MERRA2AODProcessor

The MERRA2AODProcessor class is responsible for downloading, extracting, and converting daily dust surface mass concentration (DUSMASS) values from the NASA MERRA-2 dataset. The converted data is stored as .csv files for downstream analysis and storm detection.

This module enables researchers to extract data from a user-defined region and time window, preparing it in a standardized format for further processing by other DUSTY modules.

Overview

Class: MERRA2AODProcessor Location: Dust_Storm_Modules.py

Constructor

MERRA2AODProcessor(start_date, end_date, region_bounds, output_dir="data/merra2")

start_date: datetime – Beginning of the data range
end_date: datetime – End of the data range
region_bounds: Tuple of [lat_min, lat_max, lon_min, lon_max]
output_dir: Path to save the downloaded and processed files

Methods

class Dust_Storm_Modules.MERRA2AODProcessor(start_date, end_date, region_bounds, output_dir='data/merra2')[source]

Bases: object

convert_to_csv()[source]

download_files()[source]

Workflow

`download_files()` Downloads daily MERRA-2 DUSMASS .nc4 files from NASA’s GES DISC for the specified region and date range.
`convert_to_csv()` Converts .nc4 files into flat .csv format: - Time-resolved - Includes latitude, longitude, and dust_mass columns - Filters only valid (finite) values

Notes

The processor automatically adjusts longitudes < 0 to 0–360 format, as required by MERRA-2.
The NetCDF files are opened using xarray, and the output CSVs are formatted using pandas.

Example Usage

from Dust_Storm_Modules import MERRA2AODProcessor
from datetime import datetime

processor = MERRA2AODProcessor(
    start_date=datetime(2023, 6, 1),
    end_date=datetime(2023, 6, 7),
    region_bounds=(15, 35, 40, 65),
    output_dir="data/merra2"
)
processor.download_files()
processor.convert_to_csv()