Indicator 14 - Midwinter atmospheric temperature at altitude 87km

Geographic Coverage is

Latitude (-68.5767 to -68.5766)
Longitude (77.9673 to 77.9674)

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Date entered	Evaluation
15-Apr-2002	The yearly winter temperature data at ~87 km above Davis have been evaluated to determine a solar cycle (11 year, natural cyclic trend evaluted as K per sfu [=solar flux unit. Multiply by 120 to express this value as K per average solar cycle) and a linear long-term trend. [1990, 1995-2000]: solar cycle: 0.067 +/- (std. error) 0.009 K per sfu [=~8 K per solar cycle]. lower 95% confidence limit value: 0.045 K per sfu. upper 95% confidence level value: 0.090 K per sfu. linear trend: -0.47 +/- (std error) 0.13 K per annum. lower 95% confidence limit value: -0.81 K per annum. upper 95% confidence limit value: -0.13 K per annum. That looks like 'cooling is weakly significant'. I would not be prepared to support these results from the present data because an assumption of the multiple-regression analysis used to derive the values listed is that the temperature from each year is known to the same accuracy. However, the 1990 datum is the least reliable datum, but it presently dominates the trend estimate. It is necessary to wait until we reach the minimum of the present solar cycle (~5 years) to be confident that uncertainties in the 1990 datum are not the source of the excessive cooling. The significance of the 1990 datum can be gauged by removing it from the analysis. [1995-2000]: solar cycle: 0.049 +/- (std. error) 0.009 K per sfu. [=~6 K per solar cycle] lower 95% confidence limit value: 0.018 K per sfu. upper 95% confidence level value: 0.080 K per sfu. linear trend: -0.003 +/- (std error) 0.28 K per annum. lower 95% confidence limit value: -0.78 K per annum. upper 95% confidence limit value: +0.77 K per annum. No significant cooling or warming trend is apparent from the most reliable, recent 6 years of data.
8-Nov-2002	Condition scale - 3 1 - the environment degraded to the point where rehabilitation is impossible 0 1 2 3 4 5 6 7 7 - the environment is pristine, in perfect condition, no anthropogenic influences State of Knowledge scale - 2 1 - Poor 0 1 2 3 4 5 6 7 7 - Excellent
11-Sep-2003	The absolute value (and standard error) for 2002 are potentially seriously misleading if this value is used for trend estimates. Our spectral calibrations for 2002 were much more variable than for recent, previous years. We have tracked a source of this variability to the photomultiplier cooler which performed poorly (variably) during 2002. We estimate that individual nightly average temperatures may be in error in our present analysis by up to 4K. Normal errors from the spectral calibration amount to less than 0.5K. If we can commit time to investigating and correcting for this variation, we may be able to improve the accuracy of the 2002 value (...but will not be able to obtain the accuracy of previous or future years). It is essential to note that there is this degree of uncertainty in the present 2002 value. Condition scale - 4 - fair condition 1 - the environment degraded to the point where rehabilitation is impossible 0 1 2 3 4 5 6 7 7 - the environment is pristine, in perfect condition, no anthropogenic influences State of Knowledge scale - 4 - Fair 1 - Poor 0 1 2 3 4 5 6 7 7 - Excellent

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Metadata SOE_hydroxyl - Midwinter atmospheric temperature at altitude ~87km

Project 701 - Long-term monitoring of the mesopause region via hydroxyl emissions at Davis

Scientific Bibliography 17315 - French, W.J.R., G.B. Burns, K.Finlayson, P.A. Greet, R.P. Lowe and P.F.B. Williams. (2000) Hydroxyl (6-2) airglow emission intensity ratios for rotational temperature determination. Annales Geophysicae, 18: 1293-1303.

Scientific Bibliography 17316 - Golitsyn, G.S., A.I. Semenov, N.N. Shefov, L.M. Fishcova, E.V. Lysenko, S.P. Perov. (1996) Long-term temperature trend in the middle and upper atmosphere Geophysical Research Letters, 23(24):1741-1744.

Scientific Bibliography 17317 - Greet, P.A, W.J.R. French, G.B. Burns, P.F.B. Williams, R.P. Lowe and K. Finlayson. (1998) OH(6-2) spectra and rotation temperature measurements at Davis, Antarctica. Annales Geophysicae, 16:79-89.

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 5 - Monthly mean mid-tropospheric temperatures above Australian Antarctic Stations

SOE Indicator 11 - Atmospheric concentrations of greenhouse gas species

SOE Indicator 12 - Noctilucent cloud observations at Davis

SOE Indicator 13 - Polar stratospheric cloud observations at Davis

SOE Indicator 15 - Stratopause region parameters for Davis

Parameters -
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC CHEMISTRY > HYDROGEN COMPOUNDS