Effects of Enhanced Ultraviolet Radiation-B on Maize in Arid Regions of Middle-high Elevation

[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.

Cultivation of Black Fungus under Forest in Middle-high Altitude Areas

[Objective] The study was to solve the contradiction between fungus and forest during the production of black fungi, and to obtain relatively high economic benefits and ecological benefits. [Method] Black fungi were cultivated in forest with middle-high altitude of 500-1 600 m. The germination time of fungus stick, germination days of buds, growth days of fruiting body, commodity exterior, marketing effect and biological efficiency of black fungi were investigated. [Result] Compared with traditional cultivation, black fungus products cultivated under forest had the taste and flavor of wild black fungus. Fungus chaff wastage was directly decomposed by the roots in forest land, improving the soil structure of forest land. The need of moisture retention and the frequent access of administrative staff reduced the probability of forest fire occurrence. [Conclusion] Cultivation of black fungus under forest saves more than 70% fixed-asset investment on fungus shed, and the biological efficiency reached 12.2%.

POSSIBLE IMPACTS OF MADDEN–JULIAN OSCILLATION ON THE SEVERE RAIN-SNOW WEATHER IN CHINA DURING NOVEMBER 2009

Possible relationships between MJO and the severe rain-snow weather in Eastern China during November of 2009 are analyzed and results show that a strong MJO process is one of the strong impact factors.MJO is very active over the Indian Ocean in November 2009.Especially,it maintains 9 days in MJO phase 3,just corresponding to the two strongest rain-snow processes.Composites of MJO events show that when the MJO convective center is located over the Indian Ocean,the probability of rainfall is significantly increased and the temperature is lower than normal in eastern China,which is consistent with the situation in November of 2009.Atmospheric circulation anomalies of mid-and higher-latitudes can be influenced by the tropical MJO convection forcing and this influence could be realized by teleconnection.When the MJO is over the Indian Ocean,it is favorable for the maintenance of a circulation pattern of two ridges versus one trough at mid-and higher-latitudes.Meanwhile,the western Pacific subtropical high is stronger and more westward than normal,and a significant convective belt appears over eastern East Asia.All these circulation anomalies shown in the composite result also appeared in the observations in November 2009,which indicates the general features of relationships between the MJO and the circulation anomalies over the extratropics.Besides the zonal circulation anomalies,the MJO convection can also lead to meridional circulation anomalies.When the MJO convection is located over the Indian Ocean,the western Pacific is dominated by anomalous descending motion,and the eastern East Asia is controlled by strong convergence and ascending motion.Therefore,an anomalous meridional circulation is formed between the tropics and middle latitudes,enhancing the northward transportation of low-level moisture.It is potentially helpful to understanding and even forecasting such kind of rain-snow weather anomalies as that in November 2009 using MJO.

DECADAL VARIABILITY OF THE ANTARCTIC OSCILLATION

This paper summarizes the long term and decadal time scale fluctuations of atmospheric circulation in the Southern(Hemisphere)middle and high latitudes.The long time series of Antarctic Oscillation Indices(AOIs)were established for January.April.July and October based on the historical sea level pressure maps and NCEP/NCAR reanalysis surface pressure data set.It was found that the AOI of January had upward trend at a rate of 1.17 hPa/100 a.and July had downward trend at a rate of—1.49 hPa/100 a since 1871.The method of wavelet analysis was applied to detect the low frequency characteristics of AOIs,and it is clear that there are decadal variations in the time scale of about 20—30 years in all 4 indices.Since the averaged value of 4 months could explain most variance of annual AOI.thus it is reasonable using the mean AOI of January,April,July and October to represent the annual AOI.The value of annual AOI was much lower in periods of about 1894—1901.1910—1935,and was much higher in periods of about 1880 —1893,1936—1945.The positive anomalies were remarkable since 1980s.Power spectra of modeled AOIs from Hadley Center Control Integration(HCCI)were compared with the observations,it is found that the interannual time scale frequencies were more significant than decadal frequencies.But.there also had the possibility for generating weak deeadal fluctuations in some special months and years by Hasselmann mechanism.