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Research
RESEARCH INTEREST:
1. Urban Air Pollution and Air Quality Impact Assessment
2. Air Quality Modelling (CALINE4, AERMOD, SMOKE/CMAQ)
3. Tropospheric Chemistry in the tropic (i.e Ozone)
4. Tropical biogenic emissions
5. Climate Change and Air Quality
CURRENT RESEARCH:
1.
LRGS (LONG TERM RESEARCH GRANT SCHEME)
Global Warming
: Drivers, Sciences, Impacts and Responses for Sustainability
Sub-Project No.3:
Climate Impacts, Vulnerability and Risks: Towards Development of Adaptation Policy
This project focusses on three issues:
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* Air quality
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* Hydrology/Flooding
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* Landslide
2. SHIVA - Stratospheric ozone: Halogen Impacts in a Varying Atmosphere
This project is an international research project supported by the 7th Framework Programme of the
Eurpean Union.
In conjunction with Mala
This project is an international research project supported by the 7th Framework Programme of the
Eurpean Union.
In conjunction with Mala
ysian research partners long term measurements will take place across the tropics. In late 2011 a
core field campaign will take place in the South China Sea, and along the coastline of Peninsula Malaysia and Borneo using the Sonne Research Vessel, the DLR Falcon
aircraft, satellites, and land-based investigation teams.
SHIVA focuses on four major objectives:
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1. Investigation of the oceanic emission strengths of a suite of halogenated
source gases: Here emphasis is put on the production, emission and transport of ODS. Inter-dependencies derived from our own field observations as well as surveys of ongoing work in
this area will help establish potential climate sensitivities of VSLS emissions.
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2. Investigation of the atmospheric transport and chemical transformation of
halogenated VSLS and their PGs during their journey from the surface to the TTL and finally into the stratosphere. Her a combination of aircraft and balloon observations together
with process-oriented meso-scale modeling is used. These investigations are corroborated by space-based remote sensing of marine phytoplankton biomass as a possible proxy for the
ocean-atmosphere flux of VSLS.
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3. Investigation of the past, present and likely future trend of the total halogen
burden in the stratosphere, which is established from the systematic VSLS emission inventory established under theme 1 and 2. Here the impact of climate-sensitive feedbacks between
transport and the delivery of ODS to the stratosphere, and their lifetime within it, is studied using tracer observations and modeling. When all this knowledge is combined, the
assessed climate sensitivities will eventually support the construction of future-climate scenarios of VSLS emissions and possible pathways for their delivery to the
stratosphere.
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4. Investigation on the impact of long and short-lived halogenated SGs and their
inorganic PGs on past, present and future ozone is assessed for the upper troposphere, TTL and global stratosphere. Here global modeling includes the contribution of all ODS,
including VSLS (which have hitherto normally been excluded from such models) to past, present and future ozone loss. The sensitivity of natural ODS emissions to climate change
parameters investigated under theme 3 is used in combination with standard IPCC climate model scenarios in order to drive measurement-calibrated chemical transport model (CTM)
simulations for present and future stratospheric ozone and to better predict the rate, timing and climate-sensitivity of ozone-layer recovery.
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Chemical species
|
Comment
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| Ozone |
Stratospheric tracer, photochemical product gas, greenhouse gas |
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Halocarbons (inc VSLS) |
(1) In situ GC-MS
(2) Whole air samples – analysis on the ground at airport |
| NO
2, BrO, IO, HONO, CH
2O, C
2H
2O
2 |
Halogen radicals (VSLS atmospheric degradation products) |
| Br
2, HBr, ClNO
2 |
VSLS degradation products |
| N
2O (nitrous oxide) |
Greenhouse gas, stratospheric tracer |
| SF
6 (sulphur hexafluoride) |
Greenhouse gas, anthropogenic tracer used for dating of stratospheric air |
| CO (carbon monoxide) |
Tracer for combustion (pollution, biomass burning) |
| CO
2 (carbon dioxide) |
Tracer |
| H
2O (water vapour) |
Tracer |
| NO, NOy |
Tracer for convective outflow, tracer for anthropogenic pollution, lightning product gas |
| Peroxyacetyl nitrate (PAN) |
Tracer for anthropogenic organic pollution, tracer for biomass burning |
| Perfluorocarbone (e.g. C7F14) |
Artificial air mass tracer for ship / aircraft - Lagrangian experiment |
There will also be measurements of temperature, pressure, wind speed, wind direction,
humidity, and altitude. Also, a forward-looking cockpit video camera will record clouds and pollution layers.
