Transcript Trends in hail and severe weather activities in China over the past

Trends in hail and thunderstorm in China over the
past 50 years under the changing monsoon climate
Qinghong Zhang1,2, Xiang Ni 1 ,
Fuqing Zhang2 , Mingxin Li 1,2
1 Department
of Atmospheric and Oceanic Sciences, Peking
University, Beijing 100871, China
2 Department of Meteorology, The Pennsylvania State
University, University Park, Pennsylvania
Trends of hail occurrence
Cao 2008
Tuovinen et al. (2009)
Kunz et al. 2009
Berthet et al.2010
Eccel et al 2011
Changnon & Changnon（2000)
Brooks and Dotzek 2008
Tippett et al. (2015)
D>20mm
Xie et. al. 2008
Kim and Ni 2015
D>2mm
Schuster et al. 2005
Understanding the potential effects of global-scale changes on localscale severe weather (like hail) is a persistent challenge for research.
Challenge: the stark mismatch of scale
It requires novel research approaches to
connect the questions and processes
across both weather and climate scales
Possible bridge between hail and climate change?
severe
convective
storm
CAPE
VWS
PW
FLH
Large scale
circulation
change
Climate
change
60
50
60
６－
８月
40 N
50
E
100
dust storm
３－
110
５月
tornado
rain >= 50mm/24h
120
130
mean wind >= 12m/s
hail
６－８月
40 N
３－５月
E
100
dust storm
110
tornado
rain >= 50mm/24h
120
130
mean wind >= 12m/s
hail
May 26-31 2005
Objective




What is the trend of convective storm
frequency in China?
Does the contribution of hail in severe storm
day changed?
How does the hail intensity changed ?
Is the changes of large scale circulation do
associated with the changes of severe storm
and hail occurrence in China?
Methodology and Data
 Datasets 1951-2013
 983 surface station observation (weather phenomenon)
 thunder storm (starting and ending time)
 hail (starting and ending time)
 lightning
 high wind
 heavy precipitation
 the maximum diameter of hailstone (start early 1980s)
 Datasets 1951-2013
 Hail data at 859 surface stations from information center of CMA
 hail starting and ending time
 NCEP/NCAR reanalysis (1961 to 2011)
Definition
1961-2011
missing
580 stations (the stations with data
rate greater than 1% are excluded)
 Hail or thunderstorm event (hail or thunder was
record within interval less than 30 min)
 Hail or thunderstorm Day (hailstorm or thunderstorm
was recorded at one station)
 Hail intensity: Maximum hail diameter D
Spatial distribution of annual
thunderstorm and hail days
Seasonal variation of 5-day annual
mean hail day in China 1960-2011
Hail seasonal variation are associated with the
onset of summer monsoon
Station mean annual thunderstorm Frequency
Trend(%)
Seasonal
and
diurnal
Variation
Trend of station mean thunderstorm (hail)
frequency and Days from 1961 to 2011
Hail
Thunderstorm
Possible density of hail intensity
Objective




What is the trend of convective storm in the
past?
Does the contribution of hail in severe storm
day changed?
How does the hail intensity changed ?
Is the changes of large scale circulation do
associated with the changes of convective
storm and hail occurrence in China?
Trend of 850 hPa circulation in warm
season 1961 to 2011
GPH
Meridian
Wind
Qv
K index
Trend of large scale circulation in warm
season from 1961 to 2011
CAPE
VWS
CIN
PW
Summary-hail frequency 1961-2011
The deduction of hail frequency and days were
associated with the deduction of thunderstorm days in
China from 1961 to 2011.
Summary-hail frequency 1960-2012
The deduction of hail frequency and days were
associated with the deduction of thunderstorm days in
China from 1961 to 2011.
VWS
Summary-hail intensity 1980-201
Larger hail decreased less than small hail
Further Research
Large scale
circulation
Number
thunderstorm
CCN
Aerosol
radiation
reginal
climate