Linking hydrological variations at local scales to regional climate teleconnection patterns

Authors: RASOULI, KABIR - Environment And Climate Change Canada; SCHAROLD, KARIS - University Of North Dakota; MAHMOOD, TAUFIQUE - University Of North Dakota; GLENN, NANCY - Boise State University; Marks, Daniel

Submitted to: Hydrological Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: This paper uses 35 years of long-term data from snow, climate, and streamflow from RCEW to investigate the relationship between measured and simulated conditions and reported broad-scale climate teleconnection patterns over the same time period. The analysis uses the Cold Regions Hydrological Modeling (CRHM) system, which has the ARS snow model Snobal as its core, to assess the relationship between year-to-year conditions and broad-scale climate. The analysis shows that there is general alignment between regional climate and conditions in RCEW, and that rain-on-snow produces significant streamflow when it occurs. The work suggests that more careful analysis needs to be done to better refine the relationship between actual conditions and broad-scale climate teleconnections.

Technical Abstract: Water budget and surface energy in topographic units at hillslope-scale play an essential role in the variability of local hydrology and regional climate. Multi-year variations of water balance fluxes in hillslopes have not been sufficiently studied in the context of large-scale climatic patterns, especially in complex terrain. In this study, the linkage between hillslope hydrological processes and atmospheric teleconnection patterns was studied under multi-year and temporally continuous hydroclimatic phases. A physically-based hydrological model was used to investigate distributed hydrological responses to climate variability over 31 years in a zero-order headwater basin within Reynolds Creek Experiment Watershed, Idaho, USA. Results show that high runoff efficiency and extreme high runoffs in the study area occur under negative phases of Arctic Oscillation – AO and Equatorial Pacific Sea Surface temperature – SST in the Niño 3.4 region, while low runoff efficiency and extreme low runoffs occur under a positive phase of North Atlantic Oscillation – NAO and a negative phase of Pacific North American pattern – PNA. More frequent rain on snow events are observed under a positive phase of Antarctic Oscillation – AAO. Runoff generated from rain on snow events varied from 73 mm below normal in a dry and positive phase of NAO and a negative phase of PNA to 57 mm above normal in a wet and positive phase of AAO. Cold and wet conditions are likely to occur under a positive phase of AAO and negative phases of NAO, AO, and SST and extremely dry and warm conditions are likely to occur under a positive phase of NAO and negative phases of AAO and PNA. Linking hillslope hydrology to the atmospheric teleconnection patterns over multi-year hydroclimatic phases can be incorporated into weather and climate models to improve hydrological forecasts and climate projections. The warm hydroclimatic phases identified in this study can be used as analogues to future climatic conditions to develop strategies for water security in snow-dominated regions.