Climate forcing of moisture variability. Combine effects from ocean/atmospheric variability on hydroclimatic variability across North America Droughts due to the Pacific, Atlantic Ocean, and /or global SSTs, temperature trends?
Typical wintertime Sea Surface Temperature (colors), Sea Level Pressure (contours) and surface windstress (arrows) anomaly patterns during warm and cool phases of PDO, ENSO
Characteristic warm-phase PDO October-March air temperature anomalies, in degrees C. This field is based on linear regressions between the gridded surface air temperature data and the SST-based PDO index, 1900-1993. Contour interval is 0.2 C.
Contour map of correlation coefficients between gridded North American December-February (DJF) precipitation and the SST-based PDO index, based upon data for the period 1900-93.
PDO: 1998-07avg = -0.0065 (N-M); 0.1846 (ann)
1988-07avg = 0.2225 (N-M); 0.1977 (ann)
AMO index: the ten-year running mean of detrended Atlantic SST anomalies north of the equator.
Correlation of the AMO index with gridded SSTA over the world ocean (all seasons). The thick contour is zero and thin contours denote the 95% signicance level.
Correlation of the AMO index with climate division rainfall with the Mississippi basin highlighted by light gray fill. The larger highlighted circles indicate correlations
above the 90% signicance level. The color bar applies to correlations in both panels.
Enfield et al. 2001: In all but the summer season (July-August-September) the patterns are different from Fig. 1c and have far fewer significant correlations. The summer season pattern is similar and has many significant correlations. We therefore believe that multidecadal variations in summer rainfall are mainly responsible for the observed relationship.
*annual AMO has been positive since 1997
http://www.usatoday.com/weather/tg/wjstream/wjstream.htm - from M. Gleuck
Climate forcing of moisture variabilityMcCabe, G. J., M. A. Palecki, and J. L. Betancourt. (2004). "Pacific and Atlantic Ocean influences on multidecadal drought frequency in the United States." Proceedings of the National Academy of Sciences 101(12): 4136-4141. PDFSeager, R., Y. Kushnir, C. Herweijer, N. Naik and J. Velez, 2005: Modeling of tropical forcing of persistent droughts and pluvials over western North America: 1856-2000. Journal of Climate, 18(19): 4065-4088. PDF
Basin OverviewsSelect a river basin of interest in western US (or North America). Investigate the climate of region (range and seasonality, variability, circulation influences), gage records available, use the longest to show hydrograph (variations on flow over the year) and variability (year to year), discuss source of water supply (e.g., summer/winter systems, snow vs rain), flow characteristics, critical activities and/or water supplies issues (endangered species, dams, hydro) in the basin. Develop a short (15 minutes) power point presentation, and write a short summary for the blog.Hydrologic data resources:Hydro-Climatic Data Network (HCDN): Streamflow Data Set, 1874 - 1988By J.R. Slack, Alan M. Lumb, and Jurate Maciunas LandwehrUSGS Water-Resources Investigations Report 93-4076 http://pubs.usgs.gov/wri/wri934076/1st_page.htmlUSGS Surface-Water Data for the Nation: http://waterdata.usgs.gov/nwis/swClimate data resources:Western Regional Climate Center, Historical Climate Information: http://www.wrcc.dri.edu/CLIMATEDATA.htmlPRISM(precipitation and temperature data in a continuous, digital grid of monthly and annual estimates): http://prism.oregonstate.edu/
WestMap: http://www.cefa.dri.edu/Westmap/ (climate by county, div)