Modeling Microclimates andClimate Change in Hawaii

Modeling Microclimates andClimate Change in Hawaii

Chunxi Zhang, Yuqing Wang, Axel Lauer and Kevin Hamilton

Modeling Microclimates and Climate
Change in Hawaii

KauaiOahuMauiBig Island

Why Worry About Climate Change in Hawaii ??

Why Worry About Climate Change in Hawaii ??

Media coverage of controversy about water rights on Maui in March 2016

March 26, 2015

Hawaii Plants and Birds

Hawaii is world’s “hot spot” of biodiversity

So dire has the plight of endemic specieson the Hawaiian Islands become, thatconservationists have bestowed the islands
with the unhappy distinction of being theendangered species capital of the country.
Already, Hawaii has lost hundreds oforiginal life forms, while hundreds moreteeter on the brink of extinction. The U.S.
has 526 plant and 88 bird species on theendangered and threatened species list;
more than a third are found in Hawaii.
Three-quarters of the United States’ extinct
plants and birds once lived only in Hawaii
even though its islands represent just
two-tenths of one percent of the nation’s
total land area.

Hawaii Plants and Birds

Hawaii is world’s “hot spot” of biodiversity

So dire has the plight of endemic specieson the Hawaiian Islands become, thatconservationists have bestowed the islands
with the unhappy distinction of being theendangered species capital of the country.
Already, Hawaii has lost hundreds oforiginal life forms, while hundreds moreteeter on the brink of extinction. The U.S.
has 526 plant and 88 bird species on theendangered and threatened species list;
more than a third are found in Hawaii.
Three-quarters of the United States’ extinct
plants and birds once lived only in Hawaii
even though its islands represent just
two-tenths of one percent of the nation’s
total land area.

Hawaii Plants and Birds

Hawaii is world’s “hot spot” of biodiversity
Hawaii is world’s “hot spot” for extinction

So dire has the plight of endemic specieson the Hawaiian Islands become, thatconservationists have bestowed the islands
with the unhappy distinction of being theendangered species capital of the country.
Already, Hawaii has lost hundreds oforiginal life forms, while hundreds moreteeter on the brink of extinction. The U.S.
has 526 plant and 88 bird species on theendangered and threatened species list;
more than a third are found in Hawaii.
Three-quarters of the United States’ extinct
plants and birds once lived only in Hawaii
even though its islands represent just
two-tenths of one percent of the nation’s
total land area.

Hawaii Plants and Birds

Hawaii is world’s “hot spot” of biodiversity
Hawaii is world’s “hot spot” for extinction

So dire has the plight of endemic specieson the Hawaiian Islands become, thatconservationists have bestowed the islands
with the unhappy distinction of being theendangered species capital of the country.
Already, Hawaii has lost hundreds oforiginal life forms, while hundreds moreteeter on the brink of extinction. The U.S.
has 526 plant and 88 bird species on theendangered and threatened species list;
more than a third are found in Hawaii.
Three-quarters of the United States’ extinct
plants and birds once lived only in Hawaii
even though its islands represent just
two-tenths of one percent of the nation’s
total land area.

Hawaii Plants and Birds

More than 90% of native Hawaiian
plants and animals are endemic, meaning
they exist nowhere else on earth.

So dire has the plight of endemic specieson the Hawaiian Islands become, thatconservationists have bestowed the islands
with the unhappy distinction of being theendangered species capital of the country.
Already, Hawaii has lost hundreds oforiginal life forms, while hundreds moreteeter on the brink of extinction. The U.S.
has 526 plant and 88 bird species on theendangered and threatened species list;
more than a third are found in Hawaii.
Three-quarters of the United States’ extinct
plants and birds once lived only in Hawaii
even though its islands represent just
two-tenths of one percent of the nation’s
total land area.

75% of the United States’ already extinct
plants and birds once lived only in Hawaii
even though its islands represent just
0.2% of the nation’s total land area.
U.S. government lists 526 plant species
and 88 bird species as threatened - morethan a 1/3 third are found in Hawaii.

Bennng et al. PNAS 2002• The Hawaiian honeycreepers (Drepanidae)• 29 species – many are already extinctalso represent a
dramatic example of anthropogenic extinction. Crop andpasture land has replaced their forest habitat, and humanintroductions of predators and diseases, particularly ofmosquitoes and avian malaria, has eliminated them fromthe remaining low- and mid-elevation forests. Landscapeanalyses of three high-elevation forest refuges show thatanthropogenic climate change is likely to combine with pastland-use changes and biological invasions to drive several of
the remaining species to extinction.

Bennng et al. PNAS 2002

• “Anthropogenic climate change is likely tocombine with past land-use changes and biologicalinvasions to drive several of the remaining species
to extinction”

Silversword

“Recent population declines in thesilversword are associated withdecreasing precipitation andincreasing temperature”.

