M. van Weele

• Dr
• Senior Researcher at Koninklijk Nederlands Meteorologisch Instituut

An improved divergence method has been developed to estimate annual methane (CH4) emissions from TROPOspheric Monitoring Instrument (TROPOMI) observations. It has been applied to the period of 2018 to 2021 over the Middle East, where the orography is complicated, and the mean mixing ratio of methane (XCH4) might be affected by albedos or aerosols o...

Meteorological fields calculated by numerical weather prediction (NWP) models drive offline chemical transport models (CTMs) to solve the transport, chemical reactions, and atmospheric interaction over the geographical domain of interest. HARMONIE (HIRLAM ALADIN Research on Mesoscale Operational NWP in Euromed) is a state-of-the-art non-hydrostatic...

An improved divergence method has been developed to estimate annual methane (CH4) emissions from TROPOspheric Monitoring Instrument (TROPOMI) observations. It has been applied to the period of 2018 to 2021 over the Middle East, where the orography is complicated, and the mean mixing ratio of methane (XCH4) might be affected by albedos or aerosols o...

Meteorological fields calculated by Numerical Weather Prediction (NWP) Models drive offline Chemical Trans port Models (CTM) to solve the transport, chemical reactions, and atmospheric interaction over the geographical domain of interest. In this way, forecasts and (re-)analyses provided by NWP can be used for air quality forecasting, climate model...

Dermal synthesis, following sun exposure, is the main source of vitamin D. This study characterizes ambient UVB radiation relevant for vitamin D production in Europe. A biological weighing function was applied to data from the Tropospheric Emissions Monitoring Internet Service (TEMIS) for 46 capital cities over an 18-year period (2004–2021) to isol...

Background The aetiology of ANCA-associated vasculitis (AAV) and triggers of relapse are poorly understood. Vitamin D (vitD) is an important immunomodulator, potentially responsible for the observed latitudinal differences between granulomatous and non-granulomatous AAV phenotypes. A narrow ultraviolet B spectrum induces vitD synthesis (vitD-UVB) v...

We present a new divergence method to estimated methane (CH4) emissions from satellite observed mean mixing ratio of methane (XCH4) by deriving the regional enhancement of XCH4 in the Planetary Boundary Layer (PBL). The applicability is proven by comparing the estimated emissions with its known emission inventory from a 3‐month GEOS‐Chem simulation...

A growing body of evidence suggests that vitamin D deficiency has been associated with an increased susceptibility to viral and bacterial respiratory infections. In this study, we aimed to examine the association between vitamin D and COVID-19 risk and outcomes. We used logistic regression to identify associations between vitamin D variables and CO...

Background The etiology of ANCA-associated vasculitis (AAV) and triggers of relapse are poorly understood. Vitamin D (vitD) is an important immunomodulator, potentially responsible for the observed latitudinal differences between granulomatous and non-granulomatous AAV phenotypes. A narrow ultraviolet B spectrum induces vitD synthesis (vitD-UVB) vi...

Ground-level ozone (O3) pollution has been steadily getting worse in most parts of eastern China during the past 5 years. The non-linearity of O3 formation with its precursors like nitrogen oxides (NOx= NO + NO2) and volatile organic compounds (VOCs) are complicating effective O3 abatement plans. The diagnosis from space-based observations, i.e. th...

Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. To answer the question for southeastern Australia, where fires were particularly severe, affecting people and ecosystems, we use a physically based inde...

Ground-level ozone (O3) pollution has been steadily getting worse in most part of eastern China during the past five years. The non-linearity of O3 formation with its precursors like nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs) are complicating effective O3 abatement plans. The diagnosis from space-based observations, the...

A growing body of evidence shows that poor vitamin D status has been associated with an increased susceptibility to viral and bacterial respiratory infections. In this study, we aimed to examine the association between vitamin D and COVID-19 risk and outcomes, and to explore potential causal effects. We used logistic regression to identify associat...

