operational atmospheric chemistry monitoring missions capacity esa contract no. 17237/03/nl/gs...
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OPERATIONAL ATMOSPHERIC CHEMISTRY MONITORING MISSIONS
‘CAPACITY’ ESA contract no. 17237/03/NL/GS
GEOPHYSICALDATA REQUIREMENTS
Michiel van Weele, KNMI
Final presentation June 2, 2005
Overview Data Requirements
• Objectives and Strategy to Geophysical Data
Requirements
• Relations to IGACO and other available
requirements
• Sampling and coverage; atmospheric domains
• Spatial resolution and revisit time
• Uncertainty
• Measurement Strategy: Ozone Layer and UV
• Measurement Strategy: Air Quality
• Measurement Strategy: Climate
• Geophysical Data Requirements Tables
• Summary
ObjectivesUser Requirements per Theme:
• Ozone Layer and Surface UV Radiation
• Air Quality
• Climate
and per User Type / Application• Protocol Monitoring
• Near-real time data use
• Assessment
Objectives Compile the user requirements per theme / user category and
interpret in terms of a required set of observables per
atmospheric domain
Define a measurement strategy for the optimal combination of
satellite observations, ground-based / in-situ observations and
use of models
Strategy to Data Requirements
• Specify for each parameter the (threshold) resolution and revisit time requirements per atmospheric domain and on the basis of the observed spatial and temporal variability
• Define a measurement strategy the different role of satellite data, ground-based networks and atmospheric models for each theme/user type combination
• Investigate the role of data assimilation for uncertainty requirements, also in relation with the established resolution and revisit time requirements and sampling/coverage
• Define the auxiliary data requirements for the applications.
• Examine and try to understand differences with tabulated data requirements such as IGACO, GMES-GATO/BICEPS, ESA studies (ACECHEM, GeoTrope, Kyoto), Eumetsat paper on Nowcasting, and MTG requirements
Relations to IGACO and other Requirements
• IGACO data requirements have not been specified per theme/user type.
Instead, distinction has been made in a group-1 (existing systems)
and group-2 (next generation systems) set of observables
• IGACO has four themes, CAPACITY only three. The fourth theme of
IGACO is the oxidising capacity, which in Capacity has been
integrated in the “assessment” of the three other themes
• IGACO requirements are given on a per species and atmospheric
domain basis, but the rationale behind each of the quantitative
requirements has not been detailed in the IGACO report.
• ACECHEM and GeoTrope are compilations of data requirements for
research missions and exceed operational data requirements
• Eumetsat Nowcasting position paper only contains requirements for
<12 hours ahead
• MTG requirements focus on the geostationary, non-global perspective
Sampling and Coverage Requirements
• The themes (Ozone Layer, Air Quality and Climate) are all of a global nature. The target requirement for satellite observations is to get as close as possible to global coverage with near-contiguous sampling.Ground-based networks should be globally representative.
• For Air Quality additional focus is on the local, regional to continental scale in Europe. Threshold coverage for satellite data and surface networks contributing to Air Quality is Europe, including Turkey and Europe’s coastal waters as well as the closest parts of the North-Atlantic.
• The aim of each component to an integrated system should be to maximize its contribution, the number of independent observations mainly being limited by any of the other data requirements on, e.g., uncertainty, resolution and revisit time.
• The integrated system will allow data gaps in space and time, however only up to a certain extent. This will depend on the application.
Atmospheric domains
US+M
MS
LS
TTL
US+M
MS
US+M
MS
LS LS
LS LS
FT+UT FT,UT
Tropics
Eq. – 30°
Mid-latitudes30° – 60°
Polar region
60° – Pole
FT FT FT
FT+UT+LS
35 km
20 km
16 km
6 km
12 km
PBL PBL PBL 2 km
80 km
Uncertainty
• The (assumed) uncertainty mainly determines the potential impact of observations in assimilation systems. These requirements are most quantitative and are ‘leading’.
• The uncertainty requirement contains a random component and a systematic component. The latter component can only be established by long-term validation with independent measurements.
• For ground-based and in-situ observations a representation error will contribute significantly to the overall uncertainty. Satellite observations suffer less from this error as long as the resolution is more or less comparable to the model grid size.
