Has the heat wave frequency or intensity changed in Poland since 1950?

Transkrypt

1 Has the heat wave frequency or intensity changed in Poland since 1950? Joanna Wibig Department of Meteorology and Climatology, University of Lodz, Poland

2 OUTLINE: Motivation Data Heat wave frequency measures number of days with Tmax > 25 number of days with Tmax > 30 Heat wave intensity measures degree-days exceeding Tmax > 25, Tmax > 30 number of days with Tmax exceeding 95 and 99 percentiles the longest annual heat wave the most intense annual heat wave Relation to precipitation Summary

3 DATA: 21 Polish stations ( ) from IMWM maximum daily temperature monthly precipitation totals Rzeszow Lesko Przemysl

4 Indices of heat wave frequency: Monthly and annual number of days with Tmax > 25 C Monthly and annual number of days with Tmax > 30 C Indices of heat wave intensity: Monthly and annual sum of Tmax exceeding 25 C Monthly and annual sum of Tmax exceeding 30 C Annual number of days with Tmax above 95 percentile of Tmax in reference period Annual number of days with Tmax above 99percentile of Tmax in reference period The longest heat wave in the year The highest sum of Tmax -30 C on all days within one heat wave

5 HEAT WAVE definition: first day Tmax 30 C a day with Tmax < 30 C does not break a heatwave if Tmax 25 C mean Tmax on all days in this heat wave is higher than 30 C

6 LEGNICA Number of days with Tmax > 25 C

7 LEGNICA Number of days with Tmax > 30 C

8 LEGNICA Sum of degreedays exceeding 25 C

9 LEGNICA Sum of degreedays exceeding 30 C

10 trend in Tmax > 25 C Station days/10 years Bielsko 0.91 Chojnice 0.87 Hel 0.22 Jelenia 1.25 Kalisz 0.98 Katowice 1.00 Legnica 1.34 Lesko 0.36 Lodz 0.94 Poznan 1.11 Przemysl 0.09 Rzeszow 1.11 Slubice 1.51 Suwalki 0.54 Swinoujscie 0.68 Szczecin 1.02 Torun 1.10 Warszawa 0.91 Wlodawa 0.53 Wroclaw 1.34 Zakopane 0.26 AUGUST Rzeszow Lesko Przemysl

11 trend in Tmax > 30 C Station days/10 years Bielsko 0.43 Chojnice 0.60 Hel 0.02 Jelenia 0.76 Kalisz 0.46 Katowice 0.56 Legnica 0.99 Lesko 1.36 Lodz 0.72 Poznan 0.85 Przemysl 0.22 Rzeszow 1.14 Slubice 1.35 Suwalki 0.31 Swinoujscie 0.51 Szczecin 0.83 Torun 0.75 Warszawa 0.62 Wlodawa 0.29 Wroclaw 0.59 Zakopane 0.02 YEAR Rzeszow Lesko Przemysl

12 trend in ΣTmax > 25 C Station deg/10 years Bielsko Chojnice Hel -0.`14 Jelenia Kalisz Katowice Legnica Lesko Lodz Poznan Przemysl Rzeszow Slubice 0.00 Suwalki Swinoujscie Szczecin Torun Warszawa Wlodawa Wroclaw Zakopane SEPTEMBER Rzeszow Lesko Przemysl

13 trend in ΣTmax > 30 C Station deg/10 years Bielsko 0.24 Chojnice 0.19 Hel Jelenia 0.63 Kalisz 0.75 Katowice 0.56 Legnica 1.55 Lesko Lodz 0.89 Poznan 1.33 Przemysl Rzeszow 0.96 Slubice 1.86 Suwalki 0.56 Swinoujscie 0.51 Szczecin 1.12 Torun 1.14 Warszawa 1.12 Wlodawa 0.78 Wroclaw 0.88 Zakopane JULY Rzeszow Lesko Przemysl

