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Connectivity between Eurasian snow extent and Canadian snow mass and river discharge. S. J. D éry, J. Sheffield, and E. F. Wood, Princeton. Decreasing river discharge in northern Canada, 1964-2003. Source: D é ry and Wood (2005), GRL.
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Connectivity between Eurasian snow extent and Canadian snow mass and river discharge S. J. Déry, J. Sheffield, and E. F. Wood, Princeton
Decreasing river discharge in northern Canada, 1964-2003 Source: Déry and Wood (2005), GRL.
Teleconnection between the AO and Hudson Bay river discharge Source: Déry and Wood (2004), GRL.
Datasets • Satellite-based measurements of mean monthly Eurasian snow extent from NOAA, 1973-2003. • CMC mean monthly snow mass over North America, 1979-1997 (Brown et al. 2003). • Canadian river discharge from HYDAT, 1973-2003 (Déry et al. 2005; Déry and Wood 2005). • Global meteorological fields from ERA-40.
Methods • Study period: 1973-2003. • Normalized time series of monthly Eurasian snow extent, annual Canadian maximum snow mass, and monthly river discharge. • Focus on Churchill River (Labrador) and Chesterfield Inlet (Nunavut) Basins. • Correlations are then performed, with time lags imposed,and are considered statistically-significant when p < 0.05.
Churchill River normalized annual snow & river discharge anomalies
Chesterfield Inlet normalized annual snow & monthly discharge anomalies
Correlation coefficient between monthly normalized Eurasian snow extent anomalies and Canadian annual maximum monthly snow mass anomalies the following year, 1980-1997
Correlation coefficient between monthly Eurasian snow extent anomalies & Canadian snow mass & river discharge anomalies the next year
Correlation coefficient between annual Eurasian snow extent anomalies & discharge anomalies the following year in 64 rivers of northern Canada
ERA-40 difference (1980-1989) in winter/spring a) SLP (hPa) and b) 500 hPa geopotential height (dam)
Difference (1980-1989) in winter/spring maximum snow mass (kg m-2) from Brown et al. (2003)
Physical Mechanism for Pan-Arctic Climate Connectivity • Soil moisture anomalies in Eurasia (Barnett et al. 1988, 1989) • North Atlantic SST anomalies (Saunders et al. 2003) • Polar wave flux activity (Gong et al. 2003) • Persistence of snow extent anomalies – AO correlates more significantly to annual (not seasonal) Eurasian snow extent anomalies.
Autocorrelation of monthly Eurasian normalized snow extent anomalies, 1973-2003
Summary • Annual maximum snow mass and streamflow in northern Quebec & Labrador is significantly correlated to Eurasian snow extent anomalies • Persistence of the Eurasian snow extent anomalies during spring is critical to pan-Arctic connectivity. • Thanks to: Land surface hydrology group at Princeton, Marc Stieglitz (Georgia Tech.), Ed McKenna, & Ross Brown (CMC).