|Indicator Definition||Monthly means of daily temperatures at the 100hPa level (lower stratosphere),|
from radiosonde soundings above Australian Antarctic stations Casey, Davis,
Mawson and Macquarie Island.
Bureau of Meteorology, Department of the Environment and Heritage Details
|The following 11 out of 15 criteria
|Date Input||Monthly measurements|
Macquarie Island Details
Geographic Coverage is
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. Ozone depletion processes are also closely linked to
|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.
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.
Temporal range of the available data, as described by the metadata record, is from 01-Apr-48.
Timespan: February-1959 to November-2013.
Number of data points: 2415.
To view or download any of the data, you must be logged in
Casey: Air Temperature
Casey: Air Temperature Anomaly
Davis: Air Temperature
Davis: Air Temperature Anomaly
Macquarie Island: Air Temperature
Macquarie Island: Air Temperature Anomaly
Mawson: Air Temperature
Mawson: Air Temperature Anomaly
|Data Quality, Interpretation and
Analysis of Indicator Data
Monthly mean lower stratospheric temperatures are calculated from daily observations of temperature at the 100hPa 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 lower stratospheric air temperature anomaly is calculated as the difference between the mean lower stratospheric air temperature for a given month and the long-term mean lower stratospheric 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
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=SOE_low_strato when using these data.
|Data Access Constraints|| '|
Data arising from this project are available from the state of the environment indicator URL given below.
For definitions of the Scale categories, consult the Explanation of the Status Categories
The properties link can be used to view details of the parameters measured for this indicator.
Citation reference for this metadata record and dataset
Download page for Australian Antarctic Data Centre