• Large numbers of independent observations from prolonged data sets with stable retrievals and limited instrumental drift will help to better characterize random and systematic components (=> mission lifetime)
• Spatio-temporal variations in (current) model uncertainties have not been taken into account. Model uncertainties are often related to intermittent processes and unpredictable events, which are often difficult to assign to certain locations and time periods and can not easily be used to relax requirements.
Spatial Resolution and Revisit Time
• Typically the resolution and revisit time requirements are determined by the known variability of the observable in space and time in the different atmospheric domains. Ultimate threshold is to observe ‘some’ of the variability.
• The horizontal resolution should be typically a factor 2-3 smaller than the error correlation length (ECL) used in the assimilation of the observable. The error correlation length is typically a function of altitude and determined by physical processes. The ECL decreases from several 100 km’s in the middle stratosphere to tens of kilometers in the troposphere and even smaller in the PBL.
• Vertical resolution requirements are related to the observed vertical gradients in the atmosphere. Requirements are most stringent in the UTLS and PBL and much less in the free troposphere and middle stratosphere and mesosphere.
• In principle, the revisit time requirements can also be based on required update frequencies from assimilation studies on anomaly correlations. These correlations however mainly depend on the predictability of the meteorology. Revisit time requirements are most stringent in the PBL.
Data Requirements per Theme and User Category
Theme A: Ozone Layer and Surface UV RadiationA1. Protocol MonitoringA2. Near-real time data useA3. Assessment
Theme B: Air QualityB1. Protocol MonitoringB2. Near-real time data useB3. Assessment
Theme C: ClimateC1. Protocol MonitoringC2. Near-real time data useC3. Assessment
Measurement Strategy A1O3/UV Protocol Monitoring
Role of Satellite measurements
Monitoring of the global total ozone spatial distribution (<3% uncertainty for individual measurements)
Contribution to the monitoring of surface UV radiation by provision of information on total ozone, solar irradiance, surface albedo, and aerosol optical depth and absorption
Role of Surface network
Trends in concentrations of regulated ozone depleting substances (ODS) Detection of ODS emissions and their trends Trend in Surface UV and the attribution of UV changes to ozone layer
changes Validation of the satellite data Weekly surface/column observations (O3, ODS) by representative surface
networks
Auxiliary dataMeteorology from NWP centers including surface data (dynamics, clouds, snow
cover)
Measurement Strategy A2O3/UV Near-real time data use
Role of Satellite Measurements
Forecasting of the Ozone layer and surface UV; Feed polar ozone reports Better representation of stratospheric transport, chemistry and radiation
in NWP to improve (medium range) weather forecasts and stratospheric near-real time monitoring, also by improving retrievals of temperature => stratospheric distribution of major greenhouse gases (CO2, H2O, O3, CH4, N2O) and aerosols
Further: tracers (B-D circulation, ST exchange), PSCs
Role of surface network and in-situ operational measurements
NRT validation of the satellite measurements Ozone/ radiosondes: NRT delivery of O3, H2O, p, T, wind NRT delivery of (UTLS) aircraft observations of O3, H2O, CO, HNO3, HCl
Auxilary dataMeteorological forecast from NWP centers including surface data (dynamics,
clouds, sunshine duration, snow cover)
Measurement Strategy A3O3/UV Assessment
Role of Satellite measurements
State of ozone layer and its evolution in time; role of dynamics, radiation, and chemistry
Changes in surface UV radiation globally, per location Distribution and trends in ODS and reservoir species The role of PSCs and of denitrification The role of volcanic eruptions (SO2, aerosol, aerosol type) Short-lived species can typically be derived from long-lived species
given that the chemistry is sufficiently understood (some exception: NO2, ClO etc)
Role of Surface network
Validation of the satellite measurements Surface UV radiation trend monitoring and attribution Concentration monitoring ODS; detection of ODS emissions
Auxiliary datameteorology from NWP centers including surface data (dynamics,
