An assessment of the radiative effects of ice supersaturation based on in situ observations. Issue 20 (28th October 2016)

• Record Type: Journal Article
• Authors: Tan, Xiaoxiao; Huang, Yi; Diao, Minghui; Bansemer, Aaron; Zondlo, Mark A.; DiGangi, Joshua P.; Volkamer, Rainer; Hu, Yongyun
• Is Part Of: Geophysical research letters. Volume 43:Issue 20(2016)
• Page Start: 11, 039
• Page End: 11, 047
• Publication Date: 2016-10-28
• Subjects: ice supersaturation -- ice clouds -- radiation flux -- heating rate -- in situ -- GCM; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL071144
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We use aircraft observations combined with the reanalysis data to investigate the radiative effects of ice supersaturation (ISS). Our results show that although the excess water vapor over ice saturation itself has relatively small radiative effects, mistaking it as ice crystals in climate models would lead to considerable impacts: on average, +2.49 W/m 2 change in the top of the atmosphere (TOA) radiation, −2.7 W/m 2 change in surface radiation, and 1.47 K/d change in heating rates. The radiative effects of ISS generally increase with the magnitudes of supersaturation. However, there is a strong dependence on the preexisting ice water path, which can even change the sign of the TOA radiative effect. It is therefore important to consider coexistence between ISS and ice clouds and to validate their relationship in the parameterizations of ISS in climate models. Key Points: Ice supersaturation (ISS) impacts on radiative flux and heating rates are quantified Mistaking ISS excess water vapor as cirrus clouds would induce significant radiative errors ISS radiative impact is dependent on pre‐existing cloud ice