Guo L.-F.,Institute of Meteorological Science of Heilongjiang Province |
Guo L.-F.,Chinese Academy of Meteorological Sciences |
Yao B.,Chinese Academy of Meteorological Sciences |
Zhou L.-X.,Chinese Academy of Meteorological Sciences |
And 2 more authors.
Huanjing Kexue/Environmental Science
Custom-made GC-MS and GC-ECD in-situ measurement systems were established at the Shangdianzi GAW Regional station. From May 2010 to May 2011, the precisions for GC-MS and GC-ECD systems were 0.23% and 0.88%, respectively, and the HCFC-142b mole fraction during the observation period ranged from 21×10-12 to 355×10-12. The result of the independent-sample T test was P>0.05, and there was no significant difference in HCFC-142b mole fraction measured by the two systems. The small difference of HCFC-142b mole fraction measured by GC-MS and GC-ECD might be associated with the different sampling time and precision of the two systems. A statistical filter of "robust local regression" was applied to separate HCFC-142b background and pollution data. The mean difference, median difference, 25 and 75 percent difference of background data measured by GC-MS and GC-ECD were all within the precisions. The pollution events captured by the two systems showed similar characters. Results from both systems showed a higher HCFC-142b level in summer and autumn than in winter. The pollution mole fraction of the two systems showed similar seasonal changes. Source
Wang P.,Institute of Meteorological Science of Heilongjiang Province |
Li S.,Institute of Meteorological Science of Heilongjiang Province |
Yan P.,Institute of Meteorological Science of Heilongjiang Province |
Zhu H.-X.,Institute of Meteorological Science of Heilongjiang Province |
And 4 more authors.
Journal of Natural Disasters
The paper calculates each observation station' s indication value of common and serious cold damage by adopting the anomaly value of mean temperature sum from May to September during growth season as chilling damage index, and using temperature, latitude and altitude data taken from 79 observatories in Heilongjiang Province during growth season from 1971 to 2006 analyzes the distribution character of cold damage in the province. The result shows that there have been nine times large - scale cold damage courses in 36 years since 1971. The frequency of cold damage increased gradually from south to north, and it is between 20% and 40% for most areas. Cold damage mostly appeared in the initial stages of 1970s, 1980s and 1990s. However, cold damage almost did not appear in fanning areas in the decade after the middle of 1990s. Source