indices for heat health warning systems - cpaess...2015/07/29 · jan 84 mrz 84 mai 84 jul 84 sep...

Indices for Heat Health Warning Systems – General Considerations –

Christina Koppe – Deutscher Wetterdienst (DWD)

2Quelle: Fotalia

Single & multi-parameter indices

Simplifiedbiometeoro-logical indices

Holistic (air mass based) approaches

Heat budget approaches

Considerationof adaptation

Chicago Workshop 2015

Perfect Heat Health Warning System

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Picture Source: Fotalia


• Forecast skill

• Health relevance

reliable easy to handle effective

• No complicated modelling

• Easy to implement

• Low requirements for input data

• universal

• Trigger interventions to prevent heat related health impacts

• communication

• sufficient lead time



Indices for Heat Health Warnings

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� Single: Tmax, Tmean

� Multi: simple combination of parametersExample single-parameter: Latvia Tmax

Level 1 (potentially dangerous) : max air temperature between 27°C and 32°C for 2 days or more

Warning-threshold has to be fitted to mortality data

Level 2 (dangerous): max. air temperature above 32°C

Chicago Workshop 2015 5


� Single: Tmax, Tmean

� Multi: simple combination of parametersExample multi-parameter: France 3 day average of 99,5th percentile Tmax (31-36°C) and Tmin (18-24°C)

Level 1: seasonal vigilance (1 June - 31 August)

Level 3: warning and action (thresholds are reached for 3 days or more)

Level 4: maximal mobilization (very long and intensive)

Level 2: short heat wave (1 or 2 days)




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• Forecast skill






• universal


• communication





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• Forecast skill






• universal


• communication





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e.g. Heat Index, Humidex, wet-bulb globe temperature, apparent temperature

Example Switzerland : Heat Index



e.g. Heat Index, Humidex, wet-bulb globe temperature, apparent temperature

Example Switzerland : Heat Index

Level 1 (considerable danger): HI > 90 for 3 consecutive days

Level 2 (great danger): HI > 93 for 5 consecutive days




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• Forecast skill






• universal


• communication





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• Forecast skill






• universal


• communication


Holistic (air mass based) approaches



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• Forecast skill






• universal


• communication

• sufficient lead timeHeat budget approaches



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e.g. Perceived Temperature PT (SET*, PET, UTCI)

Example Germany:

PT + adaptation approach (HeRATE) + OT

absolute part relative part

inclusion of absolute limits due to the constrain of keeping the core

temperature constant

short term adaptation (acclimatisation + behavioural adaptation)

extreme heat load4≥ 38

strong heat load332 to 38

moderate heat load226 to 32

slight heat load120 to 26

thermal comfort00 to 20

slight cold stress-1-13 to 0

moderate cold stress-2-26 to -13

strong cold stress-3-39 to -26

extreme cold stress-4≤ -39

Thermal load categoryPT (°C)































-10

0

10

20

30

40

50

Jan 84 Mrz 84 Mai 84 Jul 84 Sep 84 Nov 84 Jan 85Date

Per

ceiv

ed T

empe

ratu

re (

°C)

PT 12

weightedPT12

2/3 1/3

Index: Perceived Temperature (PT)

Complete heat budget model of human bodyStandardizations: • Standard Person (Klima-

Michel)• Standard Environment




e.g. Perceived Temperature PT (SET*, PET, UTCI)

Example Germany:

PT + adaptation approach (HeRATE) + OT

Operative Temperature OT calculated by building simulation modelStandardizations: • Building type• User behaviour

Level 1: variable threshold for strong heat load is exceeded for 2 consecutive days and indoor mean operative temperature during nighttime is higher than ~ 24°C

Level 2 : threshold for extreme heat load is exceeded (PT [12 UTC] >38°C)



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• Forecast skill






• universal


• communication



HHW-IndicesHeat budget approaches

� e.g. Perceived Temperature PT (SET*, PET, UTCI)

Example Germany : PT + adaptation approach (HeRATE)

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Disadvantages

� Relatively complex (2 models: indoor and PT)

� Difficult to communicate� Skill on climate time scales

problematic (radiation, humidity and wind are input parameters)

Level 1: variable threshold for strong heat load is exceeded for 2 consecutive days and indoor mean operative temperature during nighttime is higher than 24°C

Level 2 : threshold for extreme heat load is exceeded (PT [12 UTC] >38°C)

Advantages

� Physiologically relevant� no fitting to local climate needed

(exception extreme climatic conditions)

� Adaptation is included


1986-1998



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• Forecast skill






• universal


• communication

• sufficient lead timeHeat budget approaches



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• Forecast skill






• universal


• communication


Consider-ation of adaptation



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e.g. HeRATE, Excess Heat Index acclimatisation (EHIaccl)

Example Germany / EuroHEAT : T12 UTC + HeRATE

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24

26

28

30

32

34

36

38

40

0 10 20 30 40 50

weighted mean temperature of the last 30 days

wea

ther

thre

shol

d

Information about probability that threshold for heat is reached or exceeded (lead time 10 days)



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e.g. HeRATE, Excess Heat Index acclimatisation (EHIaccl)

Example Germany / EuroHEAT : T12 UTC + HeRATE

Information about probability that threshold for heat is reached or exceeded (lead time 10 days)




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• Forecast skill






• universal


• communication



Summary and Conclusions

• There are many indices / methods used for HHWS

• Perfect index / method should:

� directly linked to health impacts� include adaptation / acclimatization� model individual thermal stress level

� be universally applicable and easy to handle

� good forecast / prediction skill on all time scales

• All indices have the problem that they try to assess the thermal load on populations basis

• Warning method should be tailored to local requirements (health interventions) and data availability (forecasts, historical data, health data)

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There is no best method for triggering heat warning s


Quelle: Fotalia

Future

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There is no best method for triggering heat warning s


Quelle: Fotalia

Heatwarnings

Heatwarnings

Keep it simpleKeep it simple IndividualizationIndividualization

PBPV – 10/2013 24

Thank You

indices for heat health warning systems - cpaess...2015/07/29 · jan 84 mrz 84 mai 84 jul 84 sep...

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