) Figure 7 (a)?

[MartinLuethi]

@MartinLuethi do you have digital data for any of the profiles in Iken (1993) or Lüthi (2002) Figure 7 (a)?

sure, here are sites A and B (1989) and D (1995). Site D has 5 different boreholes with temperatures. A and B were published in 1993, D in 2002. This again illustrates that it is important to have a good file naming policy (author-year is not good, site_year_hole is better IMHO).

temp_depth89A.txt temp_depth89B.txt temp_depth95.txt

[mankoff]

What is the site name here? Something more project-specific or official than jakobshavn?

[mankoff]

Also, thank you for data! :).

[mankoff]

@MartinLuethi - do you have a suggestion how to define or select one profile for the 95D? For now I'm concatenating all except % Kette 50 kurze Thermistorenkette because of an outlier (I think these are the open diamond points in your 2002 paper)

[MartinLuethi]

Hi Ken

Ken Mankoff @.***> writes:

@MartinLuethi - do you have a suggestion how to define or select one profile for the 95D? For now I'm concatenating all except % Kette 50 kurze Thermistorenkette because of an outlier (I think these are the open diamond points in your 2002 paper)

Actually, these were digitally transmitted data from two independent deep boreholes, and analog thermistors for the shallow thermistors in even more boreholes. All were within 100 m, but maybe we should report them independently? This might be the most honest way to do it, and the user can exclude whatever they think is an outlier.

Given our experience from FOXX and GULL, I don't think the outliers are measurement errors, but show that the temperature is not homogeneous.

Best, Martin

[mankoff]

Ok. Naming suggestions? I think this means Jakobshavn95D gets split into 5. Unless I hear otherwise I will do:

• Jakobshavn95D_Kette10
• Jakobshavn95D_Kette20
• Jakobshavn95D_Kette30
• Jakobshavn95D_Kette40
• Jakobshavn95D_Kette50

[MartinLuethi]

To be consistent with the 2002 paper, Table1, I would rather use

Jakobshavn95D_I1 Jakobshavn95D_I2 Jakobshavn95D_T3 Jakobshavn95D_T4 Jakobshavn95D_T5