A new global high-resolution coupled climate model, EC-Earth3P-HR has been developed by the EC-Earth consortium, with a resolution of approximately 40 km for the atmosphere and 0.25∘ for the ocean, alongside with a standard-resolution version of the model, EC-Earth3P (80 km atmosphere, 1.0∘ ocean). The model forcing and simulations follow the High...

Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. Atmospheric emissions and concentrations of CH4 continue to increase, making CH4 the second most important human-influenced greenhouse gas in terms of climate forcing, after carbon dioxide (CO2). The relative impor...

Abstract. Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. To answer the question for southeastern Australia, where fires were particularly severe, affecting people and ecosystems, we use a physically-...

Abstract. A new global high-resolution coupled climate model, EC-Earth3P-HR has been developed by the EC-Earth consortium, with a resolution of approximately 40 km for the atmosphere and 0.25 degree for the ocean, alongside with a standard resolution version of the model, EC-Earth3P (80 km atmosphere, 1.0 degree ocean). The model forcing and simula...

Update estimates of the global methane cycle, including both natural and anthropogenic fluxes, up to 2017

Sunshine is considered to be the most important source of vitamin D. Due to an increased risk of skin cancer, sun avoidance is advised, but this directly contributes to the high prevalence of vitamin D deficiency. The simple solution is to advise vitamin D supplementation. The aim of this study is to examine the absolute and relative contribution o...

On 19 May 2016 the afternoon temperature reached 51.0 ∘C in Phalodi in the northwest of India – a new record for the highest observed maximum temperature in India. The previous year, a widely reported very lethal heat wave occurred in the southeast, in Andhra Pradesh and Telangana, killing thousands of people. In both cases it was widely assumed th...

In this paper we evaluate the long-term changes in ozone depletion within the Antarctic ozone hole using a 37 years (1979-2015) of daily Ozone Mass Deficits (OMD) derived from assimilated total ozone column data. For each year an ‘average daily OMD’ is calculated over a 60-day preferential time period DOY (Day of Year) 220-280). Excluding years wit...

The dataset used for the paper found under: http://www.atmos-chem-phys-discuss.net/acp-2016-1146/#discussion. Columns: year, day of year, 10 min dose from TEMIS x 3, time in minutes, SZA, cloud flag (0: cloudy, 1: cloudless), aod @ 340 nm, aod flag (0:false, 1: linear interpolated, 2: exact measurement), NILU dose rate x 3

The dataset used for the paper found under: http://www.atmos-chem-phys-discuss.net/acp-2016-1146/#discussion. Columns: year, day of year, 10 min dose from TEMIS x 3, time in minutes, SZA, cloud flag (0: cloudy, 1: cloudless), aod @ 340 nm, aod flag (0:false, 1: linear interpolated, 2: exact measurement), NILU dose rate x 3

On 19 May 2016 the afternoon temperature reached 51.0 ºC in Phalodi in the northwest of India, a new record for the highest observed maximum temperature in India. The previous year, a widely-reported very lethal heat wave occurred in the southeast, in Andhra Pradesh and Telangana, killing thousands of people. In both cases it was widely assumed tha...

Background: UVB-induced skin synthesis is considered the key source of vitamin D, yet exposure to UVB is poorly accounted for in epidemiological studies. Objectives: The aim of this study was to examine the association of serum 25-hydroxyvitamin D [25(OH)D] concentration with accurately measured ambient UVB dose, sun enjoyment, supplements, and oth...

This study aims to cross-validate ground-based and satellite-based models of three photobiological UV effective dose products: the Commission Internationale de l'Éclairage (CIE) erythemal UV, the production of vitamin D in the skin, and DNA damage, using high-temporal-resolution surface-based measurements of solar UV spectral irradiances from a syn...

The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH4 over the past decade. Emissions and...

This paper discusses assimilation experiments of methane (CH4) and nitrous oxide (N2O) profiles retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Here we focus on data versions 6 and 7 provided by the ESA processor. These data sets have been assimilated by the Belgian Assimilation System for Chemical ObsErvations...

