HR: 0800h
AN: C21B-0461    [Abstracts]
TI: Observations, process studies, and modeling of seasonal snow in New Zealand
AU: Hendrikx, J
EM: j.hendrikx@niwa.co.nz
AF: NIWA, 10 Kyle Street, Christchurch, 8004, New Zealand
AU: * Clark, M P
EM: mp.clark@niwa.co.nz
AF: NIWA, 10 Kyle Street, Christchurch, 8004, New Zealand
AU: Slater, A G
EM: aslater@cires.colorado.edu
AF: CIRES, University of Colorado, Boulder, CO 80309, United States
AU: Tait, A B
EM: a.tait@niwa.co.nz
AF: NIWA, 10 Kyle Street, Christchurch, 8004, New Zealand
AB: Variability of seasonal snow in New Zealand directly affects the sectors of energy, agriculture and tourism, but intensive research and monitoring programs have only been developed recently. This paper will discuss observations, process studies, and modeling of snow in New Zealand: · Observations. Observations of snow in New Zealand have recently been significantly enhanced with the establishment of the National Institute for Water and Atmospheric Research snow and ice monitoring network. This network includes multiple new permanent high elevation stations that measure a large suite of micrometeorological variables as well as snow depth. Additional instrumentation to allow for the accurate measurement of solid and liquid precipitation and SWE are being investigated. We will discuss the establishment of the monitoring network, and outline problems encountered in measuring snow and climate in an extreme maritime alpine environment. · Process Studies. There have only been a few process studies of snow in New Zealand. However, new process studies are needed because there are notable differences between snow in New Zealand and snow in many other countries: Accumulation processes in New Zealand are unique because most of the snow is above treeline and a large amount of snow is redeposited by the wind; melt processes in New Zealand are unique because melt is largest in windy humid conditions when turbulent heat fluxes of sensible and latent heat dominate the radiative heat fluxes. We will summarize results from an intensive measurement campaign aimed at documenting and understanding spatial variability of snow water equivalent. · Modelling. Building an appropriate model to simulate snow in New Zealand requires defining a model with complexity that is justified in light of the available data, the problem we are trying to solve, and processes dominant where the model is applied. Additional model complexity comes at the expense of additional model parameters (many of which are difficult to estimate), and it is difficult to define the necessary complexity a-priori. For these reasons we built a flexible snow model in which processes can be "switched on" and "switched off", and each process is parameterized in the most parsimonious manner imaginable. We will describe application of the snow model to basins in New Zealand. We will also demonstrate how observations, process studies, and modeling of snow in New Zealand contribute to models used to predict streamflow in snowmelt-dominated basins and simulate impacts of climate change on New Zealand's water resources.
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
DE: 0798 Modeling
DE: 1827 Glaciology (0736, 0776, 1863)
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
SC: Cryosphere [C]
MN: 2007 Fall Meeting