Gerard McCarthy
@germac.bsky.social
Irish Oceanographer working on Atlantic Overturning & Irish sea level. Husband & Dad. He/him
I often come back to the Atlantic being warmer than the Pacific at depth. At shallower depths, it seems obvious that the warm water is coming from the Med. But also the vertical heat transport due to overturning processes needs to be remembered. Anyone know of study partitioning those two processes?
August 22, 2025 at 2:17 PM
I often come back to the Atlantic being warmer than the Pacific at depth. At shallower depths, it seems obvious that the warm water is coming from the Med. But also the vertical heat transport due to overturning processes needs to be remembered. Anyone know of study partitioning those two processes?
The butterflies are flying it at the moment. clockwise from top (afaik at least!): red admiral, dragonfly, small tortoiseshell, holly blue (back of wings), grasshopper. From a blackberry picking session on the Old Rail Trail on Saturday.
August 11, 2025 at 6:43 AM
The butterflies are flying it at the moment. clockwise from top (afaik at least!): red admiral, dragonfly, small tortoiseshell, holly blue (back of wings), grasshopper. From a blackberry picking session on the Old Rail Trail on Saturday.
We've a great line up of MOC talks for this year's IAPSO-IAMAS-IACS conference in Busan, South Korea. I look forward to meeting colleagues and catching up.
July 17, 2025 at 6:26 PM
We've a great line up of MOC talks for this year's IAPSO-IAMAS-IACS conference in Busan, South Korea. I look forward to meeting colleagues and catching up.
I don't think the Cork hurling area connects between the Limerick border pocket (Newtown, Charleville, Ballyhea) and the Lee valley, east Cork pocket. Mallow, Clyda are strongly football and I think that connects with the Slieve Luachra, Muskerry football strongholds.
July 17, 2025 at 4:26 PM
I don't think the Cork hurling area connects between the Limerick border pocket (Newtown, Charleville, Ballyhea) and the Lee valley, east Cork pocket. Mallow, Clyda are strongly football and I think that connects with the Slieve Luachra, Muskerry football strongholds.
This is an update to the work Hannah and Amelia did last summer. We used the winning senior clubs to determine the hurling areas in Munster (circled by blue below). This year we checked that against the clubs of the squads for the final (black dots) and they matched well.
July 17, 2025 at 2:10 PM
This is an update to the work Hannah and Amelia did last summer. We used the winning senior clubs to determine the hurling areas in Munster (circled by blue below). This year we checked that against the clubs of the squads for the final (black dots) and they matched well.
Laraghbryan, home to ICARUS, hydrangas and acer going strong.
July 14, 2025 at 7:07 AM
Laraghbryan, home to ICARUS, hydrangas and acer going strong.
Lovely summer walks up from the train to the office in Maynooth.
July 14, 2025 at 7:07 AM
Lovely summer walks up from the train to the office in Maynooth.
Loadsa news up on our webpage. Particular welcome to Emma and Hannah who are with us for the summer and Jittrarast, Lionel, and JP who are doing the MSc projects in the group: icarusoceans.maynoothuniversity.ie?page_id=525
July 3, 2025 at 3:00 PM
Loadsa news up on our webpage. Particular welcome to Emma and Hannah who are with us for the summer and Jittrarast, Lionel, and JP who are doing the MSc projects in the group: icarusoceans.maynoothuniversity.ie?page_id=525
The accompanying original old maps are pretty lovely things. Here it says the 1842 measurements were 16.3 feet below the bolt in the last picture. We're lucky that some of these old marks still exist—a lot have been destroyed
May 27, 2025 at 11:06 PM
The accompanying original old maps are pretty lovely things. Here it says the 1842 measurements were 16.3 feet below the bolt in the last picture. We're lucky that some of these old marks still exist—a lot have been destroyed
As part of the Ordnance Survey, in 1842 sea level measurements were made relative to this very mark for six weeks. All we need to do is tie this mark to the modern network and we know how much sea level has risen around Ireland in 180 or so years.
May 27, 2025 at 11:06 PM
As part of the Ordnance Survey, in 1842 sea level measurements were made relative to this very mark for six weeks. All we need to do is tie this mark to the modern network and we know how much sea level has risen around Ireland in 180 or so years.
After the Mary Robinson conference in Ballina, it was west to survey an old sea level benchmark for me and Patrick. We got all the weathers but the sun shone for our survey. Croagh Patrick in the background. We are surveying a few points around Ireland to pin down Ireland's sea levels from 1842.
May 27, 2025 at 11:06 PM
After the Mary Robinson conference in Ballina, it was west to survey an old sea level benchmark for me and Patrick. We got all the weathers but the sun shone for our survey. Croagh Patrick in the background. We are surveying a few points around Ireland to pin down Ireland's sea levels from 1842.
With the turn in the weather, the marine heatwave seems to have peaked. These data are from the M3 data buoy off southwest Ireland. Source: eurosea.marine.ie/his
May 27, 2025 at 6:16 AM
With the turn in the weather, the marine heatwave seems to have peaked. These data are from the M3 data buoy off southwest Ireland. Source: eurosea.marine.ie/his
Focusing on timescales shorter than a year, we show the shelf sea-level variability is wind-driven and that it indeed is directly affecting long-shore current variability. These longshore current changes are found on the outer-shelf and only impinge on the upper slope.