This paper discusses assimilation experiments of methane (CH4) and nitrous oxide (N2O) profiles observed by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Here we focus on data versions 6 and 7 retrieved by the ESA processor. These datasets have been assimilated by the Belgian Assimilation System for Chemical ObsErvations (B...

The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH4 over the past decade. Emissions and...

In September and October 2015 widespread forest and peatland fires burned over large parts of maritime southeast Asia, most notably Indonesia, releasing large amounts of terrestrially-stored carbon into the atmosphere, primarily in the form of CO2, CO and CH4. With a mean emission rate of 11.3 Tg CO2 per day during Sept-Oct 2015, emissions from the...

The present study aims to validate different approaches for the estimation of three photobiological effective doses: the erythemal UV, the vitamin D and that for DNA damage, using high temporal resolution surface-based measurements of solar UV from 2005-2015. Data from a UV spectrophotometer, a multi-filter radiometer, and a UV radiation pyranomete...

The CH4 growth rate in the atmosphere showed large variations after the Pinatubo eruption in June 1991. A decrease of more than 10 ppb yr-1 in the growth rate over the course of 1992 was reported, and a partial recovery in the following year. Although several reasons have been proposed to explain the evolution of CH4 after the eruption, their contr...

The CH4 growth rate in the atmosphere showed large variations after the Pinatubo eruption in June 1991. A decrease of more than 10ppbyr−1 in the growth rate over the course of 1992 was reported and a partial recovery in the following year. Although several reasons have been proposed to explain the evolution of CH4 after the eruption, their contribu...

Time series of visibility and aerosol optical thickness for the Netherlands have been constructed for 1956–2100 based on observations and aerosol mass scenarios. Aerosol optical thickness from 1956 to 2013 has been reconstructed by converting time series of visibility to visible extinction which in turn are converted to aerosol optical thickness us...

This study presents a sensitivity analysis of multivariate regressions of recent springtime Antarctic vortex ozone trends using a "big data" ensemble approach. Our results indicate that the poleward heat flux (Eliassen–Palm flux) and the effective chlorine loading respectively explain most of the short-term and long-term variability in different...

The eruption of Mount Pinatubo in 1991 injected a large amount of SO2 into the stratosphere, which formed sulfate aerosols. Increased scattering and absorption of UV radiation by the enhanced stratospheric SO2 and aerosols decreased the amount of UV radiation reaching the troposphere, causing changes in tropospheric photochemistry. These changes af...

Isoprene is important in atmospheric chemistry, but its seasonal emission pattern – especially in the tropics, where most isoprene is emitted – is incompletely understood. We set out to discover generalized relationships applicable across many biomes between large-scale isoprene emission and a series of potential predictor variables, including both...

This study presents a sensitivity analysis of multi-variate regressions of recent springtime Antarctic vortex ozone trends using a "big data" ensemble approach. Multi-variate regression methods are widely used for studying the variability and detection of ozone trends. Based on multi-variate regression analysis of total Antarctic springtime vortex...

Isoprene is important in atmospheric chemistry, but its seasonal emission pattern – especially in the tropics, where most isoprene is emitted – is incompletely understood. We set out to discover general, biome-independent relationships between large-scale isoprene emission and a series of potential predictor variables, including both observed and m...

Methane is an important greenhouse gas, responsible for about 20% of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, thei...

The global methane (CH₄) growth rate showed large variations after the eruption of Mount Pinatubo in June 1991. Both sources and sinks of tropospheric CH₄ were altered following the eruption, by feedback processes between climate and tropospheric photochemistry. Such processes include Ultra Violet (UV) radiative changes due to...

We have developed an advanced chemical data assimilation system to combine observations of chemical compounds from multiple satellites. NO2, O3, CO, and HNO3 measurements from the Ozone Monitoring Instrument (OMI), Tropospheric Emission Spectrometer (TES), Measurement of Pollution in the Troposphere (MOPITT), and Microwave Limb Sounder (MLS) satell...

We have developed an advanced chemical data assimilation system to combine observations of chemical compounds from multiple satellites. NO2, O3, CO, and HNO3 measurements from the OMI, TES, MOPITT, and MLS satellite instruments are assimilated into the global chemical transport model CHASER for the years 2006-2007. The CHASER data assimilation syst...

The global methane growth rate showed large variations after the eruption of Mount Pinatubo in June 1991. Both sources and sinks of tropospheric methane were altered following the eruption, by feedback processes between climate and photo-chemistry. Such processes include Ultra Violet (UV) radiative changes due to the presence of volcanic sulfur dio...

The ESA (European Space Agency) Sentinel-5 Precursor (S-5 P) is a low Earth orbit polar satellite to provide information and services on air quality, climate and the ozone layer in the timeframe 2015–2022. The S-5 P mission is part of the Global Monitoring of the Environment and Security (GMES) Space Component Programme. The payload of the mission...

Last Year's unprecedented low ozone episode in the Arctic (March 2011) made again clear that it is important to continue to monitor the ozone layer in support of the Montreal Protocol. Although scientists showed that the developments at the Arctic could be fully understood and explained by the same heterogeneous chemistry as is used for the SP hole...

The evolution of methane in the past two decades is not entirely understood. Its growth rate showed particularly large fluctuations after the eruption of Mount Pinatubo in June 1991. Being able to quantify the processes that determined these fluctuations can help us gain a better understanding of the methane budget. Methane concentrations are deter...

The chemical composition of the troposphere in the tropics and Southern Hemisphere (SH) is significantly influenced by gaseous emissions released from African biomass burning (BB). Here we investigate how various emission estimates given in bottom-up BB inventories (GFEDv2, GFEDv3, AMMABB) affect simulations of global tropospheric composition using...

A flexible and explicit on-line parameteri-zation for the calculation of tropospheric photodissocia-tion rate constants (J -values) has been integrated into the global Chemistry Transport Model TM5. Here we pro-vide a comprehensive description of this Modified Band Ap-proach (MBA) including details of the optimization proce-dure employed, the metho...

We have investigated the effect of introducing CH 4 surface emission estimates on global chemistry transport model simulations of the composition of the global troposphere for the period 2000 to 2009. By applying both the EDGAR and LPJ-WhyMe emission inventories simultaneously, in combination with nudging to surface CH 4 observations in the backgro...

Observation-based constraints on methane (CH 4) surface emissions can be obtained from measurements of atmospheric CH 4 concentrations. Small variations in mixing ratio can be traced back to variations in surface fluxes via inverse modeling. However, surface emissions are not the only source of CH 4 concentration variations in the atmosphere. Atmos...

PREMIER will be the first mission to generate atmospheric trace gas fields at a resolution high enough to study stratosphere-troposphere exchange, tropical convection, the Indian monsoon, pyroconvection, long-range transport of air pollution (and associated chemical conversions) and signatures of mesoscale dynamics including gravity waves. Through...

The growth rate of methane (CH4) showed fluctuations in the 1990s, with particularly large anomalies after the eruption of Mount Pinatubo in June 1991. The eruption injected about 18.5 Mt of sulphur dioxide (SO2) in the stratosphere, and triggered different photochemical effects, including feedbacks between climate and atmospheric photochemistry. T...

A flexible and explicit on-line parameterization for the calculation of tropospheric photodissociation rate constants (J-values) has been integrated into the global Chemistry Transport Model TM5. Here we provide a comprehensive description of this Modified Band Approach (MBA) including details of the optimization procedure employed, the methodology...

Satellite observations show that the 2010 Antarctic ozone hole is characterized by anomalously small amounts of photochemical ozone destruction (40-60% less than the 2005-2009 average). Observations from the MLS instrument show that this is mainly related to reduced photochemical ozone destruction between 20-25 km altitude. Lower down between 15-20...

