The support of the NSF Climate Dynamics Program, NSF Award ATM-9640613 and of the Center for Clouds, Chemistry and Climate (C4) at the Scripps Institution of Oceanography is acknowledged. We appreciate the use of the δ-four stream code from Qiang Fu of Dalhousie University. We are also grateful for the assistance provided by Nicholas Nali of the University of Wisconsin, by P.-H. Wang of the Science and Technology Corporation, David Duda of NASA Goddard, and Elliot Weinstock of Harvard University. The SAGE II and ISCCP data were obtained from the NASA Langley Research Center EOSDIS Distributed Active Archive Center. We appreciate the thoughtful reviews of W. Collins, S. Aulenbach, W. Grabowski, D. Mitchell, and an anonymous reviewer.
Ackerman, T. P., K. N. Liou, F. P. J. Valero, and L. Pfister, 1988: Heating rates in tropical anvils. J. Atmos. Sci.,45, 1606–1623.
Booker, D. R., and P. G. Stickel, 1982: High altitude tropical cirrus cloud observations. Preprints, Conf. on Cloud Physics, Chicago, IL, Amer. Meteor. Soc., 215–217.
Bryson, R. A., C. A. Wilson III, and P. M. Kuhn, 1963: Some preliminary results from radiation sonde ascents over India. Proc. WMO–IUGG Symp. Tropical Meteorology, Rotorua, New Zealand, WMO–IUGG, 507–516.
Bushnell, R. H., and V. E. Suomi, 1961: Experimental flight verification of the economical net radiometer. J. Geophys. Res.,66, 2843–2848.
Churchill, D. D., and R. A. Houze Jr., 1990: Radiatively driven stratosphere–troposphere interactions near the tops of tropical cloud clusters. Preprints, Conf. on Cloud Physics, San Francisco, CA, Amer. Meteor. Soc., J125–J128.
Danielsen, E. F., 1982: A dehydration mechanism for the stratosphere. Geophys. Res. Lett.,9, 605–608.
Darkow, G. L., 1964: A study of infrared radiation measurements in the vicinity of the subtropical tropopause. Ph.D. thesis, University of Wisconsin, 67 pp. [Available from University of Wisconsin Library, B106B Library, 728 State St., Madison, WI 53706.].
Ellingson, R. G., J. Ellis, and S. Fels, 1991: The intercomparison of radiation codes used in climate models: Long wave results. J. Geophys. Res.,96, 8929–8953.
Fu, Q., and K. N. Liou, 1993: Parameterization of the radiative properties of cirrus clouds. J. Atmos. Sci.,50, 2008–2025.
Gayet, J.-F., G. Febvre, and H. Larsen, 1996: The reliability of the PMS FSSP in the presence of small ice crystals. J. Atmos. Oceanic Technol.,13, 1300–1310.
Hartmann, D. L., M. E. Ockert-Bell, and M. L. Michelsen, 1992: The effect of cloud type on earth’s energy balance: Global analysis. J. Climate,5, 1281–1304.
Heymsfield, A. J., 1986: Ice particles observed in a cirriform cloud at −83°C and implications for polar stratospheric clouds. J. Atmos. Sci.,43, 851–855.
——, and L. J. Jahnsen, 1974: Microstructure of tropopause cirrus layers. Proc. Sixth Conf. on Aerospace and Aeronautical Meteorology, El Paso, TX, Amer. Meteor. Soc., 43–48.
——, and G. M. McFarquhar, 1996: High albedos of cirrus in the tropical Pacific warm pool: Microphysical interpretations from CEPEX and from Kwajalein, Marshall Islands. J. Atmos. Sci.,53, 2424–2451.
——, and J. Iaquinta, 2000: Cirrus crystal terminal velocities. J. Atmos. Sci.,57, 914–936.
——, G. M. McFarquhar, W. D. Collins, J. A. Goldstein, F. P. J. Valero, J. Spinhirne, W. Hart, and P. Pilewskie, 1998: Cloud properties leading to highly reflective tropical cirrus: Interpretations from CEPEX, TOGA COARE, and Kwajalein, Marshall Islands. J. Geophys. Res.,103, 8805–8812.
Jensen, E. J., O. B. Toon, H. B. Selkirk, J. D. Spinhirne, and M. R. Schoeberl, 1996: On the formation and persistence of subvisible cirrus clouds near the tropical tropopause. J. Geophys. Res.,101, 21 361–21 375.
