Robert Bornstein Jamie Favors, James Thomas, Allison Charland, Shawn Padrick Department of Meteorology and Climate Science San Jose State University 4.
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Robert Bornstein Jamie Favors, James Thomas, Allison Charland, Shawn Padrick Department of Meteorology and Climate Science San Jose State University 4 June 2010
Results 1: SoCAB 1970-2005 summer (JJA) T max warming/ cooling trends ( 0 C/decade); solid, crossed, & open circles show stat p-values < 0.01, 0.05, & not significant, respectively ? ? ?
Note IPCC 2001 does show cooling over Central California!!
15 SoCAB sites used in trend-analyses over 38 years (1969-2007) All subsequent results are averages over above 15 coastal-cooling sites Values in table are number of months dropped (out of total of 38*12 = 456) for not having at least 15 days of data
Figure 1: Monthly trends in the monthly-averaged maximum temperature (Celsius) over the 1970-2005 period for Warming (red) and Cooling (blue) sites. Standard error is plotted for each point.
Figure 2: Trend in normalized observation (percentage) of daily maximum temperature above 70° (blue), 75° (magenta), 80° (yellow) and 85° (purple) Fahrenheit over the 1970-2005 period. Linear trendlines (red, dashed) are shown for each data series with the corresponding regression equation.
Time series of 1969-2007 annual max-temperature Averaged over 15 SoCAB stations Results show decreasing values over the period
Figure 3: Cumulative frequency distribution for temperatures between 60° and 100° Fahrenheit in 5° increments for 1970- 1974 (blue) and 2000-2004 (red).
Hypothesis A longer lasting stratus deck leads to decreased peak daily high temperature The more extensive the period after burn-off occurs, the higher daily high temperature Following burn-off – an upward spike of surface temperature will be observed as the surface receives increased shortwave radiation – inversion height will rise as well, due to increased vertical mixing These results can be used to estimate contribution to coastal cooling from – Stratus cover – Cold air advection
Data From Marine Stratus Initiative (MSI)1995-present From MIT Lincoln Lab via Monterey NWS 1. Pyranometer Measurement interval: 5 min averaged Used for measuring surface radiation 2. SODAR Measurement interval: 15 min averaged Used for measuring inversion height 3. ASOS Measurement interval: 15 min averaged Used for measuring surface temp