14 trend in ΣTmax > 30 C deg/10 year Bielsko 0.68 Chojnice 1.02 Hel Jelenia 1.24 Kalisz 1.25 Katowice 1.17 Legnica 2.89 Lesko Lodz 1.61 Poznan 2.04 Przemysl 0.16 Rzeszow 1.55 Slubice 3.34 Suwalki 0.67 Swinoujscie 1.25 Szczecin 1.76 Torun 1.84 Warszawa 1.53 Wlodawa 0.64 Wroclaw 1.77 Zakopane 0.02 YEAR Rzeszow Lesko Przemysl

15 The percentage of stations with significant trends Number of days Sum of degreedays Tmax > 25 C Tmax > 30 C

16 Number of days exceeding 95 and 99 percentile in Kalisz reference period:

17 days with Tmax exceeding 95 percentile days/10 year Bielsko 1.79 Chojnice 1.48 Hel 1.74 Jelenia 2.66 Kalisz 2.56 Katowice 1.74 Legnica 2.35 Lesko 2.46 Lodz 1.54 Poznan 1.84 Przemysl Rzeszow 2.34 Slubice 2.26 Suwalki Swinoujscie 2.05 Szczecin 2.46 Torun 1.43 Warszawa 1.23 Wlodawa Wroclaw 2.40 Zakopane significant from 21 Rzeszow Lesko Przemysl

18 degree-days days The longest annual heat wave in Kalisz The most intensive annual heat wave in Kalisz

19 the highest annual heat wave length days/10 year Bielsko 0.23 Chojnice 0.21 Hel 0.03 Jelenia 0.26 Kalisz 0.26 Katowice 0.26 Legnica 0.36 Lesko 0.13 Lodz 0.44 Poznan 0.27 Przemysl 0.04 Rzeszow 0.51 Slubice 0.42 Suwalki 0.19 Swinoujscie 0.20 Szczecin 0.30 Torun 0.35 Warszawa 0.39 Wlodawa 0.27 Wroclaw 0.40 Zakopane significant from 21 Rzeszow Lesko Przemysl

20 the highest annual heat wave length degreedays/10 year Bielsko 0.49 Chojnice 0.69 Hel Jelenia 0.61 Kalisz 1.00 Katowice 0.73 Legnica 1.64 Lesko Lodz 1.21 Poznan 1.01 Przemysl Rzeszow 0.86 Slubice 1.76 Suwalki 0.52 Swinoujscie 0.53 Szczecin 1.00 Torun 1.07 Warszawa 1.23 Wlodawa 0.64 Wroclaw 1.35 Zakopane significant from 21 Rzeszow Lesko Przemysl

21 Number of stations with statisticaly significant correlations between precipitation and frequency of days with Tmax >25 C April May June July August Septemb er October last month of the period of precipitation total in line with that of the index 1 month months 3 months last month of the period of precipitation total before that of the index 1 month months 3 months

22 Number of stations with statisticaly significant correlations between precipitation and frequency of days with Tmax >30 C May June July August September last month of the period of precipitation total in line with that of the index 1 month o months months last month of the period of precipitation total before that of the index 1 month months months

23 Number of stations with statisticaly significant correlations between precipitation and cumulative sum of temperature in days with Tmax >30 C May June July August September last month of the period of precipitation total in line with that of the index 1 month months months last month of the period of precipitation total before that of the index 1 month months months

24 Number of stations with statisticaly significant correlations between precipitation and cumulative sum of temperature in days with Tmax >25 C Septemb April May June July August October er last month of the period of precipitation total in line with that of the index 1 month months 3 months last month of the period of precipitation total before that of the index 1 month months 3 months

25 SUMMARY: An increase in heat wave frequency and intensity is shown by all indices but not uniform within a year (a decrease of all heat wave indices in September) An increase in heat wave frequency and intensity is still insignificant in the eastern part of Poland There is a strong relation of heat wave occurrence with precipiation (dryness) a question arises: Is it direct effect of precipitation or the fact that in summer high temperature and low precipitation are both typical for anticyclonic weather? Later in the season (August, September) the soil dryness (related to precipitation in previous months) becomes more important

26 Welcome in Łódź a host of the ECAC in th EMS & 10 ECAM, Berlin 12th September 2011