Winter anomaly

FIGURE 5.17 Pearson correlation coefficient (R) between the WIBIX and 360° zonally averaged winter anomalies (JFM) in the air temperature derived from (WCP, 1987) for slices of five degrees between 15°N and 85°N during of the last continental climate mode (1951-1986) vertical hues mark the 95% confidence level (/-distribution) while the box indicates the averaged belt of the planetary frontal zone with imbedded westerlies note the increasing poleward correlation due to the increasing effect of the AO. 

Beran, D., and W. Bangert, Trace constituents in the mesosphere and lower thermosphere during winter anomaly events, J Atmos Terr Phys 4L 1091, 1979. 

Beynon, W.J.G., E.R. Wilhams, F. Arnold, D. Krankowsky, W.C. Bain, and P.H.G. Dickinson, D-region rocket measurements in winter anomaly absorption conditions. Nature 261, 118, 1976. 

Kawahira, K., An observational study of the D-region winter anomaly and sudden stratospheric warmings. J Atmos-Terr Phys 44, 947, 1982. 

Koshelev, V.V., Variations of transport conditions and winter anomaly in the D-ionospheric region. J Atmos Terr Phys 41, 431, 1979. 

Labitzke, K., K. Paetzoldt, and H. Schwentek, Planetary waves in the strato- and mesosphere during the western European winter anomaly campaign 1975/76 and their relation to ionospheric absorption. J Atmos Terr Phys 4.1, 1149, 1979. 

Offermann, D., An integrated GBR campaign for the study of the D region winter anomaly in western Europe 1975/76. J Atm Terr Phys 4L 1047, 1979. 

Schwentek, H., Regular and irregular behavior of the winter anomaly in ionospheric absorption. J Atmos Terr Phys 33, 1647, 1971. 

Solomon, S., G.C. Reid, R.G. Roble, and P.J. Crutzen, Photochemical coupling between the thermosphere and the lower atmosphere, 2. D region ion chemistry and the winter anomaly. J Geophys Res 87, 7221, 1982b. 

Solomon, S. Reid, G.C. Roble, R.G. Cmtzen, P.J., 1982 Photochemical Coupling Between the Thermosphere and flie Lower Atmosphere. 2. D-Region Ion Chemistry and the Winter Anomaly , in Journal of Geophysical Research, 87 7221—7227. 

Fig. 9 Spatial distribution of the anomalies of winter (DJF) precipitation, projected by the two RCMs HIRHAM H (DMI.HS1) and RCAO E (SMHI.MPIA2)...

Figures 9-12 show the spatial distribution of the anomalies of winter and summer precipitation and air temperature projected by the selected two climate scenarios. It is possible to observe that projected changes show large spatial variations within the Ebro River basin, with the largest differences for the precipitation field. In addition, in some places one RCM projects an increase whereas the other projects a decrease in the seasonal precipitation (e.g. winter precipitation on the north-western part of the catchment).

And so it would be with lakes, streams, and oceans were it not for the anomaly and the bouyance of ice. The coldest water would continually sink to the bottom and freeze there. The ice, once formed, could not be melted, because the warmer water would stay at the surface. Year after year the ice would increase in winter and persist through the summer, until eventually all or much of the body of water, according to the locality, would be turned to ice. As it is, the temperature of the bottom of a body of fresh water cannot be below the point of maximum density on coohng further, the water rises and ice forms only on the surface. In this way the Liquid water below is protected from further cooling, and the body of water persists. In the Spring, the first warm weather melts the ice, and at the earliest possible moment all ice vanishes. 

A more complete presentation of the salinity field evolution from the winter to the summer gives the difference between the August and February fields shown in Fig. 8d. The prevalence of the negative (positive) salinity anomalies in August with respect to those in February in the central (near-shore) areas of the Black Sea reflects the summer decrease of the main pycnocline dome height (see Fig. 4). Meanwhile, in some regions of the central and near-shore areas of the Black Sea this regularity is broken. 

One can see that, in the period 1954-2002, most of the strongly pronounced winter SST anomalies (11 of 16) occurred either during the El Nino events or in the years immediately after them. Three anomalies (1962, 1976, and 2001) might be related to the La Nina events. The anomalies of 1961 and 1985, in the years with low values of the ENSO index, can hardly be referred to a certain phase of this atmospheric oscillation. Five of the 11 winters related to the El Nino events were cold and six others were warm. During the 1990-1995 El Nino, both cold (in 1992 and 1993), and warm (in 1995) winters were observed. It should be noted that an extreme value of the winter SST is not directly related to the intensity of El Nino. For example, one of the highest values of the winter SST was related to the relatively weak El Nino event of... 

An air-conditioned classroom in Texas is maintained at 72°F in the summer. The students attend classes in shorts, sandals, and skimpy shirts and are quite comfortable. In the same classroom during the winter, the same students wear wool slacks, long-sleeve shirts, and sweaters and are equally comfortable with the room temperature maintained at 75°F. Assuming that humidity is not a factor, explain this apparent anomaly in temperature comforf. ... 

The winter warmth after the Pinatubo emption was concentrated over Scandinavia and Siberia and central North America. These temperature anomalies were associated with marked departures in sea-level pressure patterns in the first northern winter. There was a pole-ward shift and strengthening of North Atlantic westerlies at —60° N, associated with corresponding shifts in the positions and strengths of the Iceland Low and Azores High. These effects have been modeled as a result of changes to the atmospheric circulation around the Arctic (the Arctic Oscillation Thompson and Wallace (1998)) arising from the differential heating effects of the volcanic aerosol... 

In the 1989-91, the anomaly is an intimate relation to the continuous surface temperature rise not only in summer, but also in winter seasons. 

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