Diapositiva 1

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Heat waves variability in the Mediterranean
Region, and the possible use of a
biometeorological approach in a watch/warning
system in Tuscany Italy.Giampiero
Maracchi(1), Simone Orlandini(2), Marina
Baldi(1)(1)CNR - Institute of Biometeorology
Florence, Italy(2)Dept of Agronomy and Land
Management Univ. of Florence, Italy
Thanks to M. Morabito, P.A. Modesti, L. Cecchi,
G. Gensini Interdpt Centre of Bioclimatology
Univ. of Florence, Italy F. Cesarone, G.A.
Dalu CNR - Institute of Biometeorology
Florence, Italy
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FINDINGS

• Weather has a profound effect on human health and
  well-being.
• Large increases in mortality have occurred during
  previous heat and cold waves.
• Hot weather extremes appear to have a more
  substantial impact on mortality than cold wave
  episodes.
• Threshold temperatures for cities, which
  represent maximum and minimum temperatures
  associated with increases in total mortality,
  have been determined.
• Humidity has an important impact on mortality
  since it contributes to the body's ability to
  cool itself by evaporation of perspiration.
• Precipitation in the form of rainfall and snow is
  also associated with changes in mortality.
• If future global warming induced by increased
  concentrations of trace gases does occur, it has
  the potential to significantly affect human
  mortality.
• Two areas of important future research include
  investigation of morbidity impacts and the costs
  to society of indirect impacts.

(Source WHO)
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BIOMETEOROLOGICAL STUDIES
Experimental
Studies in climatic chamber for development of
biometeorological indices
Study of interactions between atmospheric
phenomena and sanitary events relative to
specific deseases
Epidemiological
Use of experimental and epidemiological findings
in order to alert population
Monitoring and Forecast
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EPIDEMIOLOGICAL STUDIES
Analysis based on .
air masses and weather types
energy balance models
empirical biometeorological indices
single variables
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Single Variables Analysis
From Danet S, et al. Unhealthy effects of
atmospheric temperature and pressure on the
occurrence of myocardial infarction and coronary
deaths. Circulation, 1999 100 e1-e7.
Hospitalization due to myocardial infarction in
function of mean air temperature
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Use of Empirical Biometeorological Indices in
order to evaluate possible discomfort due to hot
weather
Discomfort Conditions in Florence, during the
period 1956 - 2000
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Use of Biometeorological Indices based on the
energy balance of the human body
Physiological Equivalent Temperature (PET) in
Europe during the summer 2003 heat Wave
heat
cold
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Energy Balance Models
Hospitalization of tourists in function of PET
during the summer 2003 heat wave in Florence
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Energy Balance Models
Hospitalization in Florence and PET during summer
2002 heat wave

• Case Study Hospitalization at Careggi (Florence)
  for all the pathologies, during the June 2002
  heat wave
• Methodology evaluation of the impact of meteo
  condition on the hospitalizations, using a
  biometeorological index based on the human body
  energy balance (Physiologic Equivalent
  Temperature, PET)

• Main Results
• The highest number of hospitalizations occurred 2
  days after the maximum PET value
• The heat wave effect is when the episodes occurs
  at the beginning of the summer season

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Energy Balance Models
Hospitalization at Santa Maria Nuova Hospital in
Florence of tourists coming from Central-North
Europe and PET during summer 2003 heat wave
Maximum number of hospitalization after
persistence of PET high values
Minimum number of hospitalization during days
with low PET values
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Analysis of air masses and weather types and
their possible effects on human healt
Variation of mean daily mortality in connection
with specific air masses over the region
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Analysis of air masses and weather types and
their possible effects on human healt
Variation of mean daily mortality in connection
with specific air masses over the region
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Analysis of air masses and weather types and
their possible effects on human healt
Variation of hospital admissions in connection
with specific air masses over the region (winter)
Two-day air mass sequences vs. myocardial
infarction admission above winter average.
Three-day air mass sequences vs. myocardial
infarction admission above winter average.
Mean myocardial infarction admission index (MIAI)
vs. 2-day and 3-day air mass type sequences over
the five study winters. Circles indicate
statistically significant differences in the same
day sequences (Plt0.05)
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Heat wave definition
"An extreme weather event is an event that is
rare within its statistical reference
distribution at a particular place. Definitions
of rare vary, but an extreme weather event
would normally be as rare as or rarer than the
10th or 90th percentile. By definition, the
characteristics of what is called extreme weather
may vary from place to place. An extreme climate
event is an average of a number of weather events
over a certain period of time, an average which
itself is extreme (e.g. rainfall over a season)."
(IPCC, 2001)
DMT Daily Mean Temperature s Standard
Deviation
DMT s
DMT
DMT - s
Old definition
We classify a heat (cool) wave when the
temperature is exceeding the 90th percentile
(below the 10th percentile) for 6 or more
consecutive days. (Klein Tank and Konnen, 2003)
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Distribution of heat-waves ()
June
July
August
Semptember
From the 70s the number of the heat waves
increased monotonically, with about half of the
events in the last decade
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Distribution of heat-waves ()


