The atmospheric branch of the hydrological cycle in Antarctica(HYDRANT)
Field report
31/05/2009
Dr. Irina Gorodetskaya
Prof. Dr. Nicole van Lipzig
Contents
1. Project personnel and contact details
2. Introduction
3. Key Dates
4. Field sites
5. Field work
Acknowledgements
- Project Personnel
Dr. Irina Gorodetskaya (KUL, Belgium / LGGE, France) : postdoctoral researcher, project scientist (instrument preparation, field measurements, data analysis)
Prof. Dr. Nicole van Lipzig (KUL, Belgium) : project PI
Prof. Dr. Michiel R. van den Broeke (IMAU, Netherlands) : collaborator (polar meterology)
D. Erik van Meijgaard (KNMI, Netherlands) : collaborator (regional climate modeling)
Dr. HugoDeBacker (RMI, Belgium) : collaborator (atmospheric chemistry and remote sensing)
Prof. Dr. Susanne Crewell (IGM, Germany) : collaborator (remote sensing of clouds and precipitation)
- Introduction
The main objective of the project is to contribute to a better insight into the current evolution of the atmospheric branch of the hydrologic cycle covering the chain from evaporation at the surface to snowfall. This is needed in order to get more understanding of the current evolution of the surface mass balance of the ice sheet and associated sea-level changes. Meteorological measurements (Automatic Weather Station), snow accumulation measurements (stakes), and remote sensing measurements of clouds (Ceilometer and Infrared Pyrometer, and later also Microwave Radiometer and Micro Rain Radar) are needed to be installed as part of this project. The data together with existing and newly emerging data (both ground-based and satellite) will be used to evaluate and improve the regional atmospheric climate model RACMO/ANT2 after which an updated reconstruction of the climate of Antarctica will be performed.
- Key Dates
Campaign preparation:
1. June-Sep 2008: Purchasing instruments
Responsible: Nicole van Lipzig
2. Sep 2008 - Jan 2008: Testing, preparing, and shipping the instruments
Responsible: Irina Gorodetskaya
Supervisor: Nicole van Lipzig
Field work (Irina Gorodetskaya):
Jan 24-Jan 30: Transit (Europe-Cape Town-Novolazarevskaya-Utsteinen)
Jan 31-February 22 2009: Actual field work
Feb 22: Departure from Utsteinen
- Field sites visited
The main project work was performed either on the site or in the vicinity of the main base.
Automatic Weather Station: installed on February 2 for long-term operation about 300 m east of Utsteinen ridge.
Ceilometer and IR pyrometer: installed and operating during two weeks of the field season (Feb 6-22) on the roof of the scientific container at the base camp (about 100 m south-west from Utsteinen ridge).
Additional measurements for GLACIOCLIM-BELARE project (also useful for HYDRANT project but not part of it):
Glaciological stakes: installed during February 12-13 every 3 km of the 180 km traverse from Crown Bay to Utsteinen
Snow density measurements: three sites (Feb 7: 1 km south-east from Utsteinen ridge; Feb 12: at Crown Bay; Feb 13: about 10 km south from Crown Bay along the traverse to Utsteinen)
- Field work
The Automatic Weather Station (AWS) was successfully installed on February 2, 2009 at the location about 300 m east from Utsteinen ridge, providing basic meteorological data and radiative fluxes about 4 m above the snow surface, snow temperature profile down to 1 m depth, and changes in snow height. Measurements during the campaign have been recorded continuously on the data logger and backed up on the memory card. Regular (3-hourly when possible) manual data readings were performed during the entire field campaign providing weather updates for Neumayer Antarctic Station meteorologist and Novolazarevskaya logistical air base.
There was a technical problem with the ARGOS antenna needed for the real-time data transfer to Europe. The problem was unfixable in the field and the antenna was unmounted and brought back to the engineering group of IMAU, which provides technical support for the AWS. The memory card was also brought back to IMAU for retrieving the measurements during the campaign. Currently measurements are being recorded on the data logger and will be retrieved during the next season.
