State of Environment
Indicator 5 - Monthly mean mid-tropospheric temperatures above Australian Antarctic Stations
Description
- Indicator Definition
- Monthly means of daily temperatures at the 500hPa level (mid-troposphere),
from radiosonde soundings above Australian Antarctic stations Casey, Davis,
Mawson and Macquarie Island.
Responsible organisation
Bureau of Meteorology, Department of the Environment and Heritage ( Australia )
Custodians
No custodians.
Theme area
Atmosphere
Indicator type
Condition
Criteria the indicator satisfies
The following 11 out of 15 criteria
1. | Serve as a robust indicator of environmental change |
2. | Reflect a fundamental or highly-valued aspect of the environment or an important environmental issue |
3. | Be either national in scope or applicable to regional environmental issues of national significance |
4. | Provide an early warning of potential problems |
5. | Be capable of being monitored to provide statistically verifiable and reproducible data that shows trends over time and, preferably, apply to a broad range of environmental regions |
6. | Be scientifically credible |
7. | Be easy to understand |
9. | Be cost-effective |
11. | Contribute to monitoring of progress towards implementing commitments in nationally important environmental policies |
13. | Contribute to the fulfillment of reporting obligations under international agreements |
15. | Where possible and appropriate, be consistent and comparable with other countries� and state and territory indicators |
Date input
Monthly measurements
Monitoring location
Geographic coverage
- Latitude (-69.0 to -54.0)
Longitude (61.0 to 159.0)
- 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". There is interest in climate variability and
change not just at the surface, but extending up into the atmosphere. There is
evidence of warming in the lower troposphere, but cooling in the lower
stratosphere.
- Design and Strategy For Indicator Monitoring Program
- Spatial Scale: Australian Antarctic stations: Casey (lat 660 16' 54.5" S,
long 1100 31' 39.4" E), Davis (lat 680 34' 35.8" S, long 770 58' 02.6" E),
Mawson (lat 670 36' 09.7" S, long 620 52' 25.7" E) and Macquarie Island
(lat 540 37' 59.9" S, long 1580 52' 59.9" E).
Temporal scale: Monthly.
Measurement technique: Radiosonde.
- Research Issues
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 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.
Over recent years satellite data exist, which could be used in conjunction
with radiosonde data. Satellite data and radiosonde data from other nations
should lead to a greater coverage.
Data
Temporal range of the available data, as described by the metadata record, is from
01-Apr-1948
.
- Timespan
- February-1959 to March-2020
- Number of data points
- 3037
To view or download any of the data, you must be logged in
- Hide graphs for Casey
Casey: Air Temperature
Casey: Air Temperature Anomaly
- View graphs for Davis
Davis: Air Temperature
Davis: Air Temperature Anomaly
- View graphs for Macquarie Island
Macquarie Island: Air Temperature
Macquarie Island: Air Temperature Anomaly
- View graphs for Mawson
Mawson: Air Temperature
Mawson: Air Temperature Anomaly
Data quality, interpretation and analysis of indicator data
- 'Monthly means are calculated from daily observations of temperature at the 500hPa level. Observations are restricted to within a few hours of 0000UTC to avoid biases and to allow comparison with limited historical data. If less than 25 daily observations are available for a given month, the monthly data are flagged and removed from the State of Environment dataset.
- The monthly mid-tropospheric air temperature anomaly is calculated as the difference between the mean mid-tropospheric air temperature for a given month and the long-term mean mid-tropospheric 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).
- The data are subject to a number of quality checks, although these will not prevent errors:
- - The radiosonde checks the reasonableness of raw values from the probes whilst converting to temperature.
- - The receiving station applies reasonableness checks, generally with the involvement of a human observer.'
Data usage constraints
'This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=SOE_mid_tropo when using these data.'
Data access constraints
'Data arising from this project are available from the state of the environment indicator URL given below.'
Custodian evaluation
9 May 2002
The annual cycle evident in the plots of monthly mean mid-tropospheric temperature makes it hard to see long-term trends but can be removed by using monthly anomalies, which show the difference between the value for a given month and the long-term mean value for that month.
The anomaly data indicate significant warming at Macquarie Island and, to a lesser extent, at Mawson and Casey.
It should be noted that the data have not been corrected for any changes in instrumentation or observing practices.
7 Nov 2002
Condition scale - 5
1 - the environment degraded to the point where rehabilitation is impossible
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7 - the environment is pristine, in perfect condition, no anthropogenic influences
State of Knowledge scale - 4 - Fair
1 - Poor
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7 - Excellent
5 Aug 2004
Despite a recent decrease at Casey, the anomaly data now indicate significant long-term warming at all sites. The warming is more pronounced at Macquarie Island and Casey than at Mawson and Davis.
Condition scale - 4 - fair condition
1 - the environment degraded to the point where rehabilitation is impossible
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7 - the environment is pristine, in perfect condition, no anthropogenic influences
State of Knowledge scale - 4 - Fair
1 - Poor
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7 - Excellent
For definitions of the Scale categories, consult the
Explanation of the Status Categories
Related resources
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Project 805 - Meteorology Observations
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Scientific Bibliography 17309
- French, J., Burns, G., Greet, P. & French, K. (2000) Antarctic Noctilucent Clouds: The Upper atmosphere Exposed to View. The Physicist, volume 37, Number 3
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SOE Indicator 1
- Monthly mean air temperatures at Australian Antarctic Stations
|
SOE Indicator 2
- Highest monthly air temperatures at Australian Antarctic Stations
|
SOE Indicator 3
- Lowest monthly air temperatures at Australian Antarctic Stations
|
SOE Indicator 4
- Monthly mean lower stratospheric temperatures above Australian Antarctic Stations
|
SOE Indicator 8
- Monthly mean atmospheric pressure at Australian Antarctic Stations
|
SOE Indicator 12
- Noctilucent cloud observations at Davis
|
SOE Indicator 13
- Polar stratospheric cloud observations at Davis
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SOE Indicator 14
- Midwinter atmospheric temperature at altitude 87km
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Parameters
The properties link can be used to view details of the parameters measured for this indicator.
Parameter Name |
Unit of measure |
Properties |
Air Temperature |
deg C |
Properties |
Air Temperature Anomaly |
deg C |
Properties |
The following parameters and/or sensor notes are from the metadata record.
Parameters
EARTH SCIENCE
> ATMOSPHERE
> ATMOSPHERIC TEMPERATURE
> SURFACE TEMPERATURE
Sensors
RAWINSONDES
TEMPERATURE SENSORS
Related URLs
http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=SOE_mid_tropo
Citation reference for this metadata record and dataset
http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=1272
Download page for Australian Antarctic Data Centre