中国环境科学
中國環境科學
중국배경과학
CHINA ENVIRONMENTAL SCIENCE
2014年
3期
545-554
,共10页
吴兑%陈慧忠%吴蒙%廖碧婷%王迎春%廖晓农%张小玲%权建农%刘伟东%古月%赵秀娟%孟金平%孙丹
吳兌%陳慧忠%吳矇%廖碧婷%王迎春%廖曉農%張小玲%權建農%劉偉東%古月%趙秀娟%孟金平%孫丹
오태%진혜충%오몽%료벽정%왕영춘%료효농%장소령%권건농%류위동%고월%조수연%맹금평%손단
环首都圈%霾日%轻雾(雾)日%统计方法%长期趋势
環首都圈%霾日%輕霧(霧)日%統計方法%長期趨勢
배수도권%매일%경무(무)일%통계방법%장기추세
areas around the capital%haze day%mist (fog) day%calculate method%long term trend
为了研究单次值法、日均值法、14时值法3种常用的霾日和轻雾(雾)日统计结果的异同,以环首都圈京津冀晋四省市为例进行了比较.华北地区霾日用3种方法统计的过去60余年霾日的区域分布表明,3种方法统计的霾日是单次值法>日均值法>14时值法,大致是1:0.54:0.45的关系,但区域分布趋势比较相似.典型城市霾日的长期变化趋势大都十分相似.而轻雾(雾)日的长期变化趋势表明,用单次值法统计的明显偏多,且有长期下降趋势;而用日均值法与14时值法统计的轻雾(雾)日无大差别,且没有明显的长期变化趋势,反映了年季和年代季的气候波动.从长期季节变化趋势来看,3种统计方法的结果除日数的差别外,季节分布特征比较类似.一个突出的特点是除去采暖季有较多的霾日外,在盛夏季节霾日也明显多,集中出现在6~9月,尤其是7~8月,与桑拿天同期出现,这与全国大部分城市的变化趋势完全不同.是华北地区的特有现象.用单次值法统计霾日,将包括所有的霾过程,即大范围持续时间长,且与一定天气系统与近地层扩散条件相关连的霾,及在稳定的晴朗夜间由于辐射降温,使相对湿度升高而导致能见度下降形成的霾.用日均值法,则可能更多的显示长时间大范围的霾天气过程;而使用14时法,则对早晚因湿度增加降低能见度出现的霾天气漏记,突出长时间大范围的霾天气过程.
為瞭研究單次值法、日均值法、14時值法3種常用的霾日和輕霧(霧)日統計結果的異同,以環首都圈京津冀晉四省市為例進行瞭比較.華北地區霾日用3種方法統計的過去60餘年霾日的區域分佈錶明,3種方法統計的霾日是單次值法>日均值法>14時值法,大緻是1:0.54:0.45的關繫,但區域分佈趨勢比較相似.典型城市霾日的長期變化趨勢大都十分相似.而輕霧(霧)日的長期變化趨勢錶明,用單次值法統計的明顯偏多,且有長期下降趨勢;而用日均值法與14時值法統計的輕霧(霧)日無大差彆,且沒有明顯的長期變化趨勢,反映瞭年季和年代季的氣候波動.從長期季節變化趨勢來看,3種統計方法的結果除日數的差彆外,季節分佈特徵比較類似.一箇突齣的特點是除去採暖季有較多的霾日外,在盛夏季節霾日也明顯多,集中齣現在6~9月,尤其是7~8月,與桑拿天同期齣現,這與全國大部分城市的變化趨勢完全不同.是華北地區的特有現象.用單次值法統計霾日,將包括所有的霾過程,即大範圍持續時間長,且與一定天氣繫統與近地層擴散條件相關連的霾,及在穩定的晴朗夜間由于輻射降溫,使相對濕度升高而導緻能見度下降形成的霾.用日均值法,則可能更多的顯示長時間大範圍的霾天氣過程;而使用14時法,則對早晚因濕度增加降低能見度齣現的霾天氣漏記,突齣長時間大範圍的霾天氣過程.
위료연구단차치법、일균치법、14시치법3충상용적매일화경무(무)일통계결과적이동,이배수도권경진기진사성시위례진행료비교.화북지구매일용3충방법통계적과거60여년매일적구역분포표명,3충방법통계적매일시단차치법>일균치법>14시치법,대치시1:0.54:0.45적관계,단구역분포추세비교상사.전형성시매일적장기변화추세대도십분상사.이경무(무)일적장기변화추세표명,용단차치법통계적명현편다,차유장기하강추세;이용일균치법여14시치법통계적경무(무)일무대차별,차몰유명현적장기변화추세,반영료년계화년대계적기후파동.종장기계절변화추세래간,3충통계방법적결과제일수적차별외,계절분포특정비교유사.일개돌출적특점시제거채난계유교다적매일외,재성하계절매일야명현다,집중출현재6~9월,우기시7~8월,여상나천동기출현,저여전국대부분성시적변화추세완전불동.시화북지구적특유현상.용단차치법통계매일,장포괄소유적매과정,즉대범위지속시간장,차여일정천기계통여근지층확산조건상관련적매,급재은정적청랑야간유우복사강온,사상대습도승고이도치능견도하강형성적매.용일균치법,칙가능경다적현시장시간대범위적매천기과정;이사용14시법,칙대조만인습도증가강저능견도출현적매천기루기,돌출장시간대범위적매천기과정.
This study set Beijing (BJ), Tianjin (TJ), Hebei (HB) and Shanxi (SX) among the areas around the capital as example to compare three methods on calculating haze or mist (fog) days. The three methods include single value method, daily mean method and 14:00PM moment method. The main results are as below: the regional haze days’ distribution during the past 60years in North China calculated by the three methods showed difference. The rank of the haze day numbers was single value method, daily mean method and 14:00PM moment method, with the ratio of about 1:0.54:0.45. But the regional trends appeared similar for the three methods. The long term trends of haze days for the typical cities were quite similar. The long term trends of mist (fog) days calculated by three methods turns out that single value method counted obviously more fog days and presented a long term decreasing trend, while the values gained by daily mean method and 14:00PM moment method had no significant difference, both with no significant long term trends and showed clear the interannual and inter-decadal variation. The long term trends calculated by the three methods presented obvious difference in some cities in North China. For the long term trends of seasonal variation, the seasonal distributions obtained by the three methods were similar although the difference in numbers. One outstanding feature was that there were obviously more haze days in summer besides in the heating season, mainly concentrated in June to September, especially in July to August, occurring at the same time as the sultry weather. This distribution was a unique phenomenon in North China, which was quite different from most of the other cities in China. Calculating by the single value method will include all haze processes, i.e. wide and lasting haze, which is related to the specific synoptic systems and near-surface diffusion conditions, or some other formed by decreased visibility under higher relative humidity caused by radiative cooling at the stable clear night. Calculating by the daily mean method will result in more wide and lasting haze processes, while using 14:00PM moment method can highlight the wide and lasting haze processes but neglect the haze with poor visibility caused by humidity rising in the morning and at night.