In-flight atmospheric and surface measurements using the HELiPOD helicopter-towed probe during ARTofMELT, Arctic Ocean, 2023

Falk Pätzold, Lutz Bretschneider, Andreas Schlerf, Magnus Ole Asmussen, Valtteri Hyöky, Jeffrey Welker, Sven Bollmann, Barbara Harm-Altstädter, Christian Pilz, Sebastian Düsing, Henrik Stapel, Evelyn Jäkel, Zsofia Juranyi, Anke Roiger, Astrid Lampert

The ARTofMELT expedition was carried out in the Fram Strait pack ice during the spring transition (May to June) of 2023, with the Swedish icebreaker Oden serving as research platform.

The helicopter-towed sensor system HELiPOD was deployed for 12 flights up to 2:30 hours (in total 26.5 hours) over the course of one month within a 20 NM radius around the ship. The instrumentation and flight pattern were designed to measure simultaneously the spatial variability of atmospheric and surface properties.

HELiPOD is equipped with several instruments for basic air data (wind vector, temperature, humidity), trace gas concentrations (methane, carbon dioxide, ozone) and isotopes (water vapour), aerosols in different size classes, solar and terrestrial downward and upward irradiance (VIS and FIR), surface imaging (different cameras) and topography (laser scanner).

The strength of the system is that simultaneous measurements provide the opportunity to investigate correlations between the observed parameters and, thus, improve process understanding of the interaction between atmospheric boundary layer, surface properties, radiation, trace gases and aerosol properties.

This dataset provides data for 12 flights, carried out between 2023-05-09 and 2023-06-09.

AtmosphereObservationsWindTurbulenceAir temperatureAir humidityWater isotopesAerosolsOzoneMethaneCarbon dioxideTurbulent fluxesIrradiance budgetSpatial variabilityVertical profilesSea iceSea ice classificationSea ice fractionOcean-atmosphere interfaceFram StraitARTofMELTARTofMELT 2023 expeditionIcebreaker Oden

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Citation

References

Altstädter B, Platis A, Wehner B, Scholtz A, Wildmann N, Hermann M, Käthner R, Baars H, Bange J, Lampert A (2015) ALADINA – an unmanned research aircraft for observing vertical and horizontal distributions of ultrafine particles within the atmospheric boundary layer. Atmospheric Measurement Techniques 8:1627-1639. https://doi.org/10.5194/amt-8-1627-2015

Gao RS, Telg H, McLaughlin RJ, Ciciora SJ, Watts LA, Richardson MS, Schwarz JP, Perring AE, Thornberry TD, Rollins AW, Markovic MZ, Bates TS, Johnson JE, Fahey DW (2016) A light-weight, high-sensitivity particle spectrometer for PM2.5 aerosol measurements. Aerosol Science and Technology 50:88-99. https://doi.org/10.1080/02786826.2015.1131809

Harm-Altstädter B, Bärfuss K, Bretschneider L, Schön M, Bange J, Käthner R, Krejci R, Mazzola M, Park K, Pätzold F, Peuker A, Traversi R, Wehner B, Lampert A (2023) Spatial distribution and variability of boundary layer aerosol particles observed in Ny-Ålesund during late spring in 2018. Aerosol Research 1:39-64. https://doi.org/10.5194/ar-1-39-2023

Jäkel E, Stapf J, Wendisch M, Nicolaus M, Dorn W, Rinke A (2019) Validation of the sea ice surface albedo scheme of the regional climate model HIRHAM–NAOSIM using aircraft measurements during the ACLOUD/PASCAL campaigns. The Cryosphere 13:1695–1708. https://doi.org/10.5194/tc-13-1695-2019

Lampert A, Pätzold F, Jiménez MA, Lobitz L, Martin S, Lohmann G, Canut G, Legain D, Bange J, Martínez-Villagrasa D, Cuxart J (2016) A study of local turbulence and anisotropy during the afternoon and evening transition with an unmanned aerial system and mesoscale simulation. Atmos Chem Phys 16:8009–8021. https://doi.org/10.5194/acp-16-8009-2016

Lenschow DH (1972) The Measurement of Air Velocity and Temperature Using the NCAR Buffalo Aircraft Measuring System, p. 39-55. National Center for Atmospheric Research, Boulder Colorado, NCAR-TN/EDD-74

Pätzold F, Bretschneider L, Nowak S, Brandt B, Schlerf A, Asmussen MO, Bollmann S, Bärfuss K, Harm-Altstädter B, Hecker P, Wehner B, van der Wall BG, Sachs T, Huntrieser H, Roiger A, Lampert A (2023) HELiPOD—Revolution and evolution of a helicopter-borne measurement system for multidisciplinary research in demanding environments. Elem Sci Anth 11. https://doi.org/10.1525/elementa.2023.00031

