Evidence That Nitric Acid Increases Relative Humidity in Low-Temperature Cirrus Clouds Export

@article{citeulike:555833, abstract = {In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130\% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles ({Delta}-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. {Delta}-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including {Delta}-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.}, author = {Gao, R. S. and Popp, P. J. and Fahey, D. W. and Marcy, T. P. and Herman, R. L. and Weinstock, E. M. and Baumgardner, D. G. and Garrett, T. J. and Rosenlof, K. H. and Thompson, T. L. and Bui, P. T. and Ridley, B. A. and Wofsy, S. C. and Toon, O. B. and Tolbert, M. A. and Karcher, B. and Peter, Th and Hudson, P. K. and Weinheimer, A. J. and Heymsfield, A. J.}, citeulike-article-id = {555833}, citeulike-linkout-0 = {http://dx.doi.org/10.1126/science.1091255}, citeulike-linkout-1 = {http://www.sciencemag.org/cgi/content/abstract/303/5657/516}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/14739457}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=14739457}, day = {23}, doi = {10.1126/science.1091255}, journal = {Science}, keywords = {acid, cirrus, humidity, nitric}, month = {January}, number = {5657}, pages = {516--520}, posted-at = {2006-03-17 08:33:50}, priority = {5}, title = {Evidence That Nitric Acid Increases Relative Humidity in Low-Temperature Cirrus Clouds}, url = {http://dx.doi.org/10.1126/science.1091255}, volume = {303}, year = {2004} }

TY - JOUR ID - citeulike:555833 L3 - citeulike-article-id:555833 N2 - In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles ({Delta}-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. {Delta}-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including {Delta}-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor. IS - 5657 JF - Science EP - 520 TI - Evidence That Nitric Acid Increases Relative Humidity in Low-Temperature Cirrus Clouds VL - 303 SP - 516 KW - acid KW - cirrus KW - humidity KW - nitric AU - Gao, RS AU - Popp, PJ AU - Fahey, DW AU - Marcy, TP AU - Herman, RL AU - Weinstock, EM AU - Baumgardner, DG AU - Garrett, TJ AU - Rosenlof, KH AU - Thompson, TL AU - Bui, PT AU - Ridley, BA AU - Wofsy, SC AU - Toon, OB AU - Tolbert, MA AU - Karcher, B AU - Peter, Th AU - Hudson, PK AU - Weinheimer, AJ AU - Heymsfield, AJ PY - 2004/01/23/ UR - http://dx.doi.org/10.1126/science.1091255 ER -