Kinne, S., T. P. Ackerman, A. J. Heymsfield, F. P. J. Valero, K. Sassen, and J. D. Spinhirne, 1992: Cirrus microphysics and radiative transfer: Cloud field study on 28 October 1986. Mon. Wea. Rev.,120, 661–685.
Nee, J. B., C. N. Len, W. N. Chen, and C. I. Lin, 1998: Lidar observation of the cirrus cloud in the tropopause at Chung-Li (25°N, 121°E). J. Atmos. Sci.,55, 2249–2257.
Platt, C. M. R., S. A. Young, P. J. Manson, G. R. Patterson, S. C. Marsden, and R. T. Austin, 1998: The optical properties of equatorial cirrus from observations in the ARM pilot radiation observation experiment. J. Atmos. Sci.,55, 1977–1996.
Prabhakara, C., R. S. Fraser, G. Dalu, M.-L. C. Wu, and R. J. Curran, 1988: Thin cirrus clouds: Seasonal distribution over oceans deduced from Nimbus-4 IRIS. J. Appl. Meteor.,27, 379–399.
——, D. P. Kratz, J.-M. Yoo, G. Dalu, and A. Vernekar, 1993: Optically thin cirrus clouds: Radiative impact on the warm pool. J. Quant. Spectrosc. Radiat. Transfer,49, 467–483.
Ramanathan, V., and W. Collins, 1991: Thermodynamic regulation of ocean warming by cirrus clouds deduced from observations of 1987 El Nino. Nature,351, 27–32.
Rosenfield, J. E., D. B. Considine, M. R. Schoeberl, and E. V. Browell, 1998: The impact of subvisible cirrus clouds near the tropical tropopause on stratospheric water vapor. Geophys. Res. Lett.,25, 1883–1886.
Rossow, W. B., and R. A. Schiffer, 1991: ISCCP cloud data products. Bull. Amer. Meteor. Soc.,72, 2–20.
Sandoval, A. R., 1967: Background studies for a climatology of the intertropical convergence zone in the Western Central Pacific Area. Ph.D. thesis, University of Wisconsin, 97 pp. [Available from University of Wisconsin Library, B106B Library, 728 State St., Madison, WI 53706.].
Sassen, K., and B. S. Cho, 1992: Subvisual-thin cirrus lidar dataset for satellite verification and climatological research. J. Appl. Meteor.,31, 1275–1285.
——, M. K. Griffin, and G. C. Dodd, 1989: Optical scattering and microphysical properties of subvisible cirrus clouds, and climatic implications. J. Appl. Meteor.,28, 91–98.
——, G. G. Mace, J. Hallett, and M. R. Poellot, 1998: Corona-producing ice clouds: A case study of a cold mid-latitude cirrus layer. Appl. Opt.,37, 1477–1485.
Spinhirne, J. D., M. Z. Hansen, and L. O. Caudill, 1982: Cloud top remote sensing by airborne lidar. Appl. Opt.,22, 1564–1571.
——, W. D. Hart, and D. L. Hlavka, 1996: Cirrus infrared parameters and shortwave reflectance relations from observations. J. Atmos. Sci.,53, 1438–1458.
Suomi, V. E., and P. M. Kuhn, 1958: An economical net radiometer. Tellus,10, 160–163.
Uthe, E. E., and P. B. Russell, 1977: Lidar observations of tropical high-altitude cirrus clouds. Radiation in the Atmosphere, H. J. Bolle, Ed., Science Press, 242–244.
Wang, P.-H., M. P. McCormick, L. R. Poole, W. P. Chu, G. K. Yue, G. S. Kent, and K. M. Skeens, 1994: Tropical high cloud characteristics derived from SAGE II extinction measurements. Atmos. Res.,34, 53–83.
——, ——, P. Minnis, G. S. Kent, G. K. Yue, and K. M. Skeens, 1996: Preliminary results of the vertical structure of Tropical (20°S–29°N) subvisual clouds from SAGE II observations. Proc. 12th Int. Conf. on Cloud and Precipitation, Zurich, Switzerand, International Commission on Clouds and Precipitation, 637–640.
Winker, D. M., and C. R. Trepte, 1998: Laminar cirrus observed near the tropical tropopause by LITE. Geophys. Res. Lett.,25, 3351–3354.