Background: Nephropathia epidemica (NE), an emerging rodent-borne viral disease, has become the most important cause of infectious acute renal failure in Belgium, with sharp increases in incidence occurring for more than a decade. Bank voles are the rodent reservoir of the responsible hantavirus and are known to display cyclic population peaks. We tried to relate these peaks to the cyclic NE outbreaks observed since 1993. Our hypothesis was that the ecological causal connection was the staple food source for voles, being seeds of deciduous broad-leaf trees, commonly called "mast". We also examined whether past temperature and precipitation preceding "mast years" were statistically linked to these NE outbreaks.

Rapid population growth and industrialization have driven substantial increases in Asian ozone precursor emissions over the past decade 1 , with highly uncertain impacts on regional and global tropospheric ozone levels. According to ozonesonde measurements 2,3 , tropospheric ozone concentrations at two Asian sites have increased by 1 to 3% per year since 2000, an increase thought to contribute to positive trends in the ozone levels observed at North America's West Coast 4,5 . However, model estimates of the Asian contribution to North American ozone levels are not well-constrained by observations 6,7 . Here we interpret Aura satellite measurements of tropospheric concentrations of ozone and its precursor NO 2 , along with its largest natural source, stratospheric ozone, using the TM5 global chemistry-transport model. We show that tropospheric ozone concentrations over China have increased by about 7% between 2005 and 2010 in response to two factors: a rise in Chinese emissions by about 21% and increased downward transport of stratospheric ozone. Furthermore, we find that transport from China of ozone and its precursors has o set about 43% of the 0.42 DU reduction in free-tropospheric ozone over the western United States that was expected between 2005 and 2010 as a result of emissions reductions associated with federal, state and local air quality policies. We conclude that global e orts may be required to address regional air quality and climate change.Elevated tropospheric ozone (O 3 ) concentrations have a direct adverse impact on human 8 and ecosystem health 9 at the surface, whereas in the free troposphere O 3 acts as a greenhouse gas 8,10 and drives the production of the hydroxyl radical, which controls the chemical lifetime of many atmospheric pollutants and reactive greenhouse gases. Previous studies have pointed not only to changing emissions of O 3 precursors 6,7,11-14 , but also to changes in both the net inflow of O 3 from the stratosphere 14-16 and largescale transport patterns 7,13-16 as contributing to observed trends and variability in tropospheric O 3 . For many regions outside Asia, in situ measurements suggest that tropospheric O 3 has remained relatively constant in the 2000s following substantial increases in the 1980s-1990s, at least partially due to changes in the emissions of O 3 precursors, including nitrogen oxides (NO X ) and hydrocarbons 17 . However, chemistry-transport models used for attribution of trends in Europe and North America tend to greatly underestimate the observed O 3 changes over the past several decades 18 . Furthermore, trends are generally derived from sparse surface and balloon measurements that are not necessarily representative of larger regions. This is particularly true for China, where measurements from only two ozonesonde stations are reported in the literature 2,3 .Over the past decade, satellite instruments have provided valuable information on the global distribution of tropospheric O 3 and NO X concentrations and their evolution in time. Here we use O 3 retr...

Abstract. We provide a comprehensive description of the high-resolution version of the TM5-MP global chemistry transport model, which is to be employed for deriving highly resolved vertical profiles of nitrogen dioxide (NO2), formaldehyde (CH2O), and sulfur dioxide (SO2) for use in satellite retrievals from platforms such as the Ozone Monitoring Instrument (OMI) and the Sentinel-5 Precursor, and the TROPOspheric Monitoring Instrument (tropOMI). Comparing simulations conducted at horizontal resolutions of 3°  ×  2° and 1°  ×  1° reveals differences of ±20 % exist in the global seasonal distribution of 222Rn, being larger near specific coastal locations and tropical oceans. For tropospheric ozone (O3), analysis of the chemical budget terms shows that the impact on globally integrated photolysis rates is rather low, in spite of the higher spatial variability of meteorological data fields from ERA-Interim at 1°  ×  1°. Surface concentrations of O3 in high-NOx regions decrease between 5 and 10 % at 1°  ×  1° due to a reduction in NOx recycling terms and an increase in the associated titration term of O3 by NO. At 1°  ×  1°, the net global stratosphere–troposphere exchange of O3 decreases by  ∼  7 %, with an associated shift in the hemispheric gradient. By comparing NO, NO2, HNO3 and peroxy-acetyl-nitrate (PAN) profiles against measurement composites, we show that TM5-MP captures the vertical distribution of NOx and long-lived NOx reservoirs at background locations, again with modest changes at 1°  ×  1°. Comparing monthly mean distributions in lightning NOx and applying ERA-Interim convective mass fluxes, we show that the vertical re-distribution of lightning NOx changes with enhanced release of NOx in the upper troposphere. We show that surface mixing ratios in both NO and NO2 are generally underestimated in both low- and high-NOx scenarios. For Europe, a negative bias exists for [NO] at the surface across the whole domain, with lower biases at 1°  ×  1° at only  ∼  20 % of sites. For NO2, biases are more variable, with lower (higher) biases at 1°  ×  1° occurring at  ∼  35 % ( ∼  20 %) of sites, with the remainder showing little change. For CH2O, the impact of higher resolution on the chemical budget terms is rather modest, with changes of less than 5 %. The simulated vertical distribution of CH2O agrees reasonably well with measurements in pristine locations, although column-integrated values are generally underestimated relative to satellite measurements in polluted regions. For SO2, the performance at 1°  ×  1° is principally governed by the quality of the emission inventory, with limited improvements in the site-specific biases, with most showing no significant improvement. For the vertical column, improvements near strong source regions occur which reduce the biases in the integrated column. For remote regions missing biogenic source terms are inferred.