clouds, sunshine duration, snow cover)
O3 / Surface UV Radiation: Satellite Data
Observable User(s) Domain(s)
O3 A1, A2, A3 Stratosphere, Troposphere
UV solar spectrum A1, A2, A3 Top-of-Atmosphere
UV aerosol optical depth A1, A2, A3Troposphere
UV aerosol absorption optical depth A1, A2, A3Troposphere
Spectral UV surface albedo A1, A2, A3 Surface
H2O A2, A3 StratosphereN2O A2, A3 StratosphereCH4 A2, A3 StratosphereCO2 A2, A3 StratosphereHNO3 A2, A3 StratosphereVolcanic aerosol A2, A3 Stratosphere
CFC-11 A3 StratosphereCFC-12 A3 StratosphereHCFC-22 A3 StratosphereClO A3 StratosphereBrO A3 StratosphereSO2 A3 StratosphereAerosol surface density A3 StratospherePSCs A3 StratosphereHCl A3 StratosphereClONO2 A3 StratosphereCH3Cl A3 StratosphereHBr A3 StratosphereBrONO2 A3 StratosphereCH3Br A3 Stratosphere
Measurement Strategy B1Air Quality Protocol
Monitoring
Role of Satellite Measurements
Interpolation of surface networks in the PBL Boundary conditions for regional AQ models and tropospheric
background (long-range transport) Application to inverse modeling of surface emissions (aerosols, NO2,
SO2, CO, CH2O). Formaldehyde is related to VOC emissions
Role of Surface Networks
EU Framework Directives (surface concentrations) National Emission Ceilings (concentration monitoring to derive
emissions) Gothenburg protocol on ground-level ozone Ship emissions (operational ship monitoring coastal waters) A representative network for surface concentrations and emissions in
Europe Satellite and model validation, also by boundary layer profiling
(LIDARS, Towers)
Auxiliary dataMeteorology from NWP Centers including surface data (dynamics, clouds,
surface characterization)Emission inventories
Measurement Strategy B2Air Quality Near-real time data
use
Role of Satellite Measurements
Interpolation of surface network in PBL Plume transport and plume dispersion on local, regional, continental
and global scale Boundary conditions to regional AQ models and tropospheric
background levels Early warnings on hazards and unpredictable events
Role of Surface Networks
Local Air Quality monitoring of surface levels Constraints on satellite-derived aerosol types and VOC emissions
from HCHO NRT ozone sonde data for ozone and relative humidity profiles CH4 trend monitoring
Auxiliary dataForecast meteorology from NWP centers including NRT surface /
vegetation dataEmission inventories
Measurement Strategy B3Air Quality Assessment
Role of Satellite Measurements
Global-scale oxidizing capacity components and their evolution in time (O3, CO, H2O, NOx, CH4, CH2O, UV, aerosols)
Long-range transport of pollutants; tropospheric background levels Interpolation of data from surface networks input to inverse modeling of surface emissions (CO, NOx, SO2,
CH2O) Isotopes of CO to distinguish between emission types
Role of Surface network
Assessment of surface concentrations and boundary layer pollution over Europe
Concentration monitoring to derive emissions on national levels HNO3, N2O5(at night) and org. nitrates: reservoir species to
constrain acid deposition and N budget Validation of satellite observations (including sondes, lidars, towers)
Auxilary dataMeteorology from NWP centers including surface characterisationEmission inventories
Air Quality: Satellite Data
Observable User(s) Domain(s)
O3 B1, B2, B3 PBL/TroposphereNO2 B1, B2, B3 PBL/TroposphereCO B1, B2, B3 PBL/TroposphereSO2 B1, B2, B3 PBL/TroposphereCH2O B1, B2, B3 PBL/TroposphereAerosol OD B1, B2, B3 PBL/TroposphereAerosol Type B1, B2, B3 PBL/TroposphereH2O B2, B3 PBL/TroposphereHNO3 B2, B3 PBL/TroposphereN2O5 B2, B3 PBL/TropospherePAN / Org. nitrates B2, B3 PBL/TroposphereSurface UV albedo B2, B3 Surface
Measurement Strategy C1Climate Protocol Monitoring
Role of Satellite Measurements
Concentration monitoring for inverse modeling of emissions of CH4, CO2, CO and NO2
Global concentration distributions of the mentioned gases, O3 and aerosols
Role of Surface network
Greenhouse gases trend monitoring (CO2, CH4, N2O, SF6, CF4, HFCs Weekly surface concentrations and total columns from a representative
network. Validation of satellite measurements Concentration monitoring for inverse modeling of surface emissions of
CH4, CO2, CO and NO2 Tropospheric O3: sondes, lidar and surface data; Tropospheric aerosol optical depth and aerosol absorption optical depth Trend monitoring for ozone depleting substances ODS with climate
forcing: (H)CFCs.
Auxiliary dataMeteorology from NWP centers including surface dataEmission inventories and estimates on sinks
Measurement Strategy C2Climate Near-real time data
use
Role of Satellite Measurements
For use in assimilation at NWP centers to improve on stratospheric elements
H2O, O3, stratospheric tracers, and information on aerosols and cirrus Climate monitoring (delivery time ~weeks – months) Validation of climate and NWP models (present-day climate
reconstructions)
Role of Surface network
NRT validation of satellite observations Evolution of long-lived greenhouse gases In-situ observations in the PBL of CO2 NRT delivery of ozone sonde / Lidar data: O3, H2O
Auxiliary dataForecast meteorology from NWP centers including surface data
Measurement Strategy C3Climate Assessment
Role of Satellite Measurements
Assessment radiative forcing and its changes over time, including volcanic eruptions and solar cycle: GHGs, aerosol OD, aerosol absorption, SO2, cirrus)
Assessment of stratospheric H2O budget and H2O trend monitoring The role of the ozone layer evolution on climate change: CFCs, Cly, ClO,
HNO3 The role of the oxidizing capacity of the troposphere for climate change
(CH4, CO, O3, H2O, NOx, UV) The role of a changing B-D circulation on climate change: tracers Concentration monitoring for inverse modeling of GHG & precursor
emissions
Role of Surface network
Validation of satellite observations Ozone sonde/LIDAR network for trends in strat. profiles of long-lived gases Radiosonde/GPS network for H2O and T Aerosol network UTLS operational aircraft observations of O3, H2O, CO, NOx
Auxiliary dataMeteorology from ECMWF analyses, including surface data
Climate: Satellite Data
Observable User(s) Domain(s)
CH4 C1 PBL, TroposphereCO2 C1 PBL, TroposphereCO C1 PBL, TroposphereNO2 C1 PBL, TroposphereO3 C1 PBL, TroposphereAerosol OD C1 PBL, TroposphereAerosol absorption OD C1 PBL, Troposphere
H2O C2, C3 Troposphere, StratosphereO3 C2, C3 Troposphere, StratosphereCH4 C2, C3 StratosphereCO2 C2, C3 StratosphereN2O C2, C3 StratosphereAerosol optical properties C2, C3 StratosphereCirrus optical properties C2, C3 TroposphereHNO3 C3 Troposphere, StratosphereNO2 C3 StratosphereSF6 C3 StratosphereCl compounds C3 StratosphereN2O5 C3 StratospherePAN C3 TroposphereCO, HCs, CH2O,H2O2 C3 Troposphere
Data Requirements Table Format
A1S:Ozone Layer; Protocol Monitoring; Satellite data
• Data product + Driver
• Height Range(s)
• Hor. Resolution (target/threshold)
• Vert. Resolution (target/threshold)
• Revisit time (target /threshold)
• Uncertainty (threshold)+ Similar Tables for A1-G, A2-S, A2-G, ….C3-S, C3-G (18 Tables in total)
Summary
• This work has drawn from several earlier requirement studies, but it has never been done before in such a comprehensive way with focus on atmospheric composition and for operational applications
• Geophysical Data Requirements have been tabulated per theme and within each theme per user type
• Per data product and product type (column, profile) resolution, revisit time and uncertainty have been tabulated, for each atmospheric domain
• Based on the definition of ‘drivers’ per application a measurement strategy has been proposed for satellites, ground-based/in-situ data and auxiliary data, including models
• The tables, traceable to the user requirements, served as input for the analysis of existing/planned missions and networks, and for the definition of instrument requirements for new mission concepts