NortheastTrade Winds

80%

Air temperature

Relative humidity %Big Island

Waialeale
1570 mHaleakala3050 mMauna Kea
4200 mMauna Loa
4170m

Big Island

Mauna Kea, Mauna Loa& Haleakala

DRYWET

MOST RAINAT SUMMIT

Mauna Kea, Mauna Loa& Haleakala

VERY DRY
Mauna Kea, Mauna Loa& Haleakala

Wet summits

Wetwindwardslopes

Dry summits

Sometimes, particularly inwinter, the usual trade wind
pattern breaks down andmore active weather canlead to convective rainThis is how most of the rainin the “rain shadow” regions
occurs.

March 2012
Oahu

The interaction of the atmosphericflow with the very tall and very steep
topography in leads to fine structurein the microclimatesOBSERVED CLIMATOLOGICAL
RAINFALL RATEThe interaction of the atmospheric flow with the very tall andvery steep topography in leads to fine structure in the microclimates

This leads to a big challenge for even thefinest resolution global models for climateprojections

~20 year long integrations

TL959 Dx ~ 20 km

TL959 Dx ~ 20 km

The Hawaii Regional Climate Model (HRCM)• Adapted from WRF – community Weather Research & Forecast model• 31 vertical levels (14 levels below 700 hPa)
• New data sets for: land cover/use (NLCD), surface albedo (MODIS), vegetation
types/fraction and soil types (STATSGO2)• MERRA (Modern-Era Retrospective Analysis for Research and Applications)
D2 – 3 km
reanalysis from NASA (6-hourly data @ 0.5°×0.67°)(276x186)• NOAA SSTs (daily data @ 0.25°x0.25°)
D3• 1-way nesting with up to 3 domains (D1, D2, D3)
D1 – 15 km(260x320)
D2
D3 – 1 km(154x112)

Green vegetation fraction in July

Surface albedo in July

Specification of the boundary conditions

sea level pressure

sea surface
temperature

MERRA
reanalysis data,NOAA SSTs

1990-2009

geopotential

horizontal windtemperaturehumidity

Present-dayrun

Results from the outerdomain(D1)
with15 Modelkm spacing
The Hawaii
Regional
Climate(HRCM)
D2 – 3 km(276x186)
D1 – 15 km(260x320)
D2

OBS

MODELOBS

MODEL“Winter” Rainfall
November-April“Summer” Rainfall
May-October

Time Series of Monthly Domain-Averaged Rainfall
Model Results in Blue
GPCP Observations in Red
TRMM Observations in Black

Results from the middle
domain(D2)
with3 kmspacing
The Hawaii
Regional
ClimateModel(HRCM)
D2 – 3 km(276x186)
D1 – 15 km(260x320)
D2

Daily meansurface airtemperature

Daily mean
maximum airtemperature

Domain 2results Dx ~ 3 km

Daily mean
minimum airtemperature

Daily meansurfacehumidity

Daily meansurface windspeed

Seasonal Cycle in 20-year Mean Data
At Individual Stations
Kauai

Oahu

MauiBigIslandKauaiOahu

MauiBigIsland

Time Series (6-Month Running Means)
At Individual Stations

The linear regression trend in the observed SST over 1990-2009.
The trend is expressed in degrees C over 20 years.

20 Year Annual MeanArea mean model bias is0.03 mm/day

Spatial correlation coefficienton the 3 km grid is 0.82

20 Year November-April
Area mean model bias is0.42 mm/day

Spatial correlation coefficient
On the 3 km grid is 0.84

BIAS IN MODEL SIMULATIONNARCCAP
20 year summer precipitation
bias express as % of observed% bias

12-hourly operationalsoundings are taken at
2 stations – Lihue & Hilo

Trade WindInversion Base
Height (TWIBH)

Model has a low biasof about 100-150 m
in TWI heightDiurnal Rainfall Variation

Time of Peak Climatological Rainfall Amounts

After midnight

Earlier in afternoon

Late afternoon

Early morning

After midnight

Earlier in afternoon

Late afternoonEarly morning

Diurnal Rainfall Variation

Time of Peak Climatological Rainfall Amounts

Global Warming Projection forst
Late 21 Century

Specification of the boundary conditions

Pseudo-Global-Warming Method (Kimura and Kitoh 2007; Sato et al. 2007)

sea level pressure

sea surface
temperature

MERRA
reanalysis data,
NOAA SSTs

MERRA
reanalysis data,
NOAA SSTs
Global warming
increment(monthly means)geopotential

horizontal windtemperaturehumidity

Present-day Run

Global Warming Run

Specification of the boundary conditions

Pseudo-Global-Warming Method (Kimura and Kitoh 2007; Sato et al. 2007)
CMIP3 models
BCCr-BCM2.0
CGM3
CNRM-CM3CSIRO-Mk3.0
CSIRO-Mk3.5
GFDL-CM2.0
GFDL-CM2.1
GISS-EH
GISS-ERFGOALS-g1.0
INGV-SXG
INM-CM3.0
IPSL-CM4
MIROC3.2(hires)
ECHAM5/MPI-OM
MRI-CGCM2.3.2
CCSM3
PCM
UKMO-HadCM3
UKMO-HadGEM1

