Innovative observations and analysis of human thermal comfort in Amsterdam

Innovative observations and analysis of human thermal comfort in Amsterdam Bert Heusinkveld, Gert-Jan Steeneveld, Reinder Ronda, Jisk Attema and Bert Holtslag ICUC annual meeting, Toulouse 2015

Number of tropical days (left) and trend in Summer days in NL (right) Annual average 1981-2010 Number of days with a max. temperature of 30C

Number of tropical days (left) and trend in Summer days in NL (right) Annual average 1981-2010 Number of days with a max. temperature of 30C Amsterdam Rotterdam 25 km

Big cities are urban heat islands (UHI), recent example: Rotterdam Summer UHI max ~8K

25 km Urban land use fraction (-) Urbanization Amsterdam 1900 1960 1990 25 km 0.16 0.12 0.08 0.04 2012 0 1940 1960 1980 2000 2020 Year Maps: Land use maps from Kramer H., Hazeu, G., Wageningen UR - Alterra

24 Urban weather stations

WMO reference 20 km Urban Heat Islands or Urban Cool Islands? Summer 2014, T max_urban -T max_wmo 23 km Landuse maps LGN7, 2012, Alterra

WMO reference 20 km Urban Heat Islands or Urban Cool Islands? Summer 2014, 95percentile(T max_urban -T max_wmo ) 23 km Landuse maps LGN7, 2012, Alterra

WMO reference 20 km Urban Heat Islands or Urban Cool Islands? Summer 2014, T min_urban -T min_wmo 23 km Landuse maps LGN7, 2012, Alterra

WMO reference 20 km Urban Heat Islands Summer 2014, 95percentile(T min_urban -T min_wmo ) 23 km Landuse maps LGN7, 2012, Alterra

WMO reference 20 km Nocturnal Urban Heat Islands Summer 2014, daily_maximum(t urban -T wmo ) 23 km Landuse maps LGN7, 2012, Alterra

WMO reference 20 km Nocturnal Urban Heat Islands Summer 2014, 95percentile(daily_maximum(T urban -T wmo )) 23 km Landuse maps LGN7, 2012, Alterra

20 km Nocturnal Urban Heat Islands Summer 2014, 95percentile(daily_maximum(T urban -T wmo )) 23 km Landuse maps LGN7, 2012, Alterra

NDVI (-) Fenology of vegetation, detection from space to quantify urban vegetation Groenmonitor, initiative of Alterra, Wageningen UR, the Netherlands. Gerbert Roerink & Sander Mucher, Satellites: Formosat (8m), DMC (22m), Landsat7-ETM

UHI 95% at Tmin (K) Land-use and nocturnal UHI in Amsterdam 8 7.5 7 y = -4.2x + 7.5 R² = 0.46 6.5 6 5.5 5 4.5 4 0 0.2 0.4 0.6 NDVI 100m grid (-)

Cargo bicycle measures human thermal comfort, importance of radiation (direct measurement of T mrt ) GPS: location, time, speed Air temperature, humidity (aspirated screen) Wind speed, -direction Radiation Radiation Wheel speed Design: Bert Heusinkveld

T ( C) Campus at 22 July 2013, 11 UTC: T mrt : 62 C, PET: 45 C 65 55 45 35 25 15 5 Ta Tmrt Campus 0:00 12:00 0:00 12:00 0:00 12:00 0:00 Similar values at Campus and rural station, but not the extremes

2 bicycle measurement tracks 8 km

Real-time thermal comfort measurements in Amsterdam Universal Thermal Climate Index (UTCI) scale: www.utci.org

Real-time thermal comfort measurements in Amsterdam

Real-time thermal comfort measurements in Amsterdam

Real-time thermal comfort measurements in Amsterdam UTCI

Windspeed (m/s) Cloud cover (Octas) Freq. dist (or seconds) Freq. dist. (or seconds) Amsterdam (18-19 July 2014) 450 400 350 T ( C) 35 33 31 29 27 25 23 21 19 17 10 9 8 7 6 5 4 3 2 1 0 u10 CC T_rural Stations 0 0 6 12 18 24 30 36 42 48 hours, 18-19 July 2014 (hh) 0 0 6 12 18 24 30 36 42 48 Qgl 1000 800 600 400 200 9 8 7 6 5 4 3 2 1 Global radiation (W/m2) 300 250 200 150 100 450 400 350 300 250 200 150 100 50 50 0 30 35 40 45 50 55 60 65 Tmrt 0 28 30 32 34 36 38 40 42 UTCI 19 July 11:00-12:22 (Moderate to very strong heatstress)