May 23, 2025 at 2:16 PM
Focusing on timescales shorter than a year, we show the shelf sea-level variability is wind-driven and that it indeed is directly affecting long-shore current variability. These longshore current changes are found on the outer-shelf and only impinge on the upper slope.
Study led by Dr Sam Diabaté: In this paper, we were interested in finding out whether the circulation changes recorded at various moorings on and around the Northwest European Shelf were related to the sea-level variability on the shelf.
kwnsfk27.r.eu-west-1.awstrack.me/L0/https:%2F...
kwnsfk27.r.eu-west-1.awstrack.me/L0/https:%2F...
May 23, 2025 at 2:16 PM
Study led by Dr Sam Diabaté: In this paper, we were interested in finding out whether the circulation changes recorded at various moorings on and around the Northwest European Shelf were related to the sea-level variability on the shelf.
kwnsfk27.r.eu-west-1.awstrack.me/L0/https:%2F...
kwnsfk27.r.eu-west-1.awstrack.me/L0/https:%2F...
I think the real story here is the increase in baseline temperatures. Since autumn last year, temperatures have been following the 90th percentile. Throw some calm weather on top of that and you have a severe heatwave. With warming oceans, what we now class as a heatwave will be normality.
May 23, 2025 at 10:22 AM
I think the real story here is the increase in baseline temperatures. Since autumn last year, temperatures have been following the 90th percentile. Throw some calm weather on top of that and you have a severe heatwave. With warming oceans, what we now class as a heatwave will be normality.
This satellite data is confirmed by an excellent real-time resource from the Irish Marine Institute that monitors heatwaves at sentinel locations around Ireland. You can see the blue line creeping up in sites west of Ireland. Source: eurosea.marine.ie/his
May 23, 2025 at 10:22 AM
This satellite data is confirmed by an excellent real-time resource from the Irish Marine Institute that monitors heatwaves at sentinel locations around Ireland. You can see the blue line creeping up in sites west of Ireland. Source: eurosea.marine.ie/his
This figure places it in context of the June 2023 heatwave that was at the time the severest on record. It's probably reaching higher severity than 2023 but temperatures are not as high yet as it is earlier in the year.
May 23, 2025 at 10:22 AM
This figure places it in context of the June 2023 heatwave that was at the time the severest on record. It's probably reaching higher severity than 2023 but temperatures are not as high yet as it is earlier in the year.
The heatwave is classed as severe according to the marine heatwave traceker over much of Irish waters.
May 23, 2025 at 10:22 AM
The heatwave is classed as severe according to the marine heatwave traceker over much of Irish waters.
The marine heatwave off the coast of Ireland is pretty severe at the moment. Temperatures are about 3ºC above normal for this time of the year. Source: www.marine.ie/site-area/da...
May 23, 2025 at 10:22 AM
The marine heatwave off the coast of Ireland is pretty severe at the moment. Temperatures are about 3ºC above normal for this time of the year. Source: www.marine.ie/site-area/da...
The Bealtaine fire is lit and summer welcomed on the Hill of Uisneach
May 12, 2025 at 7:32 AM
The Bealtaine fire is lit and summer welcomed on the Hill of Uisneach
And some constituents are better than others for picking up the low frequency signal—such as lower North Atlantic Deep Water. This water mass is very sensitive to low frequency AMOC change and can be reconstructed very effectively using temperature and salinity at depth on the western boundary.
April 22, 2025 at 10:00 AM
And some constituents are better than others for picking up the low frequency signal—such as lower North Atlantic Deep Water. This water mass is very sensitive to low frequency AMOC change and can be reconstructed very effectively using temperature and salinity at depth on the western boundary.
We can improve the signal to noise ratio by removing the influence of variables such as Ekman transport, which do not contribute to the low-frequency/climatic signal.
April 22, 2025 at 10:00 AM
We can improve the signal to noise ratio by removing the influence of variables such as Ekman transport, which do not contribute to the low-frequency/climatic signal.
We published a signal-to-noise analysis of AMOC observations in GRL. TLDR: Direct observations (RAPID) of the AMOC do show a decline in line with climate model projected weakening (~1 Sv/decade) but the noise is still very large in comparison to the signal. Paper: doi.org/10.1029/2025...
April 22, 2025 at 10:00 AM
We published a signal-to-noise analysis of AMOC observations in GRL. TLDR: Direct observations (RAPID) of the AMOC do show a decline in line with climate model projected weakening (~1 Sv/decade) but the noise is still very large in comparison to the signal. Paper: doi.org/10.1029/2025...
Come along to hear me present the DIAS Geophysics Statutory Public Lecture:
"When the Ocean Changes Course: The Threat of an Atlantic Meridional Overturning Circulation (AMOC) Collapse"
"When the Ocean Changes Course: The Threat of an Atlantic Meridional Overturning Circulation (AMOC) Collapse"
January 20, 2025 at 2:08 PM
Come along to hear me present the DIAS Geophysics Statutory Public Lecture:
"When the Ocean Changes Course: The Threat of an Atlantic Meridional Overturning Circulation (AMOC) Collapse"
"When the Ocean Changes Course: The Threat of an Atlantic Meridional Overturning Circulation (AMOC) Collapse"