pvlib.iotools.get_merra2#
- pvlib.iotools.get_merra2(latitude, longitude, start, end, username, password, dataset, variables, map_variables=True)[source]#
Retrieve MERRA-2 time-series irradiance and meteorological reanalysis data from NASA’s GESDISC data archive.
MERRA-2 [1] offers modeled data for many atmospheric quantities at hourly resolution on a 0.5° x 0.625° global grid.
Access must be granted to the GESDISC data archive before EarthData credentials will work. See [2] for instructions.
- Parameters:
latitude (float) – In decimal degrees, north is positive (ISO 19115).
longitude (float) – In decimal degrees, east is positive (ISO 19115).
start (datetime like or str) – First timestamp of the requested period. If a timezone is not specified, UTC is assumed.
end (datetime like or str) – Last timestamp of the requested period. If a timezone is not specified, UTC is assumed. Must be in the same year as
start.username (str) – NASA EarthData username.
password (str) – NASA EarthData password.
dataset (str) – Dataset name (with version), e.g. “M2T1NXRAD.5.12.4”.
variables (list of str) – List of variable names to retrieve. See the documentation of the specific dataset you are accessing for options.
map_variables (bool, default True) – When true, renames columns of the DataFrame to pvlib variable names where applicable. See variable
VARIABLE_MAP.
- Raises:
ValueError – If
startandendare in different years, when converted to UTC.- Returns:
data (pd.DataFrame) – Time series data. The index corresponds to the middle of the interval.
meta (dict) – Metadata.
Notes
The following datasets provide quantities useful for PV modeling:
Dataset
Variable
pvlib name
SWGDN
ghi
SWGDNCLR
ghi_clear
ALBEDO
albedo
LWGAB
longwave_down
LWGNT
longwave_net
LWGEM
longwave_up
T2M
temp_air
U10
n/a
V10
n/a
T2MDEW
temp_dew
PS
pressure
TO3
n/a
TQV
n/a
TOTEXTTAU
aod550
TOTSCATAU
n/a
TOTANGSTR
n/a
A complete list of datasets and their documentation is available at [3].
Note that MERRA2 does not currently provide DNI or DHI.
References