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Data format for the UARS97.PLT.

  COL   FMT    DESCRIPTION
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 1- 4   I4     Year
 5- 6   I2     Month
 7- 8   I2     Day
    9   1X     Blank
10-17  F8.3    Total Solar Irradiance (TSI) is reported on 'ACRIM II
               native scale' defined by operation of sensor 'B', the
               full-time monitoring sensor. Results are reconciled to 
               a heliocentric rest frame at 1  A.U. and are fully 
               corrected for sensor degradation.
   18   1X     Blank
19-23  F5.3    Standard error of the daily means (W/M*2)
   24   1X     Blank
25-32  F8.3    Acrim II data normalized to Acrim I
	       UARS/ACRIMII results reported on scale defined by operation 
	       of SMM/ACRIMI instrumentation. 

NOTE:  The 1991 - 1997 UARS/ACRIM II database has been updated to make a small
correction in the time base for 1996. It includes TSI reported on both the
'native scale' of the ACRIM II sensor and in terms of the SMM/ACRIM I
scale, as rekonned by mutual intercomparisons using the Nimbus7/ERB
results. The ratio of ACRIM I/ACRIM II (native scale) is 1.001689. 

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Total Solar Irradiance Results (TSI) from the Upper Atmosphere Research 
Satellite (UARS) Active Cavity Radiometer Irradiance Monitor II Experiment 
(ACRIM II)

The second Active Cavity Radiometer Irradiance Monitor experiment (ACRIM II)
was launched in September 1991 as part of the science payload of the Upper
Atmosphere Research Satellite (UARS). The variations on solar rotational and
active region  time scales are clearly seen. The large, short-term decreases
are caused by  the TSI blocking effect of sunspots in magnetically active
regions as they  rotate through our view from Earth. The peaks of TSI
preceding and  following these sunspot 'dips' are caused by the faculae of
solar active regions whose larger areal extent causes them to be seen first
as the region rotates onto our side of the sun and last as they rotate over
the opposite solar limb. The downward trend through the 1991-1997 period is
similar in slope and amplitude to that observed by ACRIM I during the
declining activity phase of solar cycle 21. From the peak of solar cycle 21
to its minimum the TSI decreased by about 0.08 %. It appears likely from
the ACRIM II results thus far that the cycle 22-23 minimum in TSI will
occur during 1997, near the average solar cycle period of about 11 years
after the cycle 21-22 minimum, and with a similar decrease relative to the
maximum of cycle 22 in the 1990-1991 period.