Research Article
Boundary-Layer Characteristics of Persistent Regional Haze Events and Heavy Haze Days in Eastern China
Table 1
Surface and high-pressure conditions on heavy haze days.
| Series | Types | Date (yyyy-mm-dd) | 500 hPa | 850 hPa | Stations recording heavy haze days | Stations recording haze days |
| 1 | EQP | 1987-12-26 | Southwest | Equalizing zone | 4 | 7 | 2 | 1992-10-28 | West | Equalizing zone | 3 | 6 | 3 | 1994-04-28 | Northwest | Equalizing zone | 3 | 7 | 4 | 1998-12-27 | Northwest to west | Equalizing zone | 3 | 7 | 5 | 2001-11-21 | West | Equalizing zone | 3 | 8 | 6 | 2001-11-22 | West | Equalizing zone | 3 | 7 | 7 | 2002-02-05 | Northwest to west | Equalizing zone | 3 | 7 | 8 | 2005-10-26 | Northwest to southwest | Saddle | 3 | 8 | 9 | 2007-04-06 | West | Equalizing zone | 3 | 8 | 10 | 2008-07-17 | Equalizing zone | Saddle | 3 | 5 | 11 | 2008-11-01 | West | Equalizing zone | 3 | 6 | 12 | 2012-03-06 | Southwest to west | | 3 | 8 |
| 13 | ACF | 1981-12-28 | West | Saddle | 3 | 8 | 14 | 1985-11-16 | West | Equalizing zone | 3 | 8 | 15 | 1990-10-15 | Northwest | Equalizing zone | 3 | 8 | 16 | 1999-10-28 | West | | 3 | 8 | 17 | 2002-12-31 | Northwest | Inverted trough | 3 | 8 | 18 | 2003-12-12 | Northwest | Equalizing zone | 3 | 6 | 19 | 2003-12-16 | Northwest | Base of cold vortex | 3 | 7 | 20 | 2003-12-17 | Northwest | Base of cold vortex | 3 | 8 | 21 | 2009-01-09 | Northwest to west | | 3 | 8 | 22 | 2010-11-21 | Front of trough | Base of trough | 3 | 7 | 23 | 2011-01-23 | Northwest to west | Equalizing zone | 3 | 5 | 24 | 2012-01-20 | West | Equalizing zone | 3 | 8 |
| 25 | BOH | 1992-01-25 | West | Equalizing zone | 3 | 8 | 26 | 2005-10-18 | West | Equalizing zone | 3 | 8 | 27 | 2008-03-11 | West | Backside of the high pressure | 3 | 8 | 28 | 2009-11-26 | West | Backside of the high pressure | 3 | 6 | 29 | 2011-10-08 | West | Backside of the high pressure | 3 | 6 |
| 30 | BAH | 1987-12-24 | West | Equalizing zone | 3 | 6 | 31 | 1992-01-27 | Northwest | Equalizing zone | 4 | 8 | 32 | 1992-05-31 | Equalizing zone | Equalizing zone | 3 | 6 | 33 | 1992-11-14 | | | 3 | 6 | 34 | 1996-04-26 | Northwest | | 3 | 8 | 35 | 1999-11-21 | West | | 3 | 8 | 36 | 2005-10-31 | West | Equalizing zone | 3 | 6 | 37 | 2008-04-18 | Southwest | Backside of the high pressure | 3 | 6 | 38 | 2008-10-15 | Southwest to west | Equalizing zone | 3 | 8 | 39 | 2011-06-13 | West | Equalizing zone | 4 | 6 |
| 40 | INT | 1984-04-26 | Northwest to southwest | Equalizing zone | 3 | 7 | 41 | 1992-01-28 | Northwest | Equalizing zone | 3 | 8 | 42 | 1994-11-11 | Northwest to southwest | Equalizing zone | 3 | 6 | 43 | 2004-02-19 | Front of ridge | Backside of the high pressure | 3 | 8 | 44 | 2004-05-10 | Front of ridge | Backside of the high pressure | 3 | 8 | 45 | 2009-11-08 | Southwest to west | Saddle | 3 | 7 |
| 46 | Others | 2002-01-03 | Northwest | | 3 | 5 | 47 | 2003-06-25 | Equalizing zone | Saddle | 3 | 8 | 48 | 2004-11-07 | West | Equalizing zone | 4 | 8 | 49 | 2008-05-26 | Northwest | Equalizing zone | 4 | 8 | 50 | 2011-06-03 | Equalizing zone | Equalizing zone | 3 | 7 |
|
|
Equalized pressure: EQP, advancing edge of a cold front: ACF, base of high pressure: BOH, backside of high pressure: BAH, and inverted trough: INT.
|