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We correlate annual ultraviolet dose estimates with age specific and age adjusted incidence data for non-melanoma skin cancer in the United States, United Kingdom, Canada and Australia. We first examine (1) a reciprocity or photographic model in which incidence rates (R) are related to exposure (E) which is the product of age (T) and annual dose (D). We also test several models which violate reciprocity including models identified by the labels: (2) Dose potency; (3) Double cause; (4) Age-exposure and (5) separable. Our analyses together with the recent National Cancer Institute study favors the age-exposure model and/or the double cause models. All models lead to biological amplification factors (defined as the ratio of the percent increase in skin cancer incidence due to a 1% increase in dose) greater than unity. For the U.S. we find the biological amplification to be approximately 1.8 for the population center hut greater in regions of higher UV annual dose, and less in regions of lower annual UV dose.

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Total ozorl½ n-aeasuren-sents o,.,,.,, , •' • ß ,• .......... spacecraft are compared •ith measurements from 62 Dobson and 18 M83 stations. On the average, TOMS ozone values are 6.6% smaller than Dobson and 9.1% smaller than M83; corresponding SBUV biases are 8.3% and 11.3%, respectively. Use of SBUV or TOMS as a transfer standard reveals an apparent bias between the Dobson and M83 networks of 3.0 or 2.5%, res•ctively. Major portion of the bias between the space and •ound measurements is attributed to un•rtainties in the ozone absorption coe•cients used in processing the measurements. Precision of total ozone ret•eved from either the SBUV or the TOMS instrument is shown to be better than 2%, which is comparable to that of a well run Dobson station. Precision of a typical Dobson measurement is estimated at about 2% and that of an M83 measurementis estimated to be 4%. Apparent station to station biases of up to 11.2% for Dobson and 15.5% for M83 are shown. Daily and seasonal vacations of ozone measured by the satellite over selected Dobson stations are found to be in excellent agreement with the ground observations. An instrumental drift is found in the SBUV/TOMS total ozone measurements that is essentially linear with time and has a rate of 0.5% per year for the first year of data. A better understanding of instrument changes is expected to help redu• any further drift. -LAT. 46.8øN _ LONG. 9.7øE --_ ß . ß .,.

A global ozone data set covering the two years from November 1978 until October 1980, with an average of 1200 profiles per day, has been I•roduced and archived from the solar backscattered ultraviolet (SBUV) instrument flown on the NIMBUS 7 spacecraft. The SBUV ozone profiles are compared with measurements from chemical and optical sensors launched on balloons and rockets and with ozone profiles obtained from the ground-based Dobson spectrophotometers using the Umkehr method. The biases between the SBUV results and the balloon and Umkehr results are generally less than 10%. These biases are functions of layer height and latitude and are believed to be largely due to inconsistencies in the ozone absorption cross sections used' for the various measurement systems. The precision of the SBUV measurements is found to be better than 8% for pressures between 1 and 64 mbar and better than 15% from 64 to 253 mbar. 1. INTRODUCTION The solar backscattered ultraviolet (SBUV) instrument aboard the NIMBUS 7 satellite is designed to measure total columnar ozone and its vertical distribution in the earth's atmosphere. The instrument is operated 3 out of every 4 days and provides an average of 1200 sets of measurements per day (325,000 observations per year). The observations cover the entire daylit portion of the globe and, except for the polar regions, are made close to local noon. Data for the period from October 31, 1978, until November 2, 1980, have been processed, validated, and archived. At the time of submission of this paper the instrument was still operating well. Data processing is continuing, and the remaining data will also be archived. The SBUV instrument for NIMBUS 7 is conceptually similar to the backscattered ultraviolet (BUV) instrument flown on NIMBUS 4. However, improvements were made in both the instrument and the processing algorithms used to reduce the data. The results presented herein are only applicable to the SBUV data. Great care should be exercised in comparing results from NIMBUS 7 SBUV with results from NIMBUS 4 BUV (see, for example, D. F. Heath and B. M. Schlesinger, unpublished manuscript, 1984). The NIMBUS 7 satellite is in a retrograde, near-polar, sunsynchronous orbit and crosses the equator moving northward at local noon every 104 min. Consecutive orbits are 26 ø apart in longitude. The SBUV instrument aboard this satellite contains an ultraviolet monochromator and a scene photometer that are described by Heath et al. [1975]. In its normal ozone-measuring mode the instrument looks at 200 x 200 km spots on the earth in the nadir direction and measures the intensity of solar radiation backscattered by the earth and its atmosphere in 12 discrete 1-nm-wide wavelength bands centered at 339.9, 331.3, 317.6, 312.6, 305.6, 302.0, 297.6, 292.3,287.7, 283.1,273.6, and 255.7 nm. It takes the instrument 32 s to step through these bands, during which time the satellite footprint moves by about 200 km. To account for the changes in scene in the satellite IFOV (instantaneous field of view), a 5-nm bandpass ...