Antarctic meteorology, a study with automatic weather stations

• Main Author: Reijmer, C.H.
• Other Authors: Universiteit Utrecht, Dep Natuurkunde, Oerlemans, Hans
• Format: Doctoral or Postdoctoral Thesis
• Language: unknown
• Published: 2001
• Subjects: International (English); Antarctic; Berkner Island; Dronning Maud Land; The Antarctic; Antarc*; Antarctica; DML; EPICA; Ice Sheet
• Online Access: https://dspace.library.uu.nl/handle/1874/237361

This thesis chiefly addresses a) the use of Automatic Weather Stations (AWS) in determining the near-surface climate and heat budget of Antarctica and, specifically, Dronning Maud Land (DML), and b) the determination of source regions of Antarctic moisture with the aid of a trajectory model and an atmospheric model. The primary motivation behind this interest is the drilling of two ice cores in the Antarctic ice sheet within the framework of the European Project for Ice Coring in Antarctica (EPICA). A thorough knowledge of the meteorological conditions will increase our understanding of the processes that influence the surface mass balance and heat budget. In Chapter 2, ground-based observations of broadband, narrowband, and bidirectional reflectance are used to study the albedo of blue ice and snow. During summer, surface albedo plays an important role in the amount of heat exchanged between the surface and the atmosphere. The aim is therefore to improve the methods used to derive surface albedo from satellite measurements and arrive at a better understanding of the processes influencing the magnitude of the albedo. Chapters 3, 4 and 5 describe the data obtained from ten AWS in Antarctica and how they were used to determine the local surface energy budget. The AWS were placed on two transects perpendicular to the coastline in DML and one on Berkner Island. Mainly the strength of the katabatically forced flow, in combination with the geostrophic flow, determines the near-surface conditions at these locations. The katabatic flow varies in strength depending on the magnitude of surface slope and temperature inversion, and is not active on Berkner Island, a station on a topographic dome. In DML, the strength of the katabatic flow varies, resulting in maximum wind speeds and potential temperatures at the sites with the steepest slopes, at the edge of the Antarctic plateau. The AWS data, together with a model based on Monin-Obukhov similarity theory, are used to calculate the surface energy budget for the measuring ...