#### README.TXT ####
The Atmospheric River-CONNected objECT (AR-CONNECT) algorithm applied tothe National Aeronautics and Space Administration (NASA) Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA V2) - 1983-2016

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Creators: Shearer, Eric J.; Nguyen, Phu; Sellars, Scott L.; Analui, Bita; Kawzenuk, Brian; Hsu, Kuo-Lin; Sorooshian, Soroosh
Publisher: UC San Diego Library Digital Collections
Publication year: 2020
Description: This collection contains the lifecycles of global atmospheric river (AR) objects. This data was produced by isolating regions of enhanced IVT transport events by applying the Atmospheric River-CONNected objeECT (AR-CONNECT) algorithm. AR-CONNECT is a four-dimensional (4D) object-oriented algorithm, adapted from the CONNECT algorithm developed by a team of researchers from the University of California, Irvine [Sellars et al., 2013, 2015, 2017]. The algorithm uses a seeded region growing segmentation technique to segment AR lifecycles according to their high-intensity cores. AR-CONNECT determines the lifecycles of an AR by using a flood-filling algorithm to group discrete AR timeslices where they are contiguous over time and space. Each object has a unique ID and a set of selected characteristics.

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Contents:
ARCONNECT.ar_labels.MERRA2.3hourly.<YEAR>0101:<YEAR>1231.nc4: Yearly NetCDF files of atmospheric river object identification numbers in gridded format.
	
	Varibles: 
		ar_object_labels: latitude x longitude x time grid containing the label identification numbers of ARCONNECT objects that occurred duribg the given year. Compressed using "ncks -4 -L 1" command.
		lat: Latitude array (-90 - 90, by 0.5 degrees)
		lon: Longitude array (0 - 359.375, by 0.625 degrees)
                time: Time array (00:00:00 January 1st - 21:00:00 December 31st, by 180 minute incriments)
	ncdump output for 1983 file:
	dimensions:
	        time = 2920 ;
	        lat = 361 ;
	        lon = 576 ;
	variables:
	        short ar_object_labels(time, lat, lon) ;
	                ar_object_labels:description = "labeled atmospheric river lifecycle from AR-CONNECT" ;
	        double lat(lat) ;
	                lat:standard_name = "latitude" ;
	                lat:long_name = "Latitude" ;
	                lat:units = "degrees_north" ;
	                lat:axis = "Y" ;
	        double lon(lon) ;
	                lon:standard_name = "longitude" ;
	                lon:long_name = "Longitude" ;
	                lon:units = "degrees_east" ;
	                lon:axis = "X" ;
	        double time(time) ;
	                time:standard_name = "time" ;
	                time:long_name = "time" ;
	                time:units = "minutes since 1983-01-01 00:00:00" ;
	                time:calendar = "standard" ;

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AR-CONNECT.MERRA2.1983-2016.Object_characteristics.csv: CSV file containing statistics for all AR-CONNECT Objects. Column headers are in the top row. Abbreviations defined below.

	Column headers are: Object ID, Average IVT (kg/(ms)), Max IVT (kg/(ms)), Median IVT (kg/(ms)), Standard Deviation of IVT (kg/(ms)), Sum of IVT Pixels (kg/(ms)), Max Rain Rate (mm/3hr), Total Rain Volume (cubic km), Lifecycle Central Latitude, Lifecycle Central Longitude, Duration (hours), Extent (km), Speed (km/day), Volume (cubic km), Genesis Central Latitude, Genesis Central Longitude, Terminus Central Latitude, Terminus Central Longitude, Genesis Time, Terminus Time, AAO, AMMSST (°C), AMON, ANOM12 (°C), ANOM3 (°C), ANOM34 (°C), ANOM4 (°C), AO, ATLTRI (°C), CAR, EA, EOFPAC, EPO, ESPI, GLAAM, GMSST (°C), HURR, JONESNAO, MEI, MJO_RMM1, MJO_RMM2, MJO_AMP, MJO_PHASE, NAO, NOI, NP, NTA, ONI, PACWARM, PDO, PNA, QBO, SOI, SOLAR, SWMONSOON (mm), TNA, TNI, TSA, WHWP, WP
														
Feature Abbreviations:
AAO		Antarctic Oscillation
AMMSST		Atlantic Meridional Mode Sea Surface Temperature (°C)
AMON		Atlantic Multidecadal Oscillation
ANOM12  	El Nino Southern Oscillation Region 1+2 SST anomaly (°C)
ANOM3   	El Nino Southern Oscillation Region 3 SST anomaly (°C)
ANOM34  	El Nino Southern Oscillation Region 3.4 SST anomaly (°C)
ANOM4   	El Nino Southern Oscillation Region 4 SST anomaly (°C)
AO		Arctic Oscillation
ATLTRI		Atlantic Tripole SST (°C)
CAR		Caribbean Index
EA		East Atlantic/Western Russia Index
EOFPAC		Tropical Pacific SST EOF
EPO		East Pacific/North Pacific Oscillation
ESPI		ENSO Precipitation Index
GLAAM		Globally Integrated Angular Momentum
GMSST		Global Mean Lan/Ocean Temperature (°C)
HURR    	Number of days per month with hurricane in Atlantic
JONESNAO	Jones National Atlantic Oscillation
MEI		Multivariate ENSO Index
MJO_RMM1	Real-time Multivariate Madden-Julian Oscillation series 1
MJO_RMM1	Real-time Multivariate Madden-Julian Oscillation series 2
MJO_AMP		Madden-Julian Oscillation Amplitude
MJO_PHASE	Madden-Julian Oscillation Phase
NAO		North Atlantic Oscillation
NOI		Northern Oscillation Index
NP		North Pacific Pattern
NTA		Northern Tropical Atlantic Index
ONI		Ocean Nino Index
PACWARM		Pacific Warmpool
PDO		Pacific Decadal Oscillation
PNA		Pacific North American Pattern
QBO		Quasi-Biennial Oscillation
SOI		Southern Oscillation Index
SOLAR		Solar Flux (10.7cm)
SWMONSOON	Area averaged New Mexico and Arizona precipitation (mm)
TNA		TNA Tropical Northern Atlantic Index
TNI		Trans-Nino Index
TSA		Tropical Southern Atlantic Index
WHWP		Western Hemisphere Warm Pool
WP		Western Pacific Index