Are heat waves increasing over Argentina?

A heat
Are
h t waves increa
i
asing
i over Argentina?
A
ti ?
M ild Rusticucci
Matilde
Matilde Rusticucci
R i
i
1
‐
2
G
Gustavo
Gustavo Almeira Al i
Almeira
1 Departamento Ciencias de la Atmósfe
1 p
d l
ó f ra UBA / CONICET
/
2
2 INA / SMN / UBA
/
/
mati@at fccen.uba.ar
mati@at.fc
cen uba ar
Motivation:
One exam
One exam
mple mple
Strong heat waves are close related to mortality in gh
l
l d
li y i
Buenos Aires, so an alert system is trying to be
Buenos Aires, so an alert system is trying to be implemented through the National Weather
implemented through the National Weather Service
IIn Argentina, as all over the A g ti ,
ll
th
world warm nights have been
world, warm nights have been increasing and cold nights decreasing
increasing and cold nights decreasing but the frequency of warm and cold
but the frequency of warm and cold d y h b
days has been decreasing in some d
i gi
regions. So, the objective of this work i
S th bj ti
f thi
k
is to find a definition of the heat waves
is to find a definition of the heat waves that includes both variables
that includes both variables together, and the associated warming
together, and the associated warming excess, with focus on the warm period , ith f
th
p i d
of the year Strong heat waves are close
of the year. Strong heat waves are close related to mortality in Buenos Aires so
related to mortality in Buenos Aires, so an alert system is trying to be
an alert system is trying to be i pl
implemented through the National d h gh h
i
l
W th S i Th
Weather Service. These limits were li it
considered to study the trends and
considered to study the trends and variability of heat waves occurrence
variability of heat waves occurrence and intensity
and intensity
Mortality and Temperature ‐
Mortality
and Temperature Summer heat wave in Summer heat wave in
Buenos Aiires Buenos Ai
ires
D 2000 J n 2001
Dec 2000‐Jan
2001
BUENOS AIRES
DAILY MAXIMUM TEMPERATURE VS MEAN DAILY MORTALITY (2001-2007)
BUENOS AIRESAIRES 30
0/12/2000 - 10/01/2001
Mortality
170
Temperature
300
40
250
35
200
30
150
25
100
20
50
15
0
10
160
MOR
RTALT
TY
150
140
130
120
110
100
90
80
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
30/12/2000
01/01/2001
Mortality
TEMPERATURE ((ºC))
03/01/2001
05/01/2001
Maximum Temperature
07/01/2001
09/01/2001
Minimum Temperature
Heat waves Persistence in Buenos Aires –
ONDJFM Heat wave:Tmax>32ºC and Tmin>20ºC 1959‐2010
ONDJFM Heat wave:Tmax
32 C and Tmin 20 C 1959 2010
130
120
110
100
90
80
70
60
50
40
30
20
10
0
Mean : 90 Mean
: 90
deaths/day
/ y
Mean decadal number of heat
Mean decadal
of heat waves (persistency >= 3 days)
>= 3 days)
considering TX90 OR
considering TX90 OR Tn90 Both TX90 AND Tn90
Tn90
Both TX90 AND Tn90
frrequ
uen
ncy
A heat wave was defined as :
A heat wave was defined as :
Tmax and Tmin over the 90th
Tmax and Tmin over the 90th percentile for more than 3 percentile for more than 3
consecutive days Summer: October
consecutive days. Summer: October to March
to March
2
3
4
5
6
7
Days
8
9
10
11
12
BUENOS AIRES (1)
BUENOS AIRES (1) TX90
Tn90
TX90 AND Tn90
TX90 AND Tn90
MENDOZA TX90 120
100
FRECUEENCIA
80
60
MENDOZA (6) 40
30
20
Decades from 1961/70 to 2000/2010
Decades from 1961/70 to 2000/2010 25
0
1971‐80
1981‐90 1991‐2000 2001‐2010
MENDOZA TN90 20
FR
RECUEENCIA
1961‐70
15
120
10
100
5
80
LAS LOMIITAS FR
RECUENCIA
0
1961‐70
60
1971‐80
POSADAS
POSADAS 60
1981‐90 1991‐2000 2001‐2010
60
50
40
50
40
40
FREECUENCIA
20
0
1961‐70
1971‐80
1981‐90 1991‐2000 2001‐2010
UENCIA
FFRECU
A
30
30
20
20
10
10
0
0
1961‐70
CORDOBA OBSERVATORIO TX90
CORDOBA OBSERVATORIO TX90 100
90
80
70
60
50
40
30
20
10
0
1971‐80
1981‐90
1991‐2000
1961‐70
2001‐2010
1971‐80
1981‐90
1991‐2000
2001‐2010
SANTIAGO DEL ESTERO 40
FRECU
UENCIA
A
FRECUEENCIA
30
20
CORDOBA OBSERVATORIO 50
25
CORDOBA OBSERVATORIO TN90 100
90
80
70
60
50
40
30
20
10
0
40
1961‐70
1961
70
1971‐80
1971
80
1981‐90
1981
90
1991‐2000
1991
2000
2001‐2010
2001
2010
FR
RECUENCIA
1981‐90 1991‐2000 2001‐2010
0
20
30
FREECUENC
CIA
1971‐80
60
10
30
1961‐70
RECONQUISTA
RECONQUISTA 15
20
10
10
0
5
1961‐70
1971‐80
1961‐70
1971‐80
1981‐90 1991‐2000 2001‐2010
1971‐80
1971
80
1981‐90
1991‐20002001‐2010
1981
90 1991
20002001 2010
SANTA ROSA 20
BAHIA BLANCA 30
25
15
20
FREC
CUENC
CIA
1961‐70
1961
70
15
F
FRECUE
ENCIA
A
FR
RECUENCIA
0
10
1981‐90
1991‐2000
2001‐2010
No clear trend in the l
d in the
h
No clear
trend
occurrence of heat waves is fh t
i
found regionally
found regionally.
No trend in central
No trend in central Argentina, negative trend in
Argentina, negative trend in western and northern d
h
Argentina but more heat
Argentina, but more heat waves in the last decades were
waves in the last decades were found in several stations
found in several stations. f
d
Significant positive trends in Buenos Aires and Reconquista. B
Ai
dR
q it
This behavior has not exactly This behavior has not exactly
followed the trend of Tn90 or
followed the trend of Tn90 or Tx90.
Thi i d
This index seems to be b
rigorous to describe heat
rigorous to describe heat waves it represents extreme
waves, it represents extreme and persistent Heat events
and persistent Heat events. 10
5
5
0
1961‐70
0
1961‐70
1971‐80
1981‐90 1991‐2000
0 2001‐2010
1971‐80
1981‐90 1991‐20002001‐2010
The physical reasons that Th
phy i l
th t
evolved in these events will
evolved in these events will be explored to update and
be explored to update and enhance the alert system
enhance the alert system ‘h l h h
’
‘health‐heat waves’