Summary of the heat wave events in the period
1951-2003.
Decadal distribution of summer (JJAS) heat wave
days
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Monthly comparison between T(850hPa) from ERA-40
over the Mediterranean and the surface
temperature, Tsurf, obtained averaging surface
observations over Italy.
June
July
During the warm season JJAS, the average surface
temperature over Italy is strongly correlated
with T850 of the ERA-40 averaged over the
Mediterranean the correlation is 67 in June,
falls to 60 in July, is 77 in August and 76 in
September
August
September
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Summer 2003 the heat wave summer (observations
South Italy)
June
July
August
September
Temperature time series relatively in South Italy
(the Tmean - base period is 1951-2000). The
long-lasting heat wave of summer 2003 started in
June, and, after a short break in July, it rose
again in August until beginning of September.
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Subtropical Jet Stream is a current of very
strong winds in the upper troposphere whirling
from west to east. A strong circulation
corresponds to a compressed circumpolar vortex a
weak circulation corresponds to a highly
irregular and undulating Jet Stream. Such
configurations severely affect the climate in the
Northern Hemisphere. In fact, when the
circumpolar vortex is intense, and the Jet Stream
blows strong, it follows a path approximately
parallel to the Polar regions. The southern
climatic regions have more space to move north,
monsoons arrive with regularity, and the
temperate regions are characterized by mild
climate without great temperature or rain
extremes. When the vortex becomes weak, it
flows on pronounced undulating path. The
influence of SJT arrives to lower latitude,
compressing climatic areas towards the equator
and limiting the penetration of the monsoon to
the north.
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Climalogical pattern when August is hot
GEO_300hPa (contour) from ERA-40 over the
Mediterranean and intensity of zonal wind
(shaded).
Relative vorticity (contour) and zonal wind
(shaded) at 300hPa from ERA-40 over the
Mediterranean
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MEDITERRANEAN JETSTREAM AND MEDITERRANEAN SUMMER
ANOMALIES M. Baldi, G.A. Dalu, F. Cesarone, G.
Maracchi
See Poster P110
We analyse the warm and cool spells in the
Mediterranean region during the warm season
(JJAS) using the surface temperature collected in
50 stations distributed through Italy, covering
the period 1951-2003 and the T850 from the ERA-40
reanalysis. In JJAS, the mean surface temperature
observed over Italy is strongly correlated with
T850 averaged over the Mediterranean the
correlation is 67 in June, falls to 60 in July,
is 77 in August (Fig.1) and 76 in September.
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Heat Waves study Conclusions

• From the 70s the number of the heat waves
  increased monotonically, with about half of the
  events in the last decade
• A positive anomaly of the zonal wind at 300hPa
  to the north of the Alps is associated with a
  warm anomaly in the Mediterranean
• The strong correlation between the Mediterranean
  T850 and the 300hPa geopotential confirms that
  hot summers are associated to deep tropospheric
  subsidence and high pressure field

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Monitoring and forecast
Biometeorological forecast issued by NOAA
Forecast of temperature daily maximum
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Discomfort Forecast over Tuscany
Morning 800 am
Night 1000 pm
Afternoon 300 pm
http//www.lamma.rete.toscana/bioclima
http//www.unifi.it/cib
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Monitoring and forecast
Biometeorological forecast maps
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Conclusion
The analysis based on Discomfort Days allows to
evaluate the relationship between severe
discomfort, caused by both cold and hot
conditions, and hospital admissions for MI better
and in detail than the traditional approach based
on the mean daily air temperature. The approach
might be useful for the development of an
operative weather watch/warning system for
population and for hospital professional care. A
deeper knowledge of the mechanisms leading to
heat wave events in Italy and, more in general,
to summer hot days over the Mediterranean, is
necessary for a more reliable forecast of those
episodes especially at the beginning of the
season (May-June), and for the development of a
more sophisticated discomfort forecast system.