defining the present climate: why does it matter? what help exists?
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Defining the present climate: Why does it matter? What help exists?. Pandora Hope (BMRC) and Ian Foster (DAWA) Acknowledgements: Colin Terry (Water Corp), Andrew Watkins (NCC), Jay Lawrimore (NCDC), Lynda Chambers (BMRC), Peter Powers (BMRC). Outline. ‘Standard’ meteorological climatology - PowerPoint PPT PresentationTRANSCRIPT
Defining the present climate:
Why does it matter? What help exists?
Pandora Hope (BMRC) and Ian Foster (DAWA)
Acknowledgements: Colin Terry (Water Corp), Andrew Watkins (NCC), Jay Lawrimore (NCDC), Lynda Chambers (BMRC),
Peter Powers (BMRC)
Outline
• ‘Standard’ meteorological climatology
• Observed Trends and Breakpoints
• Examples of the issues and responses in various sectors
• Available help
Defining the present climate1961-1990
http://www.bom.gov.au/silo/products/cli_chg/
Defining the present climate1961-1990
http://www.bom.gov.au/silo/products/cli_chg/
Trends – A reason to change the ‘baseline’ definition?
Combined global land-surface air and sea surface temperatures (degrees Centigrade) 1861 to 1998, relative to 1961 to1990; University of East Anglia, UKhttp://www.grida.no/climate/vital/17.htm
http://lwf.ncdc.noaa.gov/oa/climate/research/trends.html
National Climatic Data Centerhttp://lwf.ncdc.noaa.gov/oa/climate/research/trends.htm
l
National Climate Centre, Australian Bureau of Meteorology
http://www.bom.gov.au/silo/products/cli_chg/
Annual Temperature SWWAAnnual Maximum Temperature SWWA catchment
22.5
23
23.5
24
24.5
25
1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1993 1997 2001 2005
Year
deg
rees
C
Annual Minimum Temperature SWWA catchment
9
9.5
10
10.5
11
11.5
12
12.5
1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1993 1997 2001 2005
Year
deg
rees
C
Created using
“Diagnose”
Summer Temperature SWWADJF Maximum Temperature SWWA
27
27.5
28
28.5
29
29.5
30
30.5
31
1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1993 1997 2001 2005
Year
deg
rees
C
DJF Minimum Temperature SWWA
12
12.5
13
13.5
14
14.5
15
15.5
16
16.5
17
1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1993 1997 2001 2005
Year
deg
rees
C
Early Winter Temperature SWWAMJJ Maximum Temperature SWWA
15
15.5
16
16.5
17
17.5
18
18.5
19
19.5
1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1993 1997 2001 2005
Year
deg
rees
C
MJJ Minimum Temperature SWWA
6
6.5
7
7.5
8
8.5
9
1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1993 1997 2001 2005
Year
deg
rees
C
http://www.grida.no/climate/vital/18.htm
National Climate Centre, Australian Bureau of Meteorology
http://www.bom.gov.au/silo/products/cli_chg/
Seasonality of SWWA Rainfall Decrease
0
20
40
60
80
100
120
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
mm
1925-1975 1976-2003
Figure 1 Average monthly rainfall for the south west. (The area south west of the line in
Early Winter SWWA RainfallSouthwest May, June and July rainfall
100
200
300
400
500
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Year
Rai
nfal
l (m
m)
Annual
1901-75
1976-04
Break-point in time series at 1968/69NB: IOCI in general uses a breakpoint of 1975/76, which is the
breakpoint of the sea-level pressure data in the region
Changes to the ‘baseline’
• WMO suggested 1971-2000, but this was not adopted
• Some agencies are using the full period, e.g. NCDC uses 1880-2004
• Many sectors use the time-period most relevant to their purpose
Major System Impacts
http://www.watercorporation.com.au/Integrated water supply scheme – source development
plan
• 2001 had 2nd worst inflow to Perth dams
• 8 year sequence of lowered streamflow to 2005
Changes to Streamflow Probability
Period No. Yrs > 177 GL
%
1948-75 23 77
1976-2003 9 30
177 GL is the mean over 1975-96
Response of Water Corp.
• Major desalination of seawater
• Recycling of treated wastewater
• Better management of dam catchments to improve inflows
• Trading for water from irrigation cooperatives
Salt risk and land-useNB: This is an example only. The data is from station data interpolated onto a grid (Jones and Weymouth 1997). There will be differences from
maps produced using other methods of interpolation
1950-1979 1980-2004
< 900 mm < 900 mm
900-1100 mm
> 1100 mm 900-1100 mm
Forestry, Mining
Isohyet limits from Colin Terry, maps plotted using NCC gridded rainfall data by Pandora Hope
System Response - Waterlogging FrequencyWaterlogging at Katanning for a Duplex Soil 100mm
0
10
20
30
40
50
60
70
80
90
01-Mar 30-Apr 29-Jun 28-Aug 27-Oct
Occ
urr
ence
(%
)
1925-75
1976-03
Wheat Yield Trend
Source: ABS state averages
WA Wheat Yields 1950-2003
0
0.5
1
1.5
2
2.5
3
1950 1960 1970 1980 1990 2000
t /
ha
Agricultural Responses
• Fewer very wet years may have affected rates of salinity spread
• Sowing opportunities tend to occur later• Decreased waterlogging in susceptible areas.
This may have improved conditions for cropping in higher rainfall areas
• Technology changes have improved productivity despite generally drier years
Tools available
• http://www.bom.gov.au/silo/products/cli_chg/• Australian Rainman (QDNR, BoM et al)• DIAGNOSE; CD or website (v. large):
ftp://ftp.bom.gov.au/anon/home/bmrc/perm/append/install_v3/
• MetAccess (CSIRO et al)• Climate Calculator – Dept Ag• Future projections – IOCI, CSIRO
Conclusions
• There have been strong trends in rainfall in Western Australia, causing sectors to re-examine the climate ‘baseline’
• Impacts have been strong in some sectors, and variable in others
• There is a range of tools that can help define climatology, opportunities and risks.
Climate Calculator – DAWARisk Charts
Agriculture- Altered rainfall pattern
Corrigin
0
10
20
30
40
50
60
70
80
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mo
nth
ly R
ain
fall
(mm
)
Mean 1925-75
Mean 1976-2003