Pilz C, Düsing S, Wehner B, Müller T, Siebert H, Voigtländer J, Lonardi M (2022) CAMP: an instrumented platform for balloon-borne aerosol particle studies in the lower atmosphere. Atmos Meas Tech 15:6889-6905. https://doi.org/10.5194/amt-15-6889-2022

Schuchard M, Bärfuss K, Bretschneider L, Conrath T, Held A, Käthner R, Kellermann M, Lampert A, Mathes T, Müller J, Pilz C, Schlerf A, Siebert H, Wehner B, Harm-Altstädter B (2026) Arctic aerosol and meteorological observations using airborne and ground-based systems in spring 2024. Earth Syst Sci Data, submitted

Sperzel TR, Jäkel E, Pätzold F, Lampert A, Niehaus H, Spreen G, Rosenburg S, Birnbaum G, Neckel N, Wendisch M (2023) Surface albedo measurements and surface type classification from helicopter-based observations during MOSAiC. Scientific Data 10. https://doi.org/10.1038/s41597-023-02492-6

Stapel H, Pätzold F, Jäkel E, Asmussen M, Hyöky V, Bretschneider L, Schlerf A, Lampert A (2026) Airborne sea ice classification during expedition ARTofMELT, Arctic Ocean, 2023. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-artofmelt-2023-helipod-classification-1

Stull R (2017) Practical Meteorology, An Algebra-based Survey of Atmospheric Science, 926 p. ISBN-13: 978-0-88865-283-6

Data description

• Number of files: 24
• Total data size: 13.2 GB
• File formats:
  • NetCDF (nc)
  • matlab (mat)

The dataset is provided in the format of NetCDF and as MAT-struct; with both formats containing the same data as described below.

Each flight-day has one pair of nc and mat data, with flight number and date included in the file name.

Group/substruct Info

This subsection contains general metadata for each flight including take-off and landing time

Group/substruct Data (harmonised 100 Hz data)

• Data.Time all synced to UTC: UNIX time, ISO8601, hh:mm:ss, Seconds of Day (SoD), Day of Year (DoY)
• Data.Position position in WGS84 reference frame [deg][deg][m], barometric altitude [m], radar altitude [m], online derived lidar altitude [m]
• Data.Velocity velocities in WGS84 reference frame [m s⁻¹]
• Data.Attitude Eulerian angles (body fixed to WGS84), all in [deg]
• Data.SolarPosition Sun elevation and azimuth at current position [deg][deg]
• Data.Irradiance down- and upwelling short-wave and long-wave irradiance, all in [W m⁻²]
• Data.SurfaceTemperature [°C]
• Data.AirTemperature derived complementary air temperature converted to static air temperature, dry potential air temperature and virtual air temperature, all in [°C]
• Data.AirHumidity derived complementary air humidity converted to absolute [g m⁻³] and relative humidity [%], mixing ratio [g kg⁻¹] and dew point [°C]
• Data.AirPressure calibrated static air pressure [hPa], calibrated dynamic air pressure [hPa]
• Data.AirDensity Calculated air density assuming dry air and wet air [kg m⁻³] according Data.AirHumidity
• Data.WindVector Calculated 3D windvector [deg][m s⁻¹][m s⁻¹], calculated turbulent kinetic energy TKE [m² s⁻²] and turbulence anisotropy [-], each for two window sizes
• Data.Aerosols two condensation particle counter CPC (5/10nm)[# cm⁻³], optical particle counter OPC (0.3, 0.5, 0.7, 1, 2, 5 µm)[# cm⁻³], portable optical particle spectrometer POPS (140nm:(16):3µm)[# cm⁻³], black carbon concentration [Mm]
• Data.WaterIsotopes δ¹⁸O and δH isotopic ratios [per mille]
• Data.Methane Methane concentration [µmol mol⁻¹][mmol m⁻³]
• Data.Ozone Ozone concentration [ppbv]
• Data.INPsampler Operating time and total volume sampled [l]
• Data.MagneticField 3 components of Earths magentic field, all in [nT]

Group/substruct SurfaceClassification

This subsection contains solely the numerical data from the related dataset Airborne sea ice classification during expedition ARTofMELT, Arctic Ocean, 2023 (Stapel et al. 2026).

• Number of each used image (IMG_xxxxx) and the following related data:
• Time in different formats (UNIX, ISO8601, SoD, DoY)
• Position Lat [deg], Lon [deg], Alt [m] in WGS84 reference frame
• Radar altitude [m]
• Online derived lidar altitude [m]
• Fractions [-] unweighted and cosine weighted within the not masked area differed into open water, melt pond, bare ice, young ice, snow-covered ice and unclassified for each image

Group/substruct FlightSections

• Overview In chronological order, each flight is divided into the following segment types: “straight and level”, "turn", "straight climb" and "straight descent". This is a coarse semi-automated breakdown of the sections. Please note that these sections are not aligned to the same section of the sea ice surface but derived from flight states. The following data are provided per section:
  • Type
  • Starttime (all formats mentioned above)
  • Endtime (all formats mentioned above)
  • Duration [hh:ss][s]
  • Mean latitude [deg]
  • Mean longitude [deg]
  • Mean altitude [m] (for “straight and level” only)
  • Standard deviation altitude [m] (for “straight and level” only)
  • Minimun and maximum altitude [m] (for “climb” and “descent” section only)
  • Mean radar altitude [m] (for “straight and level” only)
  • Mean heading [m][cardinal direction](not for “turn” sections).

