Monthly mean air temperatures for Australian Antarctic Stations
Monthly means of three-hourly temperatures for Australian Antarctic stations Casey, Davis, Mawson, Macquarie Island and Heard Island.
TYPE OF INDICATOR
There are three types of indicators used in this report:
1.Describes the CONDITION of important elements of a system;
2.Show the extent of the major PRESSURES exerted on a system;
3.Determine RESPONSES to either condition or ... changes in the condition of a system.
This indicator is one of: CONDITION
RATIONALE FOR INDICATOR SELECTION
Global climate models show warming in response to increased greenhouse gas (carbon dioxide, methane etc) concentrations in the atmosphere; this is called the 'enhanced greenhouse effect'. Because of this, there is interest in observations of temperature across the globe, including Antarctica. Extensive high-quality observations from fixed locations are essential to serve as direct indicators of temperature changes and also confirm climate model output.
DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM
Spatial Scale: Australian Antarctic stations: Casey (lat 66 degrees 16' 54.5" S, long 110 degrees 31' 39.4" E), Davis (lat 68 degrees 34' 35.8" S, long 77 degrees 58' 02.6" E), Mawson (lat 67 degrees 36' 09.7" S, long 62 degrees 52' 25.7" E), Macquarie Island (lat 54 degrees 37' 59.9" S, long 158 degrees 52' 59.9" E), Atlas Cove, Heard Island (lat 53 degrees 1' 8" S, long 73 degrees 23' 30" E) and Spit Bay, Heard Island (lat 53 degrees 6' 30" S, 73 degrees 43' 21" E).
Measurement Technique: Thermometry
There is need to develop a high-quality data set from the available data, correcting erroneous data and estimating missing data. Adjustment may be necessary for changes in site location or exposure, and for changes in instrumentation or observing practices.
Some of these changes are documented in the station history files held by the Regional Observations Section. These history files are currently held as paper records, although more recent information is held electronically and there is an effort to digitise the older records.
Before the data can be used for the detection of change, a concerted effort will need to be made to identify deficiencies in the data, and then make compensations where possible. This is made more difficult by the lack of suitable comparison sites.
LINKS TO OTHER INDICATORS
SOE Indicators 2 - Highest monthly record of daily maximum air temperatures
SOE Indicators 3 - Lowest monthly record of daily minimum air temperatures
SOE Indicators 4 - Monthly mean of daily radiosonde temperatures at the 100hPa level (deg C)
SOE Indicators 5 - Monthly mean of daily radiosonde temperatures at the 500hPa level (deg C)
SOE Indicators 6 - Daily mean 10m Firn Temperatures at AWS sites in the AAT (deg C)
SOE Indicators 8 - Monthly mean of three-hourly mean sea level pressures (hPa)
SOE Indicators 11 - Atmospheric concentrations of greenhouse gas species
SOE Indicators 12 - Noctilucent cloud observations at Davis
SOE Indicators 14 - Midwinter atmospheric temperature at altitude 87km
SOE Indicators 16 - Extent of summer surface glacial melt (sq km)
SOE Indicators 42 - Antarctic sea ice extent and concentration
SOE Indicators 43 - Fast ice thickness at Davis and Mawson
SOE Indicators 56 - Monthly fuel usage of the generator sets and boilers
SOE Indicators 59 - Monthly electricity usage
SOE Indicators 62 - Water levels of Deep Lake, Vestfold Hills
Note - Station codes in the data are as follows:
300000 - Davis
300001 - Mawson
300004 - Macquarie Island
300005 - Atlas Cove, Heard Island
300017 - Casey
300028 - Spit Bay, Heard Island
The fields for this dataset are:
Mean Air Temperature
Data Set Citation
Monthly mean air temperatures for Australian Antarctic Stations
Dataset Series Name:
Dataset Release Date:
Australian Antarctic Data Centre
Mean monthly air temperatures are calculated from all of the available 3-hourly observations within a given month. If less than 200 observations are present, the monthly value is flagged and removed from the State of Environment dataset.
The monthly air temperature anomaly is calculated as the difference between the mean air temperature for a given month and the long-term mean air ... temperature for that calendar month between 1971 and 2000, so that:
Anomaly (for given month) = Value (for given month) - Long-term Mean (for relevant calendar month)
Although the Bureau of Meteorology uses the period from 1961 to 1990 as the standard period for calculation of long-term means, it was decided that for Antarctic stations, the 1971-2000 dataset was in most cases more complete, and would therefore provide a more accurate long-term mean.
These records require analysis for variability and trends. However, there are likely to be significant errors in the data, and these need to be addressed first (see Research Issues).
With regard to Heard Island, unfortunately, the two AWS are not 'normal' ones (they are actually ocean drifting buoys that have been strapped down). They do provide temperature and pressure, but not wind or daily maximum and minimum temps. Also, they do not report to a fixed, regular schedule, instead sending when they are within the satellite footprint. The system set up for the other sites assumes the regular 3-hourly schedule. The irregularity of the Heard data could cause curious biases, which have not been explored. Also, the criteria used to flag that there are 'enough' data (greater than 200 obs in the month) may not really work with these more frequent, and irregular, reporting schedules.
Heard Island (Atlas Cove)
WMO number: 95997
Elevation: 3 m
Barometer elevation: 3.5 m
Heard Island (The Spit)
WMO number: 94997
Elevation: 12 m
Barometer elevation: 12.5 m
Data arising from this project are available from the state of the environment indicator at the provided URL.
Data Set Progress
+61 3 6221 2043
+61 3 6221 2045
I.Barnes-Keogahn at bom.gov.au
Climate and Consultancy Section
GPO Box 727
Bureau of Meteorology
Tasmania and Antarctica Regional Office
Province or State:
CSIRO (2001), Climate Change Projections for Australia., Climate Impact Group
, 8, CSIRO Atmospheric Research, Melbourne
IAWG (2001), Climate Change Impacts for Australia., CSIRO Impacts and Adaptation Working Group., 8, CSIRO Sustainable Ecosystems, Aitkenvale
White, W.B. and Peterson, R.G. (1996), An Antarctic Circumpolar Wave in Surface Pressure, Wind, Temperature and Sea-Ice Extent., Nature, 380, 699-702
Creation and Review Dates
DIF Creation Date:
Last DIF Revision Date: