United States National Risk Management

Environmental Protection Research Laboratory

Agency Research Triangle Park, NC 27711

E AP Project Summary

Research and Development EPA/600/SR-95/091 August 1995

The document is a user’s guide for

an updated Personal Computer version

of the Biogenic Emissions Inventory

System (PC-BEIS2) allowing users to

estimate hourly emissions of biogenic

volatile organic compounds (BVOCs)

and soil nitrogen oxide emissions for

any county in the contiguous United

States. Emission rates depend on land

use, emission factors, temperature and

solar radiation. A simple canopy model

is used to adjust photosynthetically active solar radiation at five vertical levels in the forest canopy. Leaf temperature and photosynthetically active solar radiation derived from ambient conditions above the forest canopy are

then used to drive empirical equations

to estimate genus level emission rates

of BVOCs vertically through canopies.

Emission rates from vegetation other

than forests are expressed as BVOC

carbon mass per unit land area, with a

constant peak growing season biomass assumed. Light and temperature

corrections are applied, but no canopy

model is used for non-forested areas.

This Project Summary was developed

by the National Risk Management Research Laboratory’s Air Pollution Prevention and Control Division, Research

Triangle Park, NC, to announce key

findings of the research project that is

fully documented in a separate report

of the same title (see Project Report

ordering information at back).

Introduction

The Personal Computer version of the

Biogenic Emissions Inventory System (PCBEIS2) is an updated program that allows

User’s Guide to the Personal

Computer Version of the

Biogenic Emissions Inventory

System (PC-BEIS2)

Terri L. Birth

users to estimate hourly emissions of biogenic volatile organic compounds (BVOCs)

and soil nitrogen oxide emissions for any

county in the contiguous United States.

PC-BEIS2 has been compiled using

Microsoft FORTRAN and tested on IBMcompatible personal computers. The

source code is written in ANSI FORTRAN

77 and should be transportable to most

other computers. Emission rates depend

on land use, emission factors, temperature, and solar radiation. A simple canopy

model is used to adjust photosynthetically

active solar radiation at five vertical levels

in the forest canopy. Leaf temperature

and photosynthetically active solar radiation derived from ambient conditions above

the forest canopy are then used to drive

empirical equations to estimate genus level

emission rates of BVOCs vertically through

canopies. Emission rates from vegetation

other than forests are expressed as BVOC

carbon mass per unit land area, with a

constant peak growing season biomass

assumed. Light and temperature corrections are applied, but no canopy model is

used for non-forested areas.

Data Requirements

The data requirements for PC-BEIS2

are modest. The user needs to obtain

information on the county of interest and

hourly meteorological data. County land

use data and normalized emission factors

are already contained in the model. The

land use file is compressed on the diskette and must be “unzipped” using the

program PKUNZIP. To run PC-BEIS2, the

user should obtain the following data:

Site information:

- County Federal Information Processing System (FIPS) code - an index of
2

FIPS codes can be retrieved from the

same directory as the PC-BEIS2 system

- Latitude, longitude (decimal degrees,

tenths) - centered in the county, used

for solar radiation calculations

- Time zone (5=EST, 6=CST, etc.)

- Month, day, year, hour(s)

Meteorological data (hourly):

- Ambient air temperature (°C)

- Photosynthetically Active Radiation

(PAR) - not required if using cloud

cover data

- Opaque sky cover (fraction) - not required if providing PAR data

Computer Aspects

Computer aspects include installation

procedures, machine requirements, software design, and data structures associated with PC-BEIS2.

Installation Procedures

The executable file, source code, and

necessary data files are available on EPA’s

CHIEF (Clearinghouse for Inventories and

Emission Factors) electronic bulletin board

or via ftp at “ttnbbs.rtpnc.epa.gov.” The

access number for CHIEF is 919/541-

5742. To install the program, simply follow the procedures given on the bulletin

board.

Model Requirements

PC-BEIS2 is written to conform with the

FORTRAN 77 standard and has been

compiled on the PC with Microsoft FORTRAN version 5.0. The source code, however, should be easily adapted to most

FORTRAN compilers. PC-BEIS2 has been

compiled to allow its use on IBM-compatible personal computers. The current executable version does not require the use

of a math co-processor.

The executable, source code, and necessary data files needed to run PC-BEIS2

will take up approximately 3.16 MB of

memory. In order for the menu interface

to function properly, ANSI.SYS must be

installed on the PC. ANSI.SYS is available with MS-DOS. The DOS reference

book contains instructions. It is recommended, but not required, that PC-BEIS2

users have a math co-processor.

Software Design

PC-BEIS2 has been written in a modular fashion and, to the extent possible,

conforms to the ANSI FORTRAN 77 standard. It consists of a main program and

six subroutines or functions.

Terri L. Birth is with Computer Sciences Corp., Research Triangle Park, NC 27709.

Chris D. Geron is the EPA Project Officer (see below).

The complete report, entitled “User’s Guide to the Personal Computer Version of the

Biogenic Emissions Inventory System (PC-BEIS2),” (Order No. PB95-243184;

Cost: $17.50, subject to change) will be available only from:

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

Telephone: 703-487-4650

The EPA Project Officer can be contacted at:

Air Pollution Prevention and Control Division

National Risk Management Research Laboratory

U.S. Environmental Protection Agency

Research Triangle Park, NC 27711

United States

Environmental Protection Agency

National Risk Management Research Laboratory (G-72)

Cincinnati, OH 45268

Official Business

Penalty for Private Use $300

EPA/600/SR-95/091

BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35