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Measured Parameter
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Comment
|
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In seawater
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Halocarbons (inc VSLS) |
In situ GC-MS |
| Phytoplankton |
Size, cell number, species composition |
| Chlorophyll |
Concentration and photosynthetic efficiency |
| Pigments |
Chic3, peridin, fuco, 19-hex, neox, etc |
| PCO
2 (dissolved carbon dioxide) |
Sensorr |
| PO
2 (dissolved oxygen) |
Sensor and Winkler titration |
| Nutrients |
Nitrate and phosphate |
| Gas tension |
Pressure of all dissolved gases in seawater |
| Salinity |
Conductivity, Temperature, Depth (CTD) Sensor |
| Sea surface temperature |
Conductivity, Temperature, Depth (CTD) Sensor |
| DMS, N
2O,CH
4 |
In situ GC and post cruise analysis |
| Radiation |
Upward and downward fluxes |
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In air
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Halocarbons (inc VSLS) |
(1) In situ GC-MS
(2) Whole air samples – analysis on the ground at airport |
| BrO, IO |
Halogen radicals (VSLS atmospheric degradation products) |
| Br and I in aerosol |
Filter sampling |
| Ozone, methane, CO
2, H
2O |
Greenhouse gases; continuous surface measurements (UV absorption instrument and PICARRO cavity ring down spectrometer) |
| CO (carbon monoxide) |
Tracer for combustion (pollution, biomass burning) |
| CH
4 (methane) |
Greenhouse gas |
| N
2O (nitrous oxide) |
Greenhouse gas |
| OH radicals |
Determine atmospheric lifetime of VSLS and other trace gases |
| Non methane hydrocarbons |
Primary pollutants (anthropogenic tracers) |
| HCl, ClNO
3, SO
2, HNO
3 |
Chemical ionisation mass spectrometer, oxidation products |
| Radiosonde |
Balloon-borne sondes (up to 30 km altitude)
Vertical temperature, pressure, humidity, wind profiles |
| Ozonesonde |
Balloon-borne sondes (up to 30 km altitude)
Vertical profiles of ozone |
| Water vapour sondes |
Balloon-borne sondes (up to 30 km altitude) |
| COBALD sondes (clouds) |
Balloon-borne sondes (up to 30 km altitude) |
| Tracer release unit |
Release of perfluoro-carbons for ship / aircraft
Lagrangian experiment |
| Precipitation; |
In-situ measurements |
| Standard Ship parameters |
Position, temperature, pressure, humidity, wind speed and direction, water depth |
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Compund
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Lifetime
(Days)
|
Atmospheric Source / possible climate feedback
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Medium and short-lived halocarbons (mixed sources)
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| CH
3Br |
250
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Mixed sources including oceanic, biomass burning (BB), vegetation, soils, and anthropogenic. Sensitive to changing land use and climate |
| CH
3Cl |
360
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Mixed natural sources including BB and vegetation. Sensitive to changing land use and climate |
| CH
2Br
2 |
120
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Oceanic, climate sensitive |
| CHBr
3 |
26
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Oceanic (small anthropogenic source), climate sensitive |
| CH
2BrCl |
150
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Oceanic, climate sensitive |
| CHBrCl
2 |
78
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Oceanic, climate sensitive |
| CHBr
2Cl |
69
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Oceanic, climate sensitive |
| C
2H
5Br |
34
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Oceanic and anthropogenic, climate sensitive |
| CH
3I |
7
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Oceanic and terrestrial, climate sensitive |
| CH
2ClI |
<1 day
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Oceanic, climate sensitive |
| CH
2BrI |
<1 day
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Oceanic, climate sensitive |
| CH
2I
2 |
<1 day
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Oceanic, climate sensitive |
| CH
2Cl
2 |
14
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Mixed sources: anthropogenic and BB, ocean |
| CHCl
3 |
150
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Mixed sources: anthropogenic, BB, soils, sensitive to changing land use / climate |
| C
2HCl
3 |
46
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Mainly anthropogenic |
| C
2Cl
4 |
99
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Mainly anthropogenic (possible oceanic source) |
| CH
2ClCH
2Cl |
70
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Mainly anthropogenic |
| C
2H
5Cl |
30
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Mainly anthropogenic |
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Long-lived anthropogenic halocarbons
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CFCs
(11, 12, 113, 114, 115)
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>45 yrs
|
Changing stratospheric transport changes fractional halogen release |
HCFCs
(22, 142b, 141b)
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>9 yrs
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Changing stratospheric transport changes fractional halogen release |
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CH
3CCl
3
|
5 yrs
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Changing stratospheric transport changes fractional halogen release |
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CCl
4
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26 yrs
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Changing stratospheric transport changes fractional halogen release |
Halons
(1301, 1211, 2402)
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>16 yrs
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Changing stratospheric transport changes fractional halogen release |
updated on 2011-07-08 20:04:14 by Justin Sentian, Dr
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