Dataset: HOBO U20L water level and seafloor temperature - Inside and outside kelp

Name: Water level and seafloor temperature from Onset HOBO U20L loggers deployed on the seafloor adjacent to instrument moorings inside and outside of kelp forests near the Monterey Peninsula, California, USA from June to August 2018 and 2019
Published: 2021-11-12
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.864720.1

Spatial Extent: N:36.63088 E:-121.897 S:36.61795 W:-121.9188

Temporal Extent: 2018-06-07 - 2019-08-07

Project:

Collaborative Research: RUI: Building a mechanistic understanding of water column chemistry alteration by kelp forests: emerging contributions of foundation species (Kelp forest biogeochemistry)

Principal Investigator:

Kerry J. Nickols (California State University Northridge, CSUN)

Co-Principal Investigator:

Robert B. Dunbar (Stanford University)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2021-11-12

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Water level and seafloor temperature from Onset HOBO U20L loggers deployed on the seafloor adjacent to instrument moorings inside and outside of kelp forests near the Monterey Peninsula, California, USA from June to August 2018 and 2019

Abstract:

These data are from Onset HOBO U20L data loggers recording at 1-minute intervals deployed on the seafloor from June to August in 2018 and 2019. The HOBO loggers were deployed adjacent to instrument moorings inside and outside of kelp forests near the Monterey Peninsula, California, USA.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2021-11-12	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.864720.1	2022-03-30

Methods & Sampling

Sampling Locations:
Sampling was conducted near the Monterey Peninsula near Pacific Grove and Monterey, California, USA. Kelp sites ranged from 8.8 to 10.3 meters deep and offshore sites ranged from 13.1 to 16.5 m deep.

Instrument moorings were deployed in 2018 in the following areas: a wave-protected kelp forest, ~100 meters offshore of the protected site, in a wave-exposed site devoid of kelp (historically has had kelp), and ~100 meters offshore of the exposed site.

Instrument moorings were deployed in 2019 in the following areas: a wave-protected kelp forest, ~175 meters offshore of the protected site, in a wave-exposed kelp site, and ~180 meters offshore of the exposed site.

Location Abbreviations:
PK = Protected kelp 2018,
PO = Protected offshore 2018,
EK = Exposed ‘kelp’ 2018,
EO = Exposed offshore 2018,
MK = Protected kelp 2019,
MO = Protected offshore 2019,
OK = exposed kelp 2019,
OO = Exposed offshore 2019.

Methodology:
HOBO U20L water level and temperature loggers were attached to the bottom of each instrument mooring ~0.45 m above the seafloor. Instruments had to be swapped out periodically during deployment due to data storage capacity. Time and depth of deployment were recorded each time a sensor was deployed.

Data Processing Description

Data Processing:
Data were processed using R software version 1.4.1717. Data from multiple instruments at each site were stitched together based on deployment times and data outside of deployment times was trimmed off.

BCO-DMO Processing:
- converted local date to ISO8601 format;
- created the ISO8601 date-time field in UTC;
- replaced "NA" with "nd" (no data).

Data Files

File
HOBO_U20L.csv (Comma Separated Values (.csv), 77.12 MB) MD5:4e69296e6ba4e03d74eafbc8c21310f7 Primary data file for dataset ID 864720

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1737176
NSF Division of Ocean Sciences	OCE-1737096

Deployments

None available yet

Instruments

Onset HOBO U20L water level logger series

Supplied Name: HOBO U20L water level and temperature logger

Supplied Description:

Instrument Type

Generic Name: Onset HOBO U20L water level logger series

Acronym: HOBO U20L

Generic Description:

The HOBO U20L is designed for monitoring changing water levels in a variety of applications including tidal areas, streams, lakes, wetlands, and groundwater. It outputs pressure, water level, and temperature data. The instrument can record samples, sensor measurements at each logging interval, and events data, occurrences such as a bad battery or host connected. The samples are recorded as absolute pressure values, which are later converted to water level readings using software. Absolute pressure is atmospheric pressure plus water head. The deployment of an additional HOBO U20L at the surface can be used to compensate for barometric pressure changes. Each instrument is individually calibrated. They require a coupler and optic base station or HOBO waterproof shuttle to connect to a computer. The instrument is operated with a 3.6 V lithium battery.

This series contains 3 models, U20L-01, U20L-02, and U20L-04, with different operation ranges, calibrated ranges, and burst pressures. The pressure sensor is temperature compensated between 0 and 40 degrees Celsius (C), and calibrated between 69 and a maximum of 400 kPa (depending on the model). Its accuracy is within 0.3 % of the full scale for absolute pressure, and 0.1 % FS for water level readings. The temperature sensor operates between -20 and 50 degrees C, with an accuracy of 0.44 deg C, and a resolution of 0.1 deg C. The drift is 0.1 deg C per year.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Site	Site code: PK = Protected kelp 2018, PO = Protected offshore 2018, EK = Exposed kelp 2018, EO = Exposed offshore 2018, MK = Protected kelp 2019, MO = Protected offshore 2019, OK = exposed kelp 2019, OO = Exposed offshore 2019.	unitless	site
ISO_DateTime_Local	Date and time (PST) in ISO8601 format: YYYY-MM-DDThh:mm:ss Format: %Y-%m-%dT%H:%M:%S	unitless	ISO_DateTime_Local
Time_zone	Indicates the local time zone (PST)	unitless	time_zone
ISO_DateTime_UTC	Date and time (UTC) in ISO8601 format: YYYY-MM-DDThh:mm:ssZ Format: %Y-%m-%dT%H:%M:%SZ	unitless	ISO_DateTime_UTC
Site_depth_0_tide	Depth of the site at at 0 tide	meters (m)	depth
Latitude	Latitude	decimal degrees North	lat
Longitude	Longitude	decimal degrees West	lon
Location	Indicates if the location is Kelp or Offshore	unitless	site_descrip
Temperature_C	Temperature	degrees Celsius	temp
AbsPres_kPa	Pressure	kiloPascals (kPa)	press
AbsPres_decibar	Pressure	decibars	press
AbsPres_decibar_corrected	Pressure minus atmospheric pressure	decibars	press

Database

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Dataset: HOBO U20L water level and seafloor temperature - Inside and outside kelp