App development: Forecasting Thermal comfort in a complex environment The idea is to present a location specific 3 h weather forecast of human thermal comfort up to 36 h ahead. Requirements: Use of a modern thermal comfort scale: UTCI (Universal Thermal Climate Index) No numbers (only a colour scale) Thermal stress levels as text (UTCI scale) Includes land-use effects (temperature, wind speed, radiation) Based on: Thermal comfort measurements/analysis: Bert Heusinkveld, session NONTM11 WRF simulation: Reinder Ronda, session TUKUP4 Land-use map 25 m resolution: Jisk Attema, session GD5 Global model forecast: GFS, NCEP, U.S.A. Technical realisation: Master student Gert Sterenborg

App Thermal comfort 1. Use location data Smartphone 2. Download forecast 3. Display forecast Add symbol sun Wind/obstructed

App: Thermal comfort Today 16 to 19 h Wind protected Windy location

Concluding remarks Urban space during heat wave conditions: Amsterdam has a substantial nocturnal urban heat island effect (canals don t help) Thermal comfort varies strongly among built up areas Parks with short vegetation are urban hot spots (during daytime) Narrow street canyons can be more thermally comfortable than a WMO weather station location (air temperature and UTCI)

Thank you for your attention! 160 m 600 m BERT.HEUSINKVELD@WUR.N L

Very detailed geographical data available Lidar altimetry map: Waterschapshuis Rijkswaterstaat the Netherlands Aerial photographs: Aerodata

T ( C) 40 30 Ta Td 20 10 21-07-13 0:00 21-07-13 12:00 22-07-13 0:00 22-07-13 12:00 23-07-13 0:00 23-07-13 12:00 24-07-13 0:00 1000 Q global Radiation (W m-2) 800 Q diffuse 600 400 200 0 600 21-07-13 0:00 400 200 21-07-13 12:00 22-07-13 0:00 22-07-13 12:00 23-07-13 0:00 23-07-13 12:00 24-07-13 0:00 Date & Time Ql_in Ql_out 0 21-07-13 0:00 21-07-13 12:00 22-07-13 0:00 22-07-13 12:00 23-07-13 0:00 23-07-13 12:00 24-07-13 0:00 6 v (m s-1) Radiation (W m-2) Heat wave July 2013 Observations Rural station Date & Time 4 Wind speed 2 0 21-07-13 0:00 21-07-13 12:00 22-07-13 0:00 22-07-13 12:00 23-07-13 0:00 23-07-13 12:00 24-07-13 0:00 Date & Time

Mean radiant temperature and PET, rural station 50 PET T ( C) 40 Ta 30 20 10 0 70 60 Ta T ( C) 50 Tmrt 40 30 20 10 0 21-07-13 0:00 21-07-13 12:00 22-07-13 0:00 22-07-13 12:00 23-07-13 0:00 23-07-13 12:00 24-07-13 0:00 Date & Time PET: Calculated with a human thermal energy balance model Rayman (Matzarakis et al.)

Temperature ( C) Realtime thermal comfort measurements in Amsterdam 35 34 33 32 31 30 29 28 27 26 25 15:21 0 0.5 Frequency density distrubution (-) T ( C) 35 33 31 29 27 25 23 21 19 17 T_rural Stations Qgl 0 6 12 18 24 30 36 hours, 18-19 July 2014 (hh) 42 48 1000 800 600 400 200 0 Global radiation (W/m2) Error bars: 95percentile of a 1 hour measurement of 24 stations

Urban heat island Amsterdam Temperature ( C) 35 15:21 34 33 32 31 30 29 28 27 26 25 Temperature ( C) 0 0.5 Frequency density distrubution (-) 30 29 28 27 26 25 24 23 22 21 20 01:59 T ( C) 0 0.5 Frequency density distrubution (-) 35 33 31 29 27 25 23 21 19 17 T_rural Stations Qgl 0 6 12 18 24 30 36 hours, 18-19 July 2014 (hh) 42 48 1000 800 600 400 200 0 Global radiation (W/m2) Error bars: 95-percentile of a 1 hour measurement of 24 stations

Measured variation in thermal comfort UTCI

Urban heat islands (UHI) on climate maps?