Two cloud instruments (Ceilometer measuring the vertical atmospheric backscatter profile and cloud base height at several levels, and IR Pyrometer measuring cloud base temperature) were installed temporarily during the field season on the roof of a scientific container at the base camp (about 100 m south-west from Utsteinen ridge). Long-term (over-winter) installation necessary for the project was not possible because both instruments need continuous power supply from the main station, which was not available during the past season. Even though the measurement period was short (February 6-22), this allowed to test instrument behaviour during changing weather conditions and provided valuable data on cloud properties and occurrence of the snow fall/drift during the end of the summer season. Special efforts were made to have the instruments running continuously during both day and night times. Ceilometer measurements of the cloud base height were also regularly reported as part of the weather updates to Neumayer station and Novolazarevskaya air base (valuable information for flight operations).
Recording meteorological and cloud conditions during storms is a key goal of our project. Past season showed that simultaneous measurements by ceilometer and pyrometer can give a picture of a storm evolution (changes in the cloud height and temperature). Each storm during February was characterized by strong south-east winds and blowing snow in a layer at least 300 m high. Cloud conditions prior to the storm onset however showed different patterns with different times of occurrence of high, mid and low-level clouds. All storms were associated with warm advection and increased cloud base temperatures (by up to 500C) as recorded by IR pyrometer. This is valuable information for understanding the role of clouds in the surface radiative budget and surface air temperature changes.
With these instruments however we cannot see if there was snow precipitation from the clouds or only snow redistribution by the wind during the storm events, which is important for understanding surface mass balance. Such information can be derived from micro-rain radar measurements, installation of which is planned during later phase of the project (possibly next season).
As part of collaboration with GLACIOCLIM-BELARE project with Christophe Genthon from Laboratoire de Glaciologie et Géophysique de l'Environnement (France) and Alain Hubert (IPF), glaciological stakes were installed during the traverse from Crown Bay to Utsteinen every 3 km during 180 km from Crown Bay to Utsteinen during February 12-13. GPS position and emergence above the snow surface were recorded for each stake. Redoing such measurements each year will show changes in snow accumulation and ice movement between Utsteinen nunatak and the coast. The data on snow accumulation along the traverse are valuable for our project as most of precipitation in this region is associated with synoptic systems originating over the ocean.
To convert the snow height measurements to a surface mass balance value (in water equivalent), knowledge of the density distribution of the observed sample is required. Several snow density profiles have been made aiding both GLACIOCLIM-BELARE and HYDRANT projects. Three snow cores were extracted using manual drill: 4m core near Utsteinen site (1 km south-east from Utsteinen ridge, on Feb 7), 2m core at Crown Bay (next to the coast logistical camp at the first glaciological stake point, Feb 12) and 2m core about 10 km south from Crown Bay along the traverse line to Utsteinen, Feb 13. Obtained data and problems encountered during measurements have been reported to Christophe Genthon (LGGE) and will be discussed with him in more detail to ensure more complete measurements during future seasons.
Acknowledgements
This project has been possible thanks to many people.
We would like to thank Wim Boot, the engineer at IMAU, for providing support for the AWS station both during the preparation and field work.
Many thanks to Alexander Mangold from RMI, who helped with the AWS installation.
Big thanks to Marie Dumont and Hélèn Castebrunet (LGGE) for the training in snow density measurements in the Alps.
Many thanks to Toon Helsen for helping with cloud instrument installation and snow density measurements in Antarctica.
Special thanks to the engineers at the Department of Earth and Environmental Sciences at KU Leuven Jos Meersmans, Valentijn Tuts and Mustafa Ayyad for working with us on cloud instrument preparation and testing (this includes ordering additional material, constructing a set up for pyrometer, helping with installation of the instruments for test runs at KU Leuven site, and helping with shipping the instruments).
We would like to acknowledge great help from the military, engineering, field guides and management staff during the field work in Antarctica.
Also we would like to thank Laurence Vanlede (IPF) and Michel de Wouters (IPF) for efficient communication and organization before and after the campaign in Belgium and Cape Town.
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