Multi-model mean
20C3M
average 1990-1999
Multi-model mean
SRESA1B
average 2090-2099

Global warming
increments(monthly means)Global warming increment: SST
Future scenario (SRES A1B, 2090-2099) – present-day (20C3M, 1990-1999)

Multi-model mean (16 CMIP3 models)“21st century change” = (2081-2100) – (1990-2009)

1990-2009

2081-2100

21st Century Change

surface air temperatureintensified
warming ataltitude

SIMULATED SURFACE AIR WARMINGOVER THE BIG ISLANDMultimodel Mean
Zonal-Mean
Temperature Change in
A Greenhouse Gas
Driven Warming

Multimodel Mean
Zonal-Mean
Temperature Change in
A Greenhouse Gas
Driven Warmingd(DT)/dz > 0Multimodel Mean
Zonal-Mean
Temperature Change in
A Greenhouse Gas
Driven Warmingd(DT)/dz > 04C

Multimodel Mean
Zonal-Mean
Temperature Change in
A Greenhouse Gas
Driven Warmingd(DT)/dz > 06C

4C

Rate of increase in warmingwith height is even larger
than expected based onchanges in moist adiabat

Rate of increase in warmingwith height is even larger
than expected based onchanges in moist adiabat

Tropical troposphere is stabilized on averageby the global warming effects

Rate of increase in warmingwith height is even larger
than expected based onchanges in moist adiabat

Tropical troposphere is stabilized on averageby the global warming effects

Rate of increase in warmingwith height is even larger
than expected based onchanges in moist adiabat

Perhaps less convective
rainfall?

Surface Wind Speed

“WET BECOMES WETTER”

“DRY BECOMES DRIER”

Boundary Layer Moisture Flux Convergence =Divergence of boundarylayer moisture flux

Convergence/divergence whererain is projected to increase/decreasehumidity

futurepresent

Change of humidity andsame winds

horizontal windchange

Same humidity andchange of winds

~7% saturation water vapor
content per degree rise intemperature

Flux divergence change
explained just by increasein boundary layer moisturecontent

Trade wind inversion frequency (fraction)
Present-day

Future scenario

Present79.6%

Future88.4%

Days without trade wind inversion 20.4%  11.6%

Cloud base and cloud top height (km)Cloud top height

Cloud base height

Present-day

Future scenarioSnow capped Mauna Kea& Mauna Loa

White color shows
areas where 20 year
mean snowfall forthat month is morethan 5 cm

PRESENT

FUTURE

Snow capped Mauna Kea& Mauna Loa

Snow will almost
entirely disappear by
end of 21st century

Hilo

Observed and Modeled
Rainfall Trends at Hilo

ALL DAYS AT ALL LAND POINTSResults from the innerdomain (D3) with 1 km spacing* for Maui *Observations

Delta-x = 1 km

Dx = 3 km

20 year (1990-2009) mean rainfall observed and in the 3km
resolution nested grid in the Hawaii Regional Climate ModelDx = 3 km

Unfortunately adequate simulation for Maui (and probably for Oahu and Kauai)
requires quite fine horizontal resolution

Dx = 1 km

Observations

Dx = 1 km

Dx = 3 km

Unfortunately adequate simulation for Maui (and probably for
Oahu and Kauai) requires quite fine horizontal resolution

Future Work

Plant Range Model
Projections
Fortini (PICCC, PICSC FY13)

Climate Change and Avian
Malaria
Samuel, Liao (PICSC FY12)

Valuing Climate Change
Impacts on Coral Reef
Ecosystem Services
Oleson (PICSC FY13)

Carbon Storage in
Terrestrial Biosphere
Hawbaker, Litton, Giardina

Fine-Resolution Climate Projectionsfor Hawaii via Regional Modeling
Yuqing Wang, Zhang, Hamilton

Maui Biofuels Project
Sugimura, Kim

Crop Suitability Models for
Hawaii & Implications ofClimate Change
Gross, Miura

Pac RISA

Finucane,Keener, Lewis

Ground Water Modelingfor West Maui
Anthony, Mair, Al-Kadi

Conclusions

present day simulation• HRCM forced with observed boundary fields
can simulate the basic features of the mean aswell as diurnal, seasonal and interannual
variations of the precipitation in the HawaiianIslands.
• Unfortunately really adequate simulation for
Maui (and probably for Oahu and Kauai)
requires quite fine horizontal resolution

Conclusions

climate change projection• The surface and surface air temperatures areprojected to have around 2-3.5°C degree increaseover the 21st century in the SRESA1B scenario.
The surface warming is intensified with height.
• Projected rainfall changes are significant (up to~30%) and generally exhibit a wet-get-wetter,dry-gets-dryer pattern.
• The biggest practical effects may be increased
drying (more evapotranspiration, less rainfall) in
the already dry parts of each major island

有難う御座います