Advancements in the measurement of the cryosphere using geophysics — Introduction

Abstract

Frozen regions of the earth are known as the cryosphere. The arctic, Antarctica, permafrost, ice sheets, and glaciers are some of the most challenging places to measure subsurface parameters, but they can also be some of the most important places to science and engineering research due to their susceptibility to environmental change. Ground-based, airborne, and space-borne geophysical methods are deployed to observe targets below the ground or in ice that may be difficult or impossible to measure using conventional direct observations and measurements. The papers in this special section address recent advances in instrumentation development and deployment and computational capabilities that have advanced cryosphere geophysical sciences. As such, many of these papers discuss the science that the methodology has helped reveal. A wide range of cryosphere science questions are being addressed using geophysical data, and most are highly relevant to climate change. For example: How does liquid water affect snow, glacier, and permafrost dynamics; what controls snowpack distribution and water content; what controls water movement in the active layer above permafrost; and how are sensitive special features like Antarctic lakes and ice shelves evolving? In all cases, geophysical measurements provide parameters vital to understanding the system function, often in 2D or 3D space or through time. We present 21 papers that include topics ranging from long-established direct-current electrical, seismic, and ground-penetrating radar (GPR) methods, to emerging measurements such as surface nuclear magnetic resonance (NMR), all with novel examples. Holbrook et al. image snow stratigraphy and estimate snow water equivalent (SWE) from a GPR system mounted on a snowmobile. The authors measure snow thickness, snow density, …