Geography of Glacier Mass Balance

• Main Author: Braithwaite, Roger
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2019
• Subjects: Glacier; Mass balance; Sea level; Climate; Model; glacier; Greenland
• Online Access: https://research.manchester.ac.uk/en/studentTheses/7c92e0d0-9025-421f-b5ef-4e7a1d84492e; https://pure.manchester.ac.uk/ws/files/146412153/FULL_TEXT.PDF

Twelve published papers are submitted for this D.Sc. thesis. The papers were published in 1995 to 2009 when Roger Braithwaite was employed by the University of Manchester. The submitted papers relate to the general area of ‘glaciers and sea level’ and there is a strong theme that glacier conditions differ between regions, hence the title ‘geography of glacier mass balance’. Paper no. 1 analyses degree-day factors from Greenland whereby glacier melting can be calculated from temperature data. Paper no. 2 discusses the effect of glacier mass balance changes on global sea level rise, including a simple theoretical treatment and estimation of the temperature-sensitivity of global sea level using the degree-day model. The latter depends on the combined geographies of glacier area and temperature-sensitivity of glacier mass balance. Papers 3, 4 and 5 analyse observed glacier mass balance from all over the world, and papers 6, 7 and 8 discuss the modelling of mass balance with the degree-day model. A trend of increasingly negative observed mass balance is only detectable towards the end of the 1995-2009 period. Papers 9, 10 and 11 discuss the climate at the glacier equilibrium line altitude (ELA) and propose a simplified approach to calibration of the degree-day model. Paper 12 returns to the topic of global sea level change with improved insights from papers 9, 10 and 11. Observed mass balance variability (papers 3, 4 & 5) and modelled temperature-sensitivity of mass balance (papers 6, 7 & 8) both show contrasts between maritime and continental climates with lower variability and sensitivity at high latitudes and in continental interiors, and higher variability and sensitivity at lower latitudes. The underlying global geography of mass balance variability and temperature-sensitivity is therefore controlled by the geography of annual precipitation.