Natural methane (CH4) emissions from wet ecosystems are an important part of today's global CH4 budget. Climate affects the exchange of CH4 between ecosystems and the atmosphere by influencing CH4 production, oxidation, and transport in the soil. The net CH4 exchange depends on ecosystem hydrology, soil and vegetation characteristics. Here, th...

Methane (CH4) variations on orbital timescales are often associated with variations in wetland coverage, most notably in the summer monsoon areas of the Northern Hemisphere. Here we test this assumption by simulating orbitally forced variations in global wetland emissions, using a simple wetland distribution and CH4 emissions model that was coupled...

Natural methane (CH₄) emissions from wet ecosystems are an important part of today's global CH₄ budget. Climate affects the exchange of CH₄ between ecosystems and the atmosphere by influencing CH₄ production, oxidation, and transport in the soil. The net CH₄ exchange depends on ecosystem hydrol...

Rapid economic development in the East Asian region has lead to associated increases in anthropogenic emissions from e.g. growth in manufacturing, transport and energy production. Here we present results from decadal simulations for the period 1999-2008 performed with the 3D global chemistry transport model TM5-chem-v3.0 (Huijnen et al, 2010) using...

Validation is the essential part of satellite remote sensing, since the retrieved data must be fit-for-purpose and their significance quantified, whether they are for scientific research or environmental monitoring. Data are validated by comparing satellite data sets with those obtained from ground-based, balloon and airborne instrumentation, or fr...

Methane (CH₄) variations on orbital timescales are often associated with variations in wetland coverage, most notably in the summer monsoon areas of the Northern Hemisphere. Here we test this assumption by simulating orbitally forced variations in global wetland emissions, using a simple wetland distribution and CH₄ emissions...

Historical observations of the 13C/12C ratio of atmospheric CH4 are used to constrain the present‐day methane budget using optimal estimation. Three methane emission scenarios with basis in the recent literature are evaluated against historical 13CH4 observations, considering all uncertainties together. We estimate that present‐day methane emission...

The paper presents the implementation of a coupled forecast and assimilation system developed within the subproject on Global Reactive Gases (GRG) of the GEMS-project (Global and regional Earth-system (Atmosphere) Monitoring using Satellite and in-situ data, FP6). One of the main objectives of the GEMS project is to utilise ECMWFs 4D-VAR data assi...

We present a comprehensive description and benchmark evaluation of the tropospheric chemistry version of the global chemistry transport model TM5 (Tracer Model 5, version TM5-chem-v3.0). A full description is given concerning the photochemical mechanism, the interaction with aerosol, the treatment of the stratosphere, the wet and dry deposition par...

The global marine organic aerosol budget is investigated by a 3-dimensional chemistry-transport model considering recently proposed parameterisations of the primary marine organic aerosol (POA) and secondary organic aerosol (SOA) formation from the oxidation of marine volatile organic compounds. MODIS and SeaWiFS satellite data of Chlorophyll-a and...

It is an open question to what extent wetlands contributed to the interglacial-glacial decrease in atmospheric methane concentration. Here we estimate methane emissions from glacial wetlands, using newly available PMIP2 simulations of the Last Glacial Maximum (LGM) climate from coupled atmosphere-ocean and atmosphere-ocean-vegetation models. Emissi...

This paper presents an analysis of satellite and ground-based measurements of total O3 columns and the UV index of a unique event during the 2009 Antarctic O3 hole season. From 11 to 30 November 2009 the Antarctic vortex was located just south of the southern tip of South America rather than at its climatological position over Antarctica. Analysis...

We present a comprehensive description and benchmark evaluation of the tropospheric chemistry version of the global chemistry transport model TM5 (Tracer Model 5, version TM5-chem-v3.0). A full description is given concerning the photochemical mechanism, the interaction with aerosol, the treatment of the stratosphere, the wet and dry deposition par...