LAUSR

Two years after the sad and sudden loss of Professor Hugh M. French (May 11, 2019), we commemorate his scientific life, leadership, and friendship with this special issue of Permafrost and Periglacial Processes (PPP), the journal that he founded in 1990 and edited for almost 16 years until 2006. This is the second such issue in his honour, because volume 16 number 1 appeared in 2005 on the occasion of his retirement from the University of Ottawa, where he taught and carried out research from 1967 until 2003. This special issue examines some of the topics particularly dear to Hugh within areas of the world that he loved, such as the Canadian Arctic (Figure 1), the UK, and China. During his long career, Hugh wrote more than 160 papers covering many periglacial and permafrost topics. He adeptly incorporated his knowledge and field experience in The Periglacial Environment, his well-known and much-used textbook, which ran to four editions published in 1976, 1996, 2007, and 2017. While he particularly focused on ground ice and cryostratigraphy, he made substantial contributions to topics such as thermokarst processes and landforms (Figure 2), frost mounds, slope processes and pediments, periglacial involutions, and weathering processes and related landforms including in hot deserts such as in Australia (Figure 3). His interest in Quaternary environments started during his early research in the UK and continued throughout his life, with analyses of deposits and relict landforms in many parts of the world, including the eastern USA, Europe, China and Antarctica. Hugh also worked on engineering problems in permafrost areas, especially in the Canadian Arctic, including those related to oil exploratory drilling and disposal of drilling fluids. He wrote conceptual papers, especially about periglacial environments and geomorphology and geocryology, and also assessed the scientific lives of the pioneering permafrost scientists such as J. R. Mackay and S. Taber. Given the great variety of topics to which Hugh contributed, we start this special issue with the broad field of conceptual and historical papers.