MAC-v1: A new global aerosol climatology for climate studies

The Max-Planck-Institute Aerosol Climatology version 1 (MAC-v1) is introduced. It describes the optical properties of tropospheric aerosols on monthly timescales and with global coverage at a spatial resolution of 1° in latitude and longitude. By providing aerosol radiative properties for any wavelength of the solar (or shortwave) and of the terrestrial (or longwave) radiation spectrum, as needed in radiative transfer applications, this MAC-v1 data set lends itself to simplified and computationally efficient representations of tropospheric aerosol in climate studies. Estimates of aerosol radiative properties are provided for both total and anthropogenic aerosol in annual time steps from preindustrial times (i.e., starting with year 1860) well into the future (until the year 2100). Central to the aerosol climatology is the merging of monthly statistics of aerosol optical properties for current (year 2000) conditions. Hereby locally sparse but trusted high-quality data by ground-based sun-photometer networks are merged onto complete background maps defined by central data from global modeling with complex aerosol modules. This merging yields 0.13 for the global annual midvisible aerosol optical depth (AOD), with 0.07 attributed to aerosol sizes larger than 1 µm in diameter and 0.06 of attributed to aerosol sizes smaller than 1 µm in diameter. Hereby larger particles are less absorbing with a single scattering albedo (SSA) of 0.98 compared to 0.93 for smaller sizes. Simulation results of a global model are applied to prescribe the vertical distribution and to estimate anthropogenic contributions to the smaller size AOD as a function of time, with a 0.037 value for current conditions. In a demonstration application, the associated aerosol direct radiative effects are determined. For current conditions, total aerosol is estimated to reduce the combined shortwave and longwave net-flux balance at the top of the atmosphere by about −1.6 W/m2 from which −0.5 W/m2 (with an uncertainty of ±0.2 W/m2) is attributed to anthropogenic activities. Based on past and projected aerosol emission data, the global anthropogenic direct aerosol impact (i.e., ToA cooling) is currently near the maximum and is projected to drop by 2100 to about −0.3 W/m2. The reported global averages are driven by considerable spatial and temporal variability. To better convey this diversity, regional and seasonal distributions of aerosol optical properties and their radiative effects are presented. On regional scales, the anthropogenic direct aerosol forcing can be an order of magnitude stronger than the global average and it can be of either sign. It is also shown that maximum anthropogenic impacts have shifted during the last 30 years from the U.S. and Europe to eastern and southern Asia

Spontaneous thrombosis of internal carotid artery: a natural history of giant carotid cavernous aneurysms Trombose espontânea da artéria carótida interna: a história natural dos aneurismas gigantes intracavernosos

OBJECTIVE: To describe five cases of giant carotid cavernous aneurysms which evolved with spontaneous thrombosis of internal carotid artery (STICA), with emphasis at epidemiology, clinical presentation, natural history, related factors and neurological outcome. METHOD: There were 711 consecutives patients with 802 aneurysms with and without surgical treatment during a period of 19 years. We selected 35 patients with 40 carotid cavernous aneurysms (5%) of which 20 (50%) were giant aneurysms. Among those cases, 5 patients evolved with STICA (25%). Symptoms and findings at presentation were recorded and compared with those at outcome. RESULTS: Clinical presentation was commonly related to atherosclerotic factors such as elevated blood pressure (80%), diabetes mellitus (40%) and dislipidemy (40%). All patients presented with hemicranial headache, ophthalmparesy and retro bulbar pain, and after STICA all presented improvement of symptoms. After STICA, 4 patients had regression of deficit, 2 partial and 2 complete. Four patients had sensorial trigeminal neuropathy in V1 and V2 territories, also showing improvement of symptoms after STICA. CONCLUSION: STICA is a common outcome in giant carotid cavernous aneurysms, and is related with significant improvement of symptoms; however, it may be catastrophic for those patients without efficient collateral circulation.<br>OBJETIVO: Relatar cinco casos de aneurismas gigantes intracavernosos que evoluíram com trombose espontânea da artéria carótida interna (TEACI), estudando-se: prevalência, apresentação clínica, história natural, fatores associados e prognóstico neurológico. MÉTODO: Análise de 711 pacientes consecutivos com diagnóstico de 802 aneurismas cerebrais submetidos a tratamento clínico ou cirúrgico num período de 19 anos. Foram identificados 40 aneurismas intracavernosos, sendo que 20 desses eram gigantes. Dentre esses, 5 pacientes com aneurismas gigantes intracavernosos que evoluíram com TEACI (25%). Os sintomas e sinais neurológicos da apresentação foram registrados e comparados ao término do acompanhamento. RESULTADOS: Todos pacientes apresentavam cefaléia hemicraniana, apresentavam oftalmoplegia e dor retro-orbitária. Freqüentemente estavam associados a fatores ateroscleróticos como HAS (80%), diabetes melito (40%) e dislipidemia (40%) e após a TEACI evoluíram com melhora desses sintomas. Após a TEACI, 4 pacientes tiveram regressão do déficit, sendo que em 2 a regressão do déficit foi total. Quatro pacientes apresentavam hipostesia no território de V1 e V2. Todos apresentaram melhora desse sintoma. CONCLUSÃO: A TEACI é uma evolução comum em aneurismas intracavernosos gigantes, e está associada à melhora importante dos sintomas. No entanto pode ser catastrófica naqueles pacientes sem circulação colateral eficiente