Mr. Jalal Butt Profile

Jalal Butt

Undergraduate

SPIE Involvement:

Author

Publications (3)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 24 October 2018 Paper

Using a CCD camera lidar system for detection of Asian dust

Jalal Butt, Chris Oville, Nimmi C. Sharma, John Barnes

Proceedings Volume 10779, 107790Z (2018) https://doi.org/10.1117/12.2324551

KEYWORDS: Aerosols, Humidity, LIDAR, Atmospheric particles, Scattering, CCD cameras, Clouds, Atmospheric modeling, Observatories, Laser scattering

Read Abstract +

During intense spring and early summer storms, substantial volumes of dust from east Asian desert regions are lofted over the continent and transported by prevailing winds across the Pacific Ocean. The phenomenon has wide reaching effects including long range nutrient and sediment transport as well as radiative forcing. Mauna Loa Observatory (MLO) is an atmospheric baseline station in Hawaii at an altitude of 3397-m.a.s.l.. MLO’s CCD Camera Lidar (CLidar) has fine near-ground altitude resolution, which makes it a useful system for Asian dust detection, especially at high altitude sites such as MLO. A 20-Watt, 532-nm Nd:YAG laser was vertically transmitted into the atmosphere above MLO. The side-scatter from atmospheric constituents, such as clouds, aerosols, and air molecules was detected by a wide-angle CCD camera situated 139-m from the laser. The obtained signal was range-normalized using a molecular scattering model and corrected for transmission with a column-averaged aerosol phase function derived from MLO-based AERONET photometer measurements. In several of the resulting aerosol extinction profiles, notable aerosol layers were observed near altitude ranges in which Asian dust is typically transported by prevailing winds. Corresponding relative humidity measurements made by nearby radiosondes were examined to differentiate aerosol scattering from cloud scattering. To further examine layers exhibiting both aerosol extinction peaks and relative humidity levels below that of tenuous ice clouds, back trajectories were conducted using NOAA’s Hybrid Single Particle Lagrangian Integrated Trajectory model. Several layers from 2008 and 2009 were traced back to East Asian deserts.

Proceedings Article | 10 May 2018 Presentation + Paper

Using a bistatic camera lidar to profile aerosols influenced by a local source of pollution

Amin Kabir, N. Sharma, John Barnes, Jalal Butt, Mauricio Bridgewater

Proceedings Volume 10636, 106360L (2018) https://doi.org/10.1117/12.2303544

KEYWORDS: Aerosols, Atmospheric particles, LIDAR, Scattering, Humidity, Cameras, Optical testing, Laser scattering, Charge-coupled devices

Read Abstract +

A wide-angle CCD camera based bistatic lidar (CLidar) is used to monitor aerosol profiles in the atmosphere of The Bahamas. A 2-Watt CW laser beam ranging from ground to zenith is captured in a single image by a camera fitted with a fisheye lens which is placed at a different location from the laser. Scattering altitude is determined simply from the geometry of the CLidar in contrast to monostatic lidar which requires expensive electronics to measure the time of flight of the returned signal. Each image contains both molecular and aerosol single angle scattering. A cloud free image is used to normalize the signal intensity to a model of molecular scattering at a region free of aerosol layer. Then molecular portion is subtracted to retrieve aerosol side scattering. An aerosol phase function was assumed to convert side scatter to aerosol extinction. Corrections due to transmission effects are then iteratively calculated until convergence is reached. Aerosol extinction drops off sharply above 1 km indicating the planetary boundary level which agrees well with the relative humidity measurements obtained from the radiosonde data of Nassau airport observation. Additionally, aerosols originated from the smoke of a charcoal grill operating near experimental site were efficiently detected near ground levels. Aerosol extinction at 20 m above sea level is 0.085 km^-1 during grilling compared to 0.03 km^-1 during no grilling. Excellent altitude resolution of the CLidar at the ground levels allows its use for in-situ environmental characterization without the overlap effects faced when using traditional lidar.

Proceedings Article | 30 August 2017 Paper

Lidar observations of long range dust transport over Mauna Loa Observatory

Jalal Butt, Nimmi C. Sharma, John Barnes

Proceedings Volume 10406, 104060M (2017) https://doi.org/10.1117/12.2275723

KEYWORDS: Aerosols, Scattering, LIDAR, Atmospheric particles, Laser scattering, Observatories, CCD cameras, Atmospheric optics, Clouds, Light scattering

Read Abstract +

A bistatic CCD camera lidar (CLidar) was used at the National Oceanic and Atmospheric Administration’s Mauna Loa Observatory (MLO) to map aerosol light scattering. Laser light from a 532 nm, Nd:YAG laser was vertically transmitted into the atmosphere and the scatter off clouds, aerosols and air molecules was detected using a CCD camera with wide angle optics and a laser line filter. The intensity of each CCD camera pixel imaging the beam was normalized to a molecular scattering model in an aerosol free region for subtraction of molecular scattering. Aerosol extinction was derived using a column average aerosol phase function derived from AERONET sun photometer measurements at MLO. The CLidar design allows measurements of aerosol scattering all the way to the ground without an overlap correction. MLO, at 3397 m.a.s.l., typically receives free tropospheric air. During spring months, prevailing winds can occasionally transport dust from Asian sources with high dust activity over MLO. Aerosol scattering measurements were taken by the CLidar during spring months at MLO and revealed extinction peaks at mid-range altitudes. Back trajectories of air parcels from MLO at the altitudes of these peaks were conducted using NOAA’s Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and it was found that they passed over regions of Eastern Asia known as sources of high dust activity. Relative humidity data from radiosondes and the NOAA stratospheric lidar’s water vapor channel were examined to differentiate aerosol scattering from tenuous cloud scattering. This paper presents aerosol extinction data with observations of Asian dust as measured by the CLidar during spring months at MLO.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years