{"id":119026,"date":"2026-09-11T21:49:50","date_gmt":"2026-09-11T19:49:50","guid":{"rendered":"https:\/\/nilu.gnist.dev\/publikasjoner\/mesospheric-nitric-acid-enhancements-during-energetic-electron-precipitation-events-simulated-by-waccm%e2%80%90d\/"},"modified":"2026-09-11T21:49:50","modified_gmt":"2026-09-11T19:49:50","slug":"mesospheric-nitric-acid-enhancements-during-energetic-electron-precipitation-events-simulated-by-waccm%e2%80%90d","status":"publish","type":"nva_publication","link":"https:\/\/nilu.gnist.dev\/en\/publications\/mesospheric-nitric-acid-enhancements-during-energetic-electron-precipitation-events-simulated-by-waccm%e2%80%90d\/","title":{"rendered":"Mesospheric nitric acid enhancements during energetic electron precipitation events simulated by WACCM\u2010D"},"content":{"rendered":"<p class=\"wp-block-paragraph\">While observed mesospheric polar nitric acid enhancements have been attributed to energetic particle precipitation through ion cluster chemistry in the past, this phenomenon is not reproduced in current whole\u2010atmosphere chemistry\u2010climate models. We investigate such nitric acid enhancements resulting from energetic electron precipitation events using a recently developed variant of the Whole Atmosphere Community Climate Model (WACCM) that includes a sophisticated ion chemistry tailored for the D\u2010layer of the ionosphere (50\u201390 km), namely, WACCM\u2010D. Using the specified dynamics mode, that is, nudging dynamics in the troposphere and stratosphere to meteorological reanalyses, we perform a 1\u2010year\u2010long simulation (July 2009\u2013June 2010) and contrast WACCM\u2010D with the standard WACCM. Both WACCM and WACCM\u2010D simulations are performed with and without forcing from medium\u2010to\u2010high energy electron precipitation, allowing a better representation of the energetic electrons penetrating into the mesosphere. We demonstrate the effects of the strong particle precipitation events which occurred during April and May 2010 on nitric acid and on key ion cluster species, as well as other relevant species of the nitrogen family. The 1\u2010year\u2010long simulation allows the event\u2010related changes in neutral and ionic species to be placed in the context of their annual cycle. We especially highlight the role played by medium\u2010to\u2010high energy electrons in triggering ion cluster chemistry and ion\u2010ion recombinations in the mesosphere and lower thermosphere during the precipitation event, leading to enhanced production of nitric acid and raising its abundance by 2 orders of magnitude from 10\u22124 to a few 10\u22122 ppb.<\/p>\n","protected":false},"template":"","meta":{"_acf_changed":false,"_searchwp_excluded":"","_id":"","_status":"PUBLISHED","_sync_date":"2026-09-11 14:48:53","footnotes":""},"nva_tax_category":[1099],"class_list":["post-119026","nva_publication","type-nva_publication","status-publish","hentry","nva_tax_category-scientific-journal-publication"],"acf":[],"_links":{"self":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/nva_publication\/119026","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/nva_publication"}],"about":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/types\/nva_publication"}],"version-history":[{"count":0,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/nva_publication\/119026\/revisions"}],"wp:attachment":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/media?parent=119026"}],"wp:term":[{"taxonomy":"nva_tax_category","embeddable":true,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/nva_tax_category?post=119026"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}