Publications

Export 3 results:
Sort by: [ Author  (Desc)] Title Type Year
A B C D E F G H I J K L M [N] O P Q R S T U V W X Y Z   [Show ALL]
N
Nemani, RR, White MA, Cayan DR, Jones GV, Running SW, Coughlan JC, Peterson DL.  2001.  Asymmetric warming over coastal California and its impact on the premium wine industry. Climate Research. 19:25-34.   10.3354/cr019025   AbstractWebsite

Climatic changes over coastal California from 1951 to 1997 may have benefited the premium wine industry, as seen in higher quality wines and larger grape yields. Observed temperature warming trends were asymmetric, with greatest warming at night and during spring. Warming was associated with large increases in eastern Pacific sea surface temperatures (SST) and amounts of atmospheric water vapor. Although the average annual temperature warming trend was modest (1.13degreesC/47 yr), there was a 20 d reduction in frost occurrence and a 65 d increase in frost-free growing season length. In the Napa and Sonoma valleys, warmer winter and spring temperatures advanced the start of the growing season by 18 to 24 d, and enhanced atmospheric water vapor resulted in a 7% reduction in evaporative demand. Given the strong coupling between Pacific SSTs and the coastal California climate, and because regional-scale SSTs persist for 6 to 12 mo, additional research may allow the possibility of predicting vintage quantity and quality from previous winter conditions.

Namias, J, Cayan DR.  1981.  Large-scale air-sea interactions and short-period climatic fluctuations. Science. 214:869-876.   10.1126/science.214.4523.869   AbstractWebsite

Research during the last 15 years has shown that there is order in large-scale air-sea interactions, so that space scales of abnormalities of the lower atmosphere's circulation and the upper oceanic thermal structure are comparable. Because of this air-sea coupling, each oceanic or atmospheric pattern can be reasonably well specified by the other. Patterns of oceanic thermal anomalies are about an order of magnitude more persistent than those of atmospheric circulations, and empirical studies have had some success in using sea surface temperature patterns in long-range weather prediction. In addition to empirical studies, efforts continue in the development of numerical-dynamical models in order to understand the complex linkages of the large-scale air-sea system.

Namias, J, Yuan XJ, Cayan DR.  1988.  Persistence of North Pacific sea surface temperature and atmospheric flow patterns. Journal of Climate. 1:682-703.   10.1175/1520-0442(1988)001<0682:ponpss>2.0.co;2   AbstractWebsite

North Pacific monthly sea surface temperature (SST) anomalies are more persistent than a first-order Markov process, often lasting for more than 5 months. Sea surface temperature persistence undergoes an annual cycle that is attributable to the depth of the surface mixed layer and to the annual cycle of forcing. For a given lag, the pattern correlation is minimum when it involves SST during the summer months and maximum when it involves SST during the winter months. Average winter SST anomalies that have exhibited greatest persistence during the last four decades have been negative in the central North Pacific and positive along the West Coast, but antipersistent SST anomalies have not conformed to a repeatable pattern. The atmospheric 700 mb height anomalies associated with high persistence SST cases indicate that strong SST persistence is associated with long-lasting atmospheric anomaly patterns. For highly persistent January SST anomalies, 700 mb anomalies often last from December through February. The high persistence 700 mb anomalies tend lobe negative over the east-central North Pacific and positive over North America, with strong teleconnections. This pattern translates to strengthened westerlies over the subtropics and weakened westerlies in middle latitudes across the North Pacific-a zonal wind profile that is nearly opposite to that which appeared in low persistency SST cases. Over the four decades since 1947, North Pacific SST persistence has undergone substantial multiyear variability, and has increased significantly since the beginning of this record. Related low-frequency fluctuations, as well as linear trends, have occurred in the zonal mean subtropical westerlies across the North Pacific and in related large-scale atmospheric indices, the PNA pattern and the Southern Oscillation Index.