In the mat file these data are cumulated additionally in a table within this subsection.

• StraightAndLevelSections contains the same data as subsection “overview” but only for the “straight and level” sections, ignoring irrelevant data. For each of the section the following turbulent vertical fluxes were calculated, assuming linear detrending:
  • Momentum flux [m² s⁻²]
  • Sensible and latent heat flux [W m⁻²]
  • Water flux [mol m⁻² s⁻¹][kg m⁻² s⁻¹]
  • Methane flux [mol m⁻² s⁻¹][kg m⁻² s⁻¹]
  • Ozone flux [mol m⁻² s⁻¹][kg m⁻² s⁻¹]
  • Aerosol fluxes [# m⁻² s⁻¹] of both CPC readings.

Shear stress [N s⁻²] and friction velocities [m s⁻¹] were calculated and the mean and standard deviation values for the surface classification [-]. In the mat file these data are cumulated additionally in a table within this subsection.

Flight 11 does contain only a minor subset of the data.

Not included in these dataset are the outcome of the laserscanner Velodyne VLP16, which will be published as separate dataset.

Also not included are the data of the INP filter analysis, the CO concentration and aerosol measurement miniature scanning electrical mobility sizer (mSEMS) as these devices were not linked to the HELiPOD data aquisition. Please contact the respective device operator.

Full data sets of raw data and intermediate data processing steps on request to the corresponding author.

Comments

Methods

The helicopter-towed sensor system HELIPOD and the basic data handling is described by Pätzold et al. (2023). The wind vector was calculated according to Lenschow (1972), turbulence parameter and fluxes as described by Stull (201). Surface type fractions were calculated per image, accounting for lens distortion as described by Jäkel et al. (2019). The cosine weighting according to the viewing zenith angle is described by Sperzel et al. (2023).

Aerosol measurements

Aerosol particle number concentration of ultrafine particles are measured with two condensation particle counters (CPC, TSI model 3007) of the same type but with different threshold diameters of 5 and 10 nm with a upper limit of up to around 1 µm each. An optical particle counter (OPC, Met One GT-256S) is used to detect particle number concentration with six different size channels between 300 nm and up to 10 µm. The setup was equipped on a smaller compartment of a uncrewed aerial system (e.g. Altstädter et al. 2015) and used for Arctic spatial distribution measurements in Ny-Alesund (Harm-Altstädter et al. 2023 and Schuchard et al. 2026).

For ARTofMELT, a portable optical particle spectrometer [POPS, Handix Scientific model 3100] was integrated to observe aerosol particle number size distribution (e.g., Gao et al. 2016) with a single particle backscatter of a 405 nm diode laser, allowing to calculate the backscatter intensity into a size distribution between 130 nm and 3 µm. Further, a tricolor absorption photometer [STAP, Brechtel Manufacturing, model 9406] was used for measurements of the aerosol light absorption coefficient at three different wavelengths with 450 nm, 525 nm and 624 nm at a temporal resolution of about 1 Hz (e.g., Pilz et al. 2022).

Full dataset

Full raw data and image files sets can be obtained on request to the corresponding author.

AI declaration

All data were derived using heuristic methods and non-AI software. AI was used to create some code solution for data handling.

Related dataset

Airborne sea ice classification during expedition ARTofMELT, Arctic Ocean, 2023 (Stapel et al. 2026).

The expedition

Data were collected during the ARTofMELT 2023 expedition on board the Swedish icebreaker Oden, which was organized by the Swedish Polar Research Secretariat from 8 May through 14 June, 2023.

Project

The preparation and participation of the HELIPOD in the ARTofMELT campaign was funded by the German Research Foundation DFG (LA2907/21-1) under project number 510976112.

Publisher

Bolin Centre Database

License

Creative Commons Attribution 4.0 International License (CC BY 4.0)

First name

Falk

Last name or organisation

Pätzold

Email address

f.paetzold@tu-braunschweig.de

Address

Technische Universität Braunschweig; Institute of Flight Guidance

Postal code

38108

City

Braunschweig

Country

Germany

GCMD science keyword

Earth science services > Data analysis and visualization

GCMD location

Ocean > Arctic Ocean

Dataset language

English

Begin date

2023-05-09

End date

2023-06-09

DOI

Time

Versions

• 1 2026-06-11T08:26:24.802+00:00
• 1 2026-06